Probes for INS

BackgroundAryl Hydrocarbon Receptor (AHR) is a ligand-activated transcription factor that regulates the activities of multiple innate and adaptive immune cell types. Multiple ligands such as kynurenine bind to AHR driving its nuclear translocation and transcriptional activation, leading to an immunosuppressive tumor microenvironment.1 2 AHR activation is implicated in tumor development in multiple cancer types. In addition, high levels of serum kynurenine are associated with resistance to checkpoint inhibitors.3 To overcome AHR-mediated immunosuppression in cancers, we developed a selective oral AHR inhibitor IK-175 and took a combined computational and tissue-based approach to select cancer indications for its clinical development.MethodsThe aim of this work is to identify tumor indications dependent on AHR signaling and design patient selection strategies based on a proprietary transcriptional signature, mRNA and protein detection assays to evaluate AHR pathway activation in tumors.ResultsGenomic profiling of solid and hematological cancers from TCGA and Project GENIE databases identified bladder and esophageal tumors among others, as frequently harboring AHR gene amplifications.A proprietary gene signature of AHR activation was developed integrating literature, pathway analysis, RNAseq and nanostring data from PBMC, T-cells and cell lines upon AHR inhibition. Transcriptional analysis of the TCGA data using this signature demonstrated bladder cancer has the highest expressions of AHR and AHR signature genes, suggesting increased pathway activity in bladder cancer relative to other cancer types. Increased AHR signature gene expression was associated with worse overall survival in the TCGA bladder cancer cohort. Furthermore, RNAscope analysis of a tissue microarray containing 10 different tumor types revealed bladder cancer had one of the highest AHR transcript expression in the tumor compartment.Finally, nuclear localization of AHR protein was assessed as an indicator of pathway activation through the development of a novel IHC method. Extensive TMA screening of AHR protein in 15 different indications demonstrated bladder cancer as the tumor type with the highest prevalence of AHR nuclear expression.ConclusionsIn summary, we demonstrated high prevalence of nuclear AHR protein expression, AHR gene amplification and target gene expression in bladder cancer, suggesting aberrant AHR activation may play an important role in the progression of this tumor type. This study provides rationale for therapeutic targeting of AHR in bladder cancer patients. Ikena is currently evaluating the anti-tumor activity of IK-175 as a single agent and in combination with nivolumab in bladder cancer in a Phase 1a/1b clinical study (NCT04200963).ReferencesQuintana FJ, Sherr DH. Aryl hydrocarbon receptor control of adaptive immunity. Pharmacol Rev 2013 Aug 1;65(4):1148-61.Murray IA, Patterson AD, Perdew GH. Aryl hydrocarbon receptor ligands in cancer: friend and foe. Nat Rev Cancer 2014 Dec;14(12):801-14.Li, Haoxin et al. ‘Metabolomic adaptations and correlates of survival to immune checkpoint blockade.’ Nature Communications 2019 Sep 25;10:1-4346.

The emergence of single-cell RNA sequencing enables simultaneous sequencing of thousands of cells, making the analysis of cell population heterogeneity more efficient. In recent years, single-cell RNA sequencing has been used in the investigation of heterogeneous cell populations, cellular developmental trajectories, stochastic gene transcriptional kinetics, and gene regulatory networks, providing strong support in life science research. However, the application of single-cell RNA sequencing in the field of oral science has not been reviewed comprehensively yet. Therefore, this paper reviews the development and application of single-cell RNA sequencing in oral science, including fields of tissue development, teeth and jaws diseases, maxillofacial tumors, infections, etc., providing reference and prospects for using single-cell RNA sequencing in studying the oral diseases, tissue development, and regeneration.

Fluorescence in situ hybridization (FISH) has become an important tool in laboratory experimentation by providing a qualitative or semi-quantitative technique to detect nucleic acids across different sample types and species. It also serves as a promising platform for the discovery of novel RNA biomarkers and the development of molecular diagnostic assays. While technologies to detect hundreds or thousands of gene transcripts in situ with single-cell resolution are rapidly coming online, smaller scale FISH analysis continues to be highly useful in neuroscience research. In this chapter, we describe a robust, relatively fast and low cost, turnkey in situ hybridization technology (ISH) to identify one or more RNA targets together with immunohistochemical analyses. Specifically, we present a customized version of the protocol that works particularly well for spinal cord and primary sensory ganglia tissues.

A major social challenge of modern societies is to prevent and treat neurodegenerative diseases suffered by the constantly increasing elderly population. We are investigating the changes in gene expression in single neurons in response to nerve terminal dysfunction in the brain of genetically modified mice. Machine Learning approaches imported from other disciplines are key for the bioinformatic analysis of data sets comprising thousands of cells expressing thousands of genes each. Expression changes in specific genes might be essential to maintain neuronal homeostasis and, therefore, potentially useful to be targeted in the context of therapeutic strategies.

Single-cell genomics, particularly single-cell transcriptome profiling by RNA sequencing have transformed the possibilities to relate genes to functions, structures, and eventually phenotypes. We can now observe changes in each cell's transcriptome and among its neighborhoods, interrogate the sequence of transcriptional events, and assess their influence on subsequent events. This paradigm shift in biology enables us to infer causal relationships in these events with high accuracy. Here we review the latest single-cell studies in plants that uncover how cellular phenotypes emerge as a result of the transcriptome process such as waves of expression, trajectories of development and responses to the environment, and spatial information. With an eye on the advances made in animal and human studies, we further highlight some of the needed areas for future research and development, including computational methods.

Circular RNAs (circRNAs) are endogenous single-stranded RNAs characterized by covalently closed loop structures with neither 5′ to 3′ polarity nor poly(A) tails. They are generated most commonly from back-splicing of protein-coding exons. CircRNAs have a tissue-specific distribution and are evolutionarily conserved, and many circRNAs play important biological functions by combining with microRNAs and proteins to regulate protein functions and their own translation. Numerous studies have shown that circRNAs are enriched in the central nervous system (CNS) and play an important role in the development and maintenance of homeostasis. Correspondingly, they also play an important role in the occurrence and progression of CNS diseases. In this review, we highlight the current state of circRNA biogenesis, properties, function and the crucial roles they play in the CNS.

The persistence of HIV in the spleen, despite combination antiretroviral therapy (cART), is not well understood. Sustained immune dysregulation and delayed immune recovery, in addition to immune cell exhaustion, may contribute to persistence of infection in the spleen. Eliminating HIV from this secondary lymphoid organ will require a thorough understanding of antiretroviral (ARV) pharmacology in the spleen, which has been minimally investigated. Low ARV exposure within the spleen may hinder the achievement of a functional or sterilizing cure if cells are not protected from HIV infection. Here we provide an overview of the anatomy and physiology of the spleen, review the evidence of the spleen as a site for persistence of HIV, discuss the consequences of persistence of HIV in the spleen, address challenges to eradicating HIV in the spleen, and examine opportunities for future curative efforts.

Type 17 cytokines have been strongly implicated in mucosal immunity, in part by regulating the production of antimicrobial peptides. Using a mouse model of Citrobacter rodentium infection, which causes colitis, we found that intestinal IL-17RA and IL-17RC were partially required for control of infection in the colon and IL-17 regulates the production of luminal hydrogen peroxide as well as expression of Tnsf13 Reduced Tnfsf13 expression was associated with a profound defect in generating C. rodentium-specific IgA+ Ab-secreting cells. Taken together, intestinal IL-17R signaling plays key roles in controlling invading pathogens, in part by regulating luminal hydrogen peroxide as well as regulating the generation of pathogen-specific IgA+ Ab-secreting cells.

The majority of transcriptionally active RNA derived from the mammalian genome does not code for protein. Long noncoding RNA (lncRNA) is the most abundant form of noncoding RNA found in the brain and is involved in many aspects of cellular metabolism. Beyond their fundamental role in the nucleus as decoys for RNA-binding proteins associated with alternative splicing or as guides for the epigenetic regulation of protein-coding gene expression, recent findings indicate that activity-induced lncRNAs also regulate neural plasticity. In this review, we discuss how lncRNAs may exert molecular control over brain function beyond their known roles in the nucleus. We propose that subcellular localization is a critical feature of experience-dependent lncRNA activity in the brain, and that lncRNA-mediated control over RNA metabolism at the synapse serves to regulate local mRNA stability and translation, thereby influencing neuronal function, learning and memory.

Dynamic tracking of variant frequencies among viruses circulating in the global pandemic has revealed the emergence and dominance of a D614G mutation in the SARS-CoV-2 spike protein. To address whether pandemic SARS-CoV-2 G614 variant has evolved to become more pathogenic, we infected adult hamsters (>10 months old) with two natural SARS-CoV-2 variants carrying either D614 or G614 spike protein to mimic infection of the adult/elderly human population. Hamsters infected by the two variants exhibited comparable viral loads and pathology in lung tissues as well as similar amounts of virus shed in nasal washes. Altogether, our study does not find that naturally circulating D614 and G614 SARS-CoV-2 variants differ significantly in pathogenicity in hamsters.

Background: The administration of docetaxel chemotherapy is one therapeutic option to delay disease progression and increase overall survival in metastatic castration resistant prostate cancer (mCRPC). However, about 15% of patients are primary resistant to chemotherapy and hence would benefit from an alternative mCRPC treatment. Despite intensive research, there are no robust clinical validated biomarkers to predict mCRPC therapy response. Thus, the aim of the study was to determine KDM5D expression in archival radical prostatectomy specimens of patients medicated with docetaxel at time of mCRPC development in order to correlate KMD5D expression with treatment response. Methods: We used in situ hybridization (ISH) (RNA scope 2.5 HD) to determine KDM5D expression in tissue samples of 28 prostate cancer patients. KDM5D status was correlated to chemotherapy response (PSA and radiographic response). Results: Data revealed that KDM5D is significantly overexpressed in tumor cells (P

Senescent cells play relevant but context-dependent roles during tumorigenesis. Here, in an oncogenic Kras-driven lung cancer mouse model, we found that senescent cells, specifically alveolar macrophages, accumulate early in neoplasia. These macrophages have upregulated expression of p16INK4a and Cxcr1, are distinct from previously defined subsets and are sensitive to senolytic interventions, and suppress cytotoxic T cell responses. Their removal attenuates adenoma development and progression in mice, indicating their tumorigenesis-promoting role. Importantly, we found that alveolar macrophages with these properties increase with normal aging in mouse lung and in human lung adenocarcinoma in situ. Collectively, our study indicates that a subset of tissue-resident macrophages can support neoplastic transformation through altering their local microenvironment, suggesting that therapeutic interventions targeting senescent macrophages may attenuate lung cancer progression during early stages of disease.