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Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.138382.
Abstract
Triple negative breast cancers (TNBC) lack effective targeted therapies and cytotoxic chemotherapies remain the standard of care for this subtype. Owing to their increased genomic instability, PARP inhibitors (PARPi) are being tested against TNBCs. In particular, clinical trials are now interrogating the efficacy of PARPi combined with chemotherapies. Intriguingly, while response rates are low, cohorts of patients do respond. Moreover, recent studies suggest that an increase in levels of reactive oxygen species (ROS) may sensitize cells to PARPi. This represents a therapeutic opportunity, as several chemotherapies, including doxorubicin, function in part by producing ROS. We previously demonstrated that the p66ShcA adaptor protein is variably expressed in TNBCs. We now show that in response to therapy-induced stress, p66ShcA stimulates ROS production, which, in turn, potentiates synergy between doxorubicin/PARPi combination therapy in TNBCs. This p66ShcA-induced sensitivity relies on the accumulation of oxidative damage in TNBCs, rather than genomic instability, to potentiate cell death. These findings suggest that increasing the expression of p66ShcA protein levels in TNBCs represents a rational approach to bolster the synergy between PARPi and doxorubicin.
Authors
Eduardo Cepeda Cañedo, Stephanie Totten, Ryuhjin Ahn, Paul Savage, Deanna MacNeil, Jesse Hudson, Chantal Autexier, Genevieve Deblois, Morag Park, Michael Witcher, Josie Ursini-Siegel
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.141683.
Abstract
Multiple myeloma (MM) is characterized by an accumulation of malignant plasma cells (PCs) within the bone marrow (BM). The BM microenvironment supports survival of the malignant cells and is comprised of cellular fractions that foster myeloma development and progression by suppression of the immune response. Despite major progress in understanding the biology and pathophysiology of MM, this disease is still incurable and requires aggressive treatment with significant side effects. CD84 is a self-binding immuno-receptor belonging to the signaling lymphocyte activating molecule (SLAM) family. Previously, we showed that CD84 bridges between chronic lymphocytic leukemia cells and their microenvironment, and regulates T cell function. In the current study, we investigated the role of CD84 in MM. Our results show that MM cells express low levels of CD84. However, these cells secrete the cytokine macrophage migration inhibitory factor (MIF), which induces CD84 expression on cells in their microenvironment. Its activation leads to an elevation of expression of genes regulating differentiation to M/G- myeloid derived suppressor cells (MDSCs) and upregulation of PD-L1 expression on MDSCs, which together suppress T cell function. Downregulation of CD84 or its blocking reduces MDSC accumulation, resulting in elevated T cell activity and reduced tumor load. Our data suggest that CD84 might serve as a novel therapeutic target in MM.
Authors
Hadas Lewinsky, Emine Gulsen Gunes, Keren David, Lihi Radomir, Matthias P. Kramer, Bianca Pellegrino, Michal Perpinial, Jing Chen, Ting-fang He, Anthony Mansour, Kun-Yu Teng, Supriyo Bhattacharya, Enrico Caserta, Estelle Troadec, Peter P. Lee, Mingye Feng, Jonathan J. Keats, Amrita Krishnan, Michael Rosenzweig, Jianhua Yu, Michael A. Caligiuri, Yosef Cohen, Olga Shvetz, Shirly Becker-Herman, Flavia Pichiorri, Steven Rosen, Idit Shachar
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.145228.
Abstract
Novel prime-boost immunization strategies are required to control the global Tuberculosis (TB) pandemic, which claims approximately 3 lives every minute. Here, we have generated an immunogenic complex against Mycobacterium tuberculosis (M.tb), consisting of promiscuous T cell epitopes (M.tb peptides) and TLR ligands assembled in liposomes. Interestingly, this complex (PTLs; peptide-TLR agonist-liposomes) induced significant activation of CD4+ T cells and IFNγ production in the PBMCs derived from PPD+ healthy individuals as compared to PPD- controls. Furthermore, intranasal delivery of PTLs significantly reduced the bacterial burden in the infected mice by inducing M.tb specific polyfunctional (IFNγ+IL17+TNFα+IL2+) immune responses and long-lasting central memory responses thereby reducing the risk of TB recurrence in DOTS treated infected animals. The transcriptome analysis of peptide-stimulated immune cells unveiled the molecular basis of enhanced protection. Furthermore, PTLs immunization significantly boosted the BCG-primed immune responses against TB. The greatly enhanced efficacy of BCG-PTLs vaccine model in controlling pulmonary TB projects PTLs as an adjunct vaccine against TB.
Authors
Santosh Kumar, Ashima Bhaskar, Gautam Patnaik, Chetan Sharma, Dhiraj K. Singh, Sandeep Kaushik, Shivam Chaturvedi, Gobardhan Das, Ved Prakash Dwivedi
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.143299.
Abstract
Background: Mitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether circulating cell-free MT-DNA quantitation could be used to predict the risk of poor COVID-19 outcomes remains undetermined. Methods: We measured circulating MT-DNA levels in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at hospital presentation. Our primary outcome was mortality. ICU admission, intubation, vasopressor and renal replacement therapy requirements were secondary outcomes. Multivariate regression analysis determined whether MT-DNA levels were independent of other reported COVID-19 risk factors. Receiver operating characteristics and area under-the-curve assessment were used to compare MT-DNA levels to established and emerging inflammatory markers of COVID-19. Results: Circulating MT-DNA levels were highly elevated in patients who eventually died, required ICU admission, intubation, vasopressor use or renal replacement therapy. Multivariate regression revealed that high circulating MT-DNA is an independent risk factor for these outcomes after adjusting for age, sex, and comorbidities. We also found that circulating MT-DNA levels have a similar or superior area-under-the curve when compared against clinically-established measures of inflammation and emerging markers currently of interest as investigational targets for COVID-19 therapy. Conclusions: These results show that high circulating MT-DNA levels are a potential early indicator for poor COVID-19 outcomes. Funding: This project was supported by Washington University Institute of Clinical Translational Sciences COVID-19 Research Program. Sample procurement and patient outcome data collection was supported by the Washington University ICTS NIH grant UL1TR002345.
Authors
Davide Scozzi, Marlene Cano, Lina Ma, Dequan Zhou, Ji Hong Zhu, Jane A. O’Halloran, Charles W. Goss, Adriana M. Rauseo, Zhiyi Liu, Sanjaya Kumar Sahu, Valentina Peritore, Monica Rocco, Alberto Ricci, Rachele Amodeo, Laura Aimati, Mohsen Ibrahim, Ramsey R. Hachem, Daniel Kreisel, Philip A. Mudd, Hrishikesh S. Kulkarni, Andrew E. Gelman
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.143228.
Abstract
Somatostatin (SS) inhibits glucagon-like peptide-1 (GLP-1) secretion in a paracrine manner. We hypothesized that blocking somatostatin subtype receptor 2 (SSTR2) and 5 (SSTR5) would improve glycaemia by enhancing GLP-1 secretion. In the perfused mouse small intestine the selective SSTR5 antagonist (SSTR5a) stimulated glucose-induced GLP-1 secretion to a larger degree than the SSTR2 antagonist (SSTR2a). In parallel, mice lacking the SSTR5R showed increased glucose-induced GLP-1 secretion. Both antagonists improved glycaemia in vivo in a GLP-1 receptor (GLP-1R) dependent manner, as the glycaemic improvements were absent in mice with impaired GLP-1R signalling and in mice treated with a GLP-1R specific antagonist. SSTR5a had no direct effect on insulin secretion in the perfused pancreas whereas SSTR2a increased insulin secretion in a GLP-1R independent manner. Adding a dipeptidyl peptidase 4 inhibitor (DPP-4i) in vivo resulted in additive effects on glycaemia, however, when glucose was administered intraperitoneally the antagonists was incapable of lowering blood glucose. Oral administration of SSTR5a, but not SSTR2a lowered blood glucose in diet induced obese mice. In summary, we demonstrate that selective SSTR antagonists can improve glucose control primarily through the intestinal GLP-1 system in mice.
Authors
Sara L. Jepsen, Nicolai J. Wewer Albrechtsen, Johanne Agerlin Windeløv, Katrine D. Galsgaard, Jenna Elizabeth Hunt, Thomas B. Farb, Hannelouise Kissow, Jens Pedersen, Carolyn F. Deacon, Rainer E. Martin, Jens J. Holst
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.143643.
Abstract
Rewiring tumor cells to undergo drug-induced apoptosis could be a promising way to overcome chemoresistance, therefore identifying causative factors for chemoresistance is of high importance. Global proteome-profiling of sensitive, early and late cisplatin resistant OSCC lines identified CMTM6 as a top ranked up-regulated protein. Analyses of OSCC patient tumor samples demonstrated significantly higher CMTM6 expression in chemotherapy-non-responders as compared to responders. In addition, a significant association between higher CMTM6 expression and poorer relapse-free survival in ESCC, HNSCC was monitored from Kaplan-Meier-Plot analysis. Stable knockdown of CMTM6 restores cisplatin-mediated cell death in chemoresistant OSCC cell lines. Similarly, upon CMTM6 overexpression in CMTM6KD lines, the cisplatin resistant phenotype was efficiently rescued. The patient-derived cell xenograft model of chemoresistant OSCC displayed CMTM6 depletion restored the cisplatin-induced cell death and tumor burden significantly. The transcriptome analysis of CMTM6KD and control chemoresistant cells depicted enrichment of Wnt-signaling pathway. Mechanistically, we demonstrated that CMTM6 interaction with membrane bound Enolase-1 stabilized its expression, leading to AKT-GSK3β mediated activation of Wnt-signaling. CMTM6 has been identified as a stabilizer of PD-L1 thereby facilitates immune evasion by tumor cells. As CMTM6 facilitates tumor cells for immune evasion and mediates cisplatin resistance, it can be an important therapeutic target for therapy resistant OSCC.
Authors
Pallavi Mohapatra, Omprakash Shriwas, Sibasish Mohanty, Arup Ghosh, Shuchi Smita, Sandeep Rai Kaushik, Rakesh Arya, Rachna Rath, Saroj Das Majumdar, Dillip Kumar Muduly, Sunil Raghav, Ranjan K. Nanda, Rupesh Dash
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.132778.
Abstract
MC4R mutations represent the largest monogenic cause of obesity, resulting mainly from receptor misfolding and intracellular retention by the cellular quality control system. The present study aimed at determining whether pharmacological chaperones (PC) that restore folding and plasma membrane trafficking by stabilizing near native protein conformation, may represent valid therapeutic avenues for the treatment of melanocortin type 4 receptor (MC4R) linked obesity.To test the therapeutic PC potential, we engineered humanized MC4R mouse models expressing either the wild type (WT) human MC4R or a prevalent obesity-causing mutant (R165W). Administration of a PC able to rescue cell surface expression and functional activity of R165W-hMC4R in cells, restored the anorexigenic response of the R165W-hMC4R obese mice to melanocortin agonist, providing a proof-of-principle for the therapeutic potential of MC4R-targetting PC in vivo. Interestingly, the expression of the WT-hMC4R in mice revealed lower sensitivity of the human receptor to alpha-melanocyte-stimulating hormone (α-MSH) but not β-MSH or MTII, resulting in a lower penetrance obese phenotype in the WT-hMC4R versus R165W-hMC4R mice. In conclusion, we created two new obesity models, one hypomorph highlighting species differences, and one amorphic that provides a pre-clinical model to test the therapeutic potential of PC to treat MC4R-linked obesity.
Authors
Patricia René, Damien Lanfray, Denis Richard, Michel Bouvier
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.139946.
Abstract
Insulin-mediated suppression of white adipose tissue (WAT) lipolysis is an important anabolic function that is dysregulated in states of overnutrition. However, the mechanism of short-term high-fat diet (HFD)-induced WAT insulin resistance is poorly understood. Based on our recent studies we hypothesize that a short-term HFD causes WAT insulin resistance through increases in plasma membrane (PM) sn-1,2-diacylglycerols (DAG), which promotes protein kinase C-ε (PKCε) activation to impair insulin signaling by phosphorylating insulin receptor (Insr) Thr1160. To test this hypothesis, we assessed WAT insulin action in 7-day HFD-fed versus regular chow diet-fed rats during a hyperinsulinemic-euglycemic clamp. HFD feeding caused WAT insulin resistance, reflected by reductions in both insulin-mediated WAT glucose uptake and suppression of WAT lipolysis. These changes were specifically associated with increased PM sn-1,2-diacylglycerol (DAG) content, increased PKCε activation and impaired insulin-stimulated InsrY1162 phosphorylation. In order to examine the role of InsrT1160 phosphorylation in mediating lipid-induced WAT insulin resistance, we examined these same parameters in short-term HFD-fed InsrT1150A knockin mice (mouse homolog for human Thr1160). Similar to the rat study HFD feeding induced WAT insulin resistance in WT control mice but failed to induce WAT insulin resistance in InsrT1150A mice. Taken together these data demonstrate that the PM sn-1,2-DAG - PKCε - InsrT1160 phosphorylation pathway plays an important role in mediating lipid-induced WAT insulin resistance and represents a potential therapeutic target to improve insulin sensitivity in WAT.
Authors
Kun Lyu, Dongyan Zhang, Joongyu D. Song, Xiruo Li, Rachel J. Perry, Varman T. Samuel, Gerald I. Shulman
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.142376.
Abstract
Reestablishing an appropriate balance between T effector cells (Teff) and T regulatory cells (Treg) is essential for correcting autoimmunity. Multiple Sclerosis (MS) is an immune-mediated chronic central nervous system (CNS) disease characterized by neuroinflammation, demyelination, and neuronal degeneration, in which the Teff:Treg balance is skewed toward pathogenic Teff cells, Th1 and Th17 cells. Signal transducer and activator of transcription 3 (STAT3) is a key regulator of Teff:Treg balance. Using the structure-based design, we have developed a novel small-molecule prodrug LLL12b that specifically inhibits STAT3 and suppresses Th17 differentiation and expansion. Moreover, LLL12b regulates the fate decision between Th17 and Tregs in an inflammatory environment, shifting Th17:Treg balance toward Tregs and favoring the resolution of inflammation. Therapeutic administration of LLL12b after disease onset significantly suppresses disease progression in adoptively transferred, chronic, and relapsing-remitting experimental autoimmune encephalomyelitis. Disease relapses were also significantly suppressed by LLL12b given during the remission phase. Additionally, LLL12b shifts Th17:Treg balance of CD4 T cells from MS patients toward Tregs and increases Teff sensitivity to Treg-mediated suppression. These data suggest selective inhibition of STAT3 by the novel small molecule LLL12b recalibrates the effector and regulatory arms of CD4 T responses, representing a potentially clinically translatable therapeutic strategy for MS.
Authors
Saba I. Aqel, Xiaozhi Yang, Emma E. Kraus, Jinhua Song, Marissa F. Farinas, Erin Y. Zhao, Wei Pei, Amy E. Lovett-Racke, Michael K. Racke, Chenglong Li, Yuhong Yang
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.141323.
Abstract
Glucagon regulates glucose and lipid metabolism and also promotes weight loss. Thus, therapeutics stimulating glucagon-receptor (GCGR) signaling are promising for obesity treatment; however, the underlying mechanism(s) have yet to be fully elucidated. We previously identified that hepatic GCGR signaling increases circulating Fibroblast Growth Factor 21 (FGF21), a potent regulator of energy balance. We reported that mice deficient for liver Fgf21 are partially resistant to GCGR-mediated weight loss, implicating FGF21 as a regulator of glucagon’s weight-loss effects. FGF21 signaling requires an obligate co-receptor (B-Klotho, KLB), with expression limited to adipose tissue, liver, pancreas, and brain. We hypothesized that the GCGR-FGF21 system mediates weight loss through a central mechanism. Mice deficient for neuronal Klb (Klb∆CNS) exhibit a partial reduction in body weight with chronic GCGR-agonism (via IUB288) compared to controls (p<0.0001), supporting a role for central FGF21 signaling in GCGR-mediated weight loss. Substantiating these results, mice with central KLB inhibition via a pharmacological KLB antagonist (1153) also display partial weight loss (p<0.0001). Central KLB, however, is dispensable for GCGR-mediated improvements in plasma cholesterol and liver triglycerides. Together, these data suggest GCGR-agonism mediates part of its weight loss properties through central KLB and has implications for future treatments against obesity and metabolic syndrome.
Authors
Shelly R. Nason, Jessica P. Antipenko, Natalie Presedo, Stephen E. Cunningham, Tanya H. Pierre, Teayoun Kim, Jodi R. Paul, Cassie L. Holleman, Martin E. Young, Karen L. Gamble, Brian Finan, Richard DiMarchi, Chad S. Hunter, Alexei Kharitonenkov, Kirk M. Habegger
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.141776.
Abstract
Background: Loss-of-function variants in SCN1B, encoding voltage-gated sodium channel β1 subunits, are linked to human diseases with high risk of sudden death, including epileptic encephalopathy and cardiac arrhythmia. β1 subunits modulate the cell-surface localization, gating, and kinetics of sodium channel pore-forming a subunits. They also participate in cell-cell and cell-matrix adhesion, resulting in intracellular signal transduction, promotion of cell migration, calcium handling, and regulation of cell morphology. Methods: We investigated regulated intramembrane proteolysis (RIP) of β1 by BACE1 and γ-secretase.Results: We show that β1 subunits are substrates for sequential RIP by BACE1 and γ-secretase, resulting in the generation of a soluble intracellular domain (ICD) that is translocated to the nucleus. Using RNA-seq, we identified a subset of genes that are downregulated by β1-ICD overexpression in heterologous cells but upregulated in Scn1b null cardiac tissue which, by definition, lacks β1-ICD signaling, suggesting that the β1-ICD may normally function as a molecular brake on gene transcription in vivo. Conclusion: We propose that human disease variants resulting in SCN1B loss-of-function cause transcriptional dysregulation that contributes to altered excitability. These results provide important new insights into the mechanism of SCN1B-linked channelopathies, adding RIP-excitation coupling to the multi-functionality of sodium channel β1 subunits.
Authors
Alexandra A. Bouza, Nnamdi Edokobi, Samantha L. Hodges, Alexa M. Pinsky, James Offord, Lin Piao, Yan-Ting Zhao, Anatoli N. Lopatin, Luis F. Lopez-Santiago, Lori L. Isom
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.143509.
Abstract
2'3'-cGAMP is known as a non-classical 2nd messenger and small immune modulator that possesses potent anti-tumor and antiviral activities through stimulating STING-mediated signaling pathway. However, its function in regulating type 2 immune responses remains unknown. We sought to determine a role of STING activation by 2'3'-cGAMP in type 2 inflammatory reactions in multiple mouse models of eosinophilic asthma. We discovered that 2'3'-cGAMP administration strongly attenuated type 2 lung immunopathology and airway hyperresponsiveness (AHR) induced by IL-33 and a fungal allergen, A. flavus. Mechanistically, upon the respiratory delivery, 2'3'-cGAMP was mainly internalized by alveolar macrophages, in which it activated the STING-IRF3-IFN-I signaling axis to induce the production of inhibitory factors containing IFNα, which blocked the IL-33-mediated activation of group 2 innate lymphoid cells (ILC2) in vivo. We further demonstrated that 2'3'-cGAMP directly suppressed the proliferation and function of both human and mouse ILC2 in vitro. Taken together, our findings suggest that STING activation by 2'3'-cGAMP in alveolar macrophages and ILC2 cells can negatively regulate type 2 immune responses, implying that the respiratory delivery of 2'3'-cGAMP might be further developed as an alternative strategy for treating type 2 immunopathologic diseases such as eosinophilic asthma.
Authors
Li She, Gema D. Barrera, Liping Yan, Hamad Hazzaa Alanazi, Edward G. Brooks, Peter H. Dube, Yilun Sun, Hong Zan, Daniel P. Chupp, Nu Zhang, Xin Zhang, Yong Liu, Xiao-Dong Li
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.146823.
Abstract
Diarrhea is a major cause of global mortality, and outbreaks of secretory diarrhea such as cholera remain an important problem in the developing world. Current treatment of secretory diarrhea primarily involves supportive measures such as fluid replacement. The calcium-sensing receptor (CaSR) regulates multiple biological activities in response to changes in extracellular Ca+2. The FDA-approved drug cinacalcet is an allosteric activator of CaSR used for treatment of hyperparathyroidism. Here, we found by short-circuit current measurements in human colonic T84 cells that CaSR activation by cinacalcet reduced forskolin-induced Cl- secretion by greater than 80%. Cinacalcet also reduced Cl- secretion induced by cholera toxin, heat-stable E. coli enterotoxin, and vasoactive intestinal peptide (VIP). The cinacalcet effect primarily involved indirect inhibition of cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl- secretion following activation of CaSR, and downstream phospholipase C and phosphodiesterases. In mice, cinacalcet reduced fluid accumulation by more than 60% in intestinal closed-loop models of cholera and Traveler’s diarrhea. The cinacalcet effect involved both inhibition of CFTR-mediated secretion and stimulation of sodium-hydrogen exchanger 3 (NHE3)-mediated absorption. These findings support the therapeutic utility of the safe and commonly used drug cinacalcet in CFTR-dependent secretory diarrheas including cholera, Traveler’s diarrhea and VIPoma.
Authors
Apurva A. Oak, Parth D. Chhetri, Amber Rivera, Alan S. Verkman, Onur Cil
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.128456.
Abstract
Most patients with glioblastoma (GBM) die within 2 years. A major therapeutic goal is to target GBM stem cells (GSCs), a subpopulation of cells that contributes to treatment resistance and recurrence. Since their discovery in 2003, GSCs have been isolated using single surface markers, such as CD15, CD44, CD133, and alpha-6 integrin. It remains unknown how these single surface marker-defined GSC populations compare to each other in terms of signaling and function and whether expression of different combinations of these markers is associated with different functional capacity. Using mass cytometry and fresh operating room specimens, we found 15 distinct GSC subpopulations in patients and they differed in their MEK/ERK, WNT, and AKT pathway activation status. Once in culture, some subpopulations were lost, and previously undetectable ones materialized. GSCs that highly expressed all four surface markers had the greatest self-renewal capacity, WNT inhibitor sensitivity, and in vivo tumorigenicity. This work highlights the potential signaling and phenotypic diversity of GSCs. Larger patient sample sizes and antibody panels are required to confirm these findings.
Authors
Luciano Galdieri, Arijita Jash, Olga Malkova, Diane D. Mao, Patrick A. DeSouza, Yunli E. Chu, Amber Salter, Jian L. Campian, Kristen M. Naegle, Cameron W. Brennan, Hiroaki Wakimoto, Stephen T. Oh, Albert H. Kim, Milan G. Chheda
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.142640.
Abstract
Antiretroviral therapies (ART) abrogate HIV replication; however, infection persists as long-lived reservoirs of infected cells with integrated proviruses, which re-seed replication if ART is interrupted. A central tenet of our current understanding of this persistence is that infected cells are shielded from immune recognition and elimination through a lack of antigen expression from proviruses. Efforts to cure HIV infection have therefore focused on reactivating latent proviruses to enable immune-mediated clearance, but these have yet to succeed in reducing viral reservoirs. Here, we revisited the question of whether HIV reservoirs are predominately immunologically silent from a new angle: by querying the dynamics of HIV-specific T-cell responses over long-term ART for evidence of ongoing recognition of HIV-infected cells. In longitudinal assessments, we show that the rates of change in persisting HIV Nef-specific responses, but not responses to other HIV gene products, were associated with residual frequencies of infected cells. These Nef-specific responses were highly stable over time, and disproportionately exhibited a cytotoxic, effector functional profile, indicative of recent in vivo recognition of HIV antigens. These results indicate substantial visibility of the HIV-infected cells to T-cells on stable ART, presenting both opportunities and challenges for the development of therapeutic approaches to curing infection.
Authors
Eva M. Stevenson, Adam R. Ward, Ronald Truong, Allison S. Thomas, Szu-Han Huang, Thomas R. Dilling, Sandra Terry, John K. Bui, Talia M. Mota, Ali Danesh, Guinevere Q. Lee, Andrea Gramatica, Pragya Khadka, Winiffer D. Conce Alberto, Rajesh T. Gandhi, Deborah K. McMahon, Christina M. Lalama, Ronald J. Bosch, Bernard J. Macatangay, Joshua C. Cyktor, Joseph J. Eron, John W. Mellors, R. Brad Jones
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.137245.
Abstract
Osteosarcoma (OS) is an aggressive mesenchymal tumor for which no molecularly targeted therapies are available. We have previously identified TRAF2 and NCK-interacting protein kinase (TNIK) as an essential factor for the transactivation of Wnt signal target genes and shown that its inhibition leads to eradication of colorectal cancer stem cells. The involvement of Wnt signaling in the pathogenesis of OS has been implicated. The aim of the present study was to examine the potential of TNIK as a therapeutic target in OS. RNA interference or pharmacological inhibition of TNIK suppressed the proliferation of OS cells. Transcriptome analysis suggested that a small-molecule inhibitor of TNIK up-regulated the expression of genes involved in OS cell metabolism and down-regulated transcription factors essential for maintaining the stem cell phenotype. Metabolome analysis revealed that this TNIK inhibitor redirected the metabolic network from carbon flux towards lipid accumulation in OS cells. Using in vitro and in vivo OS models, we confirmed that TNIK inhibition abrogated the OS stem cell phenotype, simultaneously driving conversion of OS cells to adipocyte-like cells through induction of peroxisome proliferator-activated receptor-γ. In relation to potential therapeutic targeting in clinical practice, TNIK was confirmed to be in an active state in OS cell lines and clinical specimens. From these findings, we conclude that TNIK is applicable as a potential target for treatment of OS, affecting cell fate determination.
Authors
Toru Hirozane, Mari Masuda, Teppei Sugano, Tetsuya Sekita, Naoko Goto, Toru Aoyama, Takato Sakagami, Yuko Uno, Hideki Moriyama, Masaaki Sawa, Naofumi Asano, Masaya Nakamura, Morio Matsumoto, Robert Nakayama, Tadashi Kondo, Akira Kawai, Eisuke Kobayashi, Tesshi Yamada
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.142299.
Abstract
Infantile hemangioma is a vascular tumor characterized by the rapid growth of disorganized blood vessels followed by slow spontaneous involution. The underlying molecular mechanisms that regulate hemangioma proliferation and involution still are not well elucidated. Our previous studies reported that NOGOB receptor (NGBR), a transmembrane protein, is required for the translocation of prenylated RAS from the cytosol to the plasma membrane and promotes RAS activation. Here, we show that NGBR is highly expressed in the proliferating phase of infantile hemangioma, but its expression decreases in the involuting phase, suggesting that NGBR may be involved in regulating the growth of proliferating hemangioma. Moreover, we demonstrated that NGBR knockdown in hemangioma stem cells (HemSCs) attenuates growth factors-stimulated RAS activation and diminishes the migration and proliferation of HemSCs, which is consistent with the effects of RAS knockdown in HemSCs. In vivo differentiation assay further showed that NGBR knockdown inhibits blood vessel formation and adipocyte differentiation of HemSCs in immunodeficient mice. Our data suggest that NGBR serves as a RAS modulator in controlling the growth and differentiation of HemSCs.
Authors
Wenquan Hu, Zhong Liu, Valerie Salato, Paula E. North, Joyce Bischoff, Suresh N. Kumar, Zhi Fang, Sujith Rajan, M. Mahmood Hussain, Qing R. Miao
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.145761.
Abstract
Hepatitis B virus (HBV)-specific CD8+ T cells fail to acquire effector functions after priming in the liver, but the molecular basis for the dysfunctionality is poorly understood. By comparing the gene expression profile of intrahepatically primed, dysfunctional HBV-specific CD8+ T cells with that of systemically primed, functional effector counterparts, we found that the expression of interferon-stimulated genes (ISGs) is selectively suppressed in the dysfunctional CD8+ T cells. The ISG suppression was associated with impaired phosphorylation of STAT1 in response to IFNα treatment. Importantly, a strong induction of type interferons (IFN-Is) in the liver facilitated the functional differentiation of intrahepatically primed HBV-specific CD8+ T cells in association with the restoration of ISGs expression in the T cells. These results suggest that intrahepatic priming suppresses IFN-I signaling in CD8+ T cells, which may contribute to the dysfunctionality. The data also suggest a therapeutic value of the robust induction of intrahepatic IFN-Is for the treatment of chronic HBV infection.
Authors
Keigo Kawashima, Masanori Isogawa, Masaya Onishi, Ian Baudi, Satoru Saito, Atsushi Nakajima, Takashi Fujita, Yasuhito Tanaka
Citation Information: JCI Insight. 2021. https://doi.org/10.1172/jci.insight.143619.
Abstract
The role of insulin receptor (IR) activated by hyperinsulinemia in obesity-induced kidney injury is not well understood. We hypothesized that activation of the kidney proximal tubule epithelial IR contributes to obesity-induced kidney injury. We administered normal fat diet (NFD) or high fat diet (HFD) to Control and kidney proximal tubule IR knock out (KPTIRKO) mice for 4 months. Renal cortical IR expression was decreased by 60% in male and female KPTIRKO mice. In KPTIRKO mice baseline serum glucose, serum creatinine, and urinary albumin to creatinine ratio (ACR) were similar to Controls. On HFD, weight gain and increase in serum cholesterol were similar in Control and KPTIRKO mice; blood glucose did not change. HFD increased the following parameters in the male Control mice: renal cortical contents of phosphorylated IR and Akt, matrix proteins, urinary ACR and kidney injury molecule-1 (KIM-1) to creatinine ratio, and systolic blood pressure. Renal cortical generation of hydrogen sulfide was reduced in HFD fed male Control mice. All of these parameters were ameliorated in male KPTIRKO mice. Interestingly, female mice were resistant to HFD-induced kidney injury in both genotypes. We conclude that HFD-induced kidney injury requires renal proximal tubule IR activation in male mice.
Authors
Hak Joo Lee, Meenalakshmi M. Mariappan, Luke Norton, Terry Bakewell, Denis Feliers, Sae Byeol Oh, Andrew Donati, Cherubina S. Rubannelsonkumar, Manjeri Venkatachalam, Stephen E. Harris, Isabelle Rubera, Michel Tauc, Goutam Ghosh Choudhury, C. Ronald Kahn, Kumar Sharma, Ralph A. DeFronzo, Balakuntalam S. Kasinath
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.138385.
Abstract
Ginger is known to have anti-inflammatory and anti-oxidative effects, and has traditionally been used as an herbal supplement in the treatment of various chronic diseases. Here, we report anti-neutrophil properties of 6-gingerol, the most abundant bioactive compound of ginger root, in models of lupus and antiphospholipid syndrome (APS). Specifically, we demonstrate that 6-gingerol attenuates neutrophil extracellular trap (NET) release in response to lupus- and APS-relevant stimuli through a mechanism that at least partially dependent on inhibition of phosphodiesterases. At the same time, administration of 6-gingerol to mice reduces NET release in various models of lupus and APS, while also improving other disease-relevant endpoints such as autoantibody formation and large-vein thrombosis. In summary, this study is the first to demonstrate a protective role for ginger-derived compounds in the context of lupus, and importantly provides a potential mechanism for these effects via phosphodiesterase inhibition and attenuation of neutrophil hyperactivity.
Authors
Ramadan A. Ali, Alex A. Gandhi, Lipeng Dai, Julia K. Weiner, Shanea K. Estes, Srilakshmi Yalavarthi, Kelsey Gockman, Duxin Sun, Jason S. Knight
