Schwann Cell Precursors Generate the Majority of Chromaffin Cells in Zuckerkandl Organ and Some Sympathetic Neurons in Paraganglia

In humans, neurosecretory chromaffin cells control a number of important bodily functions, including those related to stress response. Chromaffin cells appear as a distinct cell type at the beginning of midgestation and are the main cellular source of adrenalin and noradrenalin released into the blood stream. In mammals, two different chromaffin organs emerge at a close distance to each other, the adrenal gland and Zuckerkandl organ (ZO). These two structures are found in close proximity to the kidneys and dorsal aorta, in a region where paraganglioma, pheochromocytoma and neuroblastoma originate in the majority of clinical cases. Recent studies showed that the chromaffin cells comprising the adrenal medulla are largely derived from nerve-associated multipotent Schwann cell precursors (SCPs) arriving at the adrenal anlage with the preganglionic nerve fibers, whereas the migratory neural crest cells provide only minor contribution. However, the embryonic origin of the ZO, which differs from the adrenal medulla in a number of aspects, has not been studied in detail. The ZO is composed of chromaffin cells in direct contact with the dorsal aorta and the intraperitoneal cavity and disappears through an autophagy-mediated mechanism after birth. In contrast, the adrenal medulla remains throughout the entire life and furthermore, is covered by the adrenal cortex. Using a combination of lineage tracing strategies with nerve- and cell type-specific ablations, we reveal that the ZO is largely SCP-derived and forms in synchrony with progressively increasing innervation. Moreover, the ZO develops hand-in-hand with the adjacent sympathetic ganglia that coalesce around the dorsal aorta. Finally, we were able to provide evidence for a SCP-contribution to a small but significant proportion of sympathetic neurons of the posterior paraganglia. Thus, this cellular source complements the neural crest, which acts as a main source of sympathetic neurons. Our discovery of a nerve-dependent origin of chromaffin cells and some sympathoblasts may help to understand the origin of pheochromocytoma, paraganglioma and neuroblastoma, all of which are currently thought to be derived from the neural crest or committed sympathoadrenal precursors

Preoperative atrial mechanical dysfunction may predict postoperative atrial fibrillation after coronary artery bypass graft operation: a tissue Doppler and velocity vector imaging study

WOS: 000208702604479

Progressive subclinical left ventricular systolic dysfunction in severe aortic regurgitation patients with normal ejection fraction: A 24 months follow-up velocity vector imaging study

PubMed ID: 21906163Objectives: We aimed to evaluate long-term changes in left ventricular (LV) longitudinal systolic functions in patients with asymptomatic, severe aortic regurgitation (AR) by using novel 2D strain imaging. Methods and Results: Thirty severe AR patients with normal ejection fraction (EF) and 30 healthy controls were evaluated by both conventional echocardiography and velocity vector maging (VVI) based strain imaging at baseline and 24 months follow-up. To evaluate LV longitudinal systolic function, segmental peak systolic strain and strain rate (SRs) data were acquired from apical four-chamber, two-chamber and long-axis views. Longitudinal peak systolic strain and SRs of the LV were decreased in patients with severe AR compared to controls at baseline (P = 0.0001). The impairment was more significant in 24 months follow-up (P = 0.0001 for strain, P = 0.01 for SRs). Longitudinal peak systolic strain was significantly correlated with left ventricular end-diastolic (LVEDD; r =-0.42, P = 0.0001) and left ventricular end-systolic diameter (LVESD) (r =-0.41, P = 0.0001) There was also a strong negative correlation between LV SRs and LVEDD (r =-0.50, P = 0.0001), and LVESD (r =-0.39, P = 0.0001). Conclusions: VVI-derived strain and SRs may be used as adjunctive, noninvasive parameters in the assessment of subclinical LV dysfunction and its progress during clinical follow-up, in patients with severe AR. © 2011, Wiley Periodicals, Inc

Electrospun scaffolds for tissue engineering of vascular grafts

Abstract not availableAnwarul Hasan, Adnan Memic, Nasim Annabi, Monowar Hossain, Arghya Paul, Mehmet R. Dokmeci, Fariba Dehghani, Ali Khademhossein

Mesenchymal stem cells in regenerative rehabilitation

© 2016 The Society of Physical Therapy Science. [Purpose] Regenerative medicine and rehabilitation contribute in many ways to a specific plan of care based on a patient’s medical status. The intrinsic self-renewing, multipotent, regenerative, and immunosuppressive properties of mesenchymal stem cells offer great promise in the treatment of numerous autoimmune, degenerative, and graft-versus-host diseases, as well as tissue injuries. As such, mesenchymal stem cells represent a therapeutic fortune in regenerative medicine. The aim of this review is to discuss possibilities, limitations, and future clinical applications of mesenchymal stem cells. [Subjects and Methods] The authors have identified and discussed clinically and scientifically relevant articles from PubMed that have met the inclusion criteria. [Results] Direct treatment of muscle injuries, stroke, damaged peripheral nerves, and cartilage with mesenchymal stem cells has been demonstrated to be effective, with synergies seen between cellular and physical therapies. Over the past few years, several researchers, including us, have shown that there are certain limitations in the use of mesenchymal stem cells. Aging and spontaneous malignant transformation of mesenchymal stem cells significantly affect the functionality of these cells. [Conclusion] Definitive conclusions cannot be made by these studies because limited numbers of patients were included. Studies clarifying these results are expected in the near future

Rapid fabrication of highly porous and biocompatible composite textile tubular scaffold for vascular tissue engineering

Three dimensional (3D) constructs for vascular tissue engineering applications require scaffolds with highly porous architectures, high biocompatibility and mechanical stability. In this paper, composite fibrous tubular scaffolds composed of different ratios of poly(epsilon-caprolactone) (PCL) and polyamide-6 (PA-6) were simultaneously deposited layer by layer by employing the air jet spinning (AJS) textile technique. Specifically, we report on the optimal parameters for the fabrication of composite porous scaffolds that allow for precise control over the general scaffold architecture, as well as the physical and mechanical properties of the scaffolds. In vitro cell culture study was performed to investigate the influence of polymer composition and scaffold architecture on the adhesion of EA.hy926 human endothelial cells onto the fabricated scaffolds. The cell culture results indicated that a composite scaffold with low PA-6 fibrous content is the most promising substrate for EA.hy926 adhesion and proliferation. Based on the present findings, these highly porous composite tubular constructs support endothelial cell migration and cellular infiltration, and hence represent promising nano-fibrous scaffolds for vascular tissue engineering

Parasympathetic neurons originate from nerve-associated peripheral glial progenitors

The peripheral autonomic nervous system reaches far throughout the body and includes neurons of diverse functions, such as sympathetic and parasympathetic. We show that the parasympathetic system in mice--including trunk ganglia and the cranial ciliary, pterygopalatine, lingual, submandibular, and otic ganglia--arise from glial cells in nerves, not neural crest cells. The parasympathetic fate is induced in nerve-associated Schwann cell precursors at distal peripheral sites. We used multicolor Cre-reporter lineage tracing to show that most of these neurons arise from bi-potent progenitors that generate both glia and neurons. This nerve origin places cellular elements for generating parasympathetic neurons in diverse tissues and organs, which may enable wiring of the developing parasympathetic nervous system

Molecular Architecture of the Mouse Nervous System

The mammalian nervous system executes complex behaviors controlled by specialized, precisely positioned, and interacting cell types. Here, we used RNA sequencing of half a million single cells to create a detailed census of cell types in the mouse nervous system. We mapped cell types spatially and derived a hierarchical, data-driven taxonomy. Neurons were the most diverse and were grouped by developmental anatomical units and by the expression of neurotransmitters and neuropeptides. Neuronal diversity was driven by genes encoding cell identity, synaptic connectivity, neurotransmission, and membrane conductance. We discovered seven distinct, regionally restricted astrocyte types that obeyed developmental boundaries and correlated with the spatial distribution of key glutamate and glycine neurotransmitters. In contrast, oligodendrocytes showed a loss of regional identity followed by a secondary diversification. The resource presented here lays a solid foundation for understanding the molecular architecture of the mammalian nervous system and enables genetic manipulation of specific cell types. Single-cell transcriptional profiling of the adult mouse nervous system uncovers new cell classes and types across regions, providing a clearer picture of cell diversity by region and a reference atlas for studying the mammalian nervous system. © 2018 The Author