Probes for KIT

Hedgehog-interacting protein (HHIP) sequesters Hedgehog ligands to repress Smoothened (SMO)-mediated recruitment of the GLI family of transcription factors. Allelic variation in HHIP confers risk of chronic obstructive pulmonary disease and other smoking-related lung diseases, but underlying mechanisms are unclear. Using single-cell and cell-type-specific translational profiling, we show that HHIP expression is highly enriched in medial habenula (MHb) neurons, particularly MHb cholinergic neurons that regulate aversive behavioral responses to nicotine. HHIP deficiency dysregulated the expression of genes involved in cholinergic signaling in the MHb and disrupted the function of nicotinic acetylcholine receptors (nAChRs) through a PTCH-1/cholesterol-dependent mechanism. Further, CRISPR/Cas9-mediated genomic cleavage of the <i>Hhip</i> gene in MHb neurons enhanced the motivational properties of nicotine in mice. These findings suggest that HHIP influences vulnerability to smoking-related lung diseases in part by regulating the actions of nicotine on habenular aversion circuits.

Spatial gene expression, achieved classically through in situ hybridization, is a fundamental tool for topographic phenotyping of cell types in the nervous system. Newly developed techniques allow for visualization of multiple mRNAs at single-cell resolution and greatly expand the ability to link gene expression to tissue topography, yet there are challenges in efficient quantification and analysis of these high-dimensional datasets. We have therefore developed the single-cell automated multiplex pipeline for RNA (SCAMPR), facilitating rapid and accurate segmentation of neuronal cell bodies using a dual immunohistochemistry-RNAscope protocol and quantification of low- and high-abundance mRNA signals using open-source image processing and automated segmentation tools. Proof of principle using SCAMPR focused on spatial mapping of gene expression by peripheral (vagal nodose) and central (visual cortex) neurons. The analytical effectiveness of SCAMPR is demonstrated by identifying the impact of early life stress on gene expression in vagal neuron subtypes.

Complex tissues such as tumors are comprised of multiple cells types and extracellular matrix. These cells include heterogenous populations of immune cells that infiltrate the tumors. Understanding the composition of these immune infiltrates in the tumor microenvironment (TME) can provide key insights to guide therapeutic intervention and predict treatment response. Thorough understanding of complex tissue dynamics and immune cell characterization requires a multi-omics approach. Simultaneous detection of RNA and protein using in situ hybridization (ISH) and immunohistochemistry/immunofluorescence (IHC/IF) can reveal cellular sources of secreted proteins, identify specific cell types, and visualize the spatial organization of cells within the tissue. However, a sequential workflow of ISH followed by IHC/IF frequently yields suboptimal protein detection because the protease digestion step in the ISH protocol resulting in poor antibody signal. Here we demonstrate a newly developed integrated ISH/IHC workflow that can substantially improve RNA-protein co-detection, enabling the visualization and characterization of tumor immune infiltrates at single-cell resolution with spatial and morphological context. To characterize tumor-infiltrating immune cells in a tumor TMA (tumor microarray), we utilized the RNAscope Multiplex Fluorescence assay in combination with the RNA-Protein Co-detection Kit to detect multiple immune cell populations. Immune cells such as macrophages, T cells and NK cells were detected using specific antibodies against CD68, CD8, CD4 and CD56, respectively. Precise characterization of these immune cells was achieved by using probes against targets such as CCL5, IFNG, GNZB, IL-12, NCR1 etc. that not only help in identifying specific immune cells but also assist in determining their activation states. We identified subsets of T cells such as CD4+ regulatory T cells and CD8+ cytotoxic T lymphocytes. Additionally, we were able to determine the activation states of CD8+ T cells by visualizing the expression of IFNG and GZMB. Furthermore, infiltrating macrophages were identified by detecting the CD68 protein expression while the M1 and M2 subsets were differentiated by detecting the M2-specific target RNA for CD163. Similarly, NK cells were identified by detecting CD56 protein in combination with CCL5 and NCR1 RNA expression. Interestingly, the degree of infiltration of the different immune cell populations varied based on the tumor type. In conclusion, the new RNAscope-ISH-IHC co-detection workflow and reagents enable optimized simultaneous visualization of RNA and protein targets by enhancing the compatibility of antibodies - including many previously incompatible antibodies - with RNAscope. This new workflow provides a powerful new approach to identifying and characterizing tumor infiltrating populations of immune cells.