IU Indianapolis ScholarWorks :: Browsing by Author "Hoggatt, Jonathan"

Browsing by Author "Hoggatt, Jonathan"

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Bleeding the laboratory mouse: Not all methods are equal
(Elsevier, 2016-02) Hoggatt, Jonathan; Hoggatt, Amber F.; Tate, Tiffany A.; Fortman, Jeffrey; Pelus, Louis M.; Microbiology and Immunology, School of Medicine
The laboratory mouse is the model most frequently used in hematologic studies and assessment of blood parameters across a broad range of disciplines. Often, analysis of blood occurs in a nonterminal manner. However, the small body size of the mouse limits collection based on volume, frequency, and accessible sites. Commonly used sites in the mouse include the retro-orbital sinus, facial vein, tail vein, saphenous vein, and heart. The method of blood acquisition varies considerably across laboratories and is often not reported in detail. In this study, we report significant alterations in blood parameters, particularly of total white blood cells, specific populations of dendritic cells and myeloid-derived suppressor cells, and hematopoietic progenitor cells, as a result of site and manner of sampling. Intriguingly, warming of mice prior to tail bleeding was found to significantly alter blood values. Our findings suggest that the same method should be used across an entire study, that mice should be warmed prior to tail bleeds to make levels uniform, and that accurate description of bleeding methods in publications should be provided to allow for interpretation of comparative reports and inter- and intralaboratory experimental variability.
Differential Stem and Progenitor Cell Trafficking by Prostaglandin E2
(Springer Nature, 2013) Hoggatt, Jonathan; Mohammad, Khalid S.; Singh, Pratibha; Hoggatt, Amber F.; Chitteti, Brahmananda Reddy; Speth, Jennifer M.; Hu, Peirong; Poteat, Bradley A.; Stilger, Kayla N.; Ferraro, Francesca; Silberstein, Lev; Wong, Frankie K.; Farag, Sherif S.; Czader, Magdalena; Milne, Ginger L.; Breyer, Richard M.; Serezani, Carlos H.; Scadden, David T.; Guise, Theresa; Srour, Edward F.; Pelus, Louis M.; Medicine, School of Medicine
To maintain lifelong production of blood cells, haematopoietic stem cells (HSCs) are tightly regulated by inherent programs and extrinsic regulatory signals received from their microenvironmental niche. Long-term repopulating HSCs reside in several, perhaps overlapping, niches that produce regulatory molecules and signals necessary for homeostasis and for increased output after stress or injury. Despite considerable advances in the specific cellular or molecular mechanisms governing HSC-niche interactions, little is known about the regulatory function in the intact mammalian haematopoietic niche. Recently, we and others described a positive regulatory role for prostaglandin E2 (PGE2) on HSC function ex vivo. Here we show that inhibition of endogenous PGE2 by non-steroidal anti-inflammatory drug (NSAID) treatment in mice results in modest HSC egress from the bone marrow. Surprisingly, this was independent of the SDF-1-CXCR4 axis implicated in stem-cell migration. Stem and progenitor cells were found to have differing mechanisms of egress, with HSC transit to the periphery dependent on niche attenuation and reduction in the retentive molecule osteopontin. Haematopoietic grafts mobilized with NSAIDs had superior repopulating ability and long-term engraftment. Treatment of non-human primates and healthy human volunteers confirmed NSAID-mediated egress in other species. PGE2 receptor knockout mice demonstrated that progenitor expansion and stem/progenitor egress resulted from reduced E-prostanoid 4 (EP4) receptor signalling. These results not only uncover unique regulatory roles for EP4 signalling in HSC retention in the niche, but also define a rapidly translatable strategy to enhance transplantation therapeutically.
Pharmacologic increase in HIF1α enhances hematopoietic stem and progenitor homing and engraftment
(American Society of Hematology, 2014-01-09) Speth, Jennifer M.; Hoggatt, Jonathan; Singh, Pratibha; Pelus, Louis M.; Department of Microbiology and Immunology, IU School of Medicine
Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for a number of immunologic disorders. For effective transplant, HSCs must traffic from the peripheral blood to supportive bone marrow niches. We previously showed that HSC trafficking can be enhanced by ex vivo treatment of hematopoietic grafts with 16-16 dimethyl prostaglandin E2 (dmPGE2). While exploring regulatory molecules involved in dmPGE2 enhancement, we found that transiently increasing the transcription factor hypoxia-inducible factor 1-α (HIF1α) is required for dmPGE2-enhanced CXCR4 upregulation and enhanced migration and homing of stem and progenitor cells and that pharmacologic manipulation of HIF1α is also capable of enhancing homing and engraftment. We also now identify the specific hypoxia response element required for CXCR4 upregulation. These data define a precise mechanism through which ex vivo pulse treatment with dmPGE2 enhances the function of hematopoietic stem and progenitor cells; these data also define a role for hypoxia and HIF1α in enhancement of hematopoietic transplantation.
Prostaglandin E2 enhances long-term repopulation but does not permanently alter inherent stem cell competitiveness
(American Society of Hematology, 2013-10-24) Hoggatt, Jonathan; Mohammad, Khalid S.; Singh, Pratibha; Pelus, Louis M.; Department of Microbiology & Immunology, School of Medicine
Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for malignant and nonmalignant hematologic diseases and metabolic disorders. Although successful, hematopoietic transplantation can be hindered by inadequate stem cell number or poor engrafting efficiency. To overcome these deficits, we and others have previously reported the HSC-enhancing ability of a short-term exposure of prostaglandin E2 (PGE2); this strategy has now progressed to phase 1 clinical trials in double cord blood transplantation. To further analyze the short- and long-term effects of HSC exposure to PGE2, we followed the repopulation kinetics of PGE2-treated hematopoietic grafts through 5 serial transplantations and compared inherent long-term competitiveness in a HSC head-to-head secondary transplantation model. Treatment with PGE2 did not result in a long-term increase in HSC competitiveness, lineage bias, or enhanced proliferative potential, demonstrating that pulse exposure to PGE2 results in transient increases in HSC homing and engraftment potential.
Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators
(Cell Press, 2016-10-06) Silberstein, Lev; Goncalves, Kevin A.; Kharchenko, Peter V.; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel A.; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F.; Hoggatt, Jonathan; Tate, Tiffany; Lo Celso, Cristina; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P.; Hu, Guo-Fu; Scadden, David T.; Medicine, School of Medicine
Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on differential single-cell gene expression analysis of mesenchymal osteolineage cells close to and further removed from hematopoietic stem/progenitor cells to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. Amongst the genes which were preferentially expressed in proximal cells, we functionally examined three secreted or cell surface molecules not previously connected to HSPC biology: the secreted RNase Angiogenin, the cytokine IL18 and the adhesion molecule Embigin and discovered that all of these factors are HSPC quiescence regulators. Our proximity-based differential single cell approach therefore reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance understanding of microenvironmental regulation of stem cell function.
Rapid Mobilization Reveals a Highly Engraftable Hematopoietic Stem Cell
(Elsevier, 2018-01-11) Hoggatt, Jonathan; Singh, Pratibha; Tate, Tiffany A.; Chou, Bin-Kuan; Datari, Shruti R.; Fukuda, Seiji; Liu, Liqiong; Kharchenko, Peter V.; Schajnovitz, Amir; Baryawno, Ninib; Mercier, Francois E.; Boyer, Joseph; Gardner, Jason; Morrow, Dwight M.; Scadden, David T.; Pelus, Louis M.; Microbiology and Immunology, School of Medicine
Hematopoietic stem cell transplantation is a potential curative therapy for malignant and nonmalignant diseases. Improving the efficiency of stem cell collection and the quality of the cells acquired can broaden the donor pool and improve patient outcomes. We developed a rapid stem cell mobilization regimen utilizing a unique CXCR2 agonist, GROβ, and the CXCR4 antagonist AMD3100. A single injection of both agents resulted in stem cell mobilization peaking within 15 min that was equivalent in magnitude to a standard multi-day regimen of granulocyte colony-stimulating factor (G-CSF). Mechanistic studies determined that rapid mobilization results from synergistic signaling on neutrophils, resulting in enhanced MMP-9 release, and unexpectedly revealed genetic polymorphisms in MMP-9 that alter activity. This mobilization regimen results in preferential trafficking of stem cells that demonstrate a higher engraftment efficiency than those mobilized by G-CSF. Our studies suggest a potential new strategy for the rapid collection of an improved hematopoietic graft.
Role of lipegfilgrastim in the management of chemotherapy-induced neutropenia
(Dovepress, 2015-04) Hoggatt, Jonathan; Tate, Tiffany A.; Pelus, Louis M.; Department of Microbiology and Immunology, IU School of Medicine
Chemotherapy, irradiation, and other agents are widely used to target the process of cell division in neoplastic cells. However, while these therapies are effective against most cancers, the high proliferative rate of the cells of the hematopoietic system that produce billions of blood cells needed daily throughout life is extremely sensitive to these agents, resulting in loss of blood cell populations, which can be life threatening. Neutropenia is the most serious hematologic toxicity of chemotherapy, which can result in patient morbidity and mortality due to opportunistic infection and often is the limiting factor in dose escalation or duration of chemotherapeutic administration. Neutropenic patients often require hospitalization and incur substantial medical costs associated with anti-infective therapy. Treatment of iatrogenic and congenic neutropenia was changed in the early 1990s with the introduction of filgrastim (Neupogen®) and pegfilgrastim (Neulasta®). With the expiration of patent lives of both of these drugs, biosimilars have begun to emerge. In this review, we will summarize the chemical characteristics, pharmacokinetics, safety and efficacy of lipegfilgrastim (Lonquex®), the first long-acting biosimilar filgrastim to receive regulatory approval and enter the marketplace.
SIMPL Enhancement of Tumor Necrosis Factor-α Dependent p65-MED1 Complex Formation Is Required for Mammalian Hematopoietic Stem and Progenitor Cell Function
(Public Library of Science, 2013-04-22) Zhao, Weina; Breese, Erin; Bowers, Allison; Hoggatt, Jonathan; Pelus, Louis M.; Broxmeyer, Hal E.; Goebl, Mark; Harrington, Maureen A.; Biochemistry and Molecular Biology, School of Medicine
Significant insight into the signaling pathways leading to activation of the Rel transcription factor family, collectively termed NF-κB, has been gained. Less well understood is how subsets of NF-κB-dependent genes are regulated in a signal specific manner. The SIMPL protein (signaling molecule that interacts with mouse pelle-like kinase) is required for full Tumor Necrosis Factor-α (TNFα) induced NF-κB activity. We show that SIMPL is required for steady-state hematopoiesis and the expression of a subset of TNFα induced genes whose products regulate hematopoietic cell activity. To gain insight into the mechanism through which SIMPL modulates gene expression we focused on the Tnf gene, an immune response regulator required for steady-state hematopoiesis. In response to TNFα SIMPL localizes to the Tnf gene promoter where it modulates the initiation of Tnf gene transcription. SIMPL binding partners identified by mass spectrometry include proteins involved in transcription and the interaction between SIMPL and MED1 was characterized in more detail. In response to TNFα, SIMPL is found in p65-MED1 complexes where SIMPL enhances p65/MED1/SIMPL complex formation. Together our results indicate that SIMPL functions as a TNFα-dependent p65 co-activator by facilitating the recruitment of MED1 to p65 containing transcriptional complexes to control the expression of a subset of TNFα-induced genes.
A Single Radioprotective Dose of Prostaglandin E2 Blocks Irradiation-Induced Apoptotic Signaling and Early Cycling of Hematopoietic Stem Cells
(Elsevier, 2020-07-30) Patterson, Andrea M.; Liu, Liqiong; Sampson, Carol H.; Plett, P. Artur; Li, Hongge; Singh, Pratibha; Mohammad, Khalid S.; Hoggatt, Jonathan; Capitano, Maegan L.; Orschell, Christie M.; Pelus, Louis M.; Medicine, School of Medicine
Ionizing radiation exposure results in acute and delayed bone marrow suppression. Treatment of mice with 16,16-dimethyl prostaglandin E2 (dmPGE2) prior to lethal ionizing radiation (IR) facilitates survival, but the cellular and molecular mechanisms are unclear. In this study we show that dmPGE2 attenuates loss and enhances recovery of bone marrow cellularity, corresponding to a less severe hematopoietic stem cell nadir, and significantly preserves long-term repopulation capacity and progenitor cell function. Mechanistically, dmPGE2 suppressed hematopoietic stem cell (HSC) proliferation through 24 h post IR, which correlated with fewer DNA double-strand breaks and attenuation of apoptosis, mitochondrial compromise, oxidative stress, and senescence. RNA sequencing of HSCs at 1 h and 24 h post IR identified a predominant interference with IR-induced p53-downstream gene expression at 1 h, and confirmed the suppression of IR-induced cell-cycle genes at 24 h. These data identify mechanisms of dmPGE2 radioprotection and its potential role as a medical countermeasure against radiation exposure.
Sowing the Seeds of a Fruitful Harvest: Hematopoietic Stem Cell Mobilization
(Wiley, 2013-12) Hoggatt, Jonathan; Speth, Jennifer M.; Pelus, Louis M.; Department of Microbiology & Immunology, School of Medicine
Hematopoietic stem cell transplantation is the only curative option for a number of malignant and non-malignant diseases. As the use of hematopoietic transplant has expanded, so too has the source of stem and progenitor cells. The predominate source of stem and progenitors today, particularly in settings of autologous transplantation, is mobilized peripheral blood. This review will highlight the historical advances which lead to the widespread use of peripheral blood stem cells for transplantation, with a look towards future enhancements to mobilization strategies.

Browsing by Author "Hoggatt, Jonathan"

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