Prostaglandins and calprotectin are genetically and functionally linked to the Inflammatory Bowel Diseases.

Background: Genome wide association studies (GWAS) have identified and validated more than 200 genomic loci associated with the inflammatory bowel disease (IBD), although for most the causal gene remains unknown. Given the importance of myeloid cells in IBD pathogenesis, the current study aimed to uncover the role of genes within IBD genetic loci that are endogenously expressed in this cell lineage.

Methods: The open reading frames (ORF) of 42 genes from IBD-associated loci were expressed via lentiviral transfer in the THP-1 model of human monocytes and the impact of each of these on the cell's transcriptome was analyzed using a RNA sequencing-based approach.

Functional screen of inflammatory bowel disease genes reveals key epithelial functions.

Background: Genetic studies have been tremendously successful in identifying genomic regions associated with a wide variety of phenotypes, although the success of these studies in identifying causal genes, their variants, and their functional impacts has been more limited.

Methods: We identified 145 genes from IBD-associated genomic loci having endogenous expression within the intestinal epithelial cell compartment. We evaluated the impact of lentiviral transfer of the open reading frame (ORF) of these IBD genes into the HT-29 intestinal epithelial cell line via transcriptomic analyses.

Cardiac resident nestin(+) cells participate in reparative vascularisation.

The rodent heart contains a population of nestin((+)) cells derived from the embryonic neural crest and migrate to the scar after myocardial infarction (MI). The present study tested the hypothesis that intron 2 of the nestin gene drives expression and a subpopulation of nestin((+)) cells participate in reparative vascularisation. The directed expression of the green fluorescent protein (GFP) by the second intron of the nestin gene identified GFP/nestin((+)) cells intercalated among ventricular myocytes in the heart of normal transgenic mice.

The plating of rat scar myofibroblasts on matrigel unmasks a novel phenotype; the self assembly of lumen-like structures.

During tissue healing, the primary role of myofibroblasts involves the synthesis and deposition of collagen. However, it has also been reported that selective populations of myofibroblasts can acquire the phenotype and/or differentiate to other cells types. The present study tested the hypothesis that myofibroblasts isolated from the scar of the ischemically damaged rat heart can recapitulate an endothelial cell-like response when plated in a permissive in vitro environment.

Nestin expression is lost in ventricular fibroblasts during postnatal development of the rat heart and re-expressed in scar myofibroblasts.

Studies have reported that the intermediate filament protein nestin was expressed in various non-stem/progenitor cells during development, downregulated during postnatal growth and re-expressed following injury. The present study tested the hypothesis that an analogous paradigm was prevalent for ventricular fibroblasts. In the neonatal rat heart, nestin protein levels were significantly higher than the adult heart and the isolation of cardiac cells revealed a selective expression in ventricular fibroblasts.

Nestin (+) stem cells independently contribute to neural remodelling of the ischemic heart.

Recent studies have revealed the existence of multipotent nestin-immunoreactive cells in the adult mammalian heart. These cells were recruited to infarct site following ischemic injury and differentiated to a vascular lineage leading to de novo blood vessel formation. Here, we show that a sub-population of cardiac resident nestin((+)) cells can further differentiate to a neuronal-like fate in vivo following myocardial infarction.

The phenotype and potential origin of nestin+ cardiac myocyte-like cells following infarction.

Nestin+ cardiac myocyte-like cells were detected in the peri-infarct/infarct region of the ischemically damaged heart. The present study was undertaken to elucidate the phenotype and potential origin of nestin+ cardiac myocyte-like cells and identify stimuli implicated in their appearance. In the infarcted human and rat heart, nestin+ cardiac myocyte-like cells were morphologically and structurally immature, exhibited a desmin-immunoreactive striated phenotype, expressed the beta(1)-adrenergic receptor, and associated with an aberrant pattern of connexin-43 expression and/or organization.

Infarct size is increased in female post-MI rats treated with rapamycin.

Rapamycin represents a recognized drug-based therapeutic approach to treat cardiovascular disease. However, at least in the female heart, rapamycin may suppress the recruitment of putative signalling events conferring cardioprotection. The present study tested the hypothesis that rapamycin-sensitive signalling events contributed to the cardioprotective phenotype of the female rat heart after an ischemic insult.

The cardiac neural stem cell phenotype is compromised in streptozotocin-induced diabetic cardiomyopathy.

Neural stem cells were identified in the rat heart and during scar formation and healing participated in sympathetic fiber sprouting and angiogenesis. In the setting of diabetes, impaired wound healing represents a typical pathological feature. These findings provided the impetus to test the hypothesis that experimental diabetes adversely influenced the phenotype of cardiac neural stem cells.

The rat heart contains a neural stem cell population; role in sympathetic sprouting and angiogenesis.

Nestin-expressing cells were identified in the normal rat heart characterized by a small cell body and numerous processes and following an ischemic insult migrated to the infarct region. The present study was undertaken to identify the phenotype, origin and biological role of nestin-expressing cells during reparative fibrosis. A neural stem cell phenotype was identified based on musashi-1 expression, growth as a neurosphere, and differentiation to a neuronal cell.

Female rats fed a high-fat diet were associated with vascular dysfunction and cardiac fibrosis in the absence of overt obesity and hyperlipidemia: therapeutic potential of resveratrol.

It remains presently unknown whether vascular reactivity is impaired and whether maladaptive cardiac remodeling occurs before the onset of overt obesity and in the absence of hyperlipidemia. Normal female rats were fed a high-fat diet for 8 weeks and were associated with a modest nonsignificant increase of body weight (standard diet, 300 +/- 10, versus high-fat diet, 329 +/- 14 g) and a normal plasma lipid profile. In rats fed a high-fat diet, systolic (171 +/- 7 mm Hg) and diastolic blood pressures (109 +/- 3) were increased compared to a standard diet (systolic blood pressure, 134 +/- 8; diastolic blood pressure, 96 +/- 5 mm Hg), and acetylcholine-dependent relaxation of isolated aortic rings (high-fat diet, 22 +/- 5%, versus standard diet, 53 +/- 8%) was significantly reduced.

Dexamethasone treatment of post-MI rats attenuates sympathetic innervation of the infarct region.

Sympathetic fiber innervation of the damaged region following injury represents a conserved event of wound healing. The present study tested the hypothesis that impaired scar healing in post-myocardial infarction (post-MI) rats was associated with a reduction of sympathetic fibers innervating the infarct region. In 1-wk post-MI rats, neurofilament-M-immunoreactive fibers (1,116 +/- 250 microm(2)/mm(2)) were detected innervating the infarct region and observed in close proximity to a modest number of endothelial nitric oxide synthase-immunoreactive scar-residing vessels.

Effects of resveratrol (trans-3,5,4'-trihydroxystilbene) treatment on cardiac remodeling following myocardial infarction.

Resveratrol (RES; trans-3,5,4'-trihydroxystilbene) has been shown to improve health and slow the progression of disease in various models. Several cardioprotective mechanisms have been identified including antioxidant, anti-inflammatory, and antifibrotic actions. Each of these actions is thought to have the ability to attenuate the pathophysiology underlying the deleterious cardiac structural remodeling that results from acute myocardial infarction (MI).

Antagonism of stromal cell-derived factor-1alpha reduces infarct size and improves ventricular function after myocardial infarction.

To examine the biological impact of locally expressed stromal cell-derived factor-1alpha (SDF-1alpha) during the acute phase of remodeling after myocardial infarction (MI), rats were treated with the selective CXCR4 receptor antagonist AMD3100 (1 mg/kg; given 24 h post-MI and continued for 6 days). In 1-week post-MI rats, intense SDF-1 immunoreactivity was detected in scar-residing vessels, and SDF-1alpha messenger ribonucleic acid (mRNA) levels were significantly greater in the infarct region compared to the noninfarcted left ventricle (NILV). AMD3100 treatment of post-MI rats reduced infarct size, improved systolic function, and partially suppressed the increased expression of atrial natriuretic peptide mRNA in the NILV.

Tamoxifen treatment of myocardial infarcted female rats exacerbates scar formation.

Hormonal replacement therapy in postmenopausal women was associated with an increased incidence of nonfatal myocardial infarction. Selective estrogen receptor modulators were considered an alternative pharmacological approach. However, selective estrogen receptor modulators acting via estrogen receptor-dependent and receptor-independent mechanisms may negatively influence cardiac remodeling.

Disparate regulation of signaling proteins after exercise and myocardial infarction.

Introduction: The signaling proteins extracellular signal-regulated kinase (ERK1/2) and protein kinase B (PKB) were implicated in the development of pathological cardiac hypertrophy. The present study examined whether the progression of physiological eccentric cardiac hypertrophy was associated with ERK1/2 and PKB recruitment.

Methods And Results: Following 1 and 3 wk of voluntary exercise, female Sprague-Dawley rats ran a total distance of 55 +/- 10 and 195 +/- 19 km, respectively.

Nitric oxide-mediated inhibition of DNA synthesis was attenuated in hypertrophied neonatal rat ventricular myocytes.

The antiproliferative action of nitric oxide (NO) has been well established and increased production was reported in the infarcted rat heart. Concomitantly, increased DNA synthesis and hyperplasia of cardiac myocytes were documented in the hypertrophied myocardium. Despite these observations, the effect of NO on DNA synthesis in hypertrophied cardiac myocytes remains unexamined.

Scar myofibroblasts of the infarcted rat heart express natriuretic peptides.

The present study examined whether natriuretic peptide expression in the scar of post-myocardial infarcted (MI) rats was derived at least in part by residing myofibroblasts. ANP and BNP mRNA levels were significantly increased in the non-infarcted left ventricle and scar of 1-week post-MI male rats, as compared to the left ventricle of normal rats. The infarct region contained myofibroblasts and contracted cardiac myocytes residing predominantly in the epicardial border zone.

Resident nestin+ neural-like cells and fibers are detected in normal and damaged rat myocardium.

The present study examined whether nestin+ neural-like stem cells detected in the scar tissue of rats 1 week after myocardial infarction (MI) were derived from bone marrow and/or were resident cells of the normal myocardium. Irradiated male Wistar rats transplanted with beta-actin promoter-driven, green fluorescent protein (GFP)-labeled, unfractionated bone marrow cells were subjected to coronary artery ligation. Three weeks after MI, GFP-labeled bone marrow cells were detected in the infarct region, and a modest number were associated with nestin immunoreactivity.

Nestin-expressing neural stem cells identified in the scar following myocardial infarction.

Nerve fiber innervation of the scar following myocardial damage may have occurred either via the growth of pre-existing fibers and/or the mobilization of neural stem cells. The present study examined whether neural stem cells were recruited to the infarct region of the rat heart following coronary artery ligation. The neural stem cell marker nestin was detected in the infarct region of 1-week post-myocardial infarct (MI) male rats and cultured scar-derived neural-like cells.

Bradykinin metabolism in rat hearts with left-ventricular hypertrophy following myocardial infarction.

The aim of the present study was to assess the contribution of angiotensin I converting enzyme (ACE)and neutral endopeptidase (NEP) in the coronary degradation of bradykinin (BK) after left-ventricular hypertrophy following myocardial infarction (MI) in rats. Myocardial infarction was induced by left descendant coronary artery ligation, and the contribution of ACE and NEP in the degradation of exogenous BK after a single passage through the coronary bed was assessed at 2, 5, and 36 days post-MI. BK degradation rate (V(max)/Km) was found to be significantly lower in hearts at 36 days (3.

AT1 receptor antagonist therapy preferentially ameliorated right ventricular function and phenotype during the early phase of remodeling post-MI.

1. The influence of AII on contractile dysfunction, regulation of the tyrosine kinase-dependent signaling molecule extracellular signal-regulated kinase (ERK), and natriuretic peptide gene expression were examined in the noninfarcted left ventricle (NILV) and right ventricle (RV) during the early phase of remodeling post-myocardial infarct (MI) in the rat. The selective AT(1) receptor antagonist irbesartan was administered <10 h following coronary artery ligation, and rats were killed either at 4-day or 2-week post-MI.

Beta-adrenergic receptor-mediated DNA synthesis in neonatal rat cardiac fibroblasts proceeds via a phosphatidylinositol 3-kinase dependent pathway refractory to the antiproliferative action of cyclic AMP.

The following study was undertaken to elucidate the cytoskeletal phenotype of neonatal rat cardiac fibroblasts (NNCF) and the signaling pathways coupled to beta-adrenergic receptor stimulated DNA synthesis. The cytoskeletal proteins vimentin, and smooth muscle alpha-actin were detected in NNCF, suggestive of a myofibroblast phenotype. Isoproterenol (ISO) treatment stimulated (3)H-thymidine uptake, and concomitantly increased intracellular cyclic AMP levels.

Elevated mean arterial pressure in the ovariectomized rat was normalized by ET(A) receptor antagonist therapy: absence of cardiac hypertrophy and fibrosis.

1. The influence of menopause on ventricular function and remodelling remains undefined. The following study examined the effect of ovariectomy on ventricular contractility, cardiac hypertrophy and extracellular matrix protein expression.