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1.
Theor Popul Biol ; 157: 33-46, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38521098

ABSTRACT

In natural ecosystems, species can be characterized by the nonlinear density-dependent self-regulation of their growth profile. Species of many taxa show a substantial density-dependent reduction for low population size. Nevertheless, many show the opposite trend; density regulation is minimal for small populations and increases significantly when the population size is near the carrying capacity. The theta-logistic growth equation can portray the intraspecific density regulation in the growth profile, theta being the density regulation parameter. In this study, we examine the role of these different growth profiles on the stability of a competitive ecological community with the help of a mathematical model of competitive species interactions. This manuscript deals with the random matrix theory to understand the stability of the classical theta-logistic models of competitive interactions. Our results suggest that having more species with strong density dependence, which self-regulate at low densities, leads to more stable communities. With this, stability also depends on the complexity of the ecological network. Species network connectance (link density) shows a consistent trend of increasing stability, whereas community size (species richness) shows a context-dependent effect. We also interpret our results from the aspect of two different life history strategies: r and K-selection. Our results show that the stability of a competitive network increases with the fraction of r-selected species in the community. Our result is robust, irrespective of different network architectures.


Subject(s)
Ecosystem , Population Density , Population Dynamics , Competitive Behavior , Animals
2.
Curr Opin Lipidol ; 34(5): 196-200, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37497844

ABSTRACT

PURPOSE OF REVIEW: To explore the multiple roles that lysophosphatidic acid (LPA) plays in vascular disease and atherosclerosis. RECENT FINDINGS: A high-fat high-cholesterol diet decreases antimicrobial activity in the small intestine, which leads to increased levels of bacterial lipopolysaccharide in the mucus of the small intestine and in plasma that increase systemic inflammation, and enhance dyslipidemia and aortic atherosclerosis. Decreasing LPA production in enterocytes reduces the impact of the diet. LPA signaling inhibits glucagon-like peptide 1 secretion, promotes atherosclerosis, increases vessel permeability and infarct volume in stroke, but protects against abdominal aortic aneurysm formation and rupture. Acting through the calpain system in lymphatic endothelial cells, LPA reduces the trafficking of anti-inflammatory Treg lymphocytes, which enhances atherosclerosis. Acting through LPA receptor 1 in cardiac lymphatic endothelial cells and fibroblasts, LPA enhances hypertrophic cardiomyopathy. SUMMARY: LPA plays multiple roles in vascular disease and atherosclerosis that is cell and context dependent. In some settings LPA promotes these disease processes and in others it inhibits the disease process. Because LPA is so ubiquitous, therapeutic approaches targeting LPA must be as specific as possible for the cells and the context in which the disease process occurs.


Subject(s)
Atherosclerosis , Endothelial Cells , Humans , Lysophospholipids , Intestine, Small
3.
J Lipid Res ; 64(5): 100370, 2023 05.
Article in English | MEDLINE | ID: mdl-37059333

ABSTRACT

Conversion of lysophosphatidylcholine to lysophosphatidic acid (LPA) by autotaxin, a secreted phospholipase D, is a major pathway for producing LPA. We previously reported that feeding Ldlr-/- mice standard mouse chow supplemented with unsaturated LPA or lysophosphatidylcholine qualitatively mimicked the dyslipidemia and atherosclerosis induced by feeding a Western diet (WD). Here, we report that adding unsaturated LPA to standard mouse chow also increased the content of reactive oxygen species and oxidized phospholipids (OxPLs) in jejunum mucus. To determine the role of intestinal autotaxin, enterocyte-specific Ldlr-/-/Enpp2 KO (intestinal KO) mice were generated. In control mice, the WD increased enterocyte Enpp2 expression and raised autotaxin levels. Ex vivo, addition of OxPL to jejunum from Ldlr-/- mice on a chow diet induced expression of Enpp2. In control mice, the WD raised OxPL levels in jejunum mucus and decreased gene expression in enterocytes for a number of peptides and proteins that affect antimicrobial activity. On the WD, the control mice developed elevated levels of lipopolysaccharide in jejunum mucus and plasma, with increased dyslipidemia and increased atherosclerosis. All these changes were reduced in the intestinal KO mice. We conclude that the WD increases the formation of intestinal OxPL, which i) induce enterocyte Enpp2 and autotaxin resulting in higher enterocyte LPA levels; that ii) contribute to the formation of reactive oxygen species that help to maintain the high OxPL levels; iii) decrease intestinal antimicrobial activity; and iv) raise plasma lipopolysaccharide levels that promote systemic inflammation and enhance atherosclerosis.


Subject(s)
Anti-Infective Agents , Atherosclerosis , Dyslipidemias , Mice , Animals , Lysophosphatidylcholines , Enterocytes/metabolism , Lipopolysaccharides , Reactive Oxygen Species , Lysophospholipids/metabolism , Phosphoric Diester Hydrolases/genetics , Phosphoric Diester Hydrolases/metabolism , Diet, Western , Inflammation/genetics , Dyslipidemias/metabolism , Atherosclerosis/genetics
4.
PLoS Pathog ; 18(1): e1010160, 2022 01.
Article in English | MEDLINE | ID: mdl-34995311

ABSTRACT

Novel therapeutic strategies are needed to attenuate increased systemic and gut inflammation that contribute to morbidity and mortality in chronic HIV infection despite potent antiretroviral therapy (ART). The goal of this study is to use preclinical models of chronic treated HIV to determine whether the antioxidant and anti-inflammatory apoA-I mimetic peptides 6F and 4F attenuate systemic and gut inflammation in chronic HIV. We used two humanized murine models of HIV infection and gut explants from 10 uninfected and 10 HIV infected persons on potent ART, to determine the in vivo and ex vivo impact of apoA-I mimetics on systemic and intestinal inflammation in HIV. When compared to HIV infected humanized mice treated with ART alone, mice on oral apoA-I mimetic peptide 6F with ART had consistently reduced plasma and gut tissue cytokines (TNF-α, IL-6) and chemokines (CX3CL1) that are products of ADAM17 sheddase activity. Oral 6F attenuated gut protein levels of ADAM17 that were increased in HIV-1 infected mice on potent ART compared to uninfected mice. Adding oxidized lipoproteins and endotoxin (LPS) ex vivo to gut explants from HIV infected persons increased levels of ADAM17 in myeloid and intestinal cells, which increased TNF-α and CX3CL1. Both 4F and 6F attenuated these changes. Our preclinical data suggest that apoA-I mimetic peptides provide a novel therapeutic strategy that can target increased protein levels of ADAM17 and its sheddase activity that contribute to intestinal and systemic inflammation in treated HIV. The large repertoire of inflammatory mediators involved in ADAM17 sheddase activity places it as a pivotal orchestrator of several inflammatory pathways associated with morbidity in chronic treated HIV that make it an attractive therapeutic target.


Subject(s)
Apolipoprotein A-I , HIV Infections/pathology , Inflammation/pathology , Intestines/drug effects , Peptides/pharmacology , ADAM17 Protein/drug effects , Animals , Anti-HIV Agents/pharmacology , Humans , Mice
5.
J Lipid Res ; 63(1): 100153, 2022 01.
Article in English | MEDLINE | ID: mdl-34808192

ABSTRACT

We previously reported that adding a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to a Western diet (WD) ameliorated systemic inflammation. To determine the mechanism(s) responsible for these observations, Ldlr-/- mice were fed chow, a WD, or WD plus Tg6F. We found that a WD altered the taxonomic composition of bacteria in jejunum mucus. For example, Akkermansia muciniphila virtually disappeared, while overall bacteria numbers and lipopolysaccharide (LPS) levels increased. In addition, gut permeability increased, as did the content of reactive oxygen species and oxidized phospholipids in jejunum mucus in WD-fed mice. Moreover, gene expression in the jejunum decreased for multiple peptides and proteins that are secreted into the mucous layer of the jejunum that act to limit bacteria numbers and their interaction with enterocytes including regenerating islet-derived proteins, defensins, mucin 2, surfactant A, and apoA-I. Following WD, gene expression also decreased for Il36γ, Il23, and Il22, cytokines critical for antimicrobial activity. WD decreased expression of both Atoh1 and Gfi1, genes required for the formation of goblet and Paneth cells, and immunohistochemistry revealed decreased numbers of goblet and Paneth cells. Adding Tg6F ameliorated these WD-mediated changes. Adding oxidized phospholipids ex vivo to the jejunum from mice fed a chow diet reproduced the changes in gene expression in vivo that occurred when the mice were fed WD and were prevented with addition of 6F peptide. We conclude that Tg6F ameliorates the WD-mediated increase in oxidized phospholipids that cause changes in jejunum mucus, which induce dysbiosis and systemic inflammation.


Subject(s)
Dysbiosis
6.
Blood Cell Ther ; 5(1): 16-26, 2022 Feb 25.
Article in English | MEDLINE | ID: mdl-36714265

ABSTRACT

Purpose: Autologous stem cell transplantation (ASCT) is an established therapy for many hematological diseases. This study assessed the pattern of ASCTs at a tertiary care center and associated factors, including pre-harvest CD34+ stem cell levels, leading to improved engraftment outcomes. Methodology: A retrospective study was conducted in India, between February 2009-August 2020. Patients who underwent ASCT for different hematological malignancies (n=65) were included, and the patients' age, sex, type and stage of disease, pre- and post-harvest CD34+ counts, and time to attain platelet/neutrophil engraftment or febrile neutropenia were analyzed. The post-harvest CD34+ dose was calculated. Pre-conditioning was performed using Granulocyte Colony Stimulating Factor (GCSF)±Plerixafor. Progression-free survival (PFS) was calculated using relapse/death as the endpoint. Results: The median age of the cohort (n=65) was 49 years, with a male preponderance. Multiple myeloma was the most common malignancy (70.8% [46/65]), requiring ASCT. The median time to ASCT was 13 months. All patients had received GCSF, while Plerixafor was used in 17 patients with a pre-harvest CD34+ count of <10 cells/µL. The median pre-harvest CD34+ concentration and post-harvest CD34+ cell dose was 27.54 cells/µL (n=26) and 5.23×106 cells/kg body weight (n=65), respectively. The median time to engraftment was 11 and 12 days, for neutrophils and platelets, respectively. One patient did not engraft and was excluded from the analysis. The time required to attain neutrophil engraftment was significantly lower (p=0.02) among freshly harvested stem cells (n=48) than that of cryopreserved products (n=17). Platelet engraftment associated with CD34+ pre- and post-harvest levels was not significant (p=0.06). The time to attain neutropenia and subsequent febrile neutropenia was significantly lower with an adequate post-harvest CD34+ dose (p=0.009). Febrile neutropenia was seen in 83.1% (54/65) patients. The median time for febrile neutropenia was 4 days post-ASCT. Pre- and post-harvest CD34+ concentrations were directly proportional to each other (p<0.001). The median PFS was 112 months (n=65). Survival was better in males (median PFS: 112 months) vs. females (median PFS: 59 months) (p=0.27). Eight patients relapsed, and eight patients had died. Conclusion: Although unrelated to age or sex, the post-harvest CD34+ dose was inversely related to febrile neutropenia. As pre- and post-harvest CD34+ levels were directly proportional, pre-harvest CD34+ concentrations may be reliably used to assess engraftment outcomes. Rapid neutrophil engraftment was noted in fresh stem cells with PFS of 112 months, and was better among males, the exact reason being unknown. Thus, a larger number of patients should be followed up to obtain an accurate picture.

7.
Ann Hematol ; 100(2): 395-403, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33140134

ABSTRACT

Timely administration of appropriate empirical antibiotics in febrile neutropenia is crucial for favourable patient outcomes. There are guidelines in place recommending such antibiotics. However, regional variations and local epidemiological data must be evaluated to tailor the antibiotics for best possible and rational use. In this study, we audited the clinical and microbiological data of febrile neutropenic episodes occurring at a tertiary care haematology institution. Three hundred and ninety-three febrile neutropenic episodes occurring in 123 patients over a 1-year period were analysed for microbial profile, sensitivity and resistance patterns, and finally clinical outcomes. Gram-negative bacilli (GNB) blood stream infections (46.9%) were more prevalent as compared to gram-positive infections (41.9%). Overall mortality due to complicated neutropenic sepsis was 19.5% (24/123 patients). Increased resistance to carbapenems, beta-lactam beta-lactamase inhibitor combinations, aminoglycosides, fluoroquinolones, and cephalosporins were observed. Cefepime and tigecycline resistance were seen in 20% and 15% GNB isolates, respectively. Chest was the most frequent focus of infection, and acute myeloid leukaemia (AML) was the most common underlying disorder which correlated with the likelihood of death (p < 0.01). Multidrug-resistant GNB (esp. Klebsiella sp.) are still most worrisome isolates in neutropenic patients. Single-agent cefepime or piperacillin-tazobactam/tigecycline combination may be considered empirical agents. Chest infections and AML were independent predictors of poor clinical outcome in neutropenic patients. Regular audit of infections and antibiotic susceptibility data is needed to improve clinical outcomes in patients with febrile neutropenia.


Subject(s)
Cefepime/administration & dosage , Drug Resistance, Multiple, Bacterial , Febrile Neutropenia , Gram-Negative Bacterial Infections , Gram-Positive Bacterial Infections , Leukemia, Myeloid, Acute , Piperacillin, Tazobactam Drug Combination/administration & dosage , Tigecycline/administration & dosage , Adolescent , Adult , Febrile Neutropenia/blood , Febrile Neutropenia/drug therapy , Febrile Neutropenia/microbiology , Febrile Neutropenia/mortality , Female , Gram-Negative Bacterial Infections/blood , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/mortality , Gram-Positive Bacterial Infections/blood , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/mortality , Humans , India , Leukemia, Myeloid, Acute/blood , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/microbiology , Leukemia, Myeloid, Acute/mortality , Male , Middle Aged , Retrospective Studies
8.
AIDS ; 35(4): 543-553, 2021 03 15.
Article in English | MEDLINE | ID: mdl-33306550

ABSTRACT

OBJECTIVES: Despite antiretroviral therapy (ART), there is an unmet need for therapies to mitigate immune activation in HIV infection. The goal of this study is to determine whether the apoA-I mimetics 6F and 4F attenuate macrophage activation in chronic HIV. DESIGN: Preclinical assessment of the in-vivo impact of Tg6F and the ex-vivo impact of apoA-I mimetics on biomarkers of immune activation and gut barrier dysfunction in treated HIV. METHODS: We used two humanized murine models of HIV infection to determine the impact of oral Tg6F with ART (HIV+ART+Tg6F+) on innate immune activation (plasma human sCD14, sCD163) and gut barrier dysfunction [murine I-FABP, endotoxin (LPS), LPS-binding protein (LBP), murine sCD14]. We also used gut explants from 10 uninfected and 10 HIV-infected men on potent ART and no morbidity, to determine the impact of ex-vivo treatment with 4F for 72 h on secretion of sCD14, sCD163, and I-FABP from gut explants. RESULTS: When compared with mice treated with ART alone (HIV+ART+), HIV+ART+Tg6F+ mice attenuated macrophage activation (h-sCD14, h-sCD163), gut barrier dysfunction (m-IFABP, LPS, LBP, and m-sCD14), plasma and gut tissue oxidized lipoproteins. The results were consistent with independent mouse models and ART regimens. Both 4F and 6F attenuated shedding of I-FABP and sCD14 from gut explants from HIV-infected and uninfected participants. CONCLUSION: Given that gut barrier dysfunction and macrophage activation are contributors to comorbidities like cardiovascular disease in HIV, apoA-I mimetics should be tested as therapy for morbidity in chronic treated HIV.


Subject(s)
HIV Infections , Animals , Apolipoprotein A-I , Biomarkers , HIV Infections/drug therapy , Lipopolysaccharide Receptors , Macrophage Activation , Mice
9.
Semin Cancer Biol ; 73: 158-168, 2021 08.
Article in English | MEDLINE | ID: mdl-33188891

ABSTRACT

Peptides have many advantages over traditional therapeutics, including small molecules and other biologics, because of their low toxicity and immunogenicity, while still exhibiting efficacy. This review discusses the benefits and mechanism of action of apolipoprotein mimetic peptides in tumor biology and their potential utility in treating various cancers. Among lipoproteins in the circulation, high-density lipoprotein (HDL) and its constituents including apolipoprotein A-I (apoA-I; the predominant protein in HDL), apoJ, and apoE, harbor anti-tumorigenic activities. Peptides that mimic apoA-I function have been developed through molecular mimicry of the amphipathic α-helices of apoA-I. Oral apoA-I mimetic peptides remodel HDL, promote cholesterol efflux, sequester oxidized lipids, and activate anti-inflammatory processes. ApoA-I and apoJ mimetic peptides ameliorate various metrics of cancer progression and have demonstrated efficacy in preclinical models in the inhibition of ovarian, colon, breast, and metastatic lung cancers. Apolipoprotein mimetic peptides are poorly absorbed when administered orally and rapidly degraded when injected into the circulation. The small intestine is the major site of action for apoA-I mimetic peptides and recent studies suggest that modulation of immune cells in the lamina propria of the small intestine is, in part, a potential mechanism of action. Finally, several recent studies underscore the use of reconstituted HDL as target-specific nanoparticles carrying poorly soluble or unstable therapeutics to tumors even across the blood-brain barrier. Preclinical studies suggest that these versatile recombinant lipoprotein based nanoparticles and apolipoprotein mimetics can serve as safe, novel drug delivery, and therapeutic agents for the treatment of a number of cancers.


Subject(s)
Apolipoproteins , Molecular Mimicry , Neoplasms , Animals , Humans , Peptides
10.
Hypertension ; 76(3): 985-996, 2020 09.
Article in English | MEDLINE | ID: mdl-32713273

ABSTRACT

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by increased mean pulmonary arterial pressure. Elevated plasma and lung concentrations of oxidized lipids, including 15-hydroxyeicosatetraenoic acid (15-HETE), have been demonstrated in patients with PAH and animal models. We previously demonstrated that feeding mice with 15-HETE is sufficient to induce pulmonary hypertension, but the mechanisms remain unknown. RNA sequencing data from the mouse lungs on 15-HETE diet revealed significant activation of pathways involved in both antigen processing and presentation and T cell-mediated cytotoxicity. Analysis of human microarray from patients with PAH also identified activation of identical pathways compared with controls. We show that in both 15-HETE-fed mice and patients with PAH, expression of the immunoproteasome subunit 5 is significantly increased, which was concomitant with an increase in the number of CD8/CD69 (cluster of differentiation 8 / cluster of differentiation 69) double-positive cells, as well as pulmonary arterial endothelial cell apoptosis in mice. Human pulmonary arterial endothelial cells cultured with 15-HETE were more prone to apoptosis when exposed to CD8 cells. Cultured intestinal epithelial cells secreted more oxidized lipids in response to 15-HETE, which is consistent with accumulation of circulating oxidized lipids in 15-HETE-fed mice. Administration of an apoA-I (apolipoprotein A-I) mimetic peptide, Tg6F (transgenic 6F), which is known to prevent accumulation of circulating oxidized lipids, not only inhibited pulmonary arterial endothelial cell apoptosis but also prevented and rescued 15-HETE-induced pulmonary hypertension in mice. In conclusion, our results suggest that (1) 15-HETE diet induces pulmonary hypertension by a mechanism that involves oxidized lipid-mediated T cell-dependent pulmonary arterial endothelial cell apoptosis and (2) Tg6F administration may be a novel therapy for treating PAH.


Subject(s)
Apoptosis , Endothelial Cells , Hydroxyeicosatetraenoic Acids/metabolism , Hypertension, Pulmonary/metabolism , Peptides/pharmacology , Pulmonary Artery , Animals , Apoptosis/drug effects , Apoptosis/immunology , Cell Differentiation , Cell Proliferation , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Hypertension, Pulmonary/prevention & control , Immunologic Factors/pharmacology , Immunoproteins , Lipid Metabolism/drug effects , Mice , Proteasome Endopeptidase Complex , Pulmonary Artery/metabolism , Pulmonary Artery/pathology , T-Lymphocytes
11.
Curr Opin Lipidol ; 30(5): 383-387, 2019 10.
Article in English | MEDLINE | ID: mdl-31356236

ABSTRACT

PURPOSE OF REVIEW: To discuss recent findings on the importance of the small intestine in modulating metabolism and inflammation in atherosclerosis and cancer. RECENT FINDINGS: Integrin ß7 natural gut intraepithelial T cells modulated metabolism and accelerated atherosclerosis in mice. Reducing the generation of lysophospholipids in the small intestine mimicked bariatric surgery and improved diabetes. Enterocyte-specific knockdown of stearoyl-CoA desaturase-1 significantly improved dyslipidemia in LDL receptor null (Ldlr) mice fed a Western diet. Adding a concentrate of tomatoes transgenic for the apolipoprotein A-I mimetic peptide 6F to the chow of wild-type mice altered lipid metabolism in the small intestine, preserved Notch signaling and reduced tumor burden in mouse models. The phospholipid-remodeling enzyme Lpcat3 regulated intestinal stem cells and progenitor cells by stimulating cholesterol biosynthesis; increasing cholesterol in the diet or through genetic manipulation promoted tumorigenesis in Apc mice. SUMMARY: The small intestine is important for regulating metabolism and inflammation in animal models of both atherosclerosis and cancer.


Subject(s)
1-Acylglycerophosphocholine O-Acyltransferase/genetics , Atherosclerosis/genetics , Neoplasms/genetics , Receptors, LDL/genetics , Stearoyl-CoA Desaturase/genetics , Animals , Atherosclerosis/metabolism , Atherosclerosis/pathology , Disease Models, Animal , Humans , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Integrin beta Chains/genetics , Intestine, Small/metabolism , Mice , Neoplasms/metabolism , Neoplasms/pathology
12.
Oman Med J ; 34(2): 131-136, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30918607

ABSTRACT

OBJECTIVES: Blood counts are commonly performed tests in neonatal intensive care units with the results having various clinical ramifications. Interpreting blood counts as normal or abnormal requires reference ranges as per gestation. Studies on reference ranges for neonatal neutrophil counts are already scarce, and data is lacking in the Asian context. We sought to formulate gestation-wise reference ranges of neutrophil counts in an Indian setting. METHODS: Healthy, newborn babies of either gender, aged between 30 to 41 weeks gestation were included in the study. Gestational age was corroborated through first trimester dating scan and postnatally by the New Ballard Score. Single venous blood samples were drawn on day three and day five for estimation of total leukocyte count, differential count (neutrophils, lymphocytes), and peripheral blood smear examination. RESULTS: We evaluated the data of 420 newborns. The normative values were compiled week-wise for gestational ages of 30 to 41 weeks at birth. We observed a clustering of neutrophil count values below 8000 cells/µL on day three and below 5000 cells/µL on day five. No gender-based differences in counts were observed. We were able to generate reference range curves for neutrophil counts as per gestational age. CONCLUSIONS: The absolute neutrophil counts of term and preterm Indian newborns are higher than the values depicted in the standard reference chart used currently. This indicates that a different standard chart as per gestation should be used in Indo-Asian countries to differentiate 'normal' from 'abnormal'.

13.
J Lipid Res ; 59(10): 1818-1840, 2018 10.
Article in English | MEDLINE | ID: mdl-30139760

ABSTRACT

After crossing floxed stearoyl-CoA desaturase-1 (Scd1fl/fl) mice with LDL receptor-null (ldlr-/-) mice, and then Villin Cre (VilCre) mice, enterocyte Scd1 expression in Scd1fl/fl/ldlr-/-/VilCre mice was reduced 70%. On Western diet (WD), Scd1fl/fl/ldlr-/- mice gained more weight than Scd1fl/fl/ldlr-/-/VilCre mice (P < 0.0023). On WD, jejunum levels of lysophosphatidylcholine (LysoPC) 18:1 and lysophosphatidic acid (LPA) 18:1 were significantly less in Scd1fl/fl/ldlr-/-/VilCre compared with Scd1fl/fl/ldlr-/- mice (P < 0.0004 and P < 0.026, respectively). On WD, Scd1fl/fl/ldlr-/-/VilCre mice compared with Scd1fl/fl/ldlr-/- mice had lower protein levels of lipopolysaccharide-binding protein (LBP), cluster of differentiation 14 (CD14), toll-like receptor 4 (TLR4), and myeloid differentiation factor-88 (MyD88) in enterocytes and plasma, and less dyslipidemia and systemic inflammation. Adding a concentrate of tomatoes transgenic for the apoA-I mimetic peptide 6F (Tg6F) to WD resulted in reduced enterocyte protein levels of LBP, CD14, TLR4, and MyD88 in Scd1fl/fl/ldlr-/- mice similar to that seen in Scd1fl/fl/ldlr-/-/VilCre mice. Adding LysoPC 18:1 to WD did not reverse the effects of enterocyte Scd1 knockdown. Adding LysoPC 18:1 (but not LysoPC 18:0) to chow induced jejunum Scd1 expression and increased dyslipidemia and plasma serum amyloid A and interleukin 6 levels in Scd1fl/fl/ldlr-/- mice, but not in Scd1fl/fl/ldlr-/-/VilCre mice. We conclude that enterocyte Scd1 is partially responsible for LysoPC 18:1- and WD-induced dyslipidemia and inflammation in ldlr-/- mice.


Subject(s)
Enterocytes/enzymology , Gene Deletion , Receptors, LDL/deficiency , Receptors, LDL/genetics , Stearoyl-CoA Desaturase/metabolism , Acute-Phase Proteins/metabolism , Animals , Body Weight , Carrier Proteins/metabolism , Cholesterol, HDL/blood , Dyslipidemias/enzymology , Dyslipidemias/genetics , Dyslipidemias/metabolism , Female , Gene Expression Regulation, Enzymologic , Gene Knockdown Techniques , Jejunum/metabolism , Lipopolysaccharide Receptors/metabolism , Lysophosphatidylcholines/metabolism , Male , Membrane Glycoproteins/metabolism , Mice , Mice, Inbred C57BL , Myeloid Differentiation Factor 88/metabolism , Stearoyl-CoA Desaturase/deficiency , Stearoyl-CoA Desaturase/genetics , Toll-Like Receptor 4/metabolism
14.
Sci Rep ; 8(1): 9032, 2018 06 13.
Article in English | MEDLINE | ID: mdl-29899427

ABSTRACT

Having demonstrated that apolipoprotein A-I (apoA-I) mimetic peptides ameliorate cancer in mouse models, we sought to determine the mechanism for the anti-tumorigenic function of these peptides. CT-26 cells (colon cancer cells that implant and grow into tumors in the lungs) were injected into wild-type BALB/c mice. The day after injection, mice were either continued on chow or switched to chow containing 0.06% of a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F). After four weeks, the number of lung tumors was significantly lower in Tg6F-fed mice. Gene expression array analyses of jejunum and lung identified Notch pathway genes significantly upregulated, whereas osteopontin (Spp1) was significantly downregulated by Tg6F in both jejunum and lung. In jejunum, Tg6F increased protein levels for Notch1, Notch2, Dll1, and Dll4. In lung, Tg6F increased protein levels for Notch1 and Dll4 and decreased Spp1. Tg6F reduced oxidized phospholipid levels (E06 immunoreactivity) and reduced 25-hydroxycholesterol (25-OHC) levels, which are known to inhibit Notch1 and induce Spp1, respectively. Notch pathway promotes anti-tumorigenic patrolling monocytes, while Spp1 facilitates pro-tumorigenic myeloid derived suppressor cells (MDSCs) formation. Tg6F-fed mice had higher numbers of patrolling monocytes in jejunum and in lung (p < 0.02), and lower plasma levels of Spp1 with reduced numbers of MDSCs in jejunum and in lung (p < 0.03). We conclude that Tg6F alters levels of specific oxidized lipids and 25-OHC to modulate Notch pathways and Spp1, which alter small intestine immune cells, leading to similar changes in lung that reduce tumor burden.


Subject(s)
Apolipoprotein A-I/metabolism , Lung Neoplasms/prevention & control , Neoplasms, Experimental/drug therapy , Peptides/pharmacology , Tumor Burden/drug effects , Animals , Apolipoprotein A-I/chemistry , Cell Line, Tumor , Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic/drug effects , Jejunum/drug effects , Jejunum/metabolism , Jejunum/pathology , Lung/drug effects , Lung/metabolism , Lung/pathology , Lung Neoplasms/genetics , Lung Neoplasms/secondary , Mice, Inbred BALB C , Mice, Inbred C57BL , Neoplasms, Experimental/pathology , Receptors, Notch/genetics , Signal Transduction/drug effects , Signal Transduction/genetics , Tumor Burden/genetics
15.
Ann Hematol ; 97(9): 1689-1694, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29740685

ABSTRACT

To study safety, efficacy (hemoglobin and hemoglobin F percentage increment in non-transfusion-dependent patients and decrease in transfusion frequency in transfusion-dependent patients), and determinants of response of decitabine in patients with HbE/ß-thalassemia. Thirty patients of HbE/ß-thalassemia (age > 18 years) were enrolled. Both transfusion-dependent (TDT) and non-transfusion-dependent (NTDT) patients were included after obtaining informed consent. Participants received 0.2 mg/kg of 5-aza-2'-deoxycytidine (decitabine) subcutaneously on 2 consecutive days a week for at least 12 weeks. Complete hemogram was done every 2 weeks and HPLC at every 4-week interval, until 2 months after last dose of drug for response assessment. Various factors like XMN1 polymorphism, IVS 1-5, alpha deletion, alpha triplication, baseline hemoglobin F, and baseline total hemoglobin were evaluated as determinants of response. Mean therapy period was 20.32 weeks. For NTDT group, peak mean increment in hemoglobin was 0.938 g/dl (p value < .001) and hemoglobin F percentage was 9.62% (p value < .001). Transfusion requirement decreased to 0.25 units compared to 0.96 units per patient per month for TDT patients over a period of last 1 year. Common side effects were respiratory tract infection (grade I/II) in three patients, chest tightness in one patient (grade I), and gastric erosion (grade III) in one patient. Decitabine is safe and efficacious in HbE/ß-thalassemia.


Subject(s)
Blood Transfusion , Decitabine/administration & dosage , Fetal Hemoglobin/metabolism , Hemoglobin E/metabolism , beta-Thalassemia/therapy , Adolescent , Adult , Decitabine/adverse effects , Female , Humans , Male , Middle Aged , beta-Thalassemia/blood
16.
J Lipid Res ; 58(8): 1636-1647, 2017 08.
Article in English | MEDLINE | ID: mdl-28592401

ABSTRACT

Feeding LDL receptor (LDLR)-null mice a Western diet (WD) increased the expression of IFN-ß in jejunum as determined by quantitative RT-PCR (RT-qPCR), immunohistochemistry (IHC), and ELISA (all P < 0.0001). WD also increased the expression of cholesterol 25-hydroxylase (CH25H) as measured by RT-qPCR (P < 0.0001), IHC (P = 0.0019), and ELISA (P < 0.0001), resulting in increased levels of 25-hydroxycholesterol (25-OHC) in jejunum as determined by LC-MS/MS (P < 0.0001). Adding ezetimibe at 10 mg/kg/day or adding a concentrate of transgenic tomatoes expressing the 6F peptide (Tg6F) at 0.06% by weight of diet substantially ameliorated these changes. Adding either ezetimibe or Tg6F to WD also ameliorated WD-induced changes in plasma lipids, serum amyloid A, and HDL cholesterol. Adding the same doses of ezetimibe and Tg6F together to WD (combined formulation) was generally more efficacious compared with adding either agent alone. Surprisingly, adding ezetimibe during the preparation of Tg6F, but before addition to WD, was more effective than the combined formulation for all parameters measured in jejunum (P = 0.0329 to P < 0.0001). We conclude the following: i) WD induces IFN-ß, CH25H, and 25-OHC in jejunum; and ii) Tg6F and ezetimibe partially ameliorate WD-induced inflammation by preventing WD-induced increases in IFN-ß, CH25H, and 25-OHC.


Subject(s)
Diet, Western/adverse effects , Ezetimibe/pharmacology , Interferon-beta/metabolism , Jejunum/metabolism , Peptides/genetics , Solanum lycopersicum/genetics , Steroid Hydroxylases/metabolism , Animals , Duodenum/drug effects , Duodenum/metabolism , Dyslipidemias/drug therapy , Dyslipidemias/genetics , Ezetimibe/therapeutic use , Gene Expression , Interferon-alpha/genetics , Interferon-alpha/metabolism , Interferon-beta/genetics , Jejunum/drug effects , Mice , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Messenger/metabolism , Steroid Hydroxylases/genetics
17.
J Lipid Res ; 57(5): 832-47, 2016 05.
Article in English | MEDLINE | ID: mdl-26965826

ABSTRACT

Mouse chow supplemented with lysophosphatidylcholine with oleic acid at sn-1 and a hydroxyl group at sn-2 (LysoPC 18:1) increased LysoPC 18:1 in tissue of the jejunum of LDL receptor (LDLR)-null mice by 8.9 ± 1.7-fold compared with chow alone. Western diet (WD) contained dramatically less phosphatidylcholine 18:1 or LysoPC 18:1 compared with chow, but feeding WD increased LysoPC 18:1 in the jejunum by 7.5 ± 1.4-fold compared with chow. Feeding LysoPC 18:1 or feeding WD increased oxidized phospholipids in the jejunum by 5.2 ± 3.0-fold or 8.6 ± 2.2-fold, respectively, in LDLR-null mice (P < 0.0004), and 2.6 ± 1.5-fold or 2.4 ± 0.92-fold, respectively, in WT C57BL/6J mice (P < 0.0001). Adding 0.06% by weight of a concentrate of transgenic tomatoes expressing the 6F peptide (Tg6F) decreased LysoPC 18:1 in the jejunum of LDLR-null mice on both diets (P < 0.0001), and prevented the increase in oxidized phospholipids in the jejunum in LDLR-null and WT mice on both diets (P < 0.008). Tg6F decreased inflammatory cells in the villi of the jejunum, decreased dyslipidemia, and decreased systemic inflammation in LDLR-null and WT mice on both diets. We conclude that Tg6F reduces diet-induced inflammation by reducing the content of unsaturated LysoPC and oxidized phospholipids in the jejunum of mice.


Subject(s)
Diet, Western/adverse effects , Jejunum/metabolism , Lysophosphatidylcholines/adverse effects , Peptides/administration & dosage , Phospholipids/metabolism , Administration, Oral , Animals , Dyslipidemias/blood , Dyslipidemias/drug therapy , Dyslipidemias/etiology , Enterocytes/metabolism , Female , Jejunum/drug effects , Solanum lycopersicum/chemistry , Solanum lycopersicum/genetics , Lysophosphatidylcholines/blood , Mice, Inbred C57BL , Mice, Knockout , Oxidation-Reduction , Plants, Genetically Modified/chemistry , Plants, Genetically Modified/genetics , Receptors, LDL/genetics
18.
Plant Biotechnol J ; 14(6): 1394-405, 2016 06.
Article in English | MEDLINE | ID: mdl-26798990

ABSTRACT

Soya bean (Glycine max) and grass pea (Lathyrus sativus) seeds are important sources of dietary proteins; however, they also contain antinutritional metabolite oxalic acid (OA). Excess dietary intake of OA leads to nephrolithiasis due to the formation of calcium oxalate crystals in kidneys. Besides, OA is also a known precursor of ß-N-oxalyl-L-α,ß-diaminopropionic acid (ß-ODAP), a neurotoxin found in grass pea. Here, we report the reduction in OA level in soya bean (up to 73%) and grass pea (up to 75%) seeds by constitutive and/or seed-specific expression of an oxalate-degrading enzyme, oxalate decarboxylase (FvOXDC) of Flammulina velutipes. In addition, ß-ODAP level of grass pea seeds was also reduced up to 73%. Reduced OA content was interrelated with the associated increase in seeds micronutrients such as calcium, iron and zinc. Moreover, constitutive expression of FvOXDC led to improved tolerance to the fungal pathogen Sclerotinia sclerotiorum that requires OA during host colonization. Importantly, FvOXDC-expressing soya bean and grass pea plants were similar to the wild type with respect to the morphology and photosynthetic rates, and seed protein pool remained unaltered as revealed by the comparative proteomic analysis. Taken together, these results demonstrated improved seed quality and tolerance to the fungal pathogen in two important legume crops, by the expression of an oxalate-degrading enzyme.


Subject(s)
Carboxy-Lyases/genetics , Disease Resistance/genetics , Glycine max/genetics , Lathyrus/genetics , Nutritive Value/genetics , Oxalic Acid/metabolism , Carboxy-Lyases/metabolism , Carboxy-Lyases/physiology , Flammulina/genetics , Lathyrus/chemistry , Lathyrus/metabolism , Plants, Genetically Modified/metabolism , Seeds/chemistry , Seeds/metabolism , Glycine max/chemistry , Glycine max/metabolism
19.
Pharmacol Res Perspect ; 3(4): e00154, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26171234

ABSTRACT

We previously reported that adding freeze-dried tomato powder from transgenic plants expressing the apolipoprotein A-I mimetic peptide 6F at 2.2% by weight to a Western diet (WD) ameliorated dyslipidemia and atherosclerosis in mice. The same dose in a human would require three cups of tomato powder three times daily. To reduce the volume, we sought a method to concentrate 6F. Remarkably, extracting the transgenic freeze-dried tomato overnight in ethyl acetate with 5% acetic acid resulted in a 37-fold reduction in the amount of transgenic tomato needed for biologic activity. In a mouse model of dyslipidemia, adding 0.06% by weight of the tomato concentrate expressing the 6F peptide (Tg6F) to a WD significantly reduced plasma total cholesterol and triglycerides (P < 0.0065). In a mouse model of colon cancer metastatic to the lungs, adding 0.06% of Tg6F, but not a control tomato concentrate (EV), to standard mouse chow reduced tumor-associated neutrophils by 94 ± 1.1% (P = 0.0052), and reduced tumor burden by two-thirds (P = 0.0371). Adding 0.06% of either EV or Tg6F by weight to standard mouse chow significantly reduced tumor burden in a mouse model of ovarian cancer; however, Tg6F was significantly more effective (35% reduction for EV vs. 53% reduction for Tg6F; P = 0.0069). Providing the same dose of tomato concentrate to humans would require only two tablespoons three times daily making this a practical approach for testing oral apoA-I mimetic therapy in the treatment of dyslipidemia and cancer.

20.
Biofactors ; 41(3): 153-9, 2015 May 06.
Article in English | MEDLINE | ID: mdl-26072738

ABSTRACT

High density lipoprotein (HDL) has long been considered a protective factor against the development of coronary heart disease. Two important roles of HDL include reverse cholesterol transport (RCT) and the modulation of inflammation. The main protein component of HDL; apolipoprotein A-I (apo A-I) is primarily responsible for RCT. Apo A-I can be damaged by oxidative mechanisms, which reduce the protein's ability to promote RCT. In disease states such as diabetes, associated with a chronic acute-phase response, HDL has been found to be dysfunctional and pro-inflammatory. HDL cholesterol levels do not predict composition and/or function and therefore it is important to evaluate the quality and not just the quantity of HDL cholesterol when considering the risk of cardiovascular events. In clinical practice, there are currently no widely available tests for measuring the composition, functionality, and inflammatory properties of HDL. Small peptides that mimic some of the properties of apo A-I have been shown in pre-clinical models to improve HDL function and reduce atherosclerosis without altering HDL cholesterol levels. Clinical trials using HDL and HDL mimetics as therapeutic agents are currently underway. Results in animal studies and early clinical trials will be reviewed.


Subject(s)
Anti-Inflammatory Agents/metabolism , Atherosclerosis/metabolism , Coronary Disease/metabolism , Diabetes Mellitus/metabolism , Lipoproteins, HDL/metabolism , Animals , Anti-Inflammatory Agents/therapeutic use , Apolipoprotein A-I/metabolism , Atherosclerosis/drug therapy , Atherosclerosis/pathology , Biological Transport , Cholesterol/metabolism , Clinical Trials as Topic , Coronary Disease/drug therapy , Coronary Disease/pathology , Diabetes Mellitus/drug therapy , Diabetes Mellitus/pathology , Humans , Inflammation , Lipoproteins, HDL/therapeutic use , Oxidation-Reduction , Peptides/metabolism , Peptides/therapeutic use , Peptidomimetics/metabolism , Peptidomimetics/therapeutic use , Risk Factors
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