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1.
Aging Cell ; 22(2): e13765, 2023 02.
Article in English | MEDLINE | ID: mdl-36633253

ABSTRACT

Genome-wide association studies (GWAS) have validated a strong association of atherosclerosis with the CDKN2A/B locus, a locus harboring three tumor suppressor genes: p14ARF , p15INK4b , and p16INK4a . Post-GWAS functional analysis reveals that CUX is a transcriptional activator of p16INK4a via its specific binding to a functional SNP (fSNP) rs1537371 on the atherosclerosis-associated CDKN2A/B locus, regulating endothelial senescence. In this work, we characterize SATB2, another transcription factor that specifically binds to rs1537371. We demonstrate that even though both CUX1 and SATB2 are the homeodomain transcription factors, unlike CUX1, SATB2 is a transcriptional suppressor of p16INK4a and overexpression of SATB2 competes with CUX1 for its binding to rs1537371, which inhibits p16INK4a and p16INK4a -dependent cellular senescence in human endothelial cells (ECs). Surprisingly, we discovered that SATB2 expression is transcriptionally repressed by CUX1. Therefore, upregulation of CUX1 inhibits SATB2 expression, which enhances the binding of CUX1 to rs1537371 and subsequently fine-tunes p16INK4a expression. Remarkably, we also demonstrate that IL-1ß, a senescence-associated secretory phenotype (SASP) gene itself and a biomarker for atherosclerosis, induces cellular senescence also by upregulating CUX1 and/or downregulating SATB2 in human ECs. A model is proposed to reconcile our findings showing how both primary and secondary senescence are activated via the atherosclerosis-associated p16INK4a expression.


Subject(s)
Atherosclerosis , Matrix Attachment Region Binding Proteins , Humans , Atherosclerosis/genetics , Cellular Senescence/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Endothelial Cells/metabolism , Genome-Wide Association Study , Homeodomain Proteins/genetics , Matrix Attachment Region Binding Proteins/genetics , Phenotype , Repressor Proteins/genetics , Transcription Factors/genetics , Interferon beta-1b/pharmacology
2.
J Physiol ; 601(11): 2099-2120, 2023 06.
Article in English | MEDLINE | ID: mdl-35661362

ABSTRACT

Visceral adipose tissue (VAT) is a metabolic organ known to regulate fat mass, and glucose and nutrient homeostasis. VAT is an active endocrine gland that synthesizes and secretes numerous bioactive mediators called 'adipocytokines/adipokines' into systemic circulation. These adipocytokines act on organs of metabolic importance like the liver and skeletal muscle. Multiple preclinical and in vitro studies showed strong evidence of the roles of adipocytokines in the regulation of metabolic disorders like diabetes, obesity and insulin resistance. Adipocytokines, such as adiponectin and omentin, are anti-inflammatory and have been shown to prevent atherogenesis by increasing nitric oxide (NO) production by the endothelium, suppressing endothelium-derived inflammation and decreasing foam cell formation. By inhibiting differentiation of vascular smooth muscle cells (VSMC) into osteoblasts, adiponectin and omentin prevent vascular calcification. On the other hand, adipocytokines like leptin and resistin induce inflammation and endothelial dysfunction that leads to vasoconstriction. By promoting VSMC migration and proliferation, extracellular matrix degradation and inflammatory polarization of macrophages, leptin and resistin increase the risk of atherosclerotic plaque vulnerability and rupture. Additionally, the plasma concentrations of these adipocytokines alter in ageing, rendering older humans vulnerable to cardiovascular disease. The disturbances in the normal physiological concentrations of these adipocytokines secreted by VAT under pathological conditions impede the normal functions of various organs and affect cardiovascular health. These adipokines could be used for both diagnostic and therapeutic purposes in cardiovascular disease.


Subject(s)
Cardiovascular Diseases , Leptin , Humans , Resistin/metabolism , Adiponectin/metabolism , Cardiovascular Diseases/metabolism , Intra-Abdominal Fat/metabolism , Adipokines/metabolism , Inflammation/metabolism , Adipose Tissue/metabolism
3.
Front Immunol ; 13: 882484, 2022.
Article in English | MEDLINE | ID: mdl-35634304

ABSTRACT

Although it is well known that hypoxia incites unleashed cellular inflammation, the mechanisms of exaggerated cellular inflammation in hypoxic conditions are not known. We observed augmented proliferation of hematopoietic stem and progenitor cells (HSPC), precursors of inflammatory leukocytes, in mice under hypoxia. Consistently, a transcriptomic analysis of human HSPC exposed to hypoxic conditions revealed elevated expression of genes involved in progenitor proliferation and differentiation. Additionally, bone marrow cells in mice expressed high amount of vascular endothelial growth factor (VEGF), and HSPC elevated VEGF receptor 1 (VEGFr1) and its target genes in hypoxic conditions. In line with this, VEGFr1 blockade in vivo and in vitro decreased HSPC proliferation and attenuated inflammation. In silico and ChIP experiments demonstrated that HIF-1α binds to the promoter region of VEGFR1. Correspondingly, HIF1a silencing decreased VEGFr1 expression in HSPC and diminished their proliferation. These results indicate that VEGF signaling in HSPC is an important mediator of their proliferation and differentiation in hypoxia-induced inflammation and represents a potential therapeutic target to prevent aberrant inflammation in hypoxia-associated diseases.


Subject(s)
Hematopoietic Stem Cells , Hypoxia , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factor Receptor-1 , Animals , Cell Differentiation/genetics , Cell Proliferation/genetics , Hematopoietic Stem Cells/cytology , Humans , Hypoxia/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Inflammation , Mice , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor Receptor-1/genetics , Vascular Endothelial Growth Factor Receptor-1/metabolism
4.
Nat Aging ; 2(2): 140-154, 2022 02.
Article in English | MEDLINE | ID: mdl-37117763

ABSTRACT

Accumulation of senescent cells with age is an important driver of aging and age-related diseases. However, the mechanisms and signaling pathways that regulate senescence remain elusive. In this report, we performed post-genome-wide association studies (GWAS) functional studies on the CDKN2A/B locus, a locus known to be associated with multiple age-related diseases and overall human lifespan. We demonstrate that transcription factor CUX1 (Cut-Like Homeobox 1) specifically binds to an atherosclerosis-associated functional single-nucleotide polymorphism (fSNP) (rs1537371) within the locus and regulates the CDKN2A/B-encoded proteins p14ARF, p15INK4b and p16INK4a and the antisense noncoding RNA in the CDK4 (INK4) locus (ANRIL) in endothelial cells (ECs). Endothelial CUX1 expression correlates with telomeric length and is induced by both DNA-damaging agents and oxidative stress. Moreover, induction of CUX1 expression triggers both replicative and stress-induced senescence via activation of p16INK4a expression. Thus, our studies identify CUX1 as a regulator of p16INK4a-dependent endothelial senescence and a potential therapeutic target for atherosclerosis and other age-related diseases.


Subject(s)
Atherosclerosis , Cyclin-Dependent Kinase Inhibitor p16 , Humans , Atherosclerosis/genetics , Cellular Senescence/genetics , Cyclin-Dependent Kinase Inhibitor p15/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , Endothelial Cells/metabolism , Genome-Wide Association Study , Homeodomain Proteins/genetics , Repressor Proteins/genetics , Transcription Factors/genetics
5.
Cell Mol Immunol ; 18(2): 374-384, 2021 02.
Article in English | MEDLINE | ID: mdl-33420357

ABSTRACT

Myeloid cells, such as neutrophils, are produced in the bone marrow in high quantities and are important in the pathogenesis of vascular diseases such as pulmonary hypertension (PH). Although neutrophil recruitment into sites of inflammation has been well studied, the mechanisms of neutrophil egress from the bone marrow are not well understood. Using computational flow cytometry, we observed increased neutrophils in the lungs of patients and mice with PH. Moreover, we found elevated levels of IL-6 in the blood and lungs of patients and mice with PH. We observed that transgenic mice overexpressing Il-6 in the lungs displayed elevated neutrophil egress from the bone marrow and exaggerated neutrophil recruitment to the lungs, resulting in exacerbated pulmonary vascular remodeling, and dysfunctional hemodynamics. Mechanistically, we found that IL-6-induced neutrophil egress from the bone marrow was dependent on interferon regulatory factor 4 (IRF-4)-mediated CX3CR1 expression in neutrophils. Consequently, Cx3cr1 genetic deficiency in hematopoietic cells in Il-6-transgenic mice significantly reduced neutrophil egress from bone marrow and decreased neutrophil counts in the lungs, thus ameliorating pulmonary remodeling and hemodynamics. In summary, these findings define a novel mechanism of IL-6-induced neutrophil egress from the bone marrow and reveal a new therapeutic target to curtail neutrophil-mediated inflammation in pulmonary vascular disease.


Subject(s)
Bone Marrow Cells/pathology , Hypertension, Pulmonary/pathology , Inflammation/complications , Interleukin-6/metabolism , Lung/pathology , Neutrophil Infiltration , Neutrophils/immunology , Animals , Bone Marrow Cells/immunology , Bone Marrow Cells/metabolism , Female , Hypertension, Pulmonary/immunology , Hypertension, Pulmonary/metabolism , Inflammation/immunology , Inflammation/pathology , Interleukin-6/genetics , Lung/immunology , Lung/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic
6.
Sci Transl Med ; 12(553)2020 07 22.
Article in English | MEDLINE | ID: mdl-32718989

ABSTRACT

Patients with insulin resistance have high risk of cardiovascular disease such as myocardial infarction (MI). However, it is not known whether MI can initiate or aggravate insulin resistance. We observed that patients with ST-elevation MI and mice with MI had de novo hyperglycemia and features of insulin resistance, respectively. In mouse models of both myocardial and skeletal muscle injury, we observed that the number of visceral adipose tissue (VAT)-resident macrophages decreased because of apoptosis after these distant organ injuries. Patients displayed a similar decrease in VAT-resident macrophage numbers and developed systemic insulin resistance after ST-elevation MI. Loss of VAT-resident macrophages after MI injury led to systemic insulin resistance in non-diabetic mice. Danger signaling-associated protein high mobility group box 1 was released by the dead myocardium after MI in rodents and triggered macrophage apoptosis via Toll-like receptor 4. The VAT-resident macrophage population in the steady state in mice was transcriptomically distinct from macrophages in the brain, skin, kidney, bone marrow, lungs, and liver and was derived from hematopoietic progenitor cells just after birth. Mechanistically, VAT-resident macrophage apoptosis and de novo insulin resistance in mouse models of MI were linked to diminished concentrations of macrophage colony-stimulating factor and adiponectin. Collectively, these findings demonstrate a previously unappreciated role of adipose tissue-resident macrophages in sensing remote organ injury and promoting MI pathogenesis.


Subject(s)
Hematopoietic Stem Cell Transplantation , Insulin Resistance , Myocardial Infarction , Adipose Tissue , Animals , Apoptosis , Humans , Macrophages , Mice , Mice, Inbred C57BL
7.
Circulation ; 142(3): 244-258, 2020 07 21.
Article in English | MEDLINE | ID: mdl-32316750

ABSTRACT

BACKGROUND: Diabetes mellitus is a prevalent public health problem that affects about one-third of the US population and leads to serious vascular complications with increased risk for coronary artery disease. How bone marrow hematopoiesis contributes to diabetes mellitus complications is incompletely understood. We investigated the role of bone marrow endothelial cells in diabetic regulation of inflammatory myeloid cell production. METHODS: In 3 types of mouse diabetes mellitus, including streptozotocin, high-fat diet, and genetic induction using leptin-receptor-deficient db/db mice, we assayed leukocytes, hematopoietic stem and progenitor cells (HSPC). In addition, we investigated bone marrow endothelial cells with flow cytometry and expression profiling. RESULTS: In diabetes mellitus, we observed enhanced proliferation of HSPC leading to augmented circulating myeloid cell numbers. Analysis of bone marrow niche cells revealed that endothelial cells in diabetic mice expressed less Cxcl12, a retention factor promoting HSPC quiescence. Transcriptome-wide analysis of bone marrow endothelial cells demonstrated enrichment of genes involved in epithelial growth factor receptor (Egfr) signaling in mice with diet-induced diabetes mellitus. To explore whether endothelial Egfr plays a functional role in myelopoiesis, we generated mice with endothelial-specific deletion of Egfr (Cdh5CreEgfrfl/fl). We found enhanced HSPC proliferation and increased myeloid cell production in Cdh5CreEgfrfl/fl mice compared with wild-type mice with diabetes mellitus. Disrupted Egfr signaling in endothelial cells decreased their expression of the HSPC retention factor angiopoietin-1. We tested the functional relevance of these findings for wound healing and atherosclerosis, both implicated in complications of diabetes mellitus. Inflammatory myeloid cells accumulated more in skin wounds of diabetic Cdh5CreEgfrfl/fl mice, significantly delaying wound closure. Atherosclerosis was accelerated in Cdh5CreEgfrfl/fl mice, leading to larger and more inflamed atherosclerotic lesions in the aorta. CONCLUSIONS: In diabetes mellitus, bone marrow endothelial cells participate in the dysregulation of bone marrow hematopoiesis. Diabetes mellitus reduces endothelial production of Cxcl12, a quiescence-promoting niche factor that reduces stem cell proliferation. We describe a previously unknown counterregulatory pathway, in which protective endothelial Egfr signaling curbs HSPC proliferation and myeloid cell production.


Subject(s)
Bone Marrow Cells/metabolism , Endothelial Cells/metabolism , Myelopoiesis , Animals , Diabetes Mellitus, Experimental , Disease Models, Animal , Epidermal Growth Factor/metabolism , ErbB Receptors/metabolism , Gene Expression Profiling , Gene Expression Regulation , Male , Mice , Models, Biological , Myeloid Cells/metabolism , Myelopoiesis/genetics , Signal Transduction , Transcriptome
8.
Immunity ; 49(1): 93-106.e7, 2018 07 17.
Article in English | MEDLINE | ID: mdl-29958804

ABSTRACT

There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the ß2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.


Subject(s)
Diabetes Mellitus/physiopathology , Granulocyte-Macrophage Progenitor Cells/cytology , Granulocyte-Macrophage Progenitor Cells/metabolism , Myelopoiesis , Neuroimmunomodulation , Sympathetic Nervous System/metabolism , Adrenergic beta-2 Receptor Antagonists/pharmacology , Animals , Cell Proliferation/drug effects , Diabetes Mellitus/blood , Disease Models, Animal , Female , Humans , Leukocytes/enzymology , Leukocytes/metabolism , Male , Mice , Myeloid Cells/cytology , Myelopoiesis/drug effects , Neuroimmunomodulation/drug effects , Norepinephrine/blood , Signal Transduction/drug effects , Spleen/cytology , Spleen/innervation , Spleen/metabolism , Sympathetic Nervous System/drug effects
9.
J Immunol ; 200(10): 3612-3625, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29632145

ABSTRACT

Pulmonary inflammation, which is characterized by the presence of perivascular macrophages, has been proposed as a key pathogenic driver of pulmonary hypertension (PH), a vascular disease with increasing global significance. However, the mechanisms of expansion of lung macrophages and the role of blood-borne monocytes in PH are poorly understood. Using multicolor flow cytometric analysis of blood in mouse and rat models of PH and patients with PH, an increase in blood monocytes was observed. In parallel, lung tissue displayed increased chemokine transcript expression, including those responsible for monocyte recruitment, such as Ccl2 and Cx3cl1, accompanied by an expansion of interstitial lung macrophages. These data indicate that blood monocytes are recruited to lung perivascular spaces and differentiate into inflammatory macrophages. Correspondingly, parabiosis between congenically different hypoxic mice demonstrated that most interstitial macrophages originated from blood monocytes. To define the actions of these cells in PH in vivo, we reduced blood monocyte numbers via genetic deficiency of cx3cr1 or ccr2 in chronically hypoxic male mice and by pharmacologic inhibition of Cx3cl1 in monocrotaline-exposed rats. Both models exhibited decreased inflammatory blood monocytes, as well as interstitial macrophages, leading to a substantial decrease in arteriolar remodeling but with a less robust hemodynamic effect. This study defines a direct mechanism by which interstitial macrophages expand in PH. It also demonstrates a pathway for pulmonary vascular remodeling in PH that depends upon interstitial macrophage-dependent inflammation yet is dissociated, at least in part, from hemodynamic consequences, thus offering guidance on future anti-inflammatory therapeutic strategies in this disease.


Subject(s)
Hypertension, Pulmonary/pathology , Macrophages, Alveolar/pathology , Monocytes/pathology , Pneumonia/pathology , Animals , Chemokine CCL2/metabolism , Humans , Hypertension, Pulmonary/metabolism , Lung/metabolism , Lung/pathology , Macrophages, Alveolar/metabolism , Male , Mice , Mice, Inbred C57BL , Monocytes/metabolism , Pneumonia/metabolism , Rats , Rats, Sprague-Dawley , Receptors, CCR2/metabolism
10.
Immunol Cell Biol ; 2018 Mar 11.
Article in English | MEDLINE | ID: mdl-29526053

ABSTRACT

Splenic hematopoiesis is crucial to the pathogenesis of diseases including myocardial infarction and atherosclerosis. The spleen acts as a reservoir of myeloid cells, which are quickly expelled out in response to acute inflammation. In contrast to the well-defined bone marrow hematopoiesis, the cellular and molecular components sustaining splenic hematopoiesis are poorly understood. Surprisingly, we found that, unlike quiescent bone marrow hematopoietic stem cells (HSC), most of splenic HSC are in the G1 phase in C57BL/6 mice. Moreover, splenic HSC were enriched for genes involved in G0-G1 transition and expressed lower levels of genes responsible for G1-S transition. These data indicate that, at steady state, splenic HSC are pre-activated, which may expedite their cell cycle entry in emergency conditions. Consistently, in the acute phase of septic shock induced by LPS injection, splenic HSC entered the S-G2-M phase, whereas bone marrow HSC did not. Mobilization and transplantation experiments displayed that bone marrow HSC, once in the spleen, acquired cell cycle status similar to splenic HSC, strongly suggesting that the splenic microenvironment plays an important role in HSC pre-activation. In addition, we found that myeloid translocation gene 16 (Mtg16) deficiency in C57BL/6 mice resulted in significantly increased S-G2-M entry of splenic but not bone marrow HSC, suggesting that Mtg16 is an intrinsic negative regulator of G1-S transition in splenic HSC. Altogether, this study demonstrates that compared to bone marrow, splenic HSC are in a pre-activated state, which is driven by extracellular signals provided by splenic microenvironment and HSC intrinsic factor Mtg16.

11.
Free Radic Biol Med ; 96: 392-405, 2016 07.
Article in English | MEDLINE | ID: mdl-27156686

ABSTRACT

Monocyte-to-macrophage differentiation promotes an inflammatory environment within the arterial vessel wall that causes a mal-adaptive immune response, which contributes to the progression of atheromatous plaque formation. In the current study, we show that resveratrol, a well-known antioxidant, dose-dependently attenuated phorbol myristate acetate (PMA)-induced monocyte-to-macrophage differentiation, as measured by cell adhesion, increase in cell size, and scavenger receptor expression in THP-1 monocytes. Also, resveratrol significantly inhibited PMA-induced pro-inflammatory cytokine/chemokine and matrix metalloprotease (MMP-9) production. This inhibitory effect of resveratrol on monocyte differentiation results from its ability to restore intracellular glutathione (GSH) status, as resveratrol in the presence of buthionine sulfoximine (BSO) failed to affect monocyte differentiation. Furthermore, PMA-induced monocyte differentiation and inflammation was greatly inhibited when cells were co-treated with N-Acetyl-l-cysteine (NAC), a GSH precursor, while the presence of BSO aggravated these processes. These results also show that resveratrol mediated up-regulation of GSH is due to AMP-activated protein kinase (AMPK)-α activation, as compound C (AMPK inhibitor) treatment drastically depleted intracellular GSH and exacerbated PMA-induced monocyte differentiation and pro-inflammatory cytokine production. More importantly, chronic administration of resveratrol efficiently prevented monocyte infiltration and markedly diminished angiotensin (Ang)-II-induced atheromatous plaque formation in apolipoprotein-E knockout (ApoE(-/-)) mice. We conclude that, intracellular GSH status plays a critical role in regulating monocyte-to-macrophage differentiation and inflammation and resveratrol, by restoring GSH levels, inhibits these processes. Taken together, these results suggest that resveratrol can attenuate atherosclerosis, at least, in part, by inhibiting monocyte differentiation and pro-inflammatory cytokines production.


Subject(s)
Atherosclerosis/drug therapy , Glutathione/metabolism , Inflammation/drug therapy , Stilbenes/administration & dosage , AMP-Activated Protein Kinases/metabolism , Acetylcysteine/administration & dosage , Animals , Antioxidants/administration & dosage , Apolipoproteins E/genetics , Atherosclerosis/metabolism , Atherosclerosis/pathology , Buthionine Sulfoximine/administration & dosage , Cell Differentiation/drug effects , Homeostasis/drug effects , Humans , Inflammation/chemically induced , Inflammation/metabolism , Inflammation/pathology , Macrophages/drug effects , Matrix Metalloproteinase 9/biosynthesis , Mice , Mice, Knockout , Monocytes/drug effects , Resveratrol , Stilbenes/antagonists & inhibitors , Tetradecanoylphorbol Acetate/administration & dosage
12.
Sci Rep ; 6: 24108, 2016 Apr 11.
Article in English | MEDLINE | ID: mdl-27063143

ABSTRACT

Mitochondria-targeted compounds are emerging as a new class of drugs that can potentially alter the pathophysiology of those diseases where mitochondrial dysfunction plays a critical role. We have synthesized a novel mitochondria-targeted esculetin (Mito-Esc) with an aim to investigate its effect during oxidative stress-induced endothelial cell death and angiotensin (Ang)-II-induced atherosclerosis in ApoE(-/-) mice. Mito-Esc but not natural esculetin treatment significantly inhibited H2O2- and Ang-II-induced cell death in human aortic endothelial cells by enhancing NO production via AMPK-mediated eNOS phosphorylation. While L-NAME (NOS inhibitor) significantly abrogated Mito-Esc-mediated protective effects, Compound c (inhibitor of AMPK) significantly decreased Mito-Esc-mediated increase in NO production. Notably, Mito-Esc promoted mitochondrial biogenesis by enhancing SIRT3 expression through AMPK activation; and restored H2O2-induced inhibition of mitochondrial respiration. siSIRT3 treatment not only completely reversed Mito-Esc-mediated mitochondrial biogenetic marker expressions but also caused endothelial cell death. Furthermore, Mito-Esc administration to ApoE(-/-) mice greatly alleviated Ang-II-induced atheromatous plaque formation, monocyte infiltration and serum pro-inflammatory cytokines levels. We conclude that Mito-Esc is preferentially taken up by the mitochondria and preserves endothelial cell survival during oxidative stress by modulating NO generation via AMPK. Also, Mito-Esc-induced SIRT3 plays a pivotal role in mediating mitochondrial biogenesis and perhaps contributes to its anti-atherogenic effects.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Antioxidants/pharmacology , Mitochondria/drug effects , Mitochondria/metabolism , Nitric Oxide/metabolism , Sirtuin 3/metabolism , Umbelliferones/pharmacology , AMP-Activated Protein Kinases/antagonists & inhibitors , Angiotensin II/toxicity , Animals , Antioxidants/therapeutic use , Aorta/cytology , Aorta/pathology , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Apoptosis/drug effects , Atherosclerosis/drug therapy , Atherosclerosis/etiology , Atherosclerosis/metabolism , Cell Survival/drug effects , Cells, Cultured , Endothelial Cells/cytology , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Humans , Hydrogen Peroxide/toxicity , Male , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, Knockout , Microscopy, Confocal , NG-Nitroarginine Methyl Ester/toxicity , Nitric Oxide Synthase Type III/antagonists & inhibitors , Nitric Oxide Synthase Type III/metabolism , Oxidative Stress/drug effects , Oxygen Consumption/drug effects , Phosphorylation/drug effects , RNA Interference , RNA, Small Interfering/metabolism , Sirtuin 3/antagonists & inhibitors , Sirtuin 3/genetics , Umbelliferones/chemistry , Umbelliferones/therapeutic use
13.
Bioorg Med Chem Lett ; 26(3): 858-863, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-26748696

ABSTRACT

An efficient three-component protocol is described for the synthesis of benzo[6,7]cyclohepta[1,2-b]pyridine derivatives using ß-chloroacroleins, 1,3-dicarbonyls and ammonium acetate under catalyst free conditions by using ethanol as reaction media. The mild reaction conditions, operational simplicity and high yields are the advantages of this protocol and the broad scope of this one-pot reaction makes this procedure promising for practical usages. All the final compounds were screened for anti-inflammatory activity. Among the compounds tested, the compounds 5a, 5b, 5c, 5d, 5f, and 5k exhibited significant inhibition of IL-1ß and MCP-1 secretion as a measure of anti-inflammatory activity.


Subject(s)
Anti-Inflammatory Agents/chemistry , Pyridines/chemistry , Anti-Inflammatory Agents/chemical synthesis , Anti-Inflammatory Agents/pharmacology , Cell Line, Tumor , Chemokine CCL2/metabolism , Coumarins/chemistry , Crystallography, X-Ray , Humans , Interleukin-1beta/metabolism , Molecular Conformation , Monocytes/drug effects , Monocytes/metabolism , Pyridines/chemical synthesis
14.
Diabetes ; 64(6): 2028-41, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25552600

ABSTRACT

Monocyte-to-macrophage differentiation is a critical event that accentuates atherosclerosis by promoting an inflammatory environment within the vessel wall. In this study, we investigated the molecular mechanisms responsible for monocyte-to-macrophage differentiation and, subsequently, the effect of metformin in regressing angiotensin II (Ang-II)-mediated atheromatous plaque formation in ApoE(-/-) mice. AMPK activity was dose and time dependently downregulated during phorbol myristate acetate (PMA)-induced monocyte-to-macrophage differentiation, which was accompanied by an upregulation of proinflammatory cytokine production. Of note, AMPK activators metformin and AICAR significantly attenuated PMA-induced monocyte-to-macrophage differentiation and proinflammatory cytokine production. However, inhibition of AMPK activity alone by compound C was ineffective in promoting monocyte-to-macrophage differentiation in the absence of PMA. On the other hand, inhibition of c-Jun N-terminal kinase activity inhibited PMA-induced inflammation but not differentiation, suggesting that inflammation and differentiation are independent events. In contrast, inhibition of STAT3 activity inhibited both inflammation and monocyte-to-macrophage differentiation. By decreasing STAT3 phosphorylation, metformin and AICAR through increased AMPK activation caused inhibition of monocyte-to-macrophage differentiation. Metformin attenuated Ang-II-induced atheromatous plaque formation and aortic aneurysm in ApoE(-/-) mice partly by reducing monocyte infiltration. We conclude that the AMPK-STAT3 axis plays a pivotal role in regulating monocyte-to-macrophage differentiation and that by decreasing STAT3 phosphorylation through increased AMPK activity, AMPK activators inhibit monocyte-to-macrophage differentiation.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Atherosclerosis/metabolism , Macrophages/cytology , Macrophages/drug effects , Metformin/pharmacology , Metformin/therapeutic use , Monocytes/cytology , Monocytes/drug effects , STAT3 Transcription Factor/metabolism , Animals , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Atherosclerosis/drug therapy , Cell Differentiation/drug effects , Male , Mice , Mice, Knockout , Polymethacrylic Acids/pharmacology
15.
FEBS J ; 281(16): 3719-38, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24964743

ABSTRACT

Accumulating evidence from in vitro, in vivo, clinical and epidemiological studies shows promising results for the use of statins against many cancers including breast carcinoma. However, the molecular mechanisms responsible for the anti-proliferative and anti-invasive properties of statins still remain elusive. In this study, we investigated the involvement of nitric oxide, iron homeostasis and antioxidant defence mechanisms in mediating the anti-proliferative and anti-invasive properties of hydrophobic statins in MDA-MB-231, MDA-MB-453 and BT-549 metastatic triple negative breast cancer cells. Fluvastatin and simvastatin significantly increased cytotoxicity which was reversed with mevalonate. Interestingly, fluvastatin downregulated transferrin receptor (TfR1), with a concomitant depletion of intracellular iron levels in these cells. Statin-induced effects were mimicked by geranylgeranyl transferase inhibitor (GGTI-298) but not farnesyl transferase inhibitor (FTI-277). Further, it was observed that TfR1 downregulation is mediated by increased nitric oxide levels via inducible nitric oxide synthase (iNOS) expression. NOS inhibitors (asymmetric dimethylarginine and 1400W) counteracted and sepiapterin, a precursor of tetrahydrobiopterin, exacerbated statin-induced depletion of intracellular iron levels. Notably, fluvastatin increased manganese superoxide dismutase (by repressing the transcription factor DNA damage-binding protein 2), catalase and glutathione which, in turn, diminished H2 O2 levels. Fluvastatin-induced downregulation of TfR1, matrix metalloproteinase-2, -9 and inhibition of invasion were reversed in the presence of aminotriazole, a specific inhibitor of catalase. Finally, we conclude that fluvastatin, by altering iron homeostasis, nitric oxide generation and antioxidant defence mechanisms, induces triple negative breast cancer cell death.


Subject(s)
Antineoplastic Agents/pharmacology , Antioxidants/metabolism , Cell Proliferation/drug effects , Fatty Acids, Monounsaturated/pharmacology , Indoles/pharmacology , Iron/metabolism , Nitric Oxide/metabolism , Simvastatin/pharmacology , Antigens, CD/genetics , Antigens, CD/metabolism , Apoptosis , Biological Transport/drug effects , Cell Line, Tumor , Down-Regulation/drug effects , Drug Screening Assays, Antitumor , Female , Fluvastatin , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hydrogen Peroxide/metabolism , Mevalonic Acid/pharmacology , Nitric Oxide Synthase Type II/metabolism , Receptors, Transferrin/genetics , Receptors, Transferrin/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Transcription, Genetic , Triple Negative Breast Neoplasms
16.
Eur J Med Chem ; 80: 184-91, 2014 Jun 10.
Article in English | MEDLINE | ID: mdl-24780595

ABSTRACT

A series of novel 1,2,3-triazole substituted N-phenyl nitrone derivatives 5a-e were prepared in three steps starting from 1-substituted-1,2,3-triazole-4-carbaldehydes 2 via Schiff's base formation, reduction followed by oxidation. Similarly, 1,2,3-triazole substituted N-alkyl nitrone derivatives 6a-p were prepared in single step starting from compound 2 on reaction with N-alkyl hydroxylamine hydrochlorides. All the final compounds were screened for anti-inflammatory and anticancer activity against various cancer cell lines. Among the compounds tested, the compounds 5a, 5d, 6a, 6b, 6m and 6o exhibited significant inhibition of IL-1ß secretion as a measure of anti-inflammatory activity. Compound 5b, 5c, 6h, 6i and 6o exhibited significant activity against all the cell lines (A549, COLO 205, MDA-MB 231 and PC-3) at IC50 values of <15 µM.


Subject(s)
Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Nitrogen Oxides/chemistry , Nitrogen Oxides/pharmacology , Triazoles/chemistry , Anti-Inflammatory Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Cell Line, Tumor , Cell Survival/drug effects , Chemistry Techniques, Synthetic , Humans , Inhibitory Concentration 50 , Nitrogen Oxides/chemical synthesis
17.
Eur J Med Chem ; 75: 143-50, 2014 Mar 21.
Article in English | MEDLINE | ID: mdl-24531227

ABSTRACT

A series of novel 1,2-benzothiazine 1,1-dioxide-3-ethanone oxime N-aryl acetamide ether derivatives 7a-h and 9a-h were synthesized starting from sodium salt of saccharin 1 in series of steps. Final compounds 7a-h and 9a-h were evaluated for the anti-inflammatory activity and their ability to inhibit monocyte-to-macrophage transformation. Compounds 7e, 9b, 9e and 9h showed impressive anti-inflammatory activities (TNF-α, IL-8 and MCP-1) at micro molar concentration which was found to be better than positive control i.e., piroxicam. Compound 9e marginally and compound 9h significantly inhibited PMA-induced MMP-9 gelatinase activity. Also compounds 9e and 9h greatly inhibited the PMA-induced monocyte-to-macrophage transformation, a pre-requisite step in the formation of atheroma.


Subject(s)
Acetamides/pharmacology , Anti-Inflammatory Agents/pharmacology , Macrophages/drug effects , Monocytes/drug effects , Oximes/pharmacology , Acetamides/chemical synthesis , Acetamides/chemistry , Anti-Inflammatory Agents/chemical synthesis , Anti-Inflammatory Agents/chemistry , Cell Line , Ethers/chemical synthesis , Ethers/chemistry , Ethers/pharmacology , Humans , Interleukin-8/immunology , Macrophages/immunology , Matrix Metalloproteinase 9/immunology , Models, Molecular , Monocytes/immunology , Oximes/chemical synthesis , Oximes/chemistry , Tumor Necrosis Factor-alpha/immunology
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