Publications by authors named "Rohan Kulkarni"

35 Publications

Structural Remodeling of the Extracellular Matrix in Arteriogenesis: A Review.

Front Cardiovasc Med 2021 5;8:761007. Epub 2021 Nov 5.

Division of Vascular Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, United States.

Lower extremity arterial occlusive disease (AOD) results in significant morbidity and mortality for the population, with up to 10% of patients ultimately requiring amputation. An alternative method for non-surgical revascularization which is yet to be fully understood is the optimization of the body's own natural collateral arterial network in a process known as arteriogenesis. Under conditions of conductance vessel stenosis or occlusion resulting in increased flow, shear forces, and pressure gradients within collaterals, positive remodeling occurs to increase the diameter and capacity of these vessels. The creation of a distal arteriovenous fistula (AVF) will drive increased arteriogenesis as compared to collateral formation with the occlusion of a conductance vessel alone by further increasing flow through these arterioles, demonstrating the capacity for arteriogenesis to form larger, more efficient collaterals beyond what is spontaneously achieved after arterial occlusion. Arteries rely on an extracellular matrix (ECM) composed of elastic fibers and collagens that provide stability under hemodynamic stress, and ECM remodeling is necessary to allow for increased diameter and flow conductance in mature arterial structures. When positive remodeling occurs, digestion of lamella and the internal elastic lamina (IEL) by matrix metalloproteinases (MMPs) and other elastases results in the rearrangement and thinning of elastic structures and may be replaced with disordered elastin synthesis without recovery of elastic function. This results in transmission of wall strain to collagen and potential for aneurysmal degeneration along collateral networks, as is seen in the pancreaticoduodenal artery (PDA) after celiac occlusion and inferior mesenteric artery (IMA) with concurrent celiac and superior mesenteric artery (SMA) occlusions. Further understanding into the development of collaterals is required to both better understand aneurysmal degeneration and optimize collateral formation in AOD.
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http://dx.doi.org/10.3389/fcvm.2021.761007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8602576PMC
November 2021

Modulating endothelial cells with EGFL7 to diminish aGVHD after allogeneic bone marrow transplantation in mice.

Blood Adv 2021 Oct 15. Epub 2021 Oct 15.

Hopital Maisonneuve-Rosemont, Canada.

Acute graft versus host (aGVHD) is the second cause of death after allogeneic-hematopoietic stem cell transplant (allo-HSCT) underscoring the need for novel therapies. Based on previous work that endothelial cell dysfunction is present in aGVHD and that epidermal growth factor-like domain 7 (EGFL7) plays a significant role in decreasing inflammation by repressing endothelial cell activation and T cell migration, we hypothesized that increasing EGFL7 levels after allo-HSCT will diminish the severity of aGVHD. Here, we show that treatment with recombinant EGFL7 (rEGFL7) in two different murine models of aGVHD decreases aGVHD severity and improves survival in recipient mice after allogeneic transplantation with respect to controls without affecting graft versus leukemia effect. Furthermore, we showed that rEGFL7 treatment results in higher thymocytes, T, B and dendritic cells in recipient mice after allo-HSCT. This study constitutes a proof of concept of the ability of rEGFL7 therapy to reduce GHVD severity and mortality after allo-HSCT.
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http://dx.doi.org/10.1182/bloodadvances.2021005498DOI Listing
October 2021

Three cases of acute venous thromboembolism in females after vaccination for coronavirus disease 2019.

J Vasc Surg Venous Lymphat Disord 2021 Aug 2. Epub 2021 Aug 2.

Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pa.

Since December 2020, four vaccines for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) have been developed, and three have been approved for immediate use in the United States. Two are mRNA vaccines, and one uses a viral vector mechanism. Thrombotic complications have been reported after vaccine administration, which were primarily cerebral sinus thromboses after administration of the viral vector vaccines. To the best of our knowledge, we are the first to report venous thrombotic complications within days of administration of the mRNA-1273 (Moderna) vaccine. We present a series of three women who developed venous thromboembolism after RNA-1273 vaccination at a single healthcare system.
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http://dx.doi.org/10.1016/j.jvsv.2021.07.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8327605PMC
August 2021

Targeting BRD4 in acute myeloid leukemia with partial tandem duplication of the gene.

Haematologica 2021 09 1;106(9):2527-2532. Epub 2021 Sep 1.

The Ohio State University, Comprehensive Cancer Center, Columbus, OH, USA; Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH.

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http://dx.doi.org/10.3324/haematol.2020.271627DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8409020PMC
September 2021

Curcumin restores the engraftment capacity of aged hematopoietic stem cells and also reduces PD-1 expression on cytotoxic T cells.

J Tissue Eng Regen Med 2021 04 9;15(4):388-400. Epub 2021 Mar 9.

Department of Stem Cell Biology, National Centre for Cell Science, Pune, 411007, India.

Aging affects the functionality of hematopoietic stem cells (HSCs), and therefore, aged individuals are not preferred as donors in HSC transplantation. Such elimination leads to the restriction of donor cohort. Several efforts are being done to rejuvenate aged HSCs. Here, we show that treatment of aged mice with curcumin rejuvenates their HSCs by restoring the expression of autophagy-inducing messenger RNAs in them, and improves their engraftment capacity. Importantly, we show that curcumin is effective in rejuvenation of HSCs when administered via both, intraperitoneal as well as oral routes. Aging also affects the immune system. While elderly individuals are not immuno-deficient, they do not respond optimally to immunizations, and hence, a strategy needs to be developed to make them immunologically responsive. Programmed cell death 1 (PD-1), one of the inhibitory coreceptors, plays an important role in the regulation of autoimmunity, infectious immunity, and cancer immunity. Its expression on T cells is indicative of their exhaustion. Here, we show that curcumin reduces the frequency of PD1 cytotoxic T cells in the spleens of aged mice. Curcumin has a proven safety profile, and hence, can be used to treat aged donors to boost the functionality of their HSCs and also to improve the immunological profile of aged individuals. These data could have implications in various other regenerative medicine protocols as well.
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http://dx.doi.org/10.1002/term.3180DOI Listing
April 2021

Direct quantification of in vivo mutagenesis and carcinogenesis using duplex sequencing.

Proc Natl Acad Sci U S A 2020 12 14;117(52):33414-33425. Epub 2020 Dec 14.

TwinStrand Biosciences, Seattle, WA 98121;

The ability to accurately measure mutations is critical for basic research and identifying potential drug and chemical carcinogens. Current methods for in vivo quantification of mutagenesis are limited because they rely on transgenic rodent systems that are low-throughput, expensive, prolonged, and do not fully represent other species such as humans. Next-generation sequencing (NGS) is a conceptually attractive alternative for detecting mutations in the DNA of any organism; however, the limit of resolution for standard NGS is poor. Technical error rates (∼1 × 10) of NGS obscure the true abundance of somatic mutations, which can exist at per-nucleotide frequencies ≤1 × 10 Using duplex sequencing, an extremely accurate error-corrected NGS (ecNGS) technology, we were able to detect mutations induced by three carcinogens in five tissues of two strains of mice within 31 d following exposure. We observed a strong correlation between mutation induction measured by duplex sequencing and the gold-standard transgenic rodent mutation assay. We identified exposure-specific mutation spectra of each compound through trinucleotide patterns of base substitution. We observed variation in mutation susceptibility by genomic region, as well as by DNA strand. We also identified a primordial marker of carcinogenesis in a cancer-predisposed strain of mice, as evidenced by clonal expansions of cells carrying an activated oncogene, less than a month after carcinogen exposure. These findings demonstrate that ecNGS is a powerful method for sensitively detecting and characterizing mutagenesis and the early clonal evolutionary hallmarks of carcinogenesis. Duplex sequencing can be broadly applied to basic mutational research, regulatory safety testing, and emerging clinical applications.
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http://dx.doi.org/10.1073/pnas.2013724117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7776782PMC
December 2020

Surgical Resection of a Symptomatic Superior Vena Cava Lipoma: A Case Report and Literature Review.

Ann Vasc Surg 2021 Feb 5;71:535.e11-535.e15. Epub 2020 Nov 5.

University of Pittsburgh Medical Center, Pittsburgh, PA. Electronic address:

Background: Lipomas are the most common form of benign soft tissue neoplasms and most frequently occur in the subcutaneous tissue. Rarely does a lipoma primarily arise from the arteries or veins. The most common location for an intravascular lipoma is the inferior vena cava, and rarely lipomas originate in the superior vena cava (SVC). Large lipomas of the SVC may be associated with central venous occlusive symptoms. There are only 7 cases of SVC lipomas reported in the literature. Here, we present only the second case of a large symptomatic lipoma located in the SVC, right internal jugular vein, and innominate veins.

Methods: We present a case of a 5-cm lipoma located in the SVC, discovered incidentally and surgically resected via median sternotomy.

Results: The patient underwent a successful open surgical resection of a symptomatic lipoma located in his SVC.

Conclusions: Lipomas of the SVC are exceptionally rare, with only 7 cases described in the literature. This case demonstrates that lipomas can be safely excised from the SVC leading to resolution of central venous occlusive symptoms. A comprehensive literature review reveals that surgical resection is generally without complication, leads to resolution of symptoms, and does not require long-term follow-up.
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http://dx.doi.org/10.1016/j.avsg.2020.09.052DOI Listing
February 2021

Methylation-dependent antioxidant-redox imbalance regulates hypertensive kidney injury in aging.

Redox Biol 2020 10 10;37:101754. Epub 2020 Oct 10.

Department of Physiology, University of Louisville School of Medicine, Louisville, KY, USA. Electronic address:

The prevalence of hypertension increases with age, and oxidative stress is a major contributing factor to the pathogenesis of hypertension-induced kidney damage in aging. The nicotinamide adenine dinucleotide phosphate (NADPH) family is one of the major sources of reactive oxygen species (ROS) generation, and several NADPH oxidase isoforms are highly expressed in the kidney. Although epigenetic protein modification plays a role in organ injury, the methylation of the oxidant-antioxidant defense system and their role in hypertension-induced kidney damage in aging remains underexplored. The present study investigated the role of NADPH oxidase 4, superoxide dismutases (SODs), catalase, and NOS in Ang-II induced kidney damage in aging. Wild type (WT, C57BL/6J) mice aged 12-14 and 75-78 weeks were used and treated with or without Ang-II (1000 ng/kg/min) for 4 weeks with control mice receiving saline. Aged mice with or without Ang-II exhibited higher mean BP, lower renal blood flow, and decreased renal vascular density compared to young mice. While superoxide, 4-HNE, p22, Nox4, iNOS were increased in the aged kidney, the expression of eNOS, MnSOD, CuSOD, catalase, Sirt1, and -3 as well as the ratio of GSH/GSSG, and activities of SODs and catalase were decreased compared to young control mice. The changes further deteriorated with Ang-II treatment. In Ang-II treated aged mice, the expressions of DNMTs were increased and associated with increased methylation of SODs, Sirt1, and Nox4. We conclude that hypermethylation of antioxidant enzymes in the aged kidney during hypertension worsens redox imbalance leading to kidney damage.
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http://dx.doi.org/10.1016/j.redox.2020.101754DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7575806PMC
October 2020

Comparable Patency of Open and Hybrid Treatment of Venous Anastomotic Lesions in Thrombosed Haemodialysis Grafts.

Eur J Vasc Endovasc Surg 2020 Dec 11;60(6):897-903. Epub 2020 Sep 11.

Division of Vascular Surgery, University of Pittsburgh Medical Centre, Pittsburgh, PA, USA. Electronic address:

Objective: Arteriovenous graft (AVG) failures are typically associated with venous anastomotic (VA) stenosis. Current evidence regarding AVG thrombosis management compares surgical with purely endovascular techniques; few studies have investigated the "hybrid" intervention that combines surgical balloon thrombectomy and endovascular angioplasty and/or stenting to address VA obstruction. This study aimed to describe outcomes after hybrid intervention compared with open revision (patch venoplasty or jump bypass) of the VA in thrombosed AVGs.

Methods: Retrospective cohort study. Consecutive patients with a thrombosed AVG who underwent thrombectomy between January 2014 and July 2018 were divided into open and hybrid groups based on VA intervention; patients who underwent purely endovascular thrombectomy were excluded. Patient demographics, previous access history, central vein patency, AVG anatomy, type of intervention, and follow up data were recorded. Kaplan-Meier curves were used to analyse time from thrombectomy to first re-intervention (primary patency) and time to abandonment (secondary patency). Cox regression analysis was performed to evaluate predictors of failure.

Results: This study included 97 patients (54 females) with 39 forearm, 47 upper arm, and 11 lower extremity AVGs. There were 34 open revisions (25 patches, nine jump bypasses) and 63 hybrid interventions, which included balloon angioplasty ± adjunctive procedures (15 stents, five cutting balloons). Technique selection was based on physician preference. Primary patency for the open and hybrid groups was 27.8% and 34.2%, respectively, at six months and 17.5% and 12.9%, respectively, at 12 months (p = .71). Secondary patency was 45.1% and 38.5% for open and hybrid treatment, respectively, at 12 months (p = .87). An existing VA stent was predictive of graft abandonment (hazard ratio 4.4, 95% confidence interval 1.2-16.0; p = .024). Open vs. hybrid intervention was not predictive of failure or abandonment.

Conclusion: Hybrid interventions for thrombosed AVGs are not associated with worse patency at six and 12 months compared with open revision.
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http://dx.doi.org/10.1016/j.ejvs.2020.08.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906772PMC
December 2020

Physiological Cues Involved in the Regulation of Adhesion Mechanisms in Hematopoietic Stem Cell Fate Decision.

Front Cell Dev Biol 2020 10;8:611. Epub 2020 Jul 10.

Symbiosis Centre for Stem Cell Research, Symbiosis International University, Pune, India.

Hematopoietic stem cells (HSC) could have several fates in the body; viz. self-renewal, differentiation, migration, quiescence, and apoptosis. These fate decisions play a crucial role in maintaining homeostasis and critically depend on the interaction of the HSCs with their micro-environmental constituents. However, the physiological cues promoting these interactions have not been identified to a great extent. Intense research using various and models is going on in various laboratories to understand the mechanisms involved in these interactions, as understanding of these mechanistic would greatly help in improving clinical transplantations. However, though these elegant studies have identified the molecular interactions involved in the process, harnessing these interactions to the recipients' benefit would ultimately depend on manipulation of environmental cues initiating them : hence, these need to be identified at the earliest. HSCs reside in the bone marrow, which is a very complex tissue comprising of various types of stromal cells along with their secreted cytokines, extra-cellular matrix (ECM) molecules and extra-cellular vesicles (EVs). These components control the HSC fate decision through direct cell-cell interactions - mediated via various types of adhesion molecules -, cell-ECM interactions - mediated mostly via integrins -, or through soluble mediators like cytokines and EVs. This could be a very dynamic process involving multiple transient interactions acting concurrently or sequentially, and the adhesion molecules involved in various fate determining situations could be different. If the switch mechanisms governing these dynamic states are identified, they could be harnessed for the development of novel therapeutics. Here, in addition to reviewing the adhesion molecules involved in the regulation of HSCs, we also touch upon recent advances in our understanding of the physiological cues known to initiate specific adhesive interactions of HSCs with the marrow stromal cells or ECM molecules and EVs secreted by them.
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http://dx.doi.org/10.3389/fcell.2020.00611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7366553PMC
July 2020

Enhancing titers and productivity of rCHO clones with a combination of an optimized fed-batch process and ER-stress adaptation.

J Biotechnol 2020 Mar 15;311:49-58. Epub 2020 Feb 15.

Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India; Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai, India. Electronic address:

To increase the productivity of rCHO cells, many cell engineering approaches have been demonstrated that over-express or knockout a specific gene to achieve increased titers. In this work, we present an alternate approach, based on the concept of evolutionary adaptation, to achieve cells with higher titers. rCHO cells, producing a monoclonal antibody, are adapted to ER-stress, by continuous culturing under increasing concentration of tunicamycin. A sustained higher productivity of at-least 2-fold was achieved in all the clones, in a concentration-dependent manner. Similarly, a 1.5-2 fold increase in final titers was also achieved in the batch culture. Based on metabolic analysis of the adapted cells, a fed-batch process was designed where significantly higher titersare achieved as compared to control. Metabolic flux analysis is employed in addition with gene expression analysis of key genes to understand the basis of increased performance of the adapted cells. Overall, this work illustrates how process modifications and cellular adaptation can be used in synergy to drive up product titers.
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http://dx.doi.org/10.1016/j.jbiotec.2020.02.008DOI Listing
March 2020

In Vivo Mutagenicity Testing of Arylboronic Acids and Esters.

Environ Mol Mutagen 2019 12 17;60(9):766-777. Epub 2019 Aug 17.

Gilead Sciences, Foster City, California, 94404.

Arylboronic acids and esters (referred to collectively as arylboronic compounds) are commonly used intermediates in the synthesis of pharmaceuticals but pose a challenge for chemical syntheses because they are often positive for bacterial mutagenicity in vitro. As such, arylboronic compounds are then typically controlled to levels that are acceptable for mutagenic impurities, that is, the threshold of toxicological concern (TTC). This study used ICH M7 guidance to design and conduct a testing strategy to investigate the in vivo relevance of the in vitro positive findings of arylboronic compounds. Eight arylboronic compounds representing a variety of chemical scaffolds were tested in Sprague Dawley and/or Wistar rats in the in vivo Pig-a (peripheral blood reticulocytes and mature red blood cells) and/or comet assays (duodenum and/or liver). Five of the eight compounds were also tested in the micronucleus (peripheral blood) assay. The arylboronic compounds tested orally demonstrated high systemic exposure; thus the blood and bone marrow were adequately exposed to test article. One compound was administered intravenously due to formulation stability issues. This investigation showed that arylboronic compounds that were mutagenic in vitro were not found to be mutagenic in the corresponding in vivo assays. Therefore, arylboronic compounds similar to the scaffolds tested in this article may be considered non-mutagenic and managed in accordance with the ICH Q3A/Q3B guidelines. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/em.22320DOI Listing
December 2019

Lemierre's Syndrome: An Atypical Presentation.

Ann Vasc Surg 2019 Oct 13;60:479.e1-479.e4. Epub 2019 Jun 13.

Department of Vascular Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA.

Septic thrombophlebitis is a rare diagnosis in this era of widespread antibiotic usage. The clinical diagnosis requires astute clinical suspicion and evaluation. We describe an asplenic 63-year-old woman who presented to the emergency department with a 24-hour history of a tender, swollen, right neck and upper chest wall. She denied any recent illnesses, but two years before, she was hospitalized and treated for Streptococcus pneumoniae meningitis and endocarditis. An enhanced computed tomography scan demonstrated inflammatory changes around a thrombosed right internal jugular vein, which extended to the brachiocephalic/superior vena cava junction. A retropharyngeal effusion was present, but no pulmonary or oropharyngeal abscess was identified. Lemierre's syndrome, although rare, must be recognized promptly to reduce morbidity and mortality associated with this condition.
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http://dx.doi.org/10.1016/j.avsg.2019.03.011DOI Listing
October 2019

A comparison of transgenic rodent mutation and in vivo comet assay responses for 91 chemicals.

Mutat Res Genet Toxicol Environ Mutagen 2019 Mar 18;839:21-35. Epub 2019 Jan 18.

MilliporeSigma, BioReliance Toxicology Testing Services, Rockville, MD, USA.

A database of 91 chemicals with published data from both transgenic rodent mutation (TGR) and rodent comet assays has been compiled. The objective was to compare the sensitivity of the two assays for detecting genotoxicity. Critical aspects of study design and results were tabulated for each dataset. There were fewer datasets from rats than mice, particularly for the TGR assay, and therefore, results from both species were combined for further analysis. TGR and comet responses were compared in liver and bone marrow (the most commonly studied tissues), and in stomach and colon evaluated either separately or in combination with other GI tract segments. Overall positive, negative, or equivocal test results were assessed for each chemical across the tissues examined in the TGR and comet assays using two approaches: 1) overall calls based on weight of evidence (WoE) and expert judgement, and 2) curation of the data based on a priori acceptability criteria prior to deriving final tissue specific calls. Since the database contains a high prevalence of positive results, overall agreement between the assays was determined using statistics adjusted for prevalence (using AC1 and PABAK). These coefficients showed fair or moderate to good agreement for liver and the GI tract (predominantly stomach and colon data) using WoE, reduced agreement for stomach and colon evaluated separately using data curation, and poor or no agreement for bone marrow using both the WoE and data curation approaches. Confidence in these results is higher for liver than for the other tissues, for which there were less data. Our analysis finds that comet and TGR generally identify the same compounds (mainly potent mutagens) as genotoxic in liver, stomach and colon, but not in bone marrow. However, the current database content precluded drawing assay concordance conclusions for weak mutagens and non-DNA reactive chemicals.
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http://dx.doi.org/10.1016/j.mrgentox.2019.01.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6697155PMC
March 2019

Induction and Detection of Autophagy in Aged Hematopoietic Stem Cells by Exposing Them to Microvesicles Secreted by HSC-Supportive Mesenchymal Stromal Cells.

Methods Mol Biol 2019 ;1854:21-34

Stem Cell Lab, National Centre for Cell Science, Pune, India.

Autophagy is an important cellular process for maintenance of quality and functionality of cells. This happens through repair and renewal of cellular components like proteins and mitochondria. Reduction in autophagy process in aged hematopoietic stem cells (HSCs) leads to their compromised stemness and self-renewal capacity, and consequently, their applicability in various regenerative therapies also reduces. HSC functions are regulated by their microenvironment, known as "HSC niche," which comprises of mesenchymal stromal cells (MSCs), osteoblasts, endothelial cells, etc. In this niche, the MSCs are known to closely interact with the HSCs, and therefore, they can directly influence the stem cell fate. In our earlier studies, we have demonstrated that young MSCs or aged MSCs rejuvenated by treating them with LY294002, a PI3K inhibitor (rescued aged MSCs), rejuvenate aged HSCs via intercellular transfer of microvesicles (MVs) harboring autophagy-inducing mRNAs.Here, we describe the protocol for induction of autophagy in aged HSCs by incubating them with microvesicles (MVs) collected from young MSCs or rescued aged MSCs. We also describe the protocols for determination of autophagy levels in these HSCs.
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http://dx.doi.org/10.1007/7651_2018_166DOI Listing
June 2019

Genotoxicity assessment of the novel antitussive agent Benzonatate and its major metabolite.

Mutat Res Genet Toxicol Environ Mutagen 2018 May - Jun;829-830:19-25. Epub 2018 Mar 21.

MilliporeSigma BioReliance(®) Toxicology Services, Rockville, MD, United States.

Benzonatate (TESSALON) is a peripherally acting oral antitussive. It undergoes rapid ester hydrolysis producing 4-(butylamino) benzoic acid (BBA) and methylated polyethylene glycol (MPG) metabolites, which are eliminated in urine and feces. The nonclinical and clinical efficacy of Benzonatate has been demonstrated over the last 60 years, but its safety was not fully assessed. In this study, we tested the genotoxicity of Benzonatate and its major metabolite BBA in an in vitro bacterial reverse mutation and in vivo micronucleus assays. A chromosomal aberration assay was also performed on Benzonatate and BBA. In the reverse mutation assay, Benzonatate and BBA doses 1.5-5000 μg/plate ± S9 metabolic activation were used and the numbers of revertants/plate were compared to various controls. Chromosomal aberration assays with human peripheral blood lymphocytes used Benzonatate and BBA concentrations 25-2000 and 62.5-1930 μg/mL, respectively. A CByB6F1 mouse bone marrow micronucleus assay was performed as part of a 28-day oral toxicology study at up to 250 mg/kg/day. The frequencies of micronuclei in polychromatic erythrocytes in treated groups were compared with the control group. Neither Benzonatate nor BBA induced significant mutagenicity in any of the bacterial strains, with or without metabolic activation. They also did not produce any biologically relevant structural or numerical aberrations in human chromosomes. Benzonatate and its BBA and MPG metabolites rapidly produced from esterase activity did not produce any significant increase in the incidence of micronucleated polychromatic erythrocytes. In conclusion, Benzonatate and its major metabolite BBA were not mutagenic and did not cause numerical or structural chromosome alterations. While the MPG metabolite was not tested, studies on structural analogues indicated it was also unlikely to be genotoxic. This was supported by oral rodent carcinogenicity assays showing no increase in malignancies.
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http://dx.doi.org/10.1016/j.mrgentox.2018.03.007DOI Listing
June 2019

Plasma microbiome-modulated indole- and phenyl-derived metabolites associate with advanced atherosclerosis and postoperative outcomes.

J Vasc Surg 2018 11 13;68(5):1552-1562.e7. Epub 2017 Dec 13.

Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Ill. Electronic address:

Objective: Multiple studies have shown that gut microbes contribute to atherosclerosis, and there is mounting evidence that microbial metabolism of dietary nutrients influences pathophysiology. We hypothesized that indole- and phenyl-derived metabolites that originate solely or in part from bacterial sources would differ between patients with advanced atherosclerosis and age- and sex-matched controls without clinically apparent atherosclerosis.

Methods: Plasma from the advanced atherosclerosis cohort (n = 100) was from patients who underwent carotid endarterectomy, open infrainguinal leg revascularization, or major leg amputation for critical limb ischemia. The controls (n = 22) were age- and sex-matched participants who had no peripheral arterial disease or history of stroke or myocardial infarction. Patients with chronic kidney disease were excluded. Metabolites and internal standards were measured using high-performance liquid chromatography and tandem mass spectrometry.

Results: Plasma metabolite concentrations differed significantly between the advanced atherosclerosis and control cohorts. After adjustment for traditional atherosclerosis risk factors, indole (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.75-0.95; P = .004), tryptophan (OR, <0.001; 95% CI, <0.001-0.003; P < .001), indole-3-propionic acid (OR, 0.27; 95% CI, 0.019-0.91; P = .02), and indole-3-aldehyde (OR, 0.12; 95% CI, 0.014-0.92; P = .04) concentrations negatively associated with advanced atherosclerosis, whereas the kynurenine/tryptophan ratio (OR, 61.7; 95% CI, 1.9->999; P = .02) was positively associated. Furthermore, tryptophan and indole-3-propionic acid concentrations (Spearman coefficients of 0.63 and 0.56, respectively; P < .001) correlated with the ankle-brachial index, a surrogate for overall atherosclerotic disease burden. Fourteen patients experienced a major postoperative cardiac complication within 30 days in the advanced atherosclerosis cohort, which was associated with baseline kynurenine/tryptophan ratio (P = .001) and hippuric acid (P = .03). In a multivariate analysis, only the kynurenine/tryptophan ratio remained significantly associated with a postoperative cardiac complication (OR, 44.1; 95% CI, 3.3-587.1; P = .004). Twenty patients in the advanced atherosclerosis cohort experienced a major adverse cardiac event during the follow-up period, which was associated with hippuric acid (P = .002) and the kynurenine/tryptophan ratio (P < .001) at baseline. Both hippuric acid and the kynurenine/tryptophan ratio were independently associated with a major adverse cardiac event in multivariate analyses that included diabetes mellitus.

Conclusions: Specific microbe-derived metabolite signatures associate with advanced human atherosclerosis and postoperative cardiac complications. We suggest that these metabolites are potential novel biomarkers for atherosclerotic disease burden and that further investigation into mechanistic links between defined microbial metabolic pathways and cardiovascular disease is warranted.
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http://dx.doi.org/10.1016/j.jvs.2017.09.029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5999545PMC
November 2018

Intercellular Transfer of Microvesicles from Young Mesenchymal Stromal Cells Rejuvenates Aged Murine Hematopoietic Stem Cells.

Stem Cells 2018 03 22;36(3):420-433. Epub 2017 Dec 22.

Stem Cell Lab, National Centre for Cell Science, Ganeshkhind, Pune, Maharashtra, India.

Donor age is one of the major concerns in bone marrow transplantation, as the aged hematopoietic stem cells (HSCs) fail to engraft efficiently. Here, using murine system, we show that a brief interaction of aged HSCs with young mesenchymal stromal cells (MSCs) rejuvenates them and restores their functionality via inter-cellular transfer of microvesicles (MVs) containing autophagy-related mRNAs. Importantly, we show that MSCs gain activated AKT signaling as a function of aging. Activated AKT reduces the levels of autophagy-related mRNAs in their MVs, and partitions miR-17 and miR-34a into their exosomes, which upon transfer into HSCs downregulate their autophagy-inducing mRNAs. Our data identify previously unknown mechanisms operative in the niche-mediated aging of HSCs. Inhibition of AKT in aged MSCs increases the levels of autophagy-related mRNAs in their MVs and reduces the levels of miR-17 and miR-34a in their exosomes. Interestingly, transplantation experiments showed that the rejuvenating power of these "rescued" MVs is even better than that of the young MVs. We demonstrate that such ex vivo rejuvenation of aged HSCs could expand donor cohort and improve transplantation efficacy. Stem Cells 2018;36:420-433.
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http://dx.doi.org/10.1002/stem.2756DOI Listing
March 2018

Evaluation of genetic toxicity of 6-diazo-5-oxo-l-norleucine (DON).

Toxicol Mech Methods 2017 Sep 20;27(7):518-527. Epub 2017 Jun 20.

c National Center for Advancing Translational Sciences, NIH , Bethesda , MD , USA.

DON (6-diazo-5-oxo-l-norleucine), a glutamine antagonist, was demonstrated to exhibit analgesic, antibacterial, antiviral and anticancer properties. The study was performed to characterize its in vitro and in vivo genetic toxicity potential. DON was tested in the bacterial reverse mutation assay (Ames test) using Salmonella typhimurium tester strains (TA98, TA100, TA1535 and TA1537) and Escherichia coli tester strain (WP2 uvrA) with and without S9 and also with reductive S9. In addition, DON was tested for the chromosome aberrations in Chinese hamster ovary (CHO) cells with or without S9 to evaluate the clastogenic potential. Furthermore, DON was also evaluated for its in vivo clastogenic activity by detecting micronuclei in polychromatic erythrocyte (PCE) cells in bone marrow collected from the male mice dosed intravenously with 500, 100, 10, 1 and 0.1 mg/kg at 24 and 48-h post-dose. The Ames mutagenicity assay showed no positive mutagenic responses. However, the in vitro chromosome aberration assay demonstrated dose dependent statistically positive increase in structural aberrations at 4 and 20-h exposure without S9 and also at 4-h exposure with S9. The in vivo micronucleus assay also revealed a statistically positive response for micronucleus formation at 500, 100 and 10 mg/kg at 24 and 48-h post-dose. Thus, DON appears to be negative in the Ames test but positive in the in vitro chromosome aberration assay and in the in vivo micronucleus assay. In conclusion, the results indicate DON is a genotoxic compound with a plausible epigenetic mechanism.
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http://dx.doi.org/10.1080/15376516.2017.1333552DOI Listing
September 2017

Lack of genotoxicity in vivo for food color additive Allura Red AC.

Food Chem Toxicol 2017 Jul 27;105:308-314. Epub 2017 Apr 27.

Toxicology, Study Management, BioReliance/Sigma-Aldrich Corp., 14920 Broschart Road, Rockville, MD 20850, United States. Electronic address:

Allura Red AC is an approved food color additive internationally with INS number 129, in the United States as food color subject to batch certification "Food, Drug, and Cosmetic" (FD&C) Red No. 40, and in Europe as food color additive with E number 129. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results show clear absence of genotoxic activity for Allura Red AC, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed the study and concluded that there is no genotoxicity concern for Allura Red AC. Negative findings in parallel genotoxicity studies on Tartrazine and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors.
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http://dx.doi.org/10.1016/j.fct.2017.04.037DOI Listing
July 2017

Lack of genotoxicity in vivo for food color additive Tartrazine.

Food Chem Toxicol 2017 Jul 25;105:278-284. Epub 2017 Apr 25.

Toxicology, Study Management, BioReliance/Sigma-Aldrich Corp., 14920 Broschart Road, Rockville, MD 20850, United States. Electronic address:

Tartrazine is approved as a food color additive internationally with INS number 102, in the United States as food color subject to batch certification "Food, Drug, and Cosmetic" (FD&C) Yellow No. 5, and in Europe as food color additive with E number 102. In their evaluation of the color (2013), the European Food Safety Authority (EFSA) expressed concerns of potential genotoxicity, based primarily on one genotoxicity study that was not conducted according to Guidelines. The present in vivo genotoxicity study was conducted according to OECD Guidelines in response to EFSA's request for additional data. The animal species and strain, and the tissues examined were selected specifically to address the previously reported findings. The results of this study show clear absence of genotoxic activity for Tartrazine, in the bone marrow micronucleus assay and the Comet assay in the liver, stomach, and colon. These data addressed EFSA's concerns for genotoxicity. The Joint WHO/FAO Committee on Food Additives (JECFA) (2016) also reviewed these data and concluded that there is no genotoxicity concern for Tartrazine. Negative findings in parallel genotoxicity studies on Allura Red AC and Ponceau 4R (published separately) are consistent with lack of genotoxicity for azo dyes used as food colors.
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http://dx.doi.org/10.1016/j.fct.2017.04.034DOI Listing
July 2017

Irradiation-induced secretion of BMP4 by marrow cells causes marrow adipogenesis post-myelosuppression.

Stem Cell Res 2016 11 9;17(3):646-653. Epub 2016 Nov 9.

Stem Cell Lab, National Centre for Cell Science, Ganeshkhind, Pune, Maharashtra 411007, India. Electronic address:

Pre-transplant myeloablation is associated with marrow adipogenesis, resulting in delayed engraftment of hematopoietic stem cells (HSCs). This is strongly undesirable, especially when the donor HSCs are fewer in numbers or have compromised functionality. The molecular mechanisms behind irradiation-induced marrow adipogenesis have not been extensively investigated. Here we show that bone marrow (BM) cells, especially T-cells and stromal cells, express and secrete copious amounts of BMP4 in response to irradiation, which causes the bone marrow stromal cells to commit to adipocyte lineage, thereby contributing to an increase in bone marrow adipogenesis. We further demonstrate that Simvastatin inhibits the BMP4-mediated adipogenic commitment of marrow stromal cells by inhibiting Ppar-γ expression. Importantly, Simvastatin does not prevent BMP4 secretion by the BM cells, and thus does not interfere with its salutary role in post-transplant hematopoietic regeneration. Our data identify previously unknown mechanisms operative in marrow adipogenesis post-myeloablation. They also reveal the molecular mechanisms behind the advantage of using Simvastatin as a niche-targeting agent to improve HSC engraftment.
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http://dx.doi.org/10.1016/j.scr.2016.11.015DOI Listing
November 2016

Neuropilin-1 Is an Important Niche Component and Exerts Context-Dependent Effects on Hematopoietic Stem Cells.

Stem Cells Dev 2017 01 2;26(1):35-48. Epub 2016 Nov 2.

1 Stem Cell Laboratory, National Centre for Cell Science , Pune, India .

Marrow adipocytes pose a significant problem in post-transplant regeneration of hematopoiesis owing to their negative effects on regeneration of hematopoiesis. However, the precise mechanism operative in this negative regulation is not clear. In this study, we show that marrow adipocytes express neuropilin-1 (NRP1) as a function of differentiation and inhibit regeneration of hematopoiesis by three principal mechanisms: one, by inducing apoptosis in hematopoietic stem/progenitor cells (HSPCs) through the death receptor-mediated pathway; two, by downregulating CXCR4 expression on the HSPCs through ligand-mediated internalization; and three, by secreting copious amounts of transforming growth factor β1 (TGFβ1), a known inhibitor of hematopoiesis. Silencing of NRP1 in these adipocytes rescued the apoptosis of cocultured HSPCs and boosted the CXCR4 surface expression on them, showing an active role of NRP1 in these processes. However, such silencing had no effect on TGFβ1 secretion and consequent inhibition of hematopoiesis by them, showing that secretion of TGFβ1 by adipocytes is independent of NRP1 expression by them. Surprisingly, mesenchymal stromal cells modified with NRP1 supported expansion of HSPCs having enhanced functionality, suggesting that NRP1 exerts a context-dependent effect on hematopoiesis. Our data demonstrate that NRP1 is an important niche component and exerts context-dependent effects on HSPCs. Based on these data, we speculate that antibody- or peptide-mediated blocking of NRP1-HSC interactions coupled with a pharmacological inhibition of TGFβ1 signaling may help in combating the negative regulation of post-transplant regeneration of hematopoiesis in a more effective manner.
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http://dx.doi.org/10.1089/scd.2016.0096DOI Listing
January 2017

The EpiDerm™ 3D human reconstructed skin micronucleus (RSMN) assay: Historical control data and proof of principle studies for mechanistic assay adaptations.

Mutat Res Genet Toxicol Environ Mutagen 2016 Jul 26;805:25-37. Epub 2016 May 26.

Marilyn Aardema Consulting LLC, 5315 Oakbrook Dr., Fairfield, OH 45014, USA.

The in vitro human reconstructed skin micronucleus (RSMN) assay in EpiDerm™ is a promising novel animal alternative for evaluating genotoxicity of topically applied chemicals. It is particularly useful for assessing cosmetic ingredients that can no longer be tested using in vivo assays. To advance the use of this test especially for regulatory decision-making, we have established the RSMN assay in our laboratory according to Good Laboratory Practice and following the principles of the OECD test guideline 487 in vitro mammalian cell micronucleus test. Proficiency with the assay was established by correctly identifying direct-acting genotoxins and genotoxins requiring metabolism, as well as non-genotoxic/non-carcinogenic chemicals. We also report the analysis of our historical control data that demonstrate vehicle control and positive control values for %micronuclei in binucleated cells are in the ranges reported previously. Technical issues including evaluating various solvents with both 48h and 72h treatment regimens were investigated. For the first time, mechanistic studies using CREST analysis revealed that the RSMN assay is suitable for distinguishing aneugens and clastogens. Moreover, the assay is also suitable for measuring cytokines as markers for proliferative and toxic effects of chemicals.
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http://dx.doi.org/10.1016/j.mrgentox.2016.05.010DOI Listing
July 2016

Bacterial mutagenicity assays: Vehicle and positive control results from the standard Ames assay, the 6- and 24-well miniaturized plate incorporation assays and the Ames II™ assay.

Environ Mol Mutagen 2016 07 20;57(6):483-96. Epub 2016 May 20.

BioReliance by SAFC, Rockville, Maryland.

Bacterial mutation assays are conducted routinely as part of the safety assessment of new chemicals. The OECD Test Guideline (TG) 471 describes the conduct of the standard agar plate Ames assay, required for regulatory submissions. Higher throughput non-OECD 471 TG assays, such as the miniaturized plate incorporation and Ames II™ assays, can be used for prescreening purposes. We have compiled historical vehicle and positive control data generated using these methods. The historical database is comprised from experiments spanning 9 years and includes >1000 experiments from the standard Ames assay using the plate incorporation and pre-incubation methods (TA98, TA100, TA1535, TA1537, and WP2 uvrA), >50 experiments from the 6-well (TA98, TA100, TA1535, TA97a, and WP2 uvrA) and >100 experiments from the 24-well (TA98, TA100, TA102, TA1535, TA1537, and TA97a) plate incorporation assays, and >1000 experiments from the Ames II™ assay (TA98 and TAMix). Although miniaturization to a 24-well format made the measurement of control revertant colonies in TA1537 and TA1535 more difficult; this can be overcome by using an alternative strain with a higher spontaneous reversion rate (i.e., using TA97a instead of TA1537) or by increasing the number of replicate wells to 12 (for TA1535). All three miniaturized methods, including the Ames II™ assay, were responsive to known mutagens and the responses were reproducible over years of use. These data demonstrate the excellent reproducibility of the standard and miniaturized bacterial mutation assays using positive control chemicals. Environ. Mol. Mutagen. 57:483-496, 2016. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/em.22014DOI Listing
July 2016

Local perivascular adiponectin associates with lower extremity vascular operative wound complications.

Surgery 2016 07 14;160(1):204-210. Epub 2016 Apr 14.

Department of Surgery, Brigham and Women's Hospital/Harvard Medical School, Boston, MA. Electronic address:

Background: Wound complication rates after lower extremity vascular operative procedures stand as high as 40% and represent a major cause of morbidity, mortality, and cost. In view of increasing recognition of adipose tissue involvement in homeostasis and the response to injury, we hypothesized that adipose phenotype is linked to operative wound outcomes.

Methods: Clinical history, peripheral blood, and subcutaneous and perivascular adipose tissue were prospectively collected at the time of operation in patients undergoing lower extremity revascularization and lower extremity amputations. Nine biologic mediators (adiponectin; interleukin [IL]-1β, IL-6, and IL-8; leptin; monocyte chemoattractant protein-1; plasminogen activator inhibitor-1; resistin; and tumor necrosis factor) were assayed in the adipose tissues and plasma. The 30-day wound complications were captured in real time. Logarithmic transformation of mediator levels was performed based on positively skewed, non-Gaussian distribution, and data were compared using the Student t test. Bonferroni correction was used for multiple comparisons.

Results: Sixty-six patients undergoing lower extremity revascularization or lower extremity amputations for severe peripheral arterial disease were enrolled. The 30-day follow-up was 92.4%. In total, 19 (29%) patients developed wound complications. Patients who developed wound complications had elevated perivascular adiponectin levels (mean ± standard error, 2,372.45 ± 648.64 ng/mL vs 832.53 ± 180.54 ng/mL, P = .004). Perivascular IL-1β levels were lower among patients with wound dehiscence (0.41 ± 0.004 pg/mL vs 0.73 ± 0.09 pg/mL, P = .001).

Conclusion: Local adipose tissue mediator levels at the time of operation demonstrate a previously undescribed compartment-specific relationship to wound outcomes in patients undergoing lower extremity vascular operative procedures. These associations provide fertile directives for defining the mechanisms underlying the pathogenesis of wound complications and their prevention.
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http://dx.doi.org/10.1016/j.surg.2016.01.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4903925PMC
July 2016

Enrichment of lung microbiome with supraglottic taxa is associated with increased pulmonary inflammation.

Microbiome 2013 Jul 1;1(1):19. Epub 2013 Jul 1.

André Cournand Pulmonary Research Laboratory, Bellevue Hospital Center/New York University School of Medicine, New York, NY, USA.

Background: The lung microbiome of healthy individuals frequently harbors oral organisms. Despite evidence that microaspiration is commonly associated with smoking-related lung diseases, the effects of lung microbiome enrichment with upper airway taxa on inflammation has not been studied. We hypothesize that the presence of oral microorganisms in the lung microbiome is associated with enhanced pulmonary inflammation. To test this, we sampled bronchoalveolar lavage (BAL) from the lower airways of 29 asymptomatic subjects (nine never-smokers, 14 former-smokers, and six current-smokers). We quantified, amplified, and sequenced 16S rRNA genes from BAL samples by qPCR and 454 sequencing. Pulmonary inflammation was assessed by exhaled nitric oxide (eNO), BAL lymphocytes, and neutrophils.

Results: BAL had lower total 16S than supraglottic samples and higher than saline background. Bacterial communities in the lower airway clustered in two distinct groups that we designated as pneumotypes. The rRNA gene concentration and microbial community of the first pneumotype was similar to that of the saline background. The second pneumotype had higher rRNA gene concentration and higher relative abundance of supraglottic-characteristic taxa (SCT), such as Veillonella and Prevotella, and we called it pneumotypeSCT. Smoking had no effect on pneumotype allocation, α, or β diversity. PneumotypeSCT was associated with higher BAL lymphocyte-count (P= 0.007), BAL neutrophil-count (P= 0.034), and eNO (P= 0.022).

Conclusion: A pneumotype with high relative abundance of supraglottic-characteristic taxa is associated with enhanced subclinical lung inflammation.
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http://dx.doi.org/10.1186/2049-2618-1-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3971609PMC
July 2013

Genotoxicity of doxorubicin in F344 rats by combining the comet assay, flow-cytometric peripheral blood micronucleus test, and pathway-focused gene expression profiling.

Environ Mol Mutagen 2014 Jan 24;55(1):24-34. Epub 2013 Oct 24.

Division of Genetic and Molecular Toxicology, US Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.

Doxorubicin (DOX) is an antineoplastic drug effective against many human malignancies. DOX's clinical efficacy is greatly limited because of severe cardiotoxicity. To evaluate if DOX is genotoxic in the heart, ~7-week-old, male F344 rats were administered intravenously 1, 2, and 3 mg/kg bw DOX at 0, 24, 48, and 69 hr and the Comet assays in heart, liver, kidney, and testis and micronucleus (MN) assay in the peripheral blood (PB) erythrocytes using flow cytometry were conducted. Rats were euthanized at 72 hr and PB was removed for the MN assay and single cells were isolated from multiple tissues for the Comet assays. None of the doses of DOX induced a significant DNA damage in any of the tissues examined by the alkaline Comet assay. Contrastingly, the glycosylase enzymes-modified Comet assay showed a significant dose dependent increase in the oxidative DNA damage in the cardiac tissue (P ≤ 0.05). In the liver, only the top dose induced significant increase in the oxidative DNA damage (P ≤ 0.05). The histopathology showed no severe cardiotoxicity but non-neoplastic lesions were present in both untreated and treated samples. A severe toxicity likely occurred in the bone marrow because no viable reticulocytes could be screened for the MN assay. Gene expression profiling of the heart tissues showed a significant alteration in the expression of 11 DNA damage and repair genes. These results suggest that DOX is genotoxic in the heart and the DNA damage may be induced primarily via the production of reactive oxygen species.
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http://dx.doi.org/10.1002/em.21822DOI Listing
January 2014

Comparison of WTC dust size on macrophage inflammatory cytokine release in vivo and in vitro.

PLoS One 2012 18;7(7):e40016. Epub 2012 Jul 18.

Division of Pulmonary, Critical Care and Sleep Medicine, New York University School of Medicine, New York, New York, United States of America.

Background: The WTC collapse exposed over 300,000 people to high concentrations of WTC-PM; particulates up to ∼50 mm were recovered from rescue workers' lungs. Elevated MDC and GM-CSF independently predicted subsequent lung injury in WTC-PM-exposed workers. Our hypotheses are that components of WTC dust strongly induce GM-CSF and MDC in AM; and that these two risk factors are in separate inflammatory pathways.

Methodology/principal Findings: Normal adherent AM from 15 subjects without WTC-exposure were incubated in media alone, LPS 40 ng/mL, or suspensions of WTC-PM(10-53) or WTC-PM(2.5) at concentrations of 10, 50 or 100 µg/mL for 24 hours; supernatants assayed for 39 chemokines/cytokines. In addition, sera from WTC-exposed subjects who developed lung injury were assayed for the same cytokines. In the in vitro studies, cytokines formed two clusters with GM-CSF and MDC as a result of PM(10-53) and PM(2.5). GM-CSF clustered with IL-6 and IL-12(p70) at baseline, after exposure to WTC-PM(10-53) and in sera of WTC dust-exposed subjects (n = 70) with WTC lung injury. Similarly, MDC clustered with GRO and MCP-1. WTC-PM(10-53) consistently induced more cytokine release than WTC-PM(2.5) at 100 µg/mL. Individual baseline expression correlated with WTC-PM-induced GM-CSF and MDC.

Conclusions: WTC-PM(10-53) induced a stronger inflammatory response by human AM than WTC-PM(2.5). This large particle exposure may have contributed to the high incidence of lung injury in those exposed to particles at the WTC site. GM-CSF and MDC consistently cluster separately, suggesting a role for differential cytokine release in WTC-PM injury. Subject-specific response to WTC-PM may underlie individual susceptibility to lung injury after irritant dust exposure.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0040016PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399845PMC
March 2013
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