IU Indianapolis ScholarWorks :: Browsing by Author "Doud, Emma H."

Browsing by Author "Doud, Emma H."

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A human skeletal muscle stem/myotube model reveals multiple signaling targets of cancer secretome in skeletal muscle
(Elsevier, 2023-03-31) Wang, Ruizhong; Kumar, Brijesh; Bhat-Nakshatri, Poornima; Khatpe, Aditi S.; Murphy, Michael P.; Wanczyk, Kristen E.; Simpson, Edward; Chen, Duojiao; Gao, Hongyu; Liu, Yunlong; Doud, Emma H.; Mosley, Amber L.; Nakshatri, Harikrishna; Surgery, School of Medicine
Skeletal muscle dysfunction or reprogramming due to the effects of the cancer secretome is observed in multiple malignancies. Although mouse models are routinely used to study skeletal muscle defects in cancer, because of species specificity of certain cytokines/chemokines in the secretome, a human model system is required. Here, we establish simplified multiple skeletal muscle stem cell lines (hMuSCs), which can be differentiated into myotubes. Using single nuclei ATAC-seq (snATAC-seq) and RNA-seq (snRNA-seq), we document chromatin accessibility and transcriptomic changes associated with the transition of hMuSCs to myotubes. Cancer secretome accelerated stem to myotube differentiation, altered the alternative splicing machinery and increased inflammatory, glucocorticoid receptor, and wound healing pathways in hMuSCs. Additionally, cancer secretome reduced metabolic and survival pathway associated miR-486, AKT, and p53 signaling in hMuSCs. hMuSCs underwent myotube differentiation when engrafted into NSG mice and thus providing a humanized in vivo skeletal muscle model system to study cancer cachexia.
Bis-aryl-α,β-unsaturated ketone (ABK) chaperonin inhibitors exhibit selective cytotoxicity to colorectal cancer cells that correlates with levels of aberrant HSP60 in the cytosol
(Elsevier, 2022) Chitre, Siddhi; Ray, Anne-Marie; Stevens, Mckayla; Doud, Emma H.; Liechty, Hope; Washburn, Alex; Tepper, Katelyn; Sivinski, Jared; O’Hagan, Heather M.; Georgiadis, Millie M.; Chapman, Eli; Johnson, Steven M.; Biochemistry and Molecular Biology, School of Medicine
While many studies have established the importance of protein homeostasis in tumor progression, little effort has been made to examine the therapeutic potential of targeting the HSP60 chaperonin system. In healthy cells, HSP60 is localized to the mitochondrial matrix; however, emerging evidence indicates HSP60 can be over-expressed and mis-localized to the cytosol of cancer cells, which is hypothesized to promote tumor cell survival and proliferation. This opens a potential avenue to selectively target the aberrant HSP60 in the cytosol as a chemotherapeutic strategy. In the present work, we examined a series of bis-aryl-α,β-unsaturated ketone (ABK) HSP60 inhibitors for their ability to selectively target cancerous vs non-cancerous colon and intestine cells. We found that lead analogs inhibited migration and clonogenicity of cancer cells, with cytotoxicity correlating with the level of aberrant HSP60 in the cytosol.
Characterization of BioID tagging systems in budding yeast and exploring the interactome of the Ccr4-Not complex
(Oxford University Press, 2024) Pfannenstein, Jeffrey; Tyryshkin, Misha; Gulden, Moira E.; Doud, Emma H.; Mosley, Amber L.; Reese, Joseph C.; Biochemistry and Molecular Biology, School of Medicine
The modified Escherichia coli biotin ligase BirA* was the first developed for proximity labeling of proteins (BioID). However, it has low activity at temperatures below 37°C, which reduces its effectiveness in organisms growing at lower temperatures, such as budding yeast. Multiple derivatives of the enzymes have been engineered, but a thorough comparison of these variations of biotin ligases and the development of versatile tools for conducting these experiments in Saccharomyces cerevisiae would benefit the community. Here, we designed a suite of vectors to compare the activities of biotin ligase enzymes in yeast. We found that the newer TurboID versions were the most effective at labeling proteins, but they displayed low constitutive labeling of proteins even in the absence of exogenous biotin, due to biotin contained in the culture medium. We describe a simple strategy to express free BioID enzymes in cells that can be used as an appropriate control in BioID studies to account for the promiscuous labeling of proteins caused by random interactions between bait-BioID enzymes in cells. We also describe chemically induced BioID systems exploiting the rapamycin-stabilized FRB-FKBP interaction. Finally, we used the TurboID version of the enzyme to explore the interactome of different subunits of the Ccr4-Not gene regulatory complex. We find that Ccr4-Not predominantly labeled cytoplasmic mRNA regulators, consistent with its function in mRNA decay and translation quality control in this cell compartment.
Characterization of endoplasmic reticulum-associated degradation in the human fungal pathogen Candida albicans
(PeerJ, 2023-08-25) Doss, Ellen M.; Moore, Joshua M.; Harman, Bryce H.; Doud, Emma H.; Rubenstein, Eric M.; Bernstein, Douglas A.; Biochemistry and Molecular Biology, School of Medicine
Background: Candida albicans is the most prevalent human fungal pathogen. In immunocompromised individuals, C. albicans can cause serious systemic disease, and patients infected with drug-resistant isolates have few treatment options. The ubiquitin-proteasome system has not been thoroughly characterized in C. albicans. Research from other organisms has shown ubiquitination is important for protein quality control and regulated protein degradation at the endoplasmic reticulum (ER) via ER-associated protein degradation (ERAD). Methods: Here we perform the first characterization, to our knowledge, of ERAD in a human fungal pathogen. We generated functional knockouts of C. albicans genes encoding three proteins predicted to play roles in ERAD, the ubiquitin ligases Hrd1 and Doa10 and the ubiquitin-conjugating enzyme Ubc7. We assessed the fitness of each mutant in the presence of proteotoxic stress, and we used quantitative tandem mass tag mass spectrometry to characterize proteomic alterations in yeast lacking each gene. Results: Consistent with a role in protein quality control, yeast lacking proteins thought to contribute to ERAD displayed hypersensitivity to proteotoxic stress. Furthermore, each mutant displayed distinct proteomic profiles, revealing potential physiological ERAD substrates, co-factors, and compensatory stress response factors. Among candidate ERAD substrates are enzymes contributing to ergosterol synthesis, a known therapeutic vulnerability of C. albicans. Together, our results provide the first description of ERAD function in C. albicans, and, to our knowledge, any pathogenic fungus.
Comprehensive Overview of Bottom-Up Proteomics Using Mass Spectrometry
(American Chemical Society, 2024-06-04) Jiang, Yuming; Rex, Devasahayam Arokia Balaya; Schuster, Dina; Neely, Benjamin A.; Rosano, Germán L.; Volkmar, Norbert; Momenzadeh, Amanda; Peters-Clarke, Trenton M.; Egbert, Susan B.; Kreimer, Simion; Doud, Emma H.; Crook, Oliver M.; Yadav, Amit Kumar; Vanuopadath, Muralidharan; Hegeman, Adrian D.; Mayta, Martín L.; Duboff, Anna G.; Riley, Nicholas M.; Moritz, Robert L.; Meyer, Jesse G.; Biochemistry and Molecular Biology, School of Medicine
Proteomics is the large scale study of protein structure and function from biological systems through protein identification and quantification. "Shotgun proteomics" or "bottom-up proteomics" is the prevailing strategy, in which proteins are hydrolyzed into peptides that are analyzed by mass spectrometry. Proteomics studies can be applied to diverse studies ranging from simple protein identification to studies of proteoforms, protein-protein interactions, protein structural alterations, absolute and relative protein quantification, post-translational modifications, and protein stability. To enable this range of different experiments, there are diverse strategies for proteome analysis. The nuances of how proteomic workflows differ may be challenging to understand for new practitioners. Here, we provide a comprehensive overview of different proteomics methods. We cover from biochemistry basics and protein extraction to biological interpretation and orthogonal validation. We expect this Review will serve as a handbook for researchers who are new to the field of bottom-up proteomics.
Comprehensive Overview of Bottom-Up Proteomics using Mass Spectrometry
(ArXiv, 2023-11-13) Jiang, Yuming; Rex, Devasahayam Arokia Balaya; Schuster, Dina; Neely, Benjamin A.; Rosano, Germán L.; Volkmar, Norbert; Momenzadeh, Amanda; Peters-Clarke, Trenton M.; Egbert, Susan B.; Kreimer, Simion; Doud, Emma H.; Crook, Oliver M.; Yadav, Amit Kumar; Vanuopadath, Muralidharan; Mayta, Martín L.; Duboff, Anna G.; Riley, Nicholas M.; Moritz, Robert L.; Meyer, Jesse G.; Biochemistry and Molecular Biology, School of Medicine
Proteomics is the large scale study of protein structure and function from biological systems through protein identification and quantification. "Shotgun proteomics" or "bottom-up proteomics" is the prevailing strategy, in which proteins are hydrolyzed into peptides that are analyzed by mass spectrometry. Proteomics studies can be applied to diverse studies ranging from simple protein identification to studies of proteoforms, protein-protein interactions, protein structural alterations, absolute and relative protein quantification, post-translational modifications, and protein stability. To enable this range of different experiments, there are diverse strategies for proteome analysis. The nuances of how proteomic workflows differ may be challenging to understand for new practitioners. Here, we provide a comprehensive overview of different proteomics methods to aid the novice and experienced researcher. We cover from biochemistry basics and protein extraction to biological interpretation and orthogonal validation. We expect this work to serve as a basic resource for new practitioners in the field of shotgun or bottom-up proteomics.
Cryo-EM structures of prion protein filaments from Gerstmann-Sträussler-Scheinker disease
(Springer, 2022) Hallinan, Grace I.; Ozcan, Kadir A.; Hoq, Md Rejaul; Cracco, Laura; Vago, Frank S.; Bharath, Sakshibeedu R.; Li, Daoyi; Jacobsen, Max; Doud, Emma H.; Mosley, Amber L.; Fernandez, Anllely; Garringer, Holly J.; Jiang, Wen; Ghetti, Bernardino; Vidal, Ruben; Pathology and Laboratory Medicine, School of Medicine
Prion protein (PrP) aggregation and formation of PrP amyloid (APrP) are central events in the pathogenesis of prion diseases. In the dominantly inherited prion protein amyloidosis known as Gerstmann-Sträussler-Scheinker (GSS) disease, plaques made of PrP amyloid are present throughout the brain. The c.593t > c mutation in the prion protein gene (PRNP) results in a phenylalanine to serine amino acid substitution at PrP residue 198 (F198S) and causes the most severe amyloidosis among GSS variants. It has been shown that neurodegeneration in this disease is associated with the presence of extracellular APrP plaques and neuronal intracytoplasmic Tau inclusions, that have been shown to contain paired helical filaments identical to those found in Alzheimer disease. Using cryogenic electron microscopy (cryo-EM), we determined for the first time the structures of filaments of human APrP, isolated post-mortem from the brain of two symptomatic PRNP F198S mutation carriers. We report that in GSS (F198S) APrP filaments are composed of dimeric, trimeric and tetrameric left-handed protofilaments with their protomers sharing a common protein fold. The protomers in the cross-β spines consist of 62 amino acids and span from glycine 80 to phenylalanine 141, adopting a previously unseen spiral fold with a thicker outer layer and a thinner inner layer. Each protomer comprises nine short β-strands, with the β1 and β8 strands, as well as the β4 and β9 strands, forming a steric zipper. The data obtained by cryo-EM provide insights into the structural complexity of the PrP filament in a dominantly inherited human PrP amyloidosis. The novel findings highlight the urgency of extending our knowledge of the filaments' structures that may underlie distinct clinical and pathologic phenotypes of human neurodegenerative diseases.
Deletion of miR‐33, a regulator of the ABCA1–APOE pathway, ameliorates neuropathological phenotypes in APP/PS1 mice
(Wiley, 2024) Tate, Mason; Wijeratne, H. R. Sagara; Kim, Byungwook; Philtjens, Stéphanie; You, Yanwen; Lee, Do-Hun; Gutierrez, Daniela A.; Sharify, Daniel; Wells, Megan; Perez-Cardelo, Magdalena; Doud, Emma H.; Fernandez-Hernando, Carlos; Lasagna-Reeves, Cristian; Mosley, Amber L.; Kim, Jungsu; Biochemistry and Molecular Biology, School of Medicine
Introduction: Rare variants in ABCA1 increase the risk of developing Alzheimer's disease (AD). ABCA1 facilitates the lipidation of apolipoprotein E (apoE). This study investigated whether microRNA-33 (miR-33)-mediated regulation of this ABCA1-APOE pathway affects phenotypes of an amyloid mouse model. Methods: We generated mir-33+/+;APP/PS1 and mir-33-/-;APP/PS1 mice to determine changes in amyloid pathology using biochemical and histological analyses. We used RNA sequencing and mass spectrometry to identify the transcriptomic and proteomic changes between our genotypes. We also performed mechanistic experiments by determining the role of miR-33 in microglial migration and amyloid beta (Aβ) phagocytosis. Results: Mir-33 deletion increases ABCA1 levels and reduces Aβ accumulation and glial activation. Multi-omics studies suggested miR-33 regulates the activation and migration of microglia. We confirm that the inhibition of miR-33 significantly increases microglial migration and Aβ phagocytosis. Discussion: These results suggest that miR-33 might be a potential drug target by modulating ABCA1 level, apoE lipidation, Aβ level, and microglial function. Highlights: Loss of microRNA-33 (miR-33) increased ABCA1 protein levels and the lipidation of apolipoprotein E. Loss of miR-33 reduced amyloid beta (Aβ) levels, plaque deposition, and gliosis. mRNAs and proteins dysregulated by miR-33 loss relate to microglia and Alzheimer's disease. Inhibition of miR-33 increased microglial migration and Aβ phagocytosis in vitro.
Distinguishing post-translational modifications in dominantly inherited frontotemporal dementias: FTLD-TDP Type A (GRN) vs Type B (C9orf72)
(Wiley, 2022) Cracco, Laura; Doud, Emma H.; Hallinan, Grace I.; Garringer, Holly J.; Jacobsen, Max H.; Richardson, Rose M.; Buratti, Emanuele; Vidal, Ruben; Ghetti, Bernardino; Newell, Kathy L.; Pathology and Laboratory Medicine, School of Medicine
Aims: Frontotemporal dementias are neuropathologically characterised by frontotemporal lobar degeneration (FTLD). Intraneuronal inclusions of transactive response DNA-binding protein 43 kDa (TDP-43) are the defining pathological hallmark of approximately half of the FTLD cases, being referred to as FTLD-TDP. The classification of FTLD-TDP into five subtypes (Type A to Type E) is based on pathologic phenotypes; however, the molecular determinants underpinning the phenotypic heterogeneity of FTLD-TDP are not well known. It is currently undetermined whether TDP-43 post-translational modifications (PTMs) may be related to the phenotypic diversity of the FTLDs. Thus, the investigation of FTLD-TDP Type A and Type B, associated with GRN and C9orf72 mutations, becomes essential. Methods: Immunohistochemistry was used to identify and map the intraneuronal inclusions. Sarkosyl-insoluble TDP-43 was extracted from brains of GRN and C9orf72 mutation carriers post-mortem and studied by Western blot analysis, immuno-electron microscopy and mass spectrometry. Results: Filaments of TDP-43 were present in all FTLD-TDP preparations. PTM profiling identified multiple phosphorylated, N-terminal acetylated or otherwise modified residues, several of which have been identified for the first time as related to sarkosyl-insoluble TDP-43. Several PTMs were specific for either Type A or Type B, while others were identified in both types. Conclusions: The current results provide evidence that the intraneuronal inclusions in the two genetic diseases contain TDP-43 filaments. The discovery of novel, potentially type-specific TDP-43 PTMs emphasises the need to determine the mechanisms leading to filament formation and PTMs, and the necessity of exploring the validity and occupancy of PTMs in a prognostic/diagnostic setting.
Disulfide bonds are required for cell division, cell envelope biogenesis and antibiotic resistance proteins in mycobacteria
(bioRxiv, 2025-01-28) Mejia-Santana, Adrian; Collins, Rebecca; Doud, Emma H.; Landeta, Cristina; Biochemistry and Molecular Biology, School of Medicine
Mycobacteria, including Mycobacterium tuberculosis-the etiological agent of tuberculosis-have a unique cell envelope critical for their survival and resistance. The cell envelope's assembly and maintenance influence permeability, making it a key target against multidrug-resistant strains. Disulfide bond (DSB) formation is crucial for the folding of cell envelope proteins. The DSB pathway in mycobacteria includes two enzymes, DsbA and VKOR, required for survival. Using bioinformatics and cysteine profiling proteomics, we identified cell envelope proteins dependent on DSBs. We validated via in vivo alkylation that key proteins like LamA (MmpS3), PstP, LpqW, and EmbB rely on DSBs for stability. Furthermore, chemical inhibition of VKOR results in phenotypes similar to those of Δvkor. Thus, targeting DsbA-VKOR systems could compromise both cell division and mycomembrane integrity. These findings emphasize the potential of DSB inhibition as a novel strategy to combat mycobacterial infections.

Browsing by Author "Doud, Emma H."

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