Biochemical Society transactions
Jin, S;Ramos, R;
PMID: 35191953 | DOI: 10.1042/BST20210863
Tissue development and homeostasis require coordinated cell-cell communication. Recent advances in single-cell sequencing technologies have emerged as a revolutionary method to reveal cellular heterogeneity with unprecedented resolution. This offers a great opportunity to explore cell-cell communication in tissues systematically and comprehensively, and to further identify signaling mechanisms driving cell fate decisions and shaping tissue phenotypes. Using gene expression information from single-cell transcriptomics, several computational tools have been developed for inferring cell-cell communication, greatly facilitating analysis and interpretation. However, in single-cell transcriptomics, spatial information of cells is inherently lost. Given that most cell signaling events occur within a limited distance in tissues, incorporating spatial information into cell-cell communication analysis is critical for understanding tissue organization and function. Spatial transcriptomics provides spatial location of cell subsets along with their gene expression, leading to new directions for leveraging spatial information to develop computational approaches for cell-cell communication inference and analysis. These computational approaches have been successfully applied to uncover previously unrecognized mechanisms of intercellular communication within various contexts and across organ systems, including the skin, a formidable model to study mechanisms of cell-cell communication due to the complex interactions between the different cell populations that comprise it. Here, we review emergent cell-cell communication inference tools using single-cell transcriptomics and spatial transcriptomics, and highlight the biological insights gained by applying these computational tools to exploring cellular communication in skin development, homeostasis, disease and aging, as well as discuss future potential research avenues.
European Neuropsychopharmacology
Pisano, I;Begni, V;Creutzberg, K;Marchisella, F;De Rosa, F;Papp, M;Riva, M;
| DOI: 10.1016/j.euroneuro.2021.10.522
Background: Stress represents a major contributor for the development of mental illness. Accordingly, exposure of adult rats to chronic stress represents a valuable experimental tool to investigate the ability of pharmacological intervention to counteract the adverse effects produced by stress exposure. The aim of this study was to perform a time course analyses of the changes produced by the antipsychotic drug lurasidone in the Chronic Mild Stress (CMS) model, in order to identify early mechanisms that may contribute to its therapeutic activity. Methods: Adult male Wistar rats were left undisturbed or exposed to the CMS paradigm, a well-established model of depression. After two weeks of stress, both controls and CMS rats were randomly divided in two subgroups that received vehicle or lurasidone for five weeks. Sucrose consumption was used to measure anhedonia, a core symptom of depression. Animals were sacrificed after two, three or five weeks of treatment in order to investigate dynamic changes during lurasidone administration. For the sucrose consumption we performed three-way ANOVA and two-way ANOVA with Tukey's posthoc. For the molecular analysis we performed 2-way ANOVA, with Tukey's posthoc for qRT-PCR data and Sidak's posthoc for RNAscope data. Results: CMS rats show a significant reduction in sucrose consumption, (-46% after two weeks, p
Seminars in Diagnostic Pathology
Buza, N;
| DOI: 10.1053/j.semdp.2021.10.006
This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.
UV-induced reduction in Polycomb repression promotes epidermal pigmentation
Li, MY;Flora, P;Pu, H;Bar, C;Silva, J;Cohen, I;Galbo, PM;Liu, H;Yu, X;Jin, J;Koseki, H;D'Orazio, JA;Zheng, D;Ezhkova, E;
PMID: 34473941 | DOI: 10.1016/j.devcel.2021.08.006
Ultraviolet (UV) radiation is a prime environmental stressor that our epidermis is exposed to on a daily basis. To avert UV-induced damage, epidermal stem cells (EpSCs) become pigmented via a process of heterotypic interaction between melanocytes and EpSCs; however, the molecular mechanisms of this interaction are not well understood. In this study, we show that the function of a key chromatin regulator, the Polycomb complex, was reduced upon UV exposure in human and mouse epidermis. Genetic ablation of key Polycomb subunits in murine EpSCs, mimicking depletion upon UV exposure, results in an increased number of epidermal melanocytes and subsequent epidermal pigmentation. Genome-wide transcriptional and chromatin studies show that Polycomb regulates the expression of UV-responsive genes and identifies type II collagen (COL2A1) as a critical secreted regulator of melanogenesis and epidermal pigmentation. Together, our findings show how UV exposure induces Polycomb-mediated changes in EpSCs to affect melanocyte behavior and promote epidermal pigmentation.
Recent advancements in CRISPR-Cas toolbox for imaging applications
Critical reviews in biotechnology
Singh, V;Jain, M;
PMID: 34407706 | DOI: 10.1080/07388551.2021.1950608
The imaging of chromatin, genomic loci, RNAs, and proteins is very important to study their localization, interaction, and coordinated regulation. Recently, several clustered regularly interspaced short palindromic repeats (CRISPR) based imaging methods have been established. The refurbished tool kits utilizing deactivated Cas9 (dCas9) and dCas13 have been established to develop applications of CRISPR-Cas technology beyond genome editing. Here, we review recent advancements in CRISPR-based methods that enable efficient imaging and visualization of chromatin, genomic loci, RNAs, and proteins. RNA aptamers, Pumilio, SuperNova tagging system, molecular beacons, halotag, bimolecular fluorescence complementation, RNA-guided endonuclease in situ labeling, and oligonucleotide-based imaging methods utilizing fluorescent proteins, organic dyes, or quantum dots have been developed to achieve improved fluorescence and signal-to-noise ratio for the imaging of chromatin or genomic loci. RNA-guided RNA targeting CRISPR systems (CRISPR/dCas13) and gene knock-in strategies based on CRISPR/Cas9 mediated site-specific cleavage and DNA repair mechanisms have been employed for efficient RNA and protein imaging, respectively. A few CRISPR-Cas-based methods to investigate the coordinated regulation of DNA-protein, DNA-RNA, or RNA-protein interactions for understanding chromatin dynamics, transcription, and protein function are also available. Overall, the CRISPR-based methods offer a significant improvement in elucidating chromatin organization and dynamics, RNA visualization, and protein imaging. The current and future advancements in CRISPR-based imaging techniques can revolutionize genome biology research for various applications.
Npas4 regulates IQSEC3 expression in hippocampal somatostatin interneurons to mediate anxiety-like behavior
Kim, S;Park, D;Kim, J;Kim, D;Kim, H;Mori, T;Jung, H;Lee, D;Hong, S;Jeon, J;Tabuchi, K;Cheong, E;Kim, J;Um, JW;Ko, J;
PMID: 34289353 | DOI: 10.1016/j.celrep.2021.109417
Activity-dependent GABAergic synapse plasticity is important for normal brain functions, but the underlying molecular mechanisms remain incompletely understood. Here, we show that Npas4 (neuronal PAS-domain protein 4) transcriptionally regulates the expression of IQSEC3, a GABAergic synapse-specific guanine nucleotide-exchange factor for ADP-ribosylation factor (ARF-GEF) that directly interacts with gephyrin. Neuronal activation by an enriched environment induces Npas4-mediated upregulation of IQSEC3 protein specifically in CA1 stratum oriens layer somatostatin (SST)-expressing GABAergic interneurons. SST+ interneuron-specific knockout (KO) of Npas4 compromises synaptic transmission in these GABAergic interneurons, increases neuronal activity in CA1 pyramidal neurons, and reduces anxiety behavior, all of which are normalized by the expression of wild-type IQSEC3, but not a dominant-negative ARF-GEF-inactive mutant, in SST+ interneurons of Npas4-KO mice. Our results suggest that IQSEC3 is a key GABAergic synapse component that is directed by Npas4 and ARF activity, specifically in SST+ interneurons, to orchestrate excitation-to-inhibition balance and control anxiety-like behavior.
New and Promising Targeted Therapies in First and Second-Line Settings
Critical Issues in Head and Neck Oncology
Roden, D;Johnson, J;Szturz, P;Bossi, P;Argiris, A;
| DOI: 10.1007/978-3-030-63234-2_18
Deeper understanding of the molecular pathogenesis of malignancies, including head and neck squamous cell carcinoma (HNSCC), has led to the investigation of several novel targeted therapies. These therapeutic approaches may eventually replace or complement existing treatment modalities, such as surgery, radiation therapy, and traditional cytotoxic chemotherapy. Epidermal growth factor receptor (EGFR) inhibitors, and specifically cetuximab, are as of now the only class of targeted agents, excluding immune checkpoint inhibitors, with approval in the treatment of HNSCC. Beyond EGFR inhibition, novel therapies under evaluation are directed against vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR), PI3K/AKT/mTOR pathway, cell cycle regulation (for example, cyclin dependent kinases 4 and 6), HRAS, DNA repair mechanisms, and others. Development of new therapies has to take into consideration the complexity of solid tumors and their heterogeneity. Multitargeted combination therapy approaches may be required in certain cases in order to maximize antitumor effect. Ways to individualize treatment using validated biomarkers are likely to improve outcomes. We review the most relevant molecular targets in HNSCC and provide updates on clinical trial data with promising new targeted agents.
Fibrin-Associated, EBV-Negative Diffuse Large B-Cell Lymphoma Arising in Atrial Myxoma: Expanding the Spectrum of the Entity
International journal of surgical pathology
Baugh, L;Brown, N;Song, JY;Pandya, S;Montoya, V;Perry, AM;
PMID: 33913371 | DOI: 10.1177/10668969211014959
Fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL) is a provisional entity in the 2017 Revision of the World Health Organization Classification. This indolent entity, which is frequently discovered incidentally, is currently classified under the category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI), an aggressive lymphoma with poor survival. Several authors have proposed that it be classified separately since, in contrast to DLBCL-CI, transformation to aggressive lymphoma has rarely been reported and this entity has distinct clinical and histological features. We describe a rare case of a 62-year-old male with FA-DLBCL associated with atrial myxoma, which was incidentally discovered. In contrast to typically described immunophenotypic features of this entity, that is, activated B-cell phenotype (ABC) and Epstein-Barr virus (EBV) positivity, our case showed germinal center B-cell (GCB) phenotype and was EBV negative. Clinical staging revealed no evidence of lymphoma elsewhere in the body, and the patient did not receive adjuvant chemotherapy after surgical excision and remains in remission. This case illustrates that occasionally FA-DLBCL can show GCB phenotype, as opposed to the typical ABC phenotype. Moreover, we propose that the definition of the entity be expanded to include EBV-negative cases.
Bridging the Translational Divide in Pain Research: Biological, Psychological and Social Considerations
Frontiers in pharmacology
Cho, C;Deol, HK;Martin, LJ;
PMID: 33935700 | DOI: 10.3389/fphar.2021.603186
A gap exists between translating basic science research into effective pain therapies in humans. While preclinical pain research has primarily used animal models to understand biological processes, a lesser focus has been toward using animal models to fully consider other components of the pain experience, such as psychological and social influences. Herein, we provide an overview of translational studies within pain research by breaking them down into purely biological, psychological and social influences using a framework derived from the biopsychosocial model. We draw from a wide landscape of studies to illustrate that the pain experience is highly intricate, and every attempt must be made to address its multiple components and interactors to aid in fully understanding its complexity. We highlight our work where we have developed animal models to assess the cognitive and social effects on pain modulation while conducting parallel experiments in people that provide proof-of-importance for human pain modulation. In some instances, human pain research has sparked the development of novel animal models, with these animal models used to better understand the complexity of phenomena considered to be uniquely human such as placebo responses and empathy.
Microglial heterogeneity in aging and Alzheimer\'s disease: Is sex relevant?
Journal of Pharmacological Sciences
Delage, C;Šimončičová, E;Tremblay, M;
| DOI: 10.1016/j.jphs.2021.03.006
Neurodegenerative diseases and their associated cognitive decline are known to be more prevalent during aging. Recent evidence has uncovered the role of microglia, the immunocompetent cells of the brain, in dysfunctions linked to neurodegenerative diseases such as is Alzheimer's disease (AD). Similar to other pathologies, AD is shown to be sex-biased, with females being more at risk compared to males. While the mechanisms driving this prevalence are still unclear, emerging data suggest the sex differences present in microglia throughout life might lead to different responses of these cells in both health and disease. Furthermore, microglial cells have recently been recognized as a deeply heterogeneous population, with multiple subsets and/or phenotypes stemming from diverse parameters such as age, sex or state of health. Therefore, this review discusses microglial heterogeneity during aging in both basal conditions and AD with a focus on existing sex differences in this process.
Maturation stage enamel defects in Odontogenesis-associated phosphoprotein (Odaph) deficient mice
Developmental dynamics : an official publication of the American Association of Anatomists
Ji, Y;Li, C;Tian, Y;Gao, Y;Dong, Z;Xiang, L;Xu, Z;Gao, Y;Zhang, L;
PMID: 33772937 | DOI: 10.1002/dvdy.336
Mutation in Odontogenesis-associated phosphoprotein (ODAPH) has been reported to cause recessive hypomineralized amelogenesis imperfecta (AI) in human. However, the exact role of ODAPH in amelogenesis is still unknown. ODAPH was identified as a novel constituent of the atypical basal lamina located at the interface between maturation ameloblasts and the enamel by dual immunofluorescence staining of ODAPH and LAMC2. Odaph knockout mice were generated to explore the function of ODAPH in amelogenesis. Odaph-/- mice teeth showed severely attrition and reduced enamel mineralization. Histological analysis showed from transition or early-maturation stage, ameloblasts were rapidly shortened, lost cell polarity, and exhibited cell pathology. Abundant enamel matrix marked by amelogenin was retained. Temporary cyst-like structures were formed between flattened epithelial cells and the enamel from maturation stage to eruption. The integrity of the atypical basal lamina was impaired indicated by the reduced diffuse expression of LAMC2 and AMTN. The expression of maturation stage related genes of Amtn, Klk4, Integrinβ6 and Slc24a4 were significantly decreased. Our results suggested Odaph played vital roles during amelogenesis by maintaining the integrity of the atypical basal lamina in maturation stage, which may contribute to a better understanding of the pathophysiology of human AI.
Sequential progenitor states mark the generation of pancreatic endocrine lineages in mice and humans
Yu, XX;Qiu, WL;Yang, L;Wang, YC;He, MY;Wang, D;Zhang, Y;Li, LC;Zhang, J;Wang, Y;Xu, CR;
PMID: 33692492 | DOI: 10.1038/s41422-021-00486-w
The pancreatic islet contains multiple hormone+ endocrine lineages (α, β, δ, PP and ε cells), but the developmental processes that underlie endocrinogenesis are poorly understood. Here, we generated novel mouse lines and combined them with various genetic tools to enrich all types of hormone+ cells for well-based deep single-cell RNA sequencing (scRNA-seq), and gene coexpression networks were extracted from the generated data for the optimization of high-throughput droplet-based scRNA-seq analyses. These analyses defined an entire endocrinogenesis pathway in which different states of endocrine progenitor (EP) cells sequentially differentiate into specific endocrine lineages in mice. Subpopulations of the EP cells at the final stage (EP4early and EP4late) show different potentials for distinct endocrine lineages. ε cells and an intermediate cell population were identified as distinct progenitors that independently generate both α and PP cells. Single-cell analyses were also performed to delineate the human pancreatic endocrinogenesis process. Although the developmental trajectory of pancreatic lineages is generally conserved between humans and mice, clear interspecies differences, including differences in the proportions of cell types and the regulatory networks associated with the differentiation of specific lineages, have been detected. Our findings support a model in which sequential transient progenitor cell states determine the differentiation of multiple cell lineages and provide a blueprint for directing the generation of pancreatic islets in vitro.