Browsing by Author "Feng, Dongni"

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    Bone Marrow-Derived Cells Restore Functional Integrity of the Gut Epithelial and Vascular Barriers in a Model of Diabetes and ACE2 Deficiency
    (AHA, 2019-11-08) Duan, Yaqian; Prasad, Ram; Feng, Dongni; Beli, Eleni; Calzi, Sergio Li; Longhini, Ana Leda F.; Lamendella, Regina; Floyd, Jason L.; Dupont, Mariana; Noothi, Sunil K.; Sreejit, Gopal Krishan; Athmanathan, Baskaran; Wright, Justin; Jensen, Amanda R.; Oudit, Gavin Y.; Markel, Troy A.; Nagareddy, Prabhakara R; Obukhov, Alexander G.; Grant, Maria B.; Anatomy and Cell Biology, School of Medicine
    Rationale: There is incomplete knowledge of the impact of bone marrow (BM) cells on the gut microbiome and gut barrier function. Objective: We postulated that diabetes and systemic angiotensin-converting enzyme 2 (ACE2) deficiency would synergize to adversely impact both the microbiome and gut barrier function. Methods and Results: Bacterial 16S rRNA sequencing and metatranscriptomic analysis were performed on fecal samples from WT, ACE2−/y, Akita (type 1 diabetic, T1D), and ACE2−/y-Akita mice. Gut barrier integrity was assessed by immunofluorescence, and BM cell extravasation into the small intestine was evaluated by flow cytometry. In the ACE2−/y-Akita or Akita mice, the disrupted barrier was associated with reduced levels of myeloid angiogenic cells (MACs), but no increase in inflammatory monocytes was observed within the gut parenchyma. Genomic and metatranscriptomic analysis of the microbiome of ACE2−/y-Akita mice demonstrated a marked increase in peptidoglycan (PGN) producing bacteria. When compared to control cohorts treated with saline, intraperitoneal administration of MACs significantly decreased the microbiome gene expression associated with PGN biosynthesis and restored epithelial and endothelial gut barrier integrity. Also indicative of diabetic gut barrier dysfunction, increased levels of PGN and intestinal fatty acid binding protein-2 (FABP-2) were observed in plasma of human subjects with T1D (n=21) and Type 2 diabetes (T2D, n=23) compared to non-diabetic controls (n=23). Using human retinal endothelial cells, we determined that PGN activates a non-canonical Toll-like receptor-2 (TLR2) associated MyD88-ARNO-ARF6 signaling cascade, resulting in destabilization of p120-catenin and internalization of VE-cadherin as a mechanism of deleterious impact of PGN on the endothelium. Conclusion: We demonstrate for the first time that the defect in gut barrier function and dysbiosis in ACE2−/y-Akita mice can be favorably impacted by exogenous administration of MACs.
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    HUMAN ADIPOSE-DERIVED STEM CELLS ATTENUATE CIGARETTE SMOKE INDUCED BONE MARROW HYPOPLASIA VIA SECRETION OF ANTI-INFLAMMATORY CYTOKINE TSG-6
    (Office of the Vice Chancellor for Research, 2012-04-13) Xie, Jie; Petrache, Irina; Broxmeyer, Hal E.; March, Keith L.; Feng, Dongni; Cook, Todd G.; Schweitzer, Kelly; Johnstone, Brian H.
    Introduction We have previously observed bone marrow (BM) hypo-plasia in a murine model of chronic smoking, which was ameliorated by mu-rine adipose-derived stromal cells (ASC). This study was designed to test the hypothesis that ASC exert their marrow protective effects through key paracrine factors. Methods Mice (NSG or C57BL/6) were exposed to ciga-rette smoke (CS) for 1 day to 6 months. Human ASC or ASC conditioned media were administered through intravenous (i.v.) or intraperitoneal (i.p.) injections. Secretion of TSG-6 from ASC in response to TNF alpha and IL-1 beta were measured by ELISA. Expression of TSG-6 in ASC was knocked down by siRNA. BM hematopoietic progenitors were quantified by colony forming-unit assays. Possible engrafted human ASC in mouse BM were ex-amined by anti-human nuclei staining. Results The myelossupressive effect of cigarette smoking occurred acutely (1 day: 65.6% of nonsmoking control, NSC, p<0.01) and worsened with prolonged exposure (3 days: 34.3% NSC, p<0.01). Such damage could be ameliorated with either ASC (111.0% NSC, p>0.05) or ASC conditioned media (105.7% NSC, p>0.05). Inflammatory cytokines (TNF alpha and IL-1 beta) elevated in smokers (Kuschner et al, 1996; de Maat et al, 2002) demonstrated strong cross-species stimulatory effects on secretions of an anti-inflammatory cytokine, TSG-6 from ASC (TNF alpha: 8.7 +/- 1.3 fold, IL-1 beta: 8.2 +/- 1.1 fold). Knocking down TSG-6 (>90%) abolished the marrow-protective effect of ASC. No human cells were detected in recipient mouse bone marrow. Conclusions The pro-tective effects of ASC against smoking-induced myelosuppression are medi-ated by trophic factors rather than cell engraftment or differentiation. TSG-6 appears to play a significant role in the modulatory pathway: smoke--inflammatory cytokine release--TSG6 secretion from ASC--bone marrow protection.
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    Human Adipose-Derived Stem Cells Suppress Elastase-Induced Murine Abdominal Aortic Inflammation and Aneurysm Expansion Through Paracrine Factors
    (Sage, 2017-02) Xie, Jie; Jones, Thomas J.; Feng, Dongni; Cook, Todd G.; Jester, Andrea A.; Yi, Ru; Jawed, Yameena T.; Babbey, Clifford; March, Keith L.; Murphy, Michael P.; Department of Anesthesia, School of Medicine
    Abdominal aortic aneurysm (AAA) is a potentially lethal disease associated with immune activation-induced aortic degradation. We hypothesized that xenotransplantation of human adipose-derived stem cells (hADSCs) would reduce aortic inflammation and attenuate expansion in a murine AAA model. Modulatory effects of ADSCs on immune cell subtypes associated with AAA progression were investigated using human peripheral blood mononuclear cells (hPBMNCs) cocultured with ADSCs. Murine AAA was induced through elastase application to the abdominal aorta in C57BL/6 mice. ADSCs were administered intravenously, and aortic changes were determined by ultrasonography and videomicrometry. Circulating monocytes, aortic neutrophils, CD28− T cells, FoxP3+ regulatory T cells (Tregs), and CD206+ M2 macrophages were assessed at multiple terminal time points. In vitro, ADSCs induced M2 macrophage and Treg phenotypes while inhibiting neutrophil transmigration and lymphocyte activation without cellular contact. Intravenous ADSC delivery reduced aneurysmal expansion starting from day 4 [from baseline: 54.8% (saline) vs. 16.9% (ADSCs), n = 10 at baseline, n = 4 at day 4, p < 0.001], and the therapeutic effect persists through day 14 (from baseline: 64.1% saline vs. 24.6% ADSCs, n = 4, p < 0.01). ADSC administration increased aortic Tregs by 20-fold (n = 5, p < 0.01), while decreasing CD4+CD28− (-28%), CD8+CD28− T cells (-61%), and Ly6G/C+ neutrophils (-43%, n = 5, p < 0.05). Circulating CD115+CXCR1−LY6C+-activated monocytes decreased in the ADSC-treated group by day 7 (-60%, n = 10, p < 0.05), paralleled by an increase in aortic CD206+ M2 macrophages by 2.4-fold (n = 5, p < 0.05). Intravenously injected ADSCs transiently engrafted in the lung on day 1 without aortic engraftment at any time point. In conclusion, ADSCs exhibit pleiotropic immunomodulatory effects in vitro as well as in vivo during the development of AAA. The temporal evolution of these effects systemically as well as in aortic tissue suggests that ADSCs induce a sequence of anti-inflammatory cellular events mediated by paracrine factors, which leads to amelioration of AAA progression.
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    Intracoronary and retrograde coronary venous myocardial delivery of adipose-derived stem cells in swine infarction lead to transient myocardial trapping with predominant pulmonary redistribution
    (Wiley, 2014-01) Jun Hong, Soon; Hou, Dongming; Brinton, Todd J.; Johnstone, Brian; Feng, Dongni; Rogers, Pamela; Fearon, William F.; Yock, Paul; March, Keith L.; Department of Medicine, IU School of Medicine
    OBJECTIVES: To examine the comparative fate of adipose-derived stem cells (ASCs) as well as their impact on coronary microcirculation following either retrograde coronary venous (RCV) or arterial delivery. BACKGROUND: Local delivery of ASCs to the heart has been proposed as a practical approach to limiting the extent of myocardial infarction. Mouse models of mesenchymal stem cell effects on the heart have also demonstrated significant benefits from systemic (intravenous) delivery, prompting a question about the advantage of local delivery. There has been no study addressing the extent of myocardial vs. systemic disposition of ASCs in large animal models following local delivery to the myocardium. METHODS: In an initial experiment, dose-dependent effects of ASC delivery on coronary circulation in normal swine were evaluated to establish a tolerable ASC dosing range for intracoronary (IC) delivery. In a set of subsequent experiments, an anterior acute myocardial infarction (AMI) was created by balloon occlusion of the proximal left anterior descending (LAD) artery, followed by either IC or RCV infusion of 10(7) (111)Indium-labeled autologous ASCs 6 days following AMI. Indices of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were measured before sacrifices to collect tissues for analysis at 1 or 24 hr after cell delivery. RESULTS: IC delivery of porcine ASCs to normal myocardium was well tolerated up to a cumulative dose of 14 × 10(6) cells (approximately 0.5 × 10(6) cells/kg). There was evidence suggesting microcirculatory trapping of ASC: at unit doses of 50 × 10(6) ASCs, IMR and CFR were found to be persistently altered in the target LAD distribution at 7 days following delivery, whereas at 10 × 10(6) ASCs, only CFR was altered. In the context of recent MI, a significantly higher percentage of ASCs was retained at 1 hr with IC delivery compared with RCV delivery (57.2 ± 12.7% vs. 17.9 ± 1.6%, P = 0.037) but this initial difference was not apparent at 24 hr (22.6 ± 5.5% vs. 18.7 ± 8.6%; P = 0.722). In both approaches, most ASC redistributed to the pulmonary circulation by 24 hr postdelivery. There were no significant differences in CFR or IMR following ASC delivery to infarcted tissue by either route. CONCLUSIONS: Selective intravascular delivery of ASC by coronary arterial and venous routes leads to similarly limited myocardial cell retention with predominant redistribution of cells to the lungs. IC arterial delivery of ASC leads to only transiently greater myocardial retention, which is accompanied by obstruction of normal regions of coronary microcirculation at higher doses. The predominant intrapulmonary localization of cells following local delivery via both methods prompts the notion that systemic delivery of ASC might provide similarly beneficial outcomes while avoiding risks of inadvertent microcirculatory compromise.
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    Intravenous xenogeneic transplantation of human adipose-derived stem cells improves left ventricular function and microvascular integrity in swine myocardial infarction model
    (Wiley, 2015-08) Hong, Soon Jun; Rogers, Pamela I.; Kihlken, John; Warfel, Jessica; Bull, Chris; Deuter-Reinhard, Maja; Feng, Dongni; Xie, Jie; Kyle, Aaron; Merfeld-Clauss, Stephanie; Johnstone, Brian H.; Traktuev, Dmitry O.; Chen, Peng-Sheng; Lindner, Jonathan R.; March, Keith L.; Medicine, School of Medicine
    OBJECTIVES: The potential for beneficial effects of adipose-derived stem cells (ASCs) on myocardial perfusion and left ventricular dysfunction in myocardial ischemia (MI) has not been tested following intravenous delivery. METHODS: Surviving pigs following induction of MI were randomly assigned to 1 of 3 different groups: the placebo group (n = 7), the single bolus group (SB) (n = 7, 15 × 10(7) ASCs), or the divided dose group (DD) (n = 7, 5 × 10(7) ASCs/day for three consecutive days). Myocardial perfusion defect area and coronary flow reserve (CFR) were compared during the 28-day follow-up. Also, serial changes in the absolute number of circulating CD4(+) T and CD8(+) T cells were measured. RESULTS: The increases in ejection fraction were significantly greater in both the SB and the DD groups compared to the placebo group (5.4 ± 0.9%, 3.7 ± 0.7%, and -0.4 ± 0.6%, respectively), and the decrease in the perfusion defect area was significantly greater in the SB group than the placebo group (-36.3 ± 1.8 and -11.5 ± 2.8). CFR increased to a greater degree in the SB and the DD groups than in the placebo group (0.9 ± 0.2, 0.8 ± 0.1, and 0.2 ± 0.2, respectively). The circulating number of CD8(+) T cells was significantly greater in the SB and DD groups than the placebo group at day 7 (3,687 ± 317/µL, 3,454 ± 787/µL, and 1,928 ± 457/µL, respectively). The numbers of small vessels were significantly greater in the SB and the DD groups than the placebo group in the peri-infarct area. CONCLUSIONS: Both intravenous SB and DD delivery of ASCs are effective modalities for the treatment of MI in swine. Intravenous delivery of ASCs, with its immunomodulatory and angiogenic effects, is an attractive noninvasive approach for myocardial rescue.
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    Loss of Angiotensin-Converting Enzyme 2 Exacerbates Diabetic Retinopathy by Promoting Bone Marrow Dysfunction
    (Wiley, 2018-09) Duan, Yaqian; Beli, Eleni; Calzi, Sergio Li; Quigley, Judith L.; Miller, Rehae C.; Moldovan, Leni; Feng, Dongni; Salazar, Tatiana E.; Hazra, Sugata; Al-Sabah, Jude; Chalam, Kakarla V.; Trinh, Thao Le Phuong; Meroueh, Marya; Markel, Troy A.; Murray, Matthew C.; Vyas, Ruchi J.; Boulton, Michael E.; Parsons-Wingerter, Patricia; Oudit, Gavin Y.; Obukhov, Alexander G.; Grant, Maria B.; Cellular and Integrative Physiology, School of Medicine
    Angiotensin-converting enzyme 2 (ACE2) is the primary enzyme of the vasoprotective axis of the renin angiotensin system (RAS). We tested the hypothesis that loss of ACE2 would exacerbate diabetic retinopathy by promoting bone marrow dysfunction. ACE2-/y were crossed with Akita mice, a model of type 1 diabetes. When comparing the bone marrow of the ACE2-/y-Akita mice to that of Akita mice, we observed a reduction of both short-term and long-term repopulating hematopoietic stem cells, a shift of hematopoiesis towards myelopoiesis, and an impairment of lineage-c-kit+ hematopoietic stem/progenitor cell (HS/PC) migration and proliferation. Migratory and proliferative dysfunction of these cells was corrected by exposure to angiotensin-1–7 (Ang-1–7), the protective peptide generated by ACE2. Over the duration of diabetes examined, ACE2 deficiency led to progressive reduction in electrical responses assessed by electroretinography and to increases in neural infarcts observed by fundus photography. Compared to Akita mice, ACE2-/y-Akita at 9-months of diabetes showed an increased number of acellular capillaries indicative of more severe diabetic retinopathy. In diabetic and control human subjects, CD34+ cells, a key bone marrow HS/PC population, were assessed for changes in mRNA levels for MAS, the receptor for Ang-1–7. Levels were highest in CD34+ cells from diabetics without retinopathy. Higher serum Ang-1–7 levels predicted protection from development of retinopathy in diabetics. Treatment with Ang-1–7 or alamandine restored the impaired migration function of CD34+ cells from subjects with retinopathy. These data support that activation of the protective RAS within HS/PCs may represent a therapeutic strategy for prevention of diabetic retinopathy.