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
After extensive exposure to Mycobacterium tuberculosis (Mtb), most individuals acquire latent Mtb infection (LTBI) defined by a positive tuberculin skin test (TST) or interferon-γ release assay (IGRA). To identify mechanisms of resistance to Mtb infection, we compared transcriptional profiles from highly-exposed contacts who resist TST/IGRA conversion (resisters, RSTRs) and controls with LTBI using RNAseq. Gene sets related to carbon metabolism and free fatty acid (FFA) transcriptional responses enriched across two independent cohorts suggesting RSTR and LTBI monocytes have distinct activation states. We compared intracellular Mtb replication in macrophages treated with FFAs and found that palmitic acid (PA), but not oleic acid (OA), enhanced Mtb intracellular growth. This PA activity correlated with its inhibition of pro-inflammatory cytokines in Mtb-infected cells. Mtb growth restriction in PA-treated macrophages was restored by activation of AMP kinase (AMPK), a central host metabolic regulator known to be inhibited by PA. Finally, we genotyped AMPK variants and found seven SNPs in PRKAG2, which encodes the AMPKγ subunit, that strongly associated with RSTR status. Taken together, RSTR and LTBI phenotypes are distinguished by FFA transcriptional programs and by genetic variation in a central metabolic regulator, which suggests immunometabolic pathways regulate TST/IGRA conversion.
Jason D. Simmons, Phu T. Van, Catherine M. Stein, Violet Chihota, Thobani Ntshiqa, Pholo Maenetje, Glenna J. Peterson, Anthony Reynolds, Penelope Benchek, Kavindhran Velen, Katherine L. Fielding, Alison D. Grant, Andrew D. Graustein, Felicia K. Nguyen, Chetan Seshadri, Raphael Gottardo, Harriet Mayanja-Kizza, Robert S. Wallis, Gavin Churchyard, W. Henry Boom, Thomas R. Hawn
Novel mRNA-based vaccines have been proven powerful tools to combat the global pandemic caused by SARS-CoV2 with BNT162b2 (trade name: Comirnaty) efficiently protecting individuals from COVID-19 across a broad age range. Still, it remains largely unknown how renal insufficiency and immunosuppressive medication affect development of vaccine induced immunity. We therefore comprehensively analyzed humoral and cellular responses in kidney transplant recipients after the standard second vaccination dose. As opposed to all healthy vaccinees and the majority of hemodialysis patients, only 4/39 and 1/39 transplanted individuals showed IgA and IgG seroconversion at day 8 ± 1 after booster immunization with minor changes until day 23 ± 5, respectively. Although most transplanted patients mounted spike-specific T helper cell responses, frequencies were significantly reduced compared to controls and dialysis patients, accompanied by a broad impairment in effector cytokine production, memory differentiation and activation-related signatures. Spike-specific CD8+ T cell responses were less abundant than their CD4+ counterparts in healthy controls and hemodialysis patients and almost undetectable in transplant patients. Promotion of anti-HLA antibodies or acute rejection was not detected after vaccination. In summary, our data strongly suggest revised vaccination approaches in immunosuppressed patients, including individual immune monitoring for protection of this vulnerable group at risk to develop severe COVID-19.
Arne Sattler, Eva Schrezenmeier, Ulrike A. Weber, Alexander Potekhin, Friederike Bachmann, Henriette Straub-Hohenbleicher, Klemens Budde, Elena Storz, Vanessa Proß, Yasmin Bergmann, Linda M.L. Thole, Caroline Tizian, Oliver Hölsken, Andreas Diefenbach, Hubert Schrezenmeier, Bernd Jahrsdörfer, Tomasz Zemojtel, Katharina Jechow, Christian Conrad, Sören Lukassen, Diana Stauch, Nils Lachmann, Mira Choi, Fabian Halleck, Katja Kotsch
Inhibitors of mPges-1 are in the early phase of clinical development. Deletion of mPges-1 in mice confers analgesia, restrains atherogenesis and fails to accelerate thrombogenesis, while suppressing PGE2, but increasing biosynthesis of PGI2. In Ldlr-/- mice, this last effect represents the dominant mechanism by which mPges-1 deletion restrains thrombogenesis, while suppression of PGE2 accounts for its anti-atherogenic effect. However, the impact of mPges-1 depletion on BP in this setting remains unknown. Here, mPges-1 depletion significantly increased the BP response to salt loading in male Ldlr-/- mice, whereas, despite the direct vasodilator properties of PGI2, Ipr deletion suppressed it. Furthermore, combined deletion of the Ipr abrogated the exaggerated BP response in male mPges-1-/- mice. Interestingly, these unexpected BP phenotypes were not observed in female mice fed a high salt diet. This is attributable to the protective effect of estrogen in Ldlr-/- mice and in Ipr-/- /Ldlr-/- mice. Thus, estrogen compensates for a deficiency in PGI2 to maintain BP homeostasis in response to high salt in hyperlipidemic female mice. In males, by contrast, augmented formation of ANP plays a similar compensatory role, restraining hypertension and oxidant stress in the setting of Ipr depletion. Hyperlipidemic males on a high salt diet might be at risk of a hypertensive response to mPGES-1 inhibitors.
Soon Y. Tang, Hu Meng, Seán T. Anderson, Dimitra Sarantopoulou, Soumita Ghosh, Nicholas F. Lahens, Katherine N. Theken, Emanuela Ricciotti, Elizabeth J. Hennessy, Vincent Tu, Kyle Bittinger, Aalim M. Weljie, Gregory R. Grant, Garret A. FitzGerald
Androgen receptor (AR)-positive prostate cancers (PCa) and estrogen receptor (ER)-positive luminal breast cancers (BCa) are generally less responsive to immunotherapy compared to certain tumor types such as melanoma. However, the underlying mechanisms are not fully elucidated. Here we found that FOXA1 overexpression inversely correlated with interferon (IFN) signature and antigen presentation gene expression in PCa and BCa patients. FOXA1 bound STAT2 DNA binding domain and suppressed STAT2 DNA binding activity, IFN signaling gene expression and cancer immune response independently of the transactivation activity of FOXA1 and its mutations detected in prostate and breast cancers. Increased FOXA1 expression promoted cancer immuno- and chemotherapy resistance in mice and PCa and BCa patients. These findings were also validated in bladder cancer expressing high level FOXA1. FOXA1 overexpression could be a prognostic factor to predict therapy resistance and a viable target to sensitize luminal prostate, breast and bladder cancer to immuno- and chemotherapy.
Yundong He, Liguo Wang, Ting Wei, Yu-Tian Xiao, Haoyue Sheng, Hengchuan Su, Daniel P. Hollern, Xiaoling Zhang, Jian Ma, Simeng Wen, Hongyan Xie, Yuqian Yan, Yunqian Pan, Xiaonan Hou, Xiaojia Tang, Vera J. Suman, Jodi M. Carter, Richard Weinshilboum, Liewei Wang, Krishna R. Kalari, Saravut J. Weroha, Alan H. Bryce, Judy C. Boughey, Haidong Dong, Charles M. Perou, Dingwei Ye, Matthew P. Goetz, Shancheng Ren, Haojie Huang
Multiple myeloma (MM), a terminally differentiated B-cell malignancy, remains difficult to cure. Understanding the molecular mechanisms underlying the progression of MM may identify therapeutic targets and lead to a fundamental shift in treatment of the disease. Deubiquitination like ubiquitination is a highly regulated process, implicated in almost every cellular process. Multiple deubiquitinating enzymes (DUBs) have been identified but their regulation is poorly defined. Here, we determined that TRIP13 increases cellular deubiquitination. Overexpression of TRIP13 in mice and cultured cells resulted in excess cellular deubiquitination by enhancing the association of the DUB USP7 with its substrates. We show that TRIP13 is an oncogenic protein because it accelerates B-cell tumor development in transgenic mice. TRIP13-induced resistance to proteasome inhibition can be overcome by a USP7 inhibitor in vitro and in vivo. These findings point to a critical role for TRIP13 expression in B-cell lymphoma and MM by governing deubiquitination of critical oncogenic (NEK2) and tumor suppressor (PTEN, P53) proteins. High TRIP13 identifies a high-risk patient group amendable to adjuvant anti-USP7 therapy.
Can Li, Jiliang Xia, Reinaldo Franqui Machin, Fangping Chen, Yanjuan He, Timothy Cody Ashby, Feixiang Teng, Hongwei Xu, Dingxiao Liu, Dongzheng Gai, Sarah K. Johnson, Frits van Rhee, Siegfried Janz, John D. Shaughnessy Jr, Guido Tricot, Ivana Frech, Fenghuang Zhan
Cerebral cavernous malformations (CCMs) are common neurovascular lesions caused by loss-of-function mutations in one of three genes, including KRIT1 (CCM1), CCM2, and PDCD10 (CCM3), and generally regarded as an endothelial cell-autonomous disease. Here we reported that proliferative astrocytes played a critical role in CCM pathogenesis by serving as a major source of VEGF during CCM lesion formation. An increase in astrocyte VEGF synthesis is driven by endothelial nitric oxide (NO) generated as a consequence of KLF2 and KLF4-dependent elevation of eNOS in CCM endothelium. The increased brain endothelial production of NO stabilized HIF-1a in astrocytes, resulting in increased VEGF production and expression of a “hypoxic” program under normoxic conditions. We showed that the upregulation of cyclooxygenase-2 (COX-2), a direct HIF-1a target gene and a known component of the hypoxic program, contributed to the development of CCM lesions because the administration of a COX-2 inhibitor significantly prevented the progression of CCM lesions. Thus, non-cell-autonomous crosstalk between CCM endothelium and astrocytes propels vascular lesion development, and components of the hypoxic program represent potential therapeutic targets for CCMs.
Miguel Alejandro Lopez-Ramirez, Catherine Chinhchu Lai, Shady Ibrahim Soliman, Preston Hale, Angela Pham, Esau J. Estrada, Sara McCurdy, Romuald Girard, Riya Verma, Thomas Moore, Rhonda Lightle, Nicholas Hobson, Robert Shenkar, Orit Poulsen, Gabriel G. Haddad, Richard Daneman, Brendan Gongol, Hao Sun, Frederic Lagarrigue, Issam A. Awad, Mark H. Ginsberg
Peripheral T-cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcome. T-cell receptor (TCR) is emerging as a key driver of T lymphocytes transformation. However, the role of chronic TCR activation in lymphomagenesis and in survival of lymphoma cells is still poorly understood. Using an original mouse model, we report here that chronic TCR stimulation drives T-cell lymphomagenesis whereas TCR signaling does not contribute to PTCL survival. The combination of kinome, transcriptome and epigenome analyses of mouse PTCLs revealed a NK-like reprogramming of PTCL cells with expression of NK receptors (NKRs) and downstream signaling molecules such as Tyrobp and Syk. Activating NKR were functional in PTCLs and dependent of Syk activity. In vivo blockade of NKR signaling prolonged mouse survival, demonstrating the addiction of PTCLs to NKR and downstream Syk/mTOR activity for their survival. Studying a large collection of human primary samples, we identified several PTCLs recapitulating the phenotype described in this model by expressing NKR and Syk, suggesting similar mechanism of lymphomagenesis and establishing rationales for clinical trials targeting such molecules.
Sylvain Carras, Dimitri Chartoire, Sylvain Mareschal, Maël Heiblig, Antoine Marçais, Rémy Robinot, Mirjam Urb, Roxane M. Pommier, Edith Julia, Amel Chebel, Aurélie Verney, Charlotte Bertheau, Emilie Bardel, Caroline Fezelot, Lucien Courtois, Camille Lours, Alyssa Bouska, Sunandini Sharma, Christine Lefebvre, Jean-Pierre Rouault, David Sibon, Anthony Ferrari, Javeed Iqbal, Laurence de Leval, Philippe Gaulard, Alexandra Traverse-Glehen, Pierre Sujobert, Mathieu Bléry, Gilles Salles, Thierry Walzer, Emmanuel Bachy, Laurent Genestier
The role of PI3K and Hippo signaling in chronic pancreatitis (CP) pathogenesis is unclear. Therefore, we assessed the involvement of these pathways in CP by examining the PI3K and Hippo signaling components PTEN and SAV1, respectively. We observed significant decreases in pancreatic PTEN and SAV1 levels in 2 murine CP models: repeated caerulein injection and pancreatic ductal ligation. Additionally, pancreas-specific deletion of Pten and Sav1 (DKO) induced CP in mice. Pancreatic connective tissue growth factor (CTGF) was markedly upregulated in both CP models and DKO mice, and pancreatic CCAAT/enhancer-binding protein alpha (CEBPA) expression was downregulated in the CP models. Interestingly, in pancreatic acinar cells (PACs), CEBPA knockdown reduced PTEN and SAV1 and increased CTGF levels in vitro. Furthermore, CEBPA knockdown in PACs induced acinar-to-ductal metaplasia and activation of cocultured macrophages and pancreatic stellate cells. These results were mitigated by CTGF inhibition. CP in DKO mice was also ameliorated by Ctgf gene deletion, and caerulein-induced CP was alleviated by antibody-mediated CTGF neutralization. Finally, we observed significantly decreased PTEN, SAV1, and CEBPA and increased CTGF levels in human CP tissues compared to nonpancreatitis tissues. Taken together, our results indicate that dysregulation of PI3K and Hippo signaling induces CP via CTGF upregulation.
Takeshi Tamura, Takahiro Kodama, Katsuhiko Sato, Kazuhiro Murai, Teppei Yoshioka, Minoru Shigekawa, Ryoko Yamada, Hayato Hikita, Ryotaro Sakamori, Hirofumi Akita, Hidetoshi Eguchi, Randy L. Johnson, Hideki Yokoi, Masashi Mukoyama, Tomohide Tatsumi, Tetsuo Takehara
Vascular calcification (VC) predicts cardiovascular morbidity and mortality in chronic kidney disease (CKD). To date, the underlying mechanisms remain unclear. We detected leukocyte DNA N6-methyladenine (6mA) levels in CKD patients with or without aortic arch calcification. We used arteries from CKD mice infected with vascular smooth muscle cells (VSMCs)-targeted adeno-associated virus encoding alkB homolog 1 (Alkbh1) gene or Alkbh1 shRNA to evaluate features of calcification. We identified that leukocyte 6mA levels were significantly reduced as the severity of VC increased in CKD patients. Decreased 6mA demethylation resulted from the upregulation of ALKBH1. Here, ALKBH1 overexpression aggravated, whereas its depletion blunted VC progression and osteogenic reprogramming in vivo and in vitro. Mechanistically, ALKBH1-demethylated DNA 6mA modification could facilitate the binding of octamer-binding transcription factor 4 (Oct4) to bone morphogenetic protein 2 (BMP2) promoter and activate BMP2 transcription. This resulted in osteogenic reprogramming of VSMCs and subsequent VC progression. Either BMP2 or Oct4 depletion alleviated the pro-calcifying effects of ALKBH1. This suggests targeting ALKBH1 might be a therapeutic method to reduce the burden of VC in CKD.
Liu Ouyang, Xiaoyan Su, Wenxin Li, Liangqiu Tang, Mengbi Zhang, Yongjun Zhu, Changming Xie, Puhua Zhang, Jie Chen, Hui Huang
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