IU Indianapolis ScholarWorks :: Browsing by Subject "Gene expression profiling"

Browsing by Subject "Gene expression profiling"

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A graph neural network model to estimate cell-wise metabolic flux using single-cell RNA-seq data
(Cold Spring Harbor Laboratory, 2021) Alghamdi, Norah; Chang, Wennan; Dang, Pengtao; Lu, Xiaoyu; Wan, Changlin; Gampala, Silpa; Huang, Zhi; Wang, Jiashi; Ma, Qin; Zang, Yong; Fishel, Melissa; Cao, Sha; Zhang, Chi; Medical and Molecular Genetics, School of Medicine
The metabolic heterogeneity and metabolic interplay between cells are known as significant contributors to disease treatment resistance. However, with the lack of a mature high-throughput single-cell metabolomics technology, we are yet to establish systematic understanding of the intra-tissue metabolic heterogeneity and cooperative mechanisms. To mitigate this knowledge gap, we developed a novel computational method, namely, single-cell flux estimation analysis (scFEA), to infer the cell-wise fluxome from single-cell RNA-sequencing (scRNA-seq) data. scFEA is empowered by a systematically reconstructed human metabolic map as a factor graph, a novel probabilistic model to leverage the flux balance constraints on scRNA-seq data, and a novel graph neural network-based optimization solver. The intricate information cascade from transcriptome to metabolome was captured using multilayer neural networks to capitulate the nonlinear dependency between enzymatic gene expressions and reaction rates. We experimentally validated scFEA by generating an scRNA-seq data set with matched metabolomics data on cells of perturbed oxygen and genetic conditions. Application of scFEA on this data set showed the consistency between predicted flux and the observed variation of metabolite abundance in the matched metabolomics data. We also applied scFEA on five publicly available scRNA-seq and spatial transcriptomics data sets and identified context- and cell group-specific metabolic variations. The cell-wise fluxome predicted by scFEA empowers a series of downstream analyses including identification of metabolic modules or cell groups that share common metabolic variations, sensitivity evaluation of enzymes with regards to their impact on the whole metabolic flux, and inference of cell-tissue and cell-cell metabolic communications.
An atlas of healthy and injured cell states and niches in the human kidney
(Springer Nature, 2023) Lake, Blue B.; Menon, Rajasree; Winfree, Seth; Hu, Qiwen; Ferreira, Ricardo Melo; Kalhor, Kian; Barwinska, Daria; Otto, Edgar A.; Ferkowicz, Michael; Diep, Dinh; Plongthongkum, Nongluk; Knoten, Amanda; Urata, Sarah; Mariani, Laura H.; Naik, Abhijit S.; Eddy, Sean; Zhang, Bo; Wu, Yan; Salamon, Diane; Williams, James C.; Wang, Xin; Balderrama, Karol S.; Hoover, Paul J.; Murray, Evan; Marshall, Jamie L.; Noel, Teia; Vijayan, Anitha; Hartman, Austin; Chen, Fei; Waikar, Sushrut S.; Rosas, Sylvia E.; Wilson, Francis P.; Palevsky, Paul M.; Kiryluk, Krzysztof; Sedor, John R.; Toto, Robert D.; Parikh, Chirag R.; Kim, Eric H.; Satija, Rahul; Greka, Anna; Macosko, Evan Z.; Kharchenko, Peter V.; Gaut, Joseph P.; Hodgin, Jeffrey B.; KPMP Consortium; Eadon, Michael T.; Dagher, Pierre C.; El-Achkar, Tarek M.; Zhang, Kun; Kretzler, Matthias; Jain, Sanjay; Medicine, School of Medicine
Understanding kidney disease relies on defining the complexity of cell types and states, their associated molecular profiles and interactions within tissue neighbourhoods1. Here we applied multiple single-cell and single-nucleus assays (>400,000 nuclei or cells) and spatial imaging technologies to a broad spectrum of healthy reference kidneys (45 donors) and diseased kidneys (48 patients). This has provided a high-resolution cellular atlas of 51 main cell types, which include rare and previously undescribed cell populations. The multi-omic approach provides detailed transcriptomic profiles, regulatory factors and spatial localizations spanning the entire kidney. We also define 28 cellular states across nephron segments and interstitium that were altered in kidney injury, encompassing cycling, adaptive (successful or maladaptive repair), transitioning and degenerative states. Molecular signatures permitted the localization of these states within injury neighbourhoods using spatial transcriptomics, while large-scale 3D imaging analysis (around 1.2 million neighbourhoods) provided corresponding linkages to active immune responses. These analyses defined biological pathways that are relevant to injury time-course and niches, including signatures underlying epithelial repair that predicted maladaptive states associated with a decline in kidney function. This integrated multimodal spatial cell atlas of healthy and diseased human kidneys represents a comprehensive benchmark of cellular states, neighbourhoods, outcome-associated signatures and publicly available interactive visualizations.
Clinical Utility of the 40-Gene Expression Profile (40-GEP) Test for Improved Patient Management Decisions and Disease-Related Outcomes when Combined with Current Clinicopathological Risk Factors for Cutaneous Squamous Cell Carcinoma (cSCC): Case Series
(Springer, 2022-02) Au, Jeremiah H.; Hooper, Perry B.; Fitzgerald, Alison L.; Somani, Ally-Khan; Dermatology, School of Medicine
Introduction While improvements have been made to risk assessment of cutaneous squamous cell carcinoma (cSCC) patients, there is a critical need for a uniform and more precise stratification system of their care. To address this unmet clinical need, a prognostic 40-gene expression profile (40-GEP) test has recently been developed and independently validated to show improved stratification of metastatic risk in high-risk cSCC patients compared with current staging systems. Methods Two cSCC cases, both male with similar patient profiles and the same staging status across two different staging systems, yet with opposing outcomes, were chosen for retrospective review of their primary biopsy using the 40-GEP test. Results Case 1 declined further treatment, even when presented with evidence of a small focus of cSCC found in the last layer of nonmarginal tissue obtained from Mohs micrographic surgery (MMS). Case 1 remained recurrence free, and retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 1 result (low likelihood of metastasis). Case 2, even with subsequent clearing of the primary cSCC with MMS, noted another metastatic cSCC 3 months later. Case 2, after multimodal adjuvant treatments, died due to disease progression. Retrospective analysis of the initial biopsy with the 40-GEP test provided a Class 2B result (high likelihood of metastasis). Conclusions The cases discussed highlight the utility in 40-GEP to provide additional information to guide treatment decisions and improve outcomes. Integrating novel molecular prognostication with traditional clinicopathological risk factors can improve stratification of high-risk cSCC patients and may inform selection of risk-appropriate treatment and surveillance strategies.
Connection of core and tail Mediator modules restrains transcription from TFIID-dependent promoters
(Public Library of Science, 2021-08-12) Saleh, Moustafa M.; Jeronimo, Célia; Robert, François; Zentner, Gabriel E.; Medicine, School of Medicine
The Mediator coactivator complex is divided into four modules: head, middle, tail, and kinase. Deletion of the architectural subunit Med16 separates core Mediator (cMed), comprising the head, middle, and scaffold (Med14), from the tail. However, the direct global effects of tail/cMed disconnection are unclear. We find that rapid depletion of Med16 downregulates genes that require the SAGA complex for full expression, consistent with their reported tail dependence, but also moderately overactivates TFIID-dependent genes in a manner partly dependent on the separated tail, which remains associated with upstream activating sequences. Suppression of TBP dynamics via removal of the Mot1 ATPase partially restores normal transcriptional activity to Med16-depleted cells, suggesting that cMed/tail separation results in an imbalance in the levels of PIC formation at SAGA-requiring and TFIID-dependent genes. We propose that the preferential regulation of SAGA-requiring genes by tailed Mediator helps maintain a proper balance of transcription between these genes and those more dependent on TFIID.
Contemporary best practice in the management of urothelial carcinomas of the renal pelvis and ureter
(Sage, 2019-01-08) Bianconi, Maristella; Cimadamore, Alessia; Faloppi, Luca; Scartozzi, Mario; Santoni, Matteo; Lopez-Beltran, Antonio; Cheng, Liang; Scarpelli, Marina; Montironi, Rodolfo; Pathology and Laboratory Medicine, School of Medicine
Upper tract urothelial carcinoma (UTUC) accounts for 5% of urothelial carcinomas (UCs), the estimated annual incidence being 1-2 cases per 100,000 inhabitants. Similarly to bladder UC, divergent differentiations and histologic variants confer an adverse risk factor in comparison with pure UTUC. Molecular and genomic characterization studies on UTUC have shown changes occurring at differing frequencies from bladder cancer, with unique molecular and clinical subtypes, potentially with different responses to treatment. Systemic chemotherapy is the standard approach for patients with inoperable locally advanced or metastatic UCs. Although initial response rates are high, the median survival with combination chemotherapy is about 15 months. In first-line chemotherapy several cisplatin-based regimens have been proposed. For patients with advanced UC who progress to first-line treatment, the only product licensed in Europe is vinflunine, a third-generation, semisynthetic, vinca alkaloid. Better response rates (15-60%), with higher toxicity rates and no overall survival (OS) benefit, are generally achieved in multidrug combinations, which often include taxanes and gemcitabine. The US FDA has recently approved five agents targeting the programmed death-1 and programmed death ligand-1 pathway as a second-line therapy in patients with locally advanced or metastatic UC with disease progression during or following platinum-containing chemotherapy. Potential therapeutic targets are present in 69% of tumours analyzed. Specific molecular alterations include those involved in the RTK/Ras/PI(3)K, cell-cycle regulation and chromatin-remodeling pathways, many of them have either targeted therapies approved or under investigation. Angiogenic agents, anti-epidermal growth factor receptor therapy, phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) pathway inhibitors and immunotherapeutic drugs are being successfully investigated.
Crucial Genes in Aortic Dissection Identified by Weighted Gene Coexpression Network Analysis
(Hindawi, 2022-02-07) Zhang, Hongliang; Chen, Tingting; Zhang, Yunyan; Lin, Jiangbo; Zhao, Wenjun; Shi, Yangyang; Lau, Huichong; Zhang, Yang; Yang, Minjun; Xu, Cheng; Tang, Lijiang; Xu, Baohui; Jiang, Jianjun; Chen, Xiaofeng; Radiation Oncology, School of Medicine
Background: Aortic dissection (AD) is a lethal vascular disease with high mortality and morbidity. Though AD clinical pathology is well understood, its molecular mechanisms remain unclear. Specifically, gene expression profiling helps illustrate the potential mechanism of aortic dissection in terms of gene regulation and its modification by risk factors. This study was aimed at identifying the genes and molecular mechanisms in aortic dissection through bioinformatics analysis. Method: Nine patients with AD and 10 healthy controls were enrolled. The gene expression in peripheral mononuclear cells was profiled through next-generation RNA sequencing. Analyses including differential expressed gene (DEG) via DEGseq, weighted gene coexpression network (WGCNA), and VisANT were performed to identify crucial genes associated with AD. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was also utilized to analyze Gene Ontology (GO). Results: DEG analysis revealed that 1,113 genes were associated with AD. Of these, 812 genes were markedly reduced, whereas 301 genes were highly expressed, in AD patients. DEGs were rich in certain categories such as MHC class II receptor activity, MHC class II protein complex, and immune response genes. Gene coexpression networks via WGCNA identified 3 gene hub modules, with one positively and 2 negatively correlated with AD, respectively. Specifically, module 37 was the most strongly positively correlated with AD with a correlation coefficient of 0.72. Within module 37, five hub genes (AGFG1, MCEMP1, IRAK3, KCNE1, and CLEC4D) displayed high connectivity and may have clinical significance in the pathogenesis of AD. Conclusion: Our analysis provides the possible association of specific genes and gene modules for the involvement of the immune system in aortic dissection. AGFG1, MCEMP1, IRAK3, KCNE1, and CLEC4D in module M37 were highly connected and strongly linked with AD, suggesting that these genes may help understand the pathogenesis of aortic dissection.
Dbh+ catecholaminergic cardiomyocytes contribute to the structure and function of the cardiac conduction system in murine heart
(Springer Nature, 2023-11-28) Sun, Tianyi; Grassam-Rowe, Alexander; Pu, Zhaoli; Li, Yangpeng; Ren, Huiying; An, Yanru; Guo, Xinyu; Hu, Wei; Liu, Ying; Zheng, Yuqing; Liu, Zhu; Kou, Kun; Ou, Xianhong; Chen, Tangting; Fan, Xuehui; Liu, Yangyang; Tu, Shu; He, Yu; Ren, Yue; Chen, Ao; Shang, Zhouchun; Xia, Zhidao; Miquerol, Lucile; Smart, Nicola; Zhang, Henggui; Tan, Xiaoqiu; Shou, Weinian; Lei, Ming; Pediatrics, School of Medicine
The heterogeneity of functional cardiomyocytes arises during heart development, which is essential to the complex and highly coordinated cardiac physiological function. Yet the biological and physiological identities and the origin of the specialized cardiomyocyte populations have not been fully comprehended. Here we report a previously unrecognised population of cardiomyocytes expressing Dbhgene encoding dopamine beta-hydroxylase in murine heart. We determined how these myocytes are distributed across the heart by utilising advanced single-cell and spatial transcriptomic analyses, genetic fate mapping and molecular imaging with computational reconstruction. We demonstrated that they form the key functional components of the cardiac conduction system by using optogenetic electrophysiology and conditional cardiomyocyte Dbh gene deletion models. We revealed their close relationship with sympathetic innervation during cardiac conduction system formation. Our study thus provides new insights into the development and heterogeneity of the mammalian cardiac conduction system by revealing a new cardiomyocyte population with potential catecholaminergic endocrine function.
Decoding the complexities of human malaria through systems immunology
(Wiley, 2020-01) Tran, Tuan M.; Crompton, Peter D.; Medicine, School of Medicine
The complexity of the Plasmodium parasite and its life cycle poses a challenge to our understanding of the host immune response against malaria. Studying human immune responses during natural and experimental Plasmodium infections can enhance our understanding of malaria-protective immunity and inform the design of disease-modifying adjunctive therapies and next-generation malaria vaccines. Systems immunology can complement conventional approaches to facilitate our understanding of the complex immune response to the highly dynamic malaria parasite. In this review, recent studies that used systems-based approaches to evaluate human immune responses during natural and experimental Plasmodium falciparum and Plasmodium vivax infections as well as during immunization with candidate malaria vaccines are summarized and related to each other. The potential for next-generation technologies to address the current limitations of systems-based studies of human malaria are discussed.
Gene expression profiles among murine strains segregate with distinct differences in the progression of radiation-induced lung disease
(The Company of Biologists, 2017-04-01) Jackson, Isabel L.; Baye, Fitsum; Goswami, Chirayu P.; Katz, Barry P.; Zodda, Andrew; Pavlovic, Radmila; Gurung, Ganga; Winans, Don; Vujaskovic, Zeljko; Biostatistics, School of Public Health
Molecular mechanisms underlying development of acute pneumonitis and/or late fibrosis following thoracic irradiation remain poorly understood. Here, we hypothesize that heterogeneity in disease progression and phenotypic expression of radiation-induced lung disease (RILD) across murine strains presents an opportunity to better elucidate mechanisms driving tissue response toward pneumonitis and/or fibrosis. Distinct differences in disease progression were observed in age- and sex-matched CBA/J, C57L/J and C57BL/6J mice over 1 year after graded doses of whole-thorax lung irradiation (WTLI). Separately, comparison of gene expression profiles in lung tissue 24 h post-exposure demonstrated >5000 genes to be differentially expressed (P<0.01; >twofold change) between strains with early versus late onset of disease. An immediate divergence in early tissue response between radiation-sensitive and -resistant strains was observed. In pneumonitis-prone C57L/J mice, differentially expressed genes were enriched in proinflammatory pathways, whereas in fibrosis-prone C57BL/6J mice, genes were enriched in pathways involved in purine and pyrimidine synthesis, DNA replication and cell division. At 24 h post-WTLI, different patterns of cellular damage were observed at the ultrastructural level among strains but microscopic damage was not yet evident under light microscopy. These data point toward a fundamental difference in patterns of early pulmonary tissue response to WTLI, consistent with the macroscopic expression of injury manifesting weeks to months after exposure. Understanding the mechanisms underlying development of RILD might lead to more rational selection of therapeutic interventions to mitigate healthy tissue damage.
Gene Regulation and Transcriptomics
(MDPI, 2021) Samuels, D. Scott; Lybecker, Meghan C.; Yang, X. Frank; Ouyang, Zhiming; Bourret, Travis J.; Boyle, William K.; Stevenson, Brian; Drecktrah, Dan; Caimano, Melissa J.; Microbiology and Immunology, School of Medicine
Borrelia (Borreliella) burgdorferi, along with closely related species, is the etiologic agent of Lyme disease. The spirochete subsists in an enzootic cycle that encompasses acquisition from a vertebrate host to a tick vector and transmission from a tick vector to a vertebrate host. To adapt to its environment and persist in each phase of its enzootic cycle, B. burgdorferi wields three systems to regulate the expression of genes: the RpoN-RpoS alternative sigma factor cascade, the Hk1/Rrp1 two-component system and its product c-di-GMP, and the stringent response mediated by RelBbu and DksA. These regulatory systems respond to enzootic phase-specific signals and are controlled or fine- tuned by transcription factors, including BosR and BadR, as well as small RNAs, including DsrABb and Bb6S RNA. In addition, several other DNA-binding and RNA-binding proteins have been identified, although their functions have not all been defined. Global changes in gene expression revealed by high-throughput transcriptomic studies have elucidated various regulons, albeit technical obstacles have mostly limited this experimental approach to cultivated spirochetes. Regardless, we know that the spirochete, which carries a relatively small genome, regulates the expression of a considerable number of genes required for the transitions between the tick vector and the vertebrate host as well as the adaptation to each.

Browsing by Subject "Gene expression profiling"

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