Genetic Background of Hirschsprung Disease: A Bridge Between Basic Science and Clinical Application

Hirschsprung's disease (HSCR) is a congenital disorder, defined by partial or complete loss of the neuronal ganglion cells in the intestinal tract, which is caused by the failure of neural crest cells to migrate completely during intestinal development during fetal life. HSCR has a multifactorial etiology, and genetic factors play a key role in its pathogenesis; these include mutations within several gene loci. These have been identified by screening candidate genes, or by conducting genome wide association (GWAS) studies. However, only a small portion of them have been proposed as major genetic risk factors for the HSCR. In this review, we focus on those genes that have been identified as either low penetrant or high penetrant variants that determine the risk of Hirschsprung's disease. J. Cell. Biochem. 119: 28–33, 2018. © 2017 Wiley Periodicals, Inc.     

Dopaminergic differentiation using pluripotent stem cells

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The motor symptoms of PD are caused by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta of mesencephalon. The causes for death of DA neurons are not well understood, but the strongest risk factor is increasing age. There is no cure currently available for PD, and treatment is limited to management of PD symptoms in patients. Primary DA neurons are virtually unobtainable from living patients and animal studies have proven inadequate for studying the mechanism of PD development. Pluripotent stem cells (PSC) are primary self‐renewing cells capable of differentiating into all cell types of an organism, including DA neurons. PSCs represent an abundant source of cells that can be genetically modified or isolated from patients with complex diseases, enabling the production of large quantities of DA neurons for disease modeling, drug screening, and gene function studies. Furthermore, since PD arises as a result of deterioration of DA neurons in a specific brain region, it has been suggested that a relatively small number of cells could restore normal function. PSCs could provide a source of DA neurons for cell replacement therapy. In this Prospects article, we focus on the development and in vitro derivation of DA neurons from PSCs, as well as current applications of the technological advances, with the emphasis on future directions and efforts in the field. J. Cell. Biochem. 113: 3610–3619, 2012. © 2012 Wiley Periodicals, Inc.     

α-Tocopherol supplementation does not affect monocyte endothelial adhesion or C-reactive protein levels but reduces soluble vascular adhesion molecule-1 in the plasma of healthy subjects

Abstract

Vascular monocyte retention in the subintima is pivotal to the development of cardiovascular disease and is facilitated by up-regulation of adhesion molecules on monocytes/endothelial cells during oxidative stress. Epidemiological studies have shown that cardiovascular disease risk is inversely proportional to plasma levels of the dietary micronutrients, vitamin C and vitamin E (α-tocopherol). We have tested the hypothesis that α-tocopherol supplementation may alter endothelial/monocyte function and interaction in subjects with normal ascorbate levels (> 50 μM), as ascorbate has been shown to regenerate tocopherol from its oxidised tocopheroxyl radical form in vitro. Healthy male subjects received α-tocopherol supplements (400 IU RRR-α-tocopherol/day for 6 weeks) in a placebo-controlled, double-blind intervention study. There were no significant differences in monocyte CD11b expression, monocyte adhesion to endothelial cells, plasma C-reactive protein or sICAM-1 concentrations post-supplementation. There was no evidence for nuclear translocation of NF-κB in isolated resting monocytes, nor any effect of α-tocopherol supplementation. However, post-supplementation, sVCAM-1 levels were decreased in all subjects and sE-selectin levels were increased in the vitamin C-replete group only; a weak positive correlation was observed between sE-selectin and α-tocopherol concentration. In conclusion, α-tocopherol supplementation had little effect on cardiovascular disease risk factors in healthy subjects and the effects of tocopherol were not consistently affected by plasma vitamin C concentration.     

Stem cells as promising therapeutic options for neurological disorders

Due to the limitations of pharmacological and other current therapeutic strategies, stem cell therapies have emerged as promising options for treating many incurable neurologic diseases. A variety of stem cells including pluripotent stem cells (i.e., embryonic stem cells and induced pluripotent stem cells) and multipotent adult stem cells (i.e., fetal brain tissue, neural stem cells, and mesenchymal stem cells from various sources) have been explored as therapeutic options for treating many neurologic diseases, and it is becoming obvious that each type of stem cell has pros and cons as a source for cell therapy. Wise selection of stem cells with regard to the nature and status of neurologic dysfunctions is required to achieve optimal therapeutic efficacy. To this aim, the stem cell‐mediated therapeutic efforts on four major neurological diseases, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and stroke, will be introduced, and current problems and future directions will be discussed. J. Cell. Biochem. 114: 743–753, 2013. © 2012 Wiley Periodicals, Inc.     

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. Scar myofibroblasts, neonatal and adult ventricular fibroblasts express smooth muscle α-actin, collagen α(1) type 1 and a panel of pro-fibrotic and pro-angiogenic peptide growth factor mRNAs. Myofibroblasts plated alone on matrigel led to the self assembly of lumen-like structures whereas neonatal and adult rat ventricular fibroblasts were unresponsive. Myofibroblasts labeled with the fluorescent cell tracker CM-DiI were injected in the viable myocardium of 3-day post-myocardial infarcted Sprague-Dawley rats and sacrificed 7 days later. Injected CM-DiI-labeled myofibroblasts were detected predominantly in the peri-infarct/infarct region, highlighting their migration to the damaged region. However, engrafted myofibroblasts in the peri-infarct/infarct region were unable to adopt an endothelial cell-like phenotype or lead to the de novo formation of CM-DiI-labeled blood vessels. The non-permissive nature of the infarct region may be attributed at least in part to the presence of growth-promoting stimuli as TGF-β and the β-adrenergic agonist isoproterenol inhibited the self assembly of lumen-like structures by myofibroblasts. Thus, when plated in a permissive in vitro environment, scar myofibroblasts can self assemble and form lumen-like structures providing an additional novel phenotype distinguishing this population from normal ventricular fibroblasts.     

Advance in research of microRNA in Caenorhabditis elegans

microRNA (miRNA) is a family of small, non‐coding RNA first discovered as an important regulator of development in Caenorhabditis elegans (C. elegans). Numerous miRNAs have been found in C. elegans, and some of them are well conserved in many organisms. Though, the biologic function of miRNAs in C. elegans was largely unknown, more and more studies support the idea that miRNA is an important molecular for C. elegans. In this review, we revisit the research progress of miRNAs in C. elegans related with development, aging, cancer, and neurodegenerative diseases and compared the function of miRNAs between C. elegans and human. J. Cell. Biochem. 114: 994–1000, 2013. © 2012 Wiley Periodicals, Inc.     

Evidence of reactive oxygen species generation in synovial fluid from patients with temporomandibular disease by electron spin resonance spectroscopy

Abstract

Reactive oxygen species (ROS) have been implicated in the pathogenesis of temporomandibular disorders. In the present study, we provide the first evidence of ROS generation in the synovial fluid from human temporomandibular disorder patients, as shown by electron spin resonance (ESR) and spin trapping. Three distinct ESR spectra of DMPO spin adducts were observed in the synovial fluid. They corresponded to three free radical species: hydroxyl radical (HO^?), hydrogen radical (H^?), and carbon-center radical (R^?). Among them, the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OH spectrum was the most prominent, suggesting that HO^? was dominantly generated in the synovial fluid from temporomandibular disorder patients. Desferrioxamine (DFO), an iron chelator, strongly depressed the DMPO-OH signal intensity in the synovial fluid from patients with temporomandibular disorders. We successfully demonstrated ROS-induced oxidative stress in the synovial fluid from temporomandibular disorder patients. ROS generation in the temporomandibular joint could lead to exacerbation of inflammation and activation of cartilage matrix degrading enzymes that proceed to degenerative change of the temporomandibular joint. Thus, iron-dependent generation of HO ^? might have a crucial role in the pathogenesis of temporomandibular disorders.     

Combined effect of 3-aminobenzamide and N-acetylcysteine on HIV replication in chronically infected U937 cells

Summary

The existence of a close relationship between apoptosis associated with oxidative stress and the increase of viral progeny in chronically HIV-infected cells has been previously reported. The possibility of modulating both phenomena by using an antioxidant such as N-acetylcysteine (NAC) has also been demonstrated. The present investigation was designed to study the role of the nuclear enzyme poly-(ADP-ribose)-polymerase (PARP) when HIV- infected cells are treated with tumour necrosis factor alpha (TNFα), a cytokine capable of inducing both apoptosis and intracellular oxygen free radical production. PARP overexpression may result in a rapid drop of intracellular NAD⁺ and ATP concentration, thus contributing to cellular redox imbalance. We have used the specific PARP inhibitor 3- aminobenzamide (3-ABA), alone or in a combination with NAC. 3-ABA was only partially capable of inhibiting viral replication and apoptosis induced by TNFα. In contrast, the combination of NAC and 3-ABA led to an inhibition of apoptosis as well as to a marked decrease in viral particle production, with a parallel replenishment of intracellular reduced glutathione content. The results reported here confirm the potential role of antioxidant drug treatment in specific phases of HIV infection.     

Oxidative-mechanical stress signals stem cell niche mediated Lrp5 osteogenesis in eNOS(-/-) null mice

Calcific aortic valve disease (CAVD) is the most common indication for valve surgery in the USA. This study hypothesizes that CAVD develops secondary to Wnt3a/Lrp5 activation via oxidative‐mechanical stress in eNOS null mice. eNOS^?/? mice were tested with experimental diets including a control (n = 20), cholesterol (n = 20), cholesterol + Atorvastatin (n = 20). After 23 weeks the mice were tested for the development of aortic stenosis by Echo, Histology, MicroCT, and RTPCR for bone markers. In vitro studies measured Wnt3a secretion from aortic valve endothelial cells and confirmed oxidative stress via eNOS activity. Anion exchange chromatography was performed to isolate the mitogenic protein. Myofibroblast cells were tested to induce bone formation. Cholesterol treated eNOS mice develop severe stenosis with an increase in Wnt3a, Lrp5, Runx2 (threefold increase (P < 0.0001) in the bicuspid versus tricuspid aortic valves. Secretion of Wnt3a from aortic valve endothelium in the presence of abnormal oxidative stress was correlated with diminished eNOS enzymatic activity and tissue nitrite levels. Initial characterization of the architecture for a stem cell nice was determined by protein isolation using anion‐exchange chromatography and cell proliferation via thymidine incorporation. Osteoblastogenesis in the myofibroblast cell occurred via Lrp5 receptor upregulation in the presence of osteogenic media. Targeting the Wnt3a/Lrp5 pathway in valve calcification and activation of osteogenesis is via an oxidative‐mechanical stress in CAVD. These findings provide a foundation for treating this disease process by targeting the cross talk mechanism in a resident stem cell niche. J. Cell. Biochem. 113: 1623–1634, 2012. © 2011 Wiley Periodicals, Inc.