Signal Activator Research Articles

Abstract A013: Microenvironment driven dynamic deposition of histone H3.3 controls entry and exit from dormancy in disseminated cancer cells

Abstract Breast cancer metastases can go undetected for long periods of time, are highly resistant to therapy, and are the cause for more than 90% of breast cancer mortality. Dormancy is a critical step in the metastatic cascade, whereby disseminated cancer cells (DCCs) enter a non-proliferative state at distal sites until they reactivate and give rise to overt metastasis, often years after disease remission. As such, dormancy represents a major clinical obstacle in breast cancer patient care. Chromatin remodeling serves as a foundation for the cellular reprogramming required to drive cell fate transitions. However, little is known about the nature of this remodeling in dormancy. Here, we hypothesize that differential deposition of histone H3.3 determines whether DCCs enter and remain dormant in secondary organs or proliferate and form overt metastases. We used a combination of H3.3 deposition sensors and genetic tools to manipulate H3.3 and HIRA in vitro and in vivo to track H3.3 deposition through the metastatic cascade and evaluate its importance for dormancy. To evaluate relevance to patient disease we developed a dormancy score to implement from publicly available RNA seq. To define mechanism of regulation, we used a combination of whole genome sequencing (ChIP-seq, ATAC-seq and RNA-seq) followed by in-depth analysis and functional validation. Our data demonstrates that H3.3 incorporation at secondary sites is heterogenous, revealing a subset of DCCs with low H3.3 in chromatin. Blocking H3.3 deposition onto chromatin leads to a reversible arrest in G0/G1 which tracks with the activation of canonical dormancy signaling. Mechanistically, our data supports a model where blocking H3.3 incorporation into chromatin directly represses the expression of SKP2, the main regulator of progression through the restriction point of cell cycle via regulation of p27 degradation. SKP2 suppression in turn leads to the accumulation of p27 thereby causing cell cycle arrest in G0/G1 and dormancy establishment. We traced this H3.3-mediated regulation of dormancy through the dynamic regulation of H3.3 histone chaperone, HIRA, whose levels inversely correlate with dormancy in experimental models as well as in patient samples. We found that HIRA levels respond to the metastatic microenvironment where fibrotic conditions induce HIRA expression and trigger metastatic outgrowth in an H3.3-dependent manner. Together, our work unveils for the first time a patient-relevant epigenetic mechanism, impinging on H3.3 deposition, as a major regulatory point of DCCs’ cell fate at secondary organs controlling both entry of DCC’s into dormant state as well as their reactivation and thriving as overt metastasis. Citation Format: Stanislav Drapela, Cristina Megino-Luque, Rojan Chimeh Rad, Devesh Raizada, Nadir Sarigul, Didem Ilter, Brian J. Czerniecki, Jose Javier Bravo-Cordero, Ana P. Gomes. Microenvironment driven dynamic deposition of histone H3.3 controls entry and exit from dormancy in disseminated cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A013.

Abstract PR015: Sepsis-induced inflammation alters natural killer cell-mediated surveillance of liver metastasis

Abstract A majority of pancreatic ductal adenocarcinoma (PDAC) patients who undergo surgery for primary tumor resection will develop lethal metastases, despite having no evidence of metastasis at the time of their initial diagnosis. Liver metastases constitute nearly half of recurrences detected within the first six months following PDAC resection. Several clinical and experimental studies provide evidence that perioperative inflammation, including infectious complications like sepsis, positively correlates with liver metastasis across several malignancies. Despite these observations, it is still unknown whether there is a causal link between perioperative inflammation and PDAC liver metastasis. To gain mechanistic insight into the regulation of PDAC liver metastasis in the context of perioperative inflammation, we established mouse models that combine experimental PDAC liver metastasis with either the cecal ligation and puncture (CLP) model of polymicrobial sepsis or the lipopolysaccharide (LPS) model of acute sterile endotoxemia. Mice challenged with CLP prior to seeding PDAC cells in the liver had increased metastatic burden at endpoint compared to sham laparotomy controls. In contrast, mice challenged with LPS prior to PDAC cell seeding had reduced metastatic burden at endpoint compared to PBS-injected controls. We hypothesized that these opposing pro- and anti-metastatic effects of CLP and LPS, respectively, were due to qualitatively distinct inflammatory responses elicited in the liver. Our profiling of the host response to either CLP or LPS revealed shared systemic changes, including activation of the acute-phase protein response. However, LPS-associated inflammation uniquely upregulated a distinct set of interferon-regulated genes in the liver important for modifying immune cell activity (i.e., Ccl2, Ccl5, Cxcl9, Cxcl10). Accordingly, immunostaining and flow cytometry of the liver revealed that LPS uniquely increased the abundance of activated natural killer (NK) cells and MPO+ myeloid cells. We utilized Tlr4 -/- mice, which lack the primary receptor for LPS, to determine that the anti-metastatic effect of LPS required a host-facilitated response downstream of TLR4-mediated signaling. Through a series of genetic models and short-term depletion experiments, we determined that NK cells restrict PDAC cell seeding and outgrowth in our experimental liver metastasis model, and that this protective effect is further enhanced by activation of type-I interferon signaling in the host. Our findings confirm prior work identifying NK cell-mediated surveillance of disseminated cancer cells as an important mechanism in protecting against liver metastasis and show sterile endotoxemia and its associated inflammation establish a protective ‘anti-metastatic niche’ marked by enhanced NK cell activity. Further insights into the establishment of this niche may reveal potential therapeutic strategies to reduce the incidence of liver metastasis among resected PDAC patients. Citation Format: Nicole Sivetz, Patrick J. Cunniff, Christopher R. Vakoc, Semir Beyaz, Mikala Egeblad. Sepsis-induced inflammation alters natural killer cell-mediated surveillance of liver metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR015.

Abstract B018: Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer

Abstract Colorectal cancer (CRC) ranks second in mortality and advanced CRCs are resistant to current immunotherapies and prone to metastasis, which necessitates research into enhancing innate and adaptive anti-cancer immune responses. Chronic inflammation mediated by cytokines like IL6 and notably, IL17 activates the oncogenic pathways in cancer cells, promoting sporadic and inflammatory CRC. What is unknown, is the ability of cytokines to control tumor microenvironment (TME) via cell type specific mechanisms to increase cancer progression, metastasis and/or therapy resistance. Increased levels of IL17A in CRC portends poor prognosis indicating its potential involvement into metastasis. However, the role of IL17 signaling in TME in the process of CRC progression and metastasis remains enigmatic. We utilized different models of CRC progression and metastasis, as well as variety of genetic mice models and therapeutic interventions. First, using a model of colitis-associated cancer we found that “late” IL17A neutralization decreases tumor burden, possibly acting through regulation of ferroptosis, NK cells mediated cytotoxicity, as well as myeloid cells and chemokine network essential for the control of immunosuppressive TME. Next, models of CRC metastasis, including those based on MC38 cells and APTAK cancerous organoids, showed that IL17A neutralization reduces metastasis growth. Also, FACS analysis revealed that IL17A promotes the recruitment of tumor- associated macrophages and other key myeloid subsets into the metastatic liver environment. Further research, using mice with conditional knockout of IL17RC receptor in myeloid cells (Il17rc f/f -LysMCre) or hepatocytes (Il17rc f/f -AlbCre) also showed significance of IL17 signaling activation in CRC metastasis through two distinct mechanisms. Employing different techniques, from FACS, immunohistochemistry, to RNAseq and scRNAseq data analysis, we observed that local hepatic activation of IL17RC signaling recruits neutrophils and reduces infiltration of cytotoxic CD8+T and NK cells to the metastatic niche supporting tumor growth, while myeloid IL17RC signaling reshapes TME, including macrophages and neutrophils, enhancing CRC metastasis. Our research indicates that IL17 signaling plays a multifaceted pathogenic role in CRC progression by operating in at least several cell types, providing new insights into the basic biology of CRC metastasis and potentially illuminating the design and improvement of CRC treatment strategies. Citation Format: Katarzyna Chojnacka, Katrina Mae Reyes, Hana Tomizawa, Sergei Grivennikov. Multifaceted pro-metastatic role of IL-17 signaling in modulating the tumor microenvironment of colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B018.

Abstract C006: Tumor-associated macrophages drive prostate cancer progression via IL-1β signaling

Abstract Inflammation is linked to prostate cancer progression. Inflammatory cell infiltrates are commonly observed in prostate biopsies, and inflammation-induced lesions (proliferative inflammatory atrophy, PIA) are precursors of prostate cancer. However, the mechanism by which inflammation impacts prostate cancer progression is poorly understood. Here, we investigated the significance of inflammation on prostate cancer progression using a cMyc-driven prostate adenocarcinoma mouse model (Hi-Myc). We observed a robust tumor-associated macrophage (TAM) infiltrate early during progression of Hi-Myc tumors. Depleting TAMs led to a decrease in both tumor weight and invasive area, demonstrating the functional importance of TAMs in tumor maintenance. To elucidate the molecular basis of how TAMs influence tumor progression, we collected Hi-Myc tumors throughout cancer development from the precursor stage of prostatic intraepithelial neoplasia to prostate adenocarcinoma and performed single-cell RNA sequencing (scRNA-seq). Our study revealed that a gene signature of strong IL-1β signaling activation was observed in TAMs from Hi-Myc tumors, but not in macrophages from wild-type prostates. Importantly, IL-1β neutralization led to delayed tumor progression with reduced tumor weight and invasive area. Furthermore, blocking IL-1β signaling decreased TAM infiltration, suggesting a positive feedback loop created by TAMs. To understand the effect of IL-1β on cancer cell invasion, we used a protease-dependent fluorescent probe to investigate the activity of major extracellular matrix degraders and found that IL-1β neutralization impairs MMP activity, likely through loss of expression by tumor cells and macrophages. To further investigate the targets of IL-1β signaling, we analyzed Il1r1 expression levels across all cell types and found the highest levels in cancer-associated fibroblasts (CAFs). Moreover, CAFs expressed elevated levels of the myeloid chemokines Ccl2, Csf1, Cxcl1, Cxcl2 as well as Il6 compared to fibroblasts from wild-type prostates. In vitro studies of wild-type prostate fibroblasts treated with recombinant IL-1β confirmed that IL-1β directly upregulates expression of these inflammatory cytokines and chemokines. In addition, IL-1β directly promotes proliferation of tumor-derived prostate cancer organoids in vitro. Overall, our study suggests that TAMs and CAFs cooperatively drive pro-tumorigenic IL-1β signaling in prostate cancer, demonstrating a direct mechanistic link between inflammation and prostate cancer progression. Citation Format: Young Sun Lee, Jimmy L. Zhao, Max Land, Joseph Chan, Perianne Smith, Roshan Sharma, Sanjay Kottapalli, Linda Fong, Zhenghao Chen, Cathy Wang, Jesse Kirkpatrick, Ava Soleimany, Samir Zaidi, Kayla Lawrence, Amanda Kulick, Teng Han, Zhen Sun, Philip Watson, Anuradha Gopalan, Ojasvi Chaudhary, Tianhao Xu, Ignas Masilionis, Ronan Chaligne, Dana Rathkopf, Michael Morris, Sangeeta Bhatia, Michael Haffner, Dana Pe'er, Charles Sawyers. Tumor-associated macrophages drive prostate cancer progression via IL-1β signaling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C006.

NOTCH1 mitochondria localization during heart development promotes mitochondrial metabolism and the endothelial-to-mesenchymal transition in mice.

Notch signaling activation drives an endothelial-to-mesenchymal transition (EndMT) critical for heart development, although evidence suggests that the reprogramming of endothelial cell metabolism can regulate endothelial function independent of canonical cell signaling. Herein, we investigated the crosstalk between Notch signaling and metabolic reprogramming in the EndMT process. Biochemically, we find that the NOTCH1 intracellular domain (NICD1) localizes to endothelial cell mitochondria, where it interacts with and activates the complex to enhance mitochondrial metabolism. Targeting NICD1 to mitochondria induces more EndMT compared with wild-type NICD1, and small molecule activation of PDH during pregnancy improves the phenotype in a mouse model of congenital heart defect. A NOTCH1 mutation observed in non-syndromic tetralogy of Fallot patients decreases NICD1 mitochondrial localization and subsequent PDH activity in heart tissues. Altogether, our findings demonstrate NICD1 enrichment in mitochondria of the developing mouse heart, which induces EndMT by activating PDH and subsequently improving mitochondrial metabolism.

Microglial and Macrophage Plasticity and Regional Cerebral Blood Flow in the Prenatal Brain and Gut Under Vagus Nerve Stimulation.

An intricate relationship exists between the vagus nerve and systemic immune cell regulation, specifically during fetal development. Little is known about the connection between the vagus nerve and the brain's regional circulatory control. In this chapter, we present a methodology for studying the impact of vagus nerve signaling on these connections in the developing fetus using the sheep model for human fetal physiology. First, we present the protocol to study the connection between the vagus nerve physiology and the regional cerebral blood flow (rCBF). Next, we detail the protocol for measuring how vagal signaling alters microglial cell plasticity in gut and brain. In previous work, our team showed that vagotomy results in amplified redistribution of rCBF toward subcortical structures in the fetal brain. Conversely, efferent VNS reduces rCBF to cortical structures while afferent VNS diminishes the rise of rCBF to subcortical structures (independent of cortical rCBF) when compared to controls in the fetal brain. Additionally, our team showed that Iba-1 expression, a marker for microglial cellular signaling activation, rises in a dose-dependent relationship with systemic inflammatory activation in the setting of vagotomy. The findings support existing preclinical and clinical evidence in adult human physiology that vagotomy is neuroprotective for neurodegenerative diseases such as Parkinson's likely via a glial cell-mediated mechanism. Vagus nerve stimulation (VNS) has also been shown to alter rCBF patterns in adults with treatment-resistant depression, underscoring the importance of further investigation of the relationship between the vagus nerve and rCBF as early as in utero. Together, the body of evidence emphasizes that the vagal pathway is an important player in the programming of microglial cell phenotypes within the developing brain. Further study is needed to better understand the significance of these relationships for the development and treatment of early susceptibility to neuroinflammatory and neurodegenerative disorders in later life. Therefore, we present a methodology for assessing rCBF and morphometric features of microglial and macrophage cell activation to allow future teams to expand on the existing body of work and further examine these relationships at a cellular and systems' levels.

CXCL11 reprograms M2-biased macrophage polarization to alleviate pulmonary fibrosis in mice.

In understanding the pathophysiology of pulmonary fibrosis (PF), macrophage plasticity has been implicated with a crucial role in the fibrogenic process. Growing evidence indicates that accumulation of M2 macrophages correlates with the progression of PF, suggesting that targeted modulation of molecules that influence M2 macrophage polarization could be a promising therapeutic approach for PF. Here, we demonstrated a decisive role of C-X-C motif chemokine ligand 11 (CXCL11) in driving M1 macrophage polarization to alleviate PF in the bleomycin-induced murine model. We intravenously administered secretome derived from naïve (M0) and polarized macrophages (M1 and M2) into PF mice and found that lung fibrosis was effectively reversed in only the M1-treated group, with modulation of the M1/M2 ratio toward the ratio of the control group. These findings suggest that the factors secreted from M1 macrophages contribute to alleviating PF by targeting macrophages and reshaping the immunofibrotic environment in a paracrine manner. Secretome analysis of macrophages identified CXCL11 as an M1-specific chemokine, and administration of recombinant CXCL11 effectively improved fibrosis with the reduction of M2 macrophages in vivo. Furthermore, a mechanistic in vitro study revealed that CXCL11 reprogrammed macrophages from M2 to M1 through the activation of pERK, pAKT, and p65 signaling. Collectively, we demonstrate an unprecedented role for M1 macrophage-derived CXCL11 as an inducer of M1 macrophage polarization to revert the fibrogenic process in mice with PF, which may provide a clinically meaningful benefit.

Human Tendon-on-a-Chip for Modeling the Myofibroblast Microenvironment in Peritendinous Fibrosis.

Understanding the myofibroblast microenvironment is critical to developing therapies for fibrotic diseases. Here the development of a novel human tendon-on-a-chip (hToC) is reported to model this crosstalk in peritendinous adhesions, which currently lacks biological therapies. The hToC facilitates cellular and paracrine interactions between a vascular component, which contains endothelial cells and monocytes, and a tissue hydrogel component that houses tendon cells and macrophages. It is found that the hToC replicates some aspects of in vivo inflammatory and fibrotic phenotypes in preclinical and clinical samples, including activated mTOR signaling, vascular inflammation, tissue contraction induced by myofibroblast activation, inflammatory cytokines secretion, and transendothelial migration of monocytes to the tissue hydrogel. Transcriptional analysis demonstrates significant overlap in enriched pathways in the hToC with human tenolysis samples, including the activation of mTOR signaling. Rapamycin suppresses the vascular inflammation and fibrotic phenotype in the hToC, which provides proof-of-concept of its utility as an in vitro tool for investigating multicellular crosstalk in fibrosis and testing therapeutics to mitigate it.

Smads and AP-1 activation of TGF-β signaling upregulate transcription of Osteoprotegerin in Cementoblasts to inhibit osteoclastogenesis.

Orthodontically induced root resorption (OIRR) is a common side effect during orthodontic tooth treatment (OTM). The function of osteoprotegerin (OPG) is considered to protect cementum from excessive resorption to maintain root integrity. In this study, we observed that the expression of TGF-β1 and OPG was upregulated under the loading of orthodontic force in periodontal tissues. However, the specific molecular mechanisms of TGF-β1-induced OPG expression in cementoblasts are not fully elucidated. This study aims to investigate the effect of Smads and AP-1 stimulated by TGF-β signaling on the transcription of OPG in cementoblasts. Invitro, we demonstrated that TGF-β/Smad and AP-1 signaling involved in TGF-β1-induced extracellular secretion of OPG in conditioned media (CM) from cementoblasts, which further inhibited osteoclastogenesis. Reporter gene plasmids containing OPG promoter sequences of different lengths (0.5-3 kb) were constructed to investigate the potential binding sites of Smads and AP-1. We identified nine binding sites of Smads and AP-1 concentrated in the 0-0.5 and 2.3-3 kb regions of OPG promoter in cementoblasts. ChlP results showed that Smad2/3/4 and c-Jun were bound more to the OPG promoter under TGF-β1 stimulation. Invivo, localized administration of TGF-β1 in the OTM model increased OPG expression, which resulted in the inhibition of OIRR. In summary, TGF-β1-induced Smads and AP-1 can bind to the OPG promoter to promote the transcription, expression, and secretion of OPG in cementoblasts, which inhibits osteoclast differentiation and protects cementum from excessive resorption.

Placental mesenchymal stem cells suppress inflammation and promote M2-like macrophage polarization through the IL-10/STAT3/NLRP3 axis in acute lung injury

IntroductionAcute lung injury (ALI) is a clinically severe respiratory disorder that currently lacks specific and effective pharmacotherapy. The imbalance of M1/M2 macrophage polarization is pivotal in the initiation and progression of ALI. Shifting macrophage polarization from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype could be a potential therapeutic strategy. The intratracheal administration of placental mesenchymal stem cells (pMSCs) has emerged as a novel and effective treatment for ALI. This study aimed to investigate the role and downstream mechanisms of pMSCs in reprogramming macrophage polarization to exert anti-inflammatory effects in ALI.MethodsThe study used lipopolysaccharide (LPS) to induce inflammation in both cell and rat models of ALI. Intratracheal administration of pMSCs was tested as a therapeutic intervention. An expression dataset for MSCs cultured with LPS-treated macrophages was collected from the Gene Expression Omnibus database to predict downstream regulatory mechanisms. Experimental validation was conducted through in vitro and in vivo assays to assess pMSCs effects on macrophage polarization and inflammation.ResultsBoth in vitro and in vivo experiments validated that pMSCs promoted M2 macrophage polarization and reduced the release of inflammatory factors. Further analyses revealed that pMSCs activated the signal transducer and activator of transcription (STAT)3 signaling pathway by secreting interleukin (IL)-10, leading to increased STAT3 phosphorylation and nuclear translocation. This activation inhibited NLRP3 inflammasome activation, promoting M2 macrophage polarization and suppressing the inflammatory response.ConclusionThe study concluded that pMSCs alleviated lung injury in an LPS-induced ALI model by inhibiting M1 macrophage polarization and proinflammatory factor secretion, while promoting M2 macrophage polarization. This effect was mediated via the IL-10/STAT3/NLRP3 axis, presenting a novel therapeutic pathway for ALI treatment.

Humanin-G Ameliorates Hemorrhage-Induced Acute Lung Injury in Mice Through AMPKα1-Dependent and -Independent Mechanisms

Background/Objectives: The severity of acute lung injury is significantly impacted by age and sex in patients with hemorrhagic shock. AMP-activated protein kinase (AMPK) is a crucial regulator of energy metabolism but its activity declines with aging. Humanin is a mitochondrial peptide that exerts cytoprotective effects in response to oxidative stressors and is associated with longevity. Using a mouse model of hemorrhagic shock that mimics the clinical condition of adult patients, we investigated whether treatment with a humanin analog, humanin-G, mitigates lung injury and whether its mechanisms of action are dependent on the catalytic AMPKα1 subunit activation. Methods: Male and female AMPKα1 wild-type (WT) and knock-out (KO) mice (8–13 months old) were subjected to hemorrhagic shock by blood withdrawal, followed by resuscitation with shed blood and lactated Ringer’s solution. The mice were treated with PEGylated humanin-G or vehicle and euthanized 3 h post-resuscitation. Results: Sex- and genotype-related differences were observed after hemorrhagic shock as lung neutrophil infiltration was more pronounced in the male AMPKα1 WT mice than the female WT mice; also, the male AMPKα1 KO mice experienced a significant decline in mean arterial blood pressure when compared to the male WT mice after resuscitation. The scores of histological lung injury were similarly elevated in all the male and female AMPKα1 WT and KO mice when compared to the control mice. At molecular analysis, acute lung injury was associated with the downregulation of AMPKα1/α2 catalytic subunits in the WT mice, whereas an increased activation of the signal transducer and activator of transcription-3 (STAT3) was observed in all the vehicle-treated groups. The in vivo administration of humanin-G ameliorated histological lung damage in all the groups of animals and ameliorated mean arterial blood pressure in the male AMPKα1 KO mice. The in vivo administration of humanin-G lowered lung neutrophil infiltration in the male and female AMPKα1 WT mice only but not in the KO mice. The beneficial results of humanin-G correlated with the lung cytosolic and nuclear activation of AMPKα in the male and female AMPKα1 WT groups, whereas STAT3 activation was not modified. Conclusions: In adult age, hemorrhage-induced acute lung injury manifests with sex-dependent characteristics. Humanin-G has therapeutic potential and the AMPKα1subunit is an important requisite for its inhibitory effects on lung leucosequestration, but not for the amelioration of lung alveolar structure or the hemodynamic effects of the peptide.

Targeting PRMT7-mediated monomethylation of MAVS enhances antiviral innate immune responses and inhibits RNA virus replication

RIG-I-like receptors (RLRs)-mitochondrial antiviral signaling protein (MAVS) are crucial for type I interferon (IFN) signaling pathway and innate immune responses triggered by RNA viruses. However, the regulatory molecular mechanisms underlying RNA virus-activated type I IFN signaling pathway remain incompletely understood. Here, we found that protein arginine methyltransferase 7 (PRMT7) serves as a negative regulator of the type I IFN signaling pathway by interacting with MAVS and catalyzing monomethylation of arginine 232 (R232me1) in MAVS. RNA virus infection leads to the downregulation and dissociation of PRMT7 from MAVS as well as the decrease of R232me1 methylation, enhancing MAVS/RIG-I interaction, MAVS aggregation, type I IFN signaling activation, and antiviral immune responses. Knock-in mice with MAVS R232 substituted with lysine (MavsR232K-KI) are more resistant to Vesicular Stomatitis Virus infection due to enhanced antiviral immune responses. PiPRMT7-MAVS, a short peptide inhibitor designed to interrupt the interaction between PRMT7 and MAVS, inhibits R232me1 methylation, thereby enhancing MAVS/RIG-I interaction, promoting MAVS aggregation, activating type I IFN signaling, and bolstering antiviral immune responses to suppress RNA virus replication. Moreover, the clinical relevance of PRMT7 is highlighted that it is significantly downregulated in RNA virus-infected clinical samples, such as blood samples from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ebola virus, as well as H1N1-infected bronchial epithelial cells. Our findings uncovered that PRMT7-mediated arginine methylation plays critical roles in regulating MAVS-mediated antiviral innate immune responses, and targeting arginine methylation might represent a therapeutic avenue for treating RNA viral infection.

Targeting resident astrocytes attenuates neuropathic pain after spinal cord injury.

Astrocytes derive from different lineages and play a critical role in neuropathic pain after spinal cord injury (SCI). Whether selectively eliminating these main origins of astrocytes in lumbar enlargement could attenuate SCI-induced neuropathic pain remains unclear. Through transgenic mice injected with an adeno-associated virus vector and diphtheria toxin, astrocytes in lumbar enlargement were lineage traced, targeted, and selectively eliminated. Pain-related behaviors were measured with an electronic von Frey apparatus and a cold/hot plate after SCI. RNA sequencing, bioinformatics analysis, molecular experiment, and immunohistochemistry were used to explore the potential mechanisms after astrocyte elimination. Lineage tracing revealed that the resident astrocytes but not ependymal cells were the main origins of astrocytes-induced neuropathic pain. SCI-induced mice to obtain significant pain symptoms and astrocyte activation in lumbar enlargement. Selective resident astrocyte elimination in lumbar enlargement could attenuate neuropathic pain and activate microglia. Interestingly, the type I interferons (IFNs) signal was significantly activated after astrocytes elimination, and the most activated Gene Ontology terms and pathways were associated with the type I IFNs signal which was mainly activated in microglia and further verified in vitro and in vivo. Furthermore, different concentrations of interferon and Stimulator of interferon genes (STING) agonist could activate the type I IFNs signal in microglia. These results elucidate that selectively eliminating resident astrocytes attenuated neuropathic pain associated with type I IFNs signal activation in microglia. Targeting type I IFNs signals is proven to be an effective strategy for neuropathic pain treatment after SCI.

Inhibition of NPC1 suppresses cell proliferation and β-catenin signaling activation of liver cancer.

Niemann-Pick Type C1 (NPC1) plays a significant role in the development of liver diseases and liver cancer. Our objective was to investigate the involvement of NPC1 in regulating liver cancer development. We observed that high levels of NPC1 expression in tumor tissues from patients with liver cancer were associated with a poor prognosis. Through in vitro experiments, we found that inhibiting NPC1 expression reduced the proliferation, invasion, and migration of liver cancer cells, while also inducing apoptosis in these cells. Additionally, the inhibition of NPC1 led to decreased activation of Wnt/β-catenin signaling. In vivo studies further supported our findings by demonstrating that the suppression of liver cancer cell growth was effectively achieved through the inhibition of NPC1. Overall, our results strongly indicate that the inhibition of NPC1 suppresses liver cancer cell proliferation. Targeting NPC1 is a promising potential therapeutic strategy for liver cancer.

Fas Apoptosis Inhibitory Molecule 2 Inhibits Pathological Cardiac Hypertrophy by Regulating the MAPK Signaling Pathway.

Pathological cardiac hypertrophy stands as a pivotal mechanism contributing to diverse cardiovascular diseases, ultimately leading to heart failure. Despite its clinical significance, the intricate molecular mechanisms instigating pathological cardiac hypertrophy remain inadequately understood. In this study, we aim to further reveal its complex pathogenesis by exploring the role of Fas apoptotic inhibitory molecule 2 (FAIM2) in modulating pathological cardiac hypertrophy. We used phenylephrine-induced hypertrophic cardiomyocytes and also generated cardiac-specific knockout mice and adeno-associated virus serotype 9-Faim2 mice to evaluate the function of FAIM2 in pathological myocardial hypertrophy. Furthermore, unbiased RNA-sequencing analysis was used to identify the direct target and corresponding molecular events contributing to FAIM2 function. Ultimately, our study revealed a downregulation of FAIM2 expression in phenylephrine-induced hypertrophic cardiomyocytes and pressure overload-induced hypertrophic hearts. FAIM2 exhibited a significant attenuation of phenylephrine-induced enlargement of primary neonatal rat cardiomyocytes, whereas FAIM2 knockdown aggravated the hypertrophic response. Furthermore, Faim2 gene knockout significantly exacerbated cardiac hypertrophy and heart fibrosis invivo. Mechanistic investigations unveiled that FAIM2 exerts its inhibitory effect by suppressing TAK1-JNK1/2-p38 MAPK signaling cascades, thereby mitigating cardiac hypertrophy. Our findings position FAIM2 as a novel negative regulator of pathological cardiac hypertrophy through its inhibitory action on mitogen-activated protein kinase signaling activation. This identification of FAIM2's role provides crucial insights that may pave the way for the development of effective therapeutic strategies aimed at mitigating pathological cardiac hypertrophy, addressing a critical need in cardiovascular disease management.

Targeting resident astrocytes attenuates neuropathic pain after spinal cord injury

Astrocytes derive from different lineages and play a critical role in neuropathic pain after spinal cord injury (SCI). Whether selectively eliminating these main origins of astrocytes in lumbar enlargement could attenuate SCI-induced neuropathic pain remains unclear. Through transgenic mice injected with an adeno-associated virus vector and diphtheria toxin, astrocytes in lumbar enlargement were lineage traced, targeted, and selectively eliminated. Pain-related behaviors were measured with an electronic von Frey apparatus and a cold/hot plate after SCI. RNA sequencing, bioinformatics analysis, molecular experiment, and immunohistochemistry were used to explore the potential mechanisms after astrocyte elimination. Lineage tracing revealed that the resident astrocytes but not ependymal cells were the main origins of astrocytes-induced neuropathic pain. SCI-induced mice to obtain significant pain symptoms and astrocyte activation in lumbar enlargement. Selective resident astrocyte elimination in lumbar enlargement could attenuate neuropathic pain and activate microglia. Interestingly, the type I interferons (IFNs) signal was significantly activated after astrocytes elimination, and the most activated Gene Ontology terms and pathways were associated with the type I IFNs signal which was mainly activated in microglia and further verified in vitro and in vivo. Furthermore, different concentrations of interferon and Stimulator of interferon genes (STING) agonist could activate the type I IFNs signal in microglia. These results elucidate that selectively eliminating resident astrocytes attenuated neuropathic pain associated with type I IFNs signal activation in microglia. Targeting type I IFNs signals is proven to be an effective strategy for neuropathic pain treatment after SCI.

Signal Transducer and Activator of Transcription 4 (STAT4) Association with Pituitary Adenoma

Background/Objectives: This study aims to investigate whether Signal Transducer and Activator of Transcription 4 (STAT4) influences the anti-tumor immune response and is possibly involved in the initiation or relapse of pituitary adenomas (PAs) by examining STAT4 polymorphisms and serum levels. This research seeks to uncover potential connections that could inform future therapeutic strategies and improve our understanding of PA pathogenesis. Materials and Methods: This study was conducted at the Laboratory of Ophthalmology, Lithuanian University of Health Sciences. DNA was extracted from peripheral venous blood samples, and the genotyping of four STAT4 SNPs (rs7574865, rs10181656, rs7601754, and rs10168266) was performed using real-time PCR with TaqMan® Genotyping assays. The serum STAT4 levels were measured via ELISA, and the optical density was read at 450 nm. Genotype frequencies, allele distributions, and serum STAT4 levels were statistically analyzed to assess associations with pituitary adenoma occurrence. Results: A binary logistic regression revealed that the STAT4 rs7574865 GT + GG genotypes vs. TT were associated with 1.7-fold increased odds of PA occurrence under the dominant genetic model (p = 0.012). The stratification by gender showed no significant associations in females; however, in males, the STAT4 rs10168266 CC + CT genotypes compared to TT were linked to 2.5-fold increased odds of PA under the dominant genetic model (p = 0.005). STAT4 rs10181656, rs7574865, rs7601754, and rs10168266 were analyzed to evaluate the associations with the pituitary adenoma size. We found that the STAT4 rs7574865 GG genotype was statistically significantly less frequent in the macro PA group compared to in the reference group (p = 0.012). For PA relapse, the rs7574865 G allele was less frequent in the PA group without relapse (p = 0.012), and the GT + GG genotypes were associated with a 1.8-fold increase in the PA group without relapse occurrence (p = 0.008). The serum STAT4 levels were higher in the PA patients compared to those of the reference group (p < 0.001). Elevated STAT4 serum levels were observed in PA patients with the STAT4 rs10181656 CC or CG genotypes (CC: p = 0.004; CG: p = 0.023), and with the rs7574865 GG or GT genotypes (GG: p = 0.003; GT: p = 0.021). The PA patients with the STAT4 rs7601754 AA genotype exhibited higher serum levels compared to those of the reference group (p < 0.001). Similarly, higher serum levels were found in the PA patients with the STAT4 rs10168266 CC or CT genotypes (CC: p = 0.004; CT: p = 0.027). A haplotype frequency analysis revealed no statistically significant results. Conclusions: The STAT4 genotypes were significantly associated with the PA occurrence, size, and relapse. Elevated serum STAT4 levels were observed in the PA patients, highlighting its potential role in PA pathogenesis.

FOXA1 enhances antitumor immunity via repressing interferon-induced PD-L1 expression in nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a distinct subtype of head and neck cancer which is prevalent in south of China and southeastern of Asia. Consistent activation of interferon (IFN) signaling, and...

Irisin Improves Preeclampsia by Promoting Embryo Implantation and Vascular Remodeling.

Preeclampsia is a pregnancy-specific disorder with unclear pathogenesis. Irisin, a recently identified exercise-induced factor, significantly influences lipid metabolism and cardiovascular function. Nonetheless, its role in trophoblast development during human placentation and the related intracellular signaling pathways remain poorly understood. We assessed peripheral blood irisin expression in early pregnancy among patients with preeclampsia and its correlation with key clinical indicators. In trophoblast cell lines and mice, we used exogenous irisin and viral knockdown to investigate functional changes. Phosphorylation-specific antibody arrays and dual-luciferase reporter assays were used to explore downstream molecular mechanisms, which were subsequently validated in trophoblast cell lines and relevant gene knockout mice. In early pregnancy, patients with preeclampsia exhibit decreased peripheral blood irisin levels, occurring earlier than traditional predictive markers, such as PLGF (placental growth factor) and sFlt-1 (soluble fms-like tyrosine kinase-1). Furthermore, irisin concentration is positively correlated with proteinuria and abnormal blood pressure during pregnancy. Exogenous irisin significantly enhanced trophoblast cell migration, invasion, and proliferation while inhibiting apoptosis. It also increased STAT (signal transducers and activators of transcription) 4 phosphorylation and its binding to the GLUT (glucose transporter)-3 promoter, resulting in elevated GLUT-3 expression and glucose uptake in trophoblast cells. In vivo, increased peripheral irisin promoted embryo implantation, vascular remodeling, and enhanced glucose uptake, whereas reduced irisin resulted in a preeclampsia-like phenotype characterized by elevated blood pressure, proteinuria, renal-placental dysfunction, adipose accumulation, and restricted fetal growth. Peripheral irisin improves preeclampsia by promoting embryo implantation and vascular remodeling through the activation of the STAT4/GLUT-3 pathway. Reduced peripheral irisin may contribute to preeclampsia-like pathologies. This study supports the advocacy for appropriate exercise during early pregnancy and provides new insights for preeclampsia prevention.

Gallein, G protein βγ subunits inhibitor, suppresses the TGF-α-induced migration of hepatocellular carcinoma cells via inhibition of the c-Jun N-terminal kinase.

G protein-coupled receptor (GPCR) signaling regulates a wide range of pathophysiological cell functions via G protein α and βγ subunits. Small molecules targeting the subunits of Gα and Gβγ have been developed as cancer therapeutics. We have previously reported that transforming growth factor-α (TGF-α) induces the migration of human hepatocellular carcinoma (HCC) HuH7 cells through the activation of AKT, p38 mitogen-activated protein kinase (MAPK), Rho-kinase and c-Jun N-terminal kinase (JNK). This study aims to determine whether Gβγ subunits regulate the TGF-α-induced migration of HCC HuH7 cells using gallein, a Gβγ subunits inhibitor. The Janus family of tyrosine kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway was also involved in the regulation of the migration. Gallein significantly reduced the TGF-α-induced cell migration. In contrast, fluorescein, a gallein-related compound that has no effect on Gβγ subunits, failed to affect the cell migration. Gallein suppressed the TGF-α-stimulated phosphorylation of JNK without affecting the phosphorylation of epidermal growth factor receptor, AKT, p38 MAPK, target protein of Rho-kinase and STAT3. Conversely, fluorescein did not attenuate the phosphorylation of JNK. These results strongly suggest that Gβγ subunits act as positive regulators in TGF-α-induced migration of HCC cells via the JNK signalling pathway.