Virus-induced memory T cells often express functional cross-reactivity, or heterologous immunity, to other viruses and to allogeneic MHC molecules that is an important component of pathogenic responses to allogeneic transplants. During immune responses antigen-reactive naïve and central memory T cells proliferate in secondary lymphoid organs to achieve sufficient cell numbers to effectively respond whereas effector memory T cell proliferation occurs directly within the peripheral inflammatory microenvironment. Mechanisms driving heterologous memory T cell proliferation and effector function expression within peripheral tissues remain poorly understood. Here we dissected heterologous donor-reactive memory CD8 T cell proliferation and their effector functions following infiltration into heart allografts having low or high intensities of ischemic inflammation. Proliferation within both ischemic conditions requires p40 homodimer-induced IL-15 transpresentation by graft dendritic cells, but expression of effector functions mediating acute allograft injury occurs only in high-ischemic allografts. Transcriptional responses of heterologous donor-reactive memory CD8 T cells are distinct from donor antigen-primed memory CD8 T cells during early activation in allografts and at graft rejection. Overall, the results insights into mechanisms driving heterologous effector memory CD8 T cell proliferation and the separation between proliferation and effector function, that is dependent on the intensity of inflammation within the tissue microenvironment.
Hidetoshi Tsuda, Karen S. Keslar, William M. Baldwin III, Peter S. Heeger, Anna Valujskikh, Robert L. Fairchild
Loss of BRCA2 (BReast CAncer 2) is lethal for normal cells. Yet, it remains poorly understood how in BRCA2 mutation carriers, cells undergoing loss of heterozygosity overcome the lethality and undergo tissue-specific neoplastic transformation. Here, we identified mismatch repair gene, MLH1 as a genetic interactor of BRCA2 whose over-expression supports the viability of Brca2-null cells. Mechanistically, we showed that MLH1 interacts with Flap endonuclease 1 (FEN1) and competes to process the RNA flaps of Okazaki fragments. Together, they restrained the DNA2 nuclease activity on the reversed forks of lagging strands, leading to replication fork (RF) stability in BRCA2-deficient cells. In these cells, MLH1 also attenuated R-loops, allowing the progression of stable RFs, which suppressed the genomic instability and supported cell viability. We demonstrated the significance of their genetic interaction by the lethality of Brca2-mutant mice and inhibition of Brca2-deficient tumor growth in mice by Mlh1 loss. Furthermore, we described that estrogen induces MLH1 expression through estrogen receptor alpha (ERα), which might explain why the majority of BRCA2 mutation carriers develop ER positive breast cancer. Taken together, our findings reveal a role of MLH1 in relieving replicative stress and how it may contribute to the establishment of BRCA2-deficient breast tumors.
Satheesh K. Sengodan, Xiaoju Hu, Vaishnavi Peddibhotla, Kuppusamy Balamurugan, Alexander Y. Mitrophanov, Lois McKennett, Suhas S. Kharat, Rahul Sanawar, Vinod Kumar Singh, Mary E. Albaugh, Sandra S. Burkett, Yongmei Zhao, Bao Tran, Tyler Malys, Esta Sterneck, Subhajyoti De, Shyam K. Sharan
BACKGROUND. The tumor immune microenvironment can provide prognostic and therapeutic information. We aimed to develop noninvasive imaging biomarkers from computed tomography (CT) for comprehensive evaluation of immune context, and investigate their associations with prognosis and immunotherapy response in gastric cancer (GC). METHODS. This study involved 2,600 GC patients of nine independent cohorts. We developed and validated two CT imaging biomarkers [lymphoid radiomics score (LRS) and myeloid radiomics score (MRS)] for evaluating the immunohistochemistry (IHC)-derived lymphoid and myeloid immune context respectively, and then integrated them into a combined imaging biomarker [LRS/MRS: low(−) or high(+)] with four radiomics immune subtypes: 1(−/−), 2(+/−), 3(−/+), and 4(+/+). We further evaluated the imaging biomarkers' predictive values on prognosis and immunotherapy response. RESULTS. The developed imaging biomarkers (LRS and MRS) had a high accuracy in predicting lymphoid (AUC range: 0.765-0.773) and myeloid (AUC range: 0.736-0.750) immune context. Furthermore, same as IHC-derived immune context, two imaging biomarkers (HR range: 0.240-0.761 for LRS; 1.301-4.012 for MRS) and the combined biomarker were independent predictors for disease-free and overall survival in the training and all validation cohorts (all P<0.05). In addition, patient with high LRS or low MRS may benefit more from immunotherapy (P<0.001). Furthermore, a highly heterogeneous outcome on objective response rate was observed in four imaging subtypes: 1(−/−) with 27.3%, 2(+/−) with 53.3%, 3(−/+) with 10.2%, and 4(+/+) with 30.0% (P<0.0001). CONCLUSION. The noninvasive imaging biomarkers could accurately evaluate the immune context, and provide information regarding prognosis and immunotherapy for GC. FUNDING. None
Zepang Sun, Taojun Zhang, M. Usman Ahmad, Zixia Zhou, Liang Qiu, Kangneng Zhou, Wenjun Xiong, Jingjing Xie, Zhicheng Zhang, Chuanli Chen, Qingyu Yuan, Yan Chen, Wanying Feng, Yikai Xu, Lequan Yu, Wei Wang, Jiang Yu, Guoxin Li, Yuming Jiang
Maggie E. Jones-Carr, Huma Fatima, Vineeta Kumar, Douglas J. Anderson, Julie Houp, Jackson C. Perry, Gavin A. Baker, Leigh McManus, Andrew J. Shunk, Paige M. Porrett, Jayme E. Locke
Breast cancer stem cells (BCSCs) mitigate oxidative stress to maintain their viability and plasticity. However, the regulatory mechanism of oxidative stress in BCSCs remains unclear. We recently found that the histone reader ZMYND8 was upregulated in BCSCs. Here, we showed that ZMYND8 reduced ROS and iron to inhibit ferroptosis in aldehyde dehydrogenase (ALDH)high BCSCs, leading to BCSC expansion and tumor initiation in mice. The underlying mechanism involved a twofold posttranslational regulation of nuclear factor erythroid 2–related factor 2 (NRF2). ZMYND8 increased stability of NRF2 protein through KEAP1 silencing. On the other hand, ZMYND8 interacted with and recruited NRF2 to the promoters of antioxidant genes to enhance gene transcription in mammospheres. NRF2 phenocopied ZMYND8 to enhance BCSC stemness and tumor initiation by inhibiting ROS and ferroptosis. Loss of NRF2 counteracted ZMYND8’s effects on antioxidant genes and ROS in mammospheres. Interestingly, ZMYND8 expression was directly controlled by NRF2 in mammospheres. Collectively, these findings uncover a positive feedback loop that amplifies the antioxidant defense mechanism sustaining BCSC survival and stemness.
Maowu Luo, Lei Bao, Yuanyuan Xue, Ming Zhu, Ashwani Kumar, Chao Xing, Jennifer E Wang, Yingfei Wang, Weibo Luo
Ischemia reperfusion injury (IRI)-mediated primary graft dysfunction (PGD) adversely impacts both short- and long-term outcomes after lung transplantation, a procedure which remains the only treatment option for patients suffering from end-stage respiratory failure. While B cells are known to regulate adaptive immune responses, their role in lung IRI is not well understood. Here, we demonstrate by intravital imaging that B cells are rapidly recruited to injured lungs, where they extravasate into the parenchyma. Using hilar clamping and transplant models, we observe that lung-infiltrating B cells produce the monocyte chemokine CCL7 in Toll-like receptor 4 (TLR4)-TRIF-dependent fashion, a critical step contributing to classical monocyte (CM) recruitment and subsequent neutrophil extravasation, resulting in worse lung function. We find that synergistic BCR-TLR4 activation on B cells is required for the recruitment of CMs to the injured lung. Finally, we corroborate our findings in reperfused human lungs, where we observe a correlation between B cell infiltration and CM recruitment after transplantation. This study describes a role for B cells as critical orchestrators of lung IRI. As B cells can be depleted with currently available agents, our study provides a rationale for clinical trials investigating B cell-targeting therapies.
Khashayar Farahnak, Yun Zhu Bai, Yuhei Yokoyama, Deniz B. Morkan, Zhiyi Liu, Junedh M. Amrute, Alejandro De Filippis Falcon, Yuriko Terada, Fuyi Liao, Wenjun Li, Hailey M. Shepherd, Ramsey R. Hachem, Varun Puri, Kory J. Lavine, Andrew E. Gelman, Ankit Bharat, Daniel Kreisel, Ruben G. Nava
Wnts, cholesterol, and MAPK signaling are essential for development and adult homeostasis. Here we report for the first time that fatty acid hydroxylase domain containing 2 (FAXDC2), a previously uncharacterized enzyme, functions as a methyl sterol oxidase catalyzing C4 demethylation in the Kandutsch-Russell branch of the cholesterol biosynthesis pathway. FAXDC2, a paralog of MSMO1, regulates the abundance of specific C4-methyl sterols lophenol and dihydro-TMAS. Highlighting its clinical relevance, FAXDC2 is repressed in Wnt/β-catenin high cancer xenografts, in a mouse genetic model of Wnt activation, and in human colorectal cancers. Moreover, in primary human colorectal cancers, the sterol lophenol, regulated by FAXDC2, accumulates in the cancerous tissues and not in adjacent normal tissues. FAXDC2 links Wnts to RTK/MAPK signaling. Wnt inhibition drives increased recycling of RTKs and activation of the MAPK pathway, and this requires FAXDC2. Blocking Wnt signaling in Wnt-high cancers causes both differentiation and senescence; and this is prevented by knockout of FAXDC2. Our data shows the integration of three ancient pathways, Wnts, cholesterol synthesis, and RTK/MAPK signaling, in cellular proliferation and differentiation.
Babita Madan, Shawn R. Wadia, Siddhi Patnaik, Nathan Harmston, Emile K.W. Tan, Iain Bee Huat Tan, W. David Nes, Enrico Petretto, David M. Virshup
Given the leading cause of disability worldwide, low back pain (LBP) is recognized as a pivotal socio-economic challenge to the aging population, which is importantly attributed to intervertebral disc degeneration (IVDD). Elastic nucleus pulposus (NP) tissue is essential for the maintenance of IVD structural and functional integrity. The accumulation of senescent NP cells with inflammatory hypersecretory phenotype due to aging and other damaged factors is a distinctive hallmark of IVDD initiation and progression. In this study, we revealed a mechanism of IVDD progression in which aberrant genomic DNA damage promoted NP cell inflammatory senescence via activation of the cGAS-STING axis but not AIM2 inflammasome assembly. ATR deficiency destroyed genomic integrity and led to cytosolic mislocalization of genomic DNA, which acted as a powerful driver of cGAS-STING axis-dependent inflammatory phenotype acquisition during NP cell senescence. Mechanically, the disassembly of ATR-TRIM56 complex with the enzyme activity liberation of USP5 and TRIM25 drove change in ATR ubiquitination, with ATR switching from K63-linked modification to K48-linked modification, promoting ubiquitin-proteasome-dependent dynamic instability of ATR protein during NP cell senescent progression. Importantly, an engineered extracellular vesicle (EV)-based strategy for delivering ATR-overexpressing plasmid cargo efficiently diminished DNA damage-associated NP cell senescence and substantially mitigated IVDD progression, indicating promising targets and efficient approaches for ameliorating the impact of IVDD.
Weifeng Zhang, Gaocai Li, Xingyu Zhou, Huaizhen Liang, Bide Tong, Di Wu, Kevin Yang, Yu Song, Bingjin Wang, Zhiwei Liao, Liang Ma, Wencan Ke, Xiaoguang Zhang, Jie Lei, Chunchi Lei, Xiaobo Feng, Kun Wang, Kangcheng Zhao, Cao Yang
Converging studies demonstrate the dysfunction of the dopaminergic neurons following chronic opioid administration. However, the therapeutic strategies targeting opioid-responsive dopaminergic ensembles that contribute to the development of opioid withdrawal remain to be elucidated. Here, we used the neuronal activity-dependent Tet-Off system to label dopaminergic ensembles in response to initial morphine exposure (Mor-Ens) in the ventral tegmental area (VTA). Fiber optic photometry recording and transcriptome analysis revealed downregulated spontaneous activity, dysregulated mitochondrial respiratory, ultrastructure, and oxidoreductase signal pathways after chronic morphine administration in these dopaminergic ensembles. Mitochondrial fragmentation and the decreased mitochondrial fusion gene mitofusin 1 (Mfn1) were found in these ensembles after prolonged opioid withdrawal. Restoration of Mfn1 in the dopaminergic Mor-Ens attenuated excessive oxidative stress and the development of opioid withdrawal. Administration of Mdivi-1, a mitochondrial fission inhibitor, ameliorated the mitochondrial fragmentation and maladaptation of the neuronal plasticity in these Mor-Ens, accompanied by attenuated development of opioid withdrawal after chronic morphine administration, without affecting the analgesic effect of morphine. These findings highlighted the plastic architecture of mitochondria as a potential therapeutic target for opioid analgesic-induced substance use disorders.
Changyou Jiang, Han Huang, Xiao Yang, Qiumin Le, Xing Liu, Lan Ma, Feifei Wang
Kristin Gabor, Emily V. Mesev, Jennifer Madenspacher, Julie M. Meacham, Prashant Rai, Sookjin Moon, Christopher A. Wassif, Saame Raza Shaikh, Charles J. Tucker, Peer W. Karmaus, Simona Bianconi, Forbes D. Porter, Michael B. Fessler
Cancer cell plasticity contributes to therapy resistance and metastasis, which represent the main causes of cancer-related death, including in breast cancer. The tumor microenvironment drives cancer cell plasticity and metastasis, and unravelling the underlying cues may provide novel strategies to manage metastatic disease. Using breast cancer experimental models and transcriptomic analyses, we showed that stem cell antigen-1 positive (SCA1+) murine breast cancer cells enriched during tumor progression and metastasis had higher in vitro cancer stem cell-like properties, enhanced in vivo metastatic ability, and generated tumors rich in Gr1high Ly6G+CD11b+ cells. In turn, tumor-educated Gr1+CD11b+(Tu-Gr1+CD11b+) cells rapidly and transiently converted low metastatic SCA1- cells into highly metastatic SCA1+ cells via secreted OSM and IL6. JAK inhibition prevented OSM/IL6-induced SCA1+ population enrichment while OSM/IL6 depletion suppressed Tu-Gr1+CD11b+-induced SCA1+ population enrichment in vitro and metastasis in vivo. Moreover, chemotherapy-selected highly metastatic 4T1 cells maintained high SCA1+ positivity through autocrine IL6 production and in vitro JAK inhibition blunted SCA1 positivity and metastatic capacity. Importantly, Tu-Gr1+CD11b+ cells invoked a gene signature in tumor cells predicting shorter OS, RFS and lung metastasis in breast cancer patients. Collectively, our data identified OSM/IL6-JAK as a clinically relevant paracrine/autocrine axis instigating breast cancer cell plasticity and triggering metastasis.
Sanam Peyvandi, Manon Bulliard, Alev Yilmaz, Annamaria Kauzlaric, Rachel Marcone, Lisa Haerri, Oriana Coquoz, Yu-Ting Huang, Nathalie Duffey, Laetitia Gafner, Girieca Lorusso, Nadine Fournier, Qiang Lan, Curzio Rüegg
Two coding variants of apolipoprotein L1 (APOL1) called G1 and G2 explain much of the excess risk of kidney disease in African Americans. While various cytotoxic phenotypes have been reported in experimental models, the proximal mechanism by which G1 and G2 cause kidney disease is poorly understood. Here, we leveraged three experimental models and a recently reported small molecule blocker of APOL1 protein, VX-147, to identify the upstream mechanism of G1-induced cytotoxicity. In HEK293 cells, we demonstrated that G1-mediated Na+ import/K+ efflux triggered activation of G protein-coupled receptor (GPCR)-IP3-mediated calcium release from the endoplasmic reticulum (ER), impaired mitochondrial ATP production, and impaired translation, which were all reversed by VX-147. In human podocyte-like epithelial cells (HUPEC), we demonstrated that G1 caused cytotoxicity that was again reversible by VX-147. Finally, in podocytes isolated from APOL1 G1 transgenic mice, we showed that Interferon gamma (IFNγ)-mediated induction of G1 caused K+ efflux, activation of GPCR-IP3 signaling, and inhibition of translation, podocyte injury, and proteinuria, all reversed by VX-147. Together, these results establish APOL1-mediated Na+/K+ transport as the proximal driver of APOL1-mediated kidney disease.
Somenath Datta, Brett M. Antonio, Nathan H. Zahler, Jonathan W. Theile, Doug Krafte, Hengtao Zhang, Paul B. Rosenberg, Alec B. Chaves, Deborah M. Muoio, Guofang Zhang, Daniel Silas, Guojie Li, Karen Soldano, Sarah Nystrom, Davis Ferreira, Sara E. Miller, James R. Bain, Michael J. Muehlbauer, Olga Ilkayeva, Thomas C. Becker, Hans-Ewald Hohmeier, Christopher B. Newgard, Opeyemi A. Olabisi
BACKGROUND. Vaccination is typically administered without regard to site of prior vaccination but this factor may substantially impact downstream immune responses. METHODS. We assessed serological responses to initial COVID-19 vaccination in baseline seronegative adults who received second–dose boosters in the ipsilateral or contralateral arm relative to initial vaccination. We measured serum SARS-CoV2 spike-specific Ig, RBD-specific IgG, SARS-CoV-2-nucleocapsid-specific IgG, and neutralizing antibody titers against SARS-CoV-2.D614G (early strain) and SARS-CoV-2.B.1.1.529 (Omicron) at approximately 0.6, 8, and 14 months after boosting. RESULTS. In 947 individuals, contralateral boosting was associated with higher spike-specific serum Ig, and this effect increased over time from a 1.1-fold to a 1.4-fold increase by 14 months (P < 0.001). A similar pattern was seen for RBD-specific IgG. Among 54 pairs matched for age, gender and relevant time intervals, arm groups had similar antibody levels at W2 but contralateral boosting resulted in significantly higher binding and neutralizing antibody titers at W3 and W4, with progressive increase over time, ranging from 1.3-fold (total Ig, P = 0.007) to 4.0-fold (pseudovirus neutralization to B.1.1.529 P < 0.001). CONCLUSIONS. In previously unexposed adults receiving an initial vaccine series with the BNT162b2 mRNA COVID-19 vaccine, contralateral boosting substantially increases antibody magnitude and breadth at times beyond 3 weeks after vaccination. This effect should be considered during arm selection in the context of multi-dose vaccine regimens.
Sedigheh Fazli, Archana Thomas, Abram E. Estrada, Hiro A.P. Ross, David Xthona Lee, Steven Kazmierczak, Mark K. Slifka, David Montefiori, William B. Messer, Marcel E. Curlin
Spinocerebellar ataxia type 3 (SCA3) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the ataxin-3 (ATXN3) gene. No effective treatment is available for this disorder, other than symptom-directed approaches. Bile acids have shown therapeutic efficacy in neurodegenerative disease models. Here, we pinpointed tauroursodeoxycholic acid (TUDCA) as an efficient therapeutic, improving the motor and neuropathological phenotype of SCA3 nematode and mouse models. Surprisingly, transcriptomic and functional in vivo data showed that TUDCA acts in neuronal tissue through the glucocorticoid receptor (GR), but independently of its canonical receptor, the FXR. TUDCA was predicted to bind to the GR, similarly to corticosteroid molecules. GR levels were decreased in disease-affected brain regions, likely due to increased protein degradation as a consequence of ATXN3 dysfunction, being restored by TUDCA treatment. Analysis of a SCA3 clinical cohort showed intriguing correlations between the peripheral expression of GR and the predicted age at disease onset, in pre-symptomatic subjects, and of FKBP5 expression with disease progression, suggesting this pathway as a potential source of biomarkers for future study. We have established a novel in vivo mechanism for the neuroprotective effects of TUDCA in SCA3, and propose this readily available drug for clinical trials in SCA3 patients.
Sara Duarte-Silva, Jorge Diogo Da Silva, Daniela Monteiro-Fernandes, Marta Daniela Costa, Andreia Neves-Carvalho, Mafalda Raposo, Carina Soares-Cunha, Joana S. Correia, Gonçalo Nogueira-Gonçalves, Henrique S. Fernandes, Stéphanie Oliveira, Ana Rita Ferreira-Fernandes, Fernando Rodrigues, Joana Pereira-Sousa, Daniela Vilasboas-Campos, Sara Guerreiro, Jonas Campos, Liliana Meireles-Costa, Cecilia M.P. Rodrigues, Stephanie Cabantous, Sérgio F. Sousa, Manuela Lima, Andreia Teixeira-Castro, Patricia Maciel
The ability to fight or flee from a threat relies upon an acute adrenergic surge that augments cardiac output, which is dependent upon increased cardiac contractility and heart rate. This cardiac response depends on β-adrenergic-initiated reversal of the small RGK G-protein Rad-mediated inhibition of voltage-gated calcium channels (CaV) acting through the Cavβ subunit. Here, we investigate how Rad couples phosphorylation to augmented Ca2+ influx and increased cardiac contraction. We show that reversal requires phosphorylation of Ser272 and Ser300 within Rad’s polybasic, hydrophobic C-terminal domain (CTD). Phosphorylation of Ser25 and Ser38 in Rad’s N-terminal domain (NTD) alone is ineffective. Phosphorylation of Ser272 and Ser300 or the addition of four Asp to the CTD reduces Rad’s association with the negatively charged, cytoplasmic plasmalemmal surface and with CaVβ, even in the absence of CaVα, measured here by FRET. Addition of a post-translationally prenylated CAAX motif to Rad’s C-terminus, which constitutively tethers Rad to the membrane, prevents the physiological and biochemical effects of both phosphorylation and Asp-substitution. Thus, dissociation of Rad from the sarcolemma, and consequently from CaVβ, is sufficient for sympathetic up-regulation of Ca2+ currents.
Arianne Papa, Pedro J. del Rivero Morfin, Bi-Xing Chen, Lin Yang, Alex N. Katchman, Sergey I. Zakharov, Guoxia Liu, Michael S. Bohnen, Vivian Zheng, Moshe Katz, Suraj Subramaniam, Joel A. Hirsch, Sharon Weiss, Nathan Dascal, Arthur Karlin, Geoffrey S. Pitt, Henry M. Colecraft, Manu Ben Johny, Steven O. Marx
Early-life seizures (ELS) can cause permanent cognitive deficits and network hyperexcitability, but it is unclear whether ELS induce persistent alterations to specific neuronal populations and if these changes can be targeted to mitigate network dysfunction. We used the targeted recombination of activated populations (TRAP) approach to genetically label neurons activated by kainate-induced ELS in immature mice. The ELS-TRAPed neurons were mainly found in hippocampal CA1, remained uniquely susceptible to reactivation by later-life seizures, and displayed sustained enhancement in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor (AMPAR)-mediated excitatory synaptic transmission and inward rectification. ELS-TRAPed neurons, but not non-TRAPed surrounding neurons, exhibited enduring decreases in Gria2 mRNA, responsible for encoding the GluA2 subunit of the AMPARs. This was paralleled by decreased synaptic GluA2 protein expression and heightened phosphorylated GluA2 at Ser880 in dendrites, indicative of GluA2 internalization. Consistent with increased GluA2-lacking AMPARs, ELS-TRAPed neurons showed premature silent synapse depletion, impaired long-term potentiation, and impaired long-term depression. In vivo post-seizure treatment with IEM-1460, a GluA2-lacking AMPAR inhibitor, markedly mitigated ELS-induced alterations in TRAPed neurons. These findings show that enduring modifications of AMPARs occur in a subpopulation of ELS-activated neurons, contributing to synaptic dysplasticity and network hyperexcitability, but are reversible with early IEM-1460 intervention.
Bo Xing, Aaron J. Barbour, Joseph Vithayathil, Xiaofan Li, Sierra Dutko, Jessica Fawcett-Patel, Eunjoo Lancaster, Delia M. Talos, Frances E. Jensen
Nonalcoholic liver disease (NAFLD) encompasses a disease continuum from simple steatosis, to non-alcoholic steatohepatitis (NASH). However, there are currently no approved pharmacotherapies for NAFLD although several drugs are in advanced stages of clinical development. Because of the complex pathophysiology and heterogeneity of NALFD, identification of potential therapeutic targets is clinically important. Here, we demonstrated that TRIM56 protein abundance is markedly downregulated in the livers of individuals with NAFLD and mice fed a high-fat diet. Hepatocyte-specific ablation of TRIM56 exacerbated the progression of NAFLD, while hepatic TRIM56 overexpression suppressed it. Integrative analyses of interactomic and transcriptomic profiling revealed a pivotal role of TRIM56 in lipid metabolism and identified lipogenesis factor FASN as a direct binding partner of TRIM56. TRIM56 directly interacts with FASN and triggers its K48-linked ubiquitination-dependent degradation. Finally, by using AI-based virtual screening, we discovered an orally bioavailable small-molecule inhibitor of FASN (named FASstatin) which potentiates TRIM56-mediated FASN ubiquitination. Therapeutic administration of FASstatin improved NAFLD and NASH pathologies in mice with optimal safety, tolerability and pharmacokinetic profile. Our findings provide the proof-of-concept that targeting the TRIM56/FASN axis in hepatocytes may offer potential therapeutic avenues to treat NAFLD.
Suowen Xu, Xiumei Wu, Sichen Wang, Mengyun Xu, Tingyu Fang, Xiaoxuan Ma, Meijie Chen, Jiajun Fu, Juan Guo, Song Tian, Tian Tian, Xu Cheng, Hailong Yang, Junjie Zhou, Zhenya Wang, Yanjun Yin, Wen Xu, Fen Xu, Jinhua Yan, Zhihua Wang, Sihui Luo, Xiao-Jing Zhang, Yan-Xiao Ji, Jianping Weng
Choline deficiency causes disorders including hepatic abnormalities and is associated with an increased risk of multiple types of cancer(1, 2). Here, by choline free diet-associated RNA-seq analyses, we found that the tumor suppressor p53 drives the Kennedy pathway via PCYT1B to control the growth of lipid droplets (LDs) and their fueling role in tumorigenesis. Mechanistically, through upregulation of PCYT1B, p53 channeled depleted choline stores to phosphatidylcholine (PC) biosynthesis during choline starvation, thus preventing LD coalescence. Cells lacking p53 failed to complete this response to choline depletion, leading to hepatic steatosis and tumorigenesis, and these effects could be reversed by enforcing PCYT1B expression or restoring PC abundance. Furthermore, loss of p53 or defects in the Kennedy pathway increased surface localization of hormone-sensitive lipase (HSL) on LDs to release specific fatty acids that fueled tumor cells in vivo and in vitro. Thus, p53 loss leads to dysregulation of choline metabolism and LD growth, and couples perturbed LD homeostasis to tumorigenesis.
Xiuduan Xu, Jianqin Wang, Li Xu, Peng Li, Peng Jiang
BACKGROUND. Sanaria PfSPZ Vaccine, composed of attenuated Plasmodium falciparum (Pf) sporozoites (SPZ), protects against malaria. We conducted this clinical trial to assess the safety and efficacy of PfSPZ Vaccine in HIV positive (HIV+) individuals since the HIV infection status of participants in mass vaccination programs may be unknown. METHODS. This randomized, double blind, placebo-controlled trial enrolled 18-45-year-old HIV negative (HIV-) and well-controlled HIV+ Tanzanians (HIV viral load < 40 copies/mL, CD4 counts > 500 cells/µL). Participants received 5 doses of PfSPZ Vaccine or normal saline over 28 days followed by controlled human malaria infection (CHMI) 3 weeks later. RESULTS. There were no solicited adverse events in the 9 HIV- and 12 HIV+ participants. After CHMI, 6/6 normal saline (NS) controls, 1/5 HIV- vaccinees and 4/4 HIV+ vaccinees were Pf positive by qPCR. Post-immunization, anti-PfCSP (isotype and IgG subclass) and anti-PfSPZ antibodies, anti-PfSPZ CD4 T cell responses and Vδ2+ γδ CD3+ T cells were non-significantly higher in HIV- than HIV+ vaccinees. Sera from HIV- vaccinees had significantly higher inhibition of PfSPZ invasion of hepatocytes in vitro, and antibody-dependent complement deposition (ADCD) and Fcγ3B binding by anti-PfCSP and ADCD by anti-PfCelTOS antibodies. CONCLUSIONS. PfSPZ Vaccine was safe and well tolerated in HIV+ vaccinees, but not protective. Vaccine efficacy was 80% in HIV- vaccinees (P = 0.012), whose sera had significantly higher inhibition of PfSPZ invasion of hepatocytes and enrichment of multi-functional PfCSP antibodies. A more potent PfSPZ vaccine or regimen is needed to protect those living with HIV against Pf infection in Africa.
Said Jongo, L.W. Preston Church, Florence Milando, Munira Qassim, Tobias Schindler, Mohammed Rashid, Anneth Tumbo, Gloria Nyaulingo, Bakari M. Bakari, Thabit Athuman Mbaga, Latipha Mohamed, Kamaka Kassimu, Beatus S. Simon, Maxmillian Mpina, Irfan Zaidi, Patrick E. Duffy, Phillip A. Swanson II, Robert Seder, Jonathan D. Herman, Maanasa Mendu, Yonatan Zur, Galit Alter, Natasha KC, Pouria Riyahi, Yonas Abebe, Tooba Murshedkar, Eric R. James, Peter F. Billingsley, B. Kim Lee Sim, Thomas L. Richie, Claudia Daubenberger, Salim Abdulla, Stephen L. Hoffman
Neutrophil Extracellular Traps (NETs), a web-like structure of cytosolic and granule proteins assembled on decondensed chromatin, kill pathogens and causes tissue damage in diseases. Whether NETs can kill cancer cells is unexplored. Here, we report that a combination of glutaminase inhibitor CB-839 and 5-FU inhibits the growth of PIK3CA mutant colorectal cancers (CRCs) in xenograft, syngeneic, and genetically engineered mouse models in part through NETs. Disruption of NETs by either DNase I treatment or depletion of neutrophils in CRCs attenuated the efficacy of the drug combination. Moreover, NETs were present in tumor biopsies taken from patients treated with the drug combination in a phase II clinical trial. Increased NET levels in tumors are associated with longer progression-free survival. Mechanistically, the drug combination induced the expression of IL-8 preferentially in PIK3CA mutant CRCs to attract neutrophils into the tumors. Further, the drug combination increased the levels of reactive oxygen species in neutrophils, thereby inducing NETs. Cathepsin G (CTSG), a serine protease localized in NETs, enters CRC cells through the RAGE cell surface protein. The internalized CTSG cleaves 14-3-3 proteins, releases Bax, and triggers apoptosis in CRC cells. Thus, our studies illuminate a previously unrecognized mechanism by which chemotherapy-induced NETs kill cancer cells.
Yamu Li, Sulin Wu, Yiqing Zhao, Trang Dinh, Dongxu Jiang, J. Eva Selfridge, George Myers, Yuxiang Wang, Xuan Zhao, Suzanne L. Tomchuck, George Dubyak, Richard T. Lee, Bassam Estfan, Marc Shapiro, Suneel D. Kamath, Amr Mohamed, Stanley C.-C. Huang, Alex Y. Huang, Ronald A. Conlon, Smitha S. Krishnamurthi, Jennifer R. Eads, Joseph E. Willis, Alok A. Khorana, David L. Bajor, Zhenghe Wang