Electrophysiological Studies of Ion Channels and Therapeutic Potential With Adenovirus- Mediated Gene Transfer

2003 ◽  
pp. 179-212
Author(s):  
Jihong Qu ◽  
Thai V. Pham ◽  
Maria N. Obreztchikova
Author(s):  
Yoshiyuki Kojima ◽  
Kentaro Mizuno ◽  
Yukihiro Umemoto ◽  
Shoichi Sasaki ◽  
Yutaro Hayashi ◽  
...  

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Yoriko Yamazato ◽  
KwonHo Hong ◽  
Dae Song Jang ◽  
Anderson J Ferreira ◽  
Masanobu Yamazato ◽  
...  

Pulmonary hypertension (PH) is characterized by increase in pulmonary vascular resistance, and narrowing and loss of pulmonary microvasculare. There is an indispensable need to develop innovative approaches for its control since PH becomes refractory to current therapies in later stages. Recent discovery of angiotensin converting enzyme 2 (ACE2), its involvement in cardiac remodeling, coupled with the limited success of ACE inhibitors in PH has led us to hypothesize that shifting the balance of renin-angiotensin system (RAS) to vasoprotective ACE2-Ang1–7- mas receptor axis would result the beneficial outcome in PH. We tested this hypothesis with the use of ACE2 overexpression in lungs by lentiviral vector-mediated gene transfer. Lentiviral vector particle(3x10^8 TU) containing murine ACE2 (letni-ACE2) were injected into 6 weeks old C57BL/6 mice prior to induction of PH by administration of weekly 600 mg/kg of monocrotaline (MCT) for 8 weeks for prevention studies. In addition, lenti-ACE2 was delivered following 6 weeks MCT treatment in reversal studies. Right ventricle systolic pressure (RVSP), Real-time RT-PCR, immunohisitochemistory of ACE2 and Ang (1–7) and histology of lungs in control and lent-ACE2 treated mice were carried out to evaluated the outcome on PH. Delivery of lenti-ACE2 resulted in a long-term increase in ACE2 expression in the lungs. A 60% and 100 % increases in protein and mRNA levels for ACE2 were observed. ACE2 and Ang (1–7) immunoreactivity were observed in epithelial and alveolar cells and alveolar macrophages. MCT treatment increased in RVSP (MCT 44.5+/−5.7 mmHg, control 24+/−1.0mmHg), RV hypertrophy (RV/LV+Sp ratio; 0.31+/−0.01), and wall thickness of pulmonary vessels. ACE2 gene transfer prevented increases in RVSP (26.1+/− 1.1mmHg), and RV hypertrophy (0.26+/−0.1), and reduced vessel wall thickness. In addition, ACE2 overexpression resulted in a significant reversal of RVSP (23.5+/−0.6mmHg). Futhermore, ACE2 overexpression in mice exhibited better general appearance and gained weight compared to MCT-treated mice. ACE2 gene transfer to lungs prevents and reverses vascular remodeling and PH in MCT model of PH. These observations suggest that targeting of pulmonary ACE2 holds novel therapeutic potential for PH.


2021 ◽  
Vol 14 ◽  
Author(s):  
Deepanjali Dwivedi ◽  
Upinder S. Bhalla

SK, HCN, and M channels are medium afterhyperpolarization (mAHP)-mediating ion channels. The three channels co-express in various brain regions, and their collective action strongly influences cellular excitability. However, significant diversity exists in the expression of channel isoforms in distinct brain regions and various subcellular compartments, which contributes to an equally diverse set of specific neuronal functions. The current review emphasizes the collective behavior of the three classes of mAHP channels and discusses how these channels function together although they play specialized roles. We discuss the biophysical properties of these channels, signaling pathways that influence the activity of the three mAHP channels, various chemical modulators that alter channel activity and their therapeutic potential in treating various neurological anomalies. Additionally, we discuss the role of mAHP channels in the pathophysiology of various neurological diseases and how their modulation can alleviate some of the symptoms.


2005 ◽  
Vol 288 (6) ◽  
pp. R1432-R1437 ◽  
Author(s):  
Noritoshi Nagaya ◽  
Hidezo Mori ◽  
Shinsuke Murakami ◽  
Kenji Kangawa ◽  
Soichiro Kitamura

Adrenomedullin (AM) is a potent, long-lasting vasodilator peptide that was originally isolated from human pheochromocytoma. AM signaling is of particular significance in endothelial cell biology since the peptide protects cells from apoptosis, promotes angiogenesis, and affects vascular tone and permeability. The angiogenic effect of AM is mediated by activation of Akt, mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2, and focal adhesion kinase in endothelial cells. Both AM and its receptor, calcitonin receptor-like receptor, are upregulated through a hypoxia-inducible factor-1-dependent pathway under hypoxic conditions. Thus AM signaling plays an important role in the regulation of angiogenesis in hypoxic conditions. Recently, we have developed a nonviral vector, gelatin. Positively charged gelatin holds negatively charged plasmid DNA in its lattice structure. DNA-gelatin complexes can delay gene degradation, leading to efficient gene transfer. Administration of AM DNA-gelatin complexes induces potent angiogenic effects in a rabbit model of hindlimb ischemia. Thus gelatin-mediated AM gene transfer may be a new therapeutic strategy for the treatment of tissue ischemia. Endothelial progenitor cells (EPCs) play an important role in endothelial regeneration. Interestingly, EPCs phagocytose ionically linked DNA-gelatin complexes in coculture, which allows nonviral gene transfer into EPCs. AM gene transfer into EPCs inhibits cell apoptosis and induces proliferation and migration, suggesting that AM gene transfer strengthens the therapeutic potential of EPCs. Intravenous administration of AM gene-modified EPCs regenerate pulmonary endothelium, resulting in improvement of pulmonary hypertension. These results suggest that in vivo and in vitro transfer of AM gene using gelatin may be applicable for intractable cardiovascular disease.


2019 ◽  
Vol 10 ◽  
Author(s):  
Aurélien Haustrate ◽  
Aline Hantute-Ghesquier ◽  
Natalia Prevarskaya ◽  
V’yacheslav Lehen’kyi

2020 ◽  
Vol 21 (4) ◽  
pp. 1285 ◽  
Author(s):  
Eider Núñez ◽  
Arantza Muguruza-Montero ◽  
Alvaro Villarroel

Intracellular calcium is essential for many physiological processes, from neuronal signaling and exocytosis to muscle contraction and bone formation. Ca2+ signaling from the extracellular medium depends both on membrane potential, especially controlled by ion channels selective to K+, and direct permeation of this cation through specialized channels. Calmodulin (CaM), through direct binding to these proteins, participates in setting the membrane potential and the overall permeability to Ca2+. Over the past years many structures of complete channels in complex with CaM at near atomic resolution have been resolved. In combination with mutagenesis-function, structural information of individual domains and functional studies, different mechanisms employed by CaM to control channel gating are starting to be understood at atomic detail. Here, new insights regarding four types of tetrameric channels with six transmembrane (6TM) architecture, Eag1, SK2/SK4, TRPV5/TRPV6 and KCNQ1–5, and its regulation by CaM are described structurally. Different CaM regions, N-lobe, C-lobe and EF3/EF4-linker play prominent signaling roles in different complexes, emerging the realization of crucial non-canonical interactions between CaM and its target that are only evidenced in the full-channel structure. Different mechanisms to control gating are used, including direct and indirect mechanical actuation over the pore, allosteric control, indirect effect through lipid binding, as well as direct plugging of the pore. Although each CaM lobe engages through apparently similar alpha-helices, they do so using different docking strategies. We discuss how this allows selective action of drugs with great therapeutic potential.


Author(s):  
Andrey Rozenberg ◽  
Johannes Oppermann ◽  
Jonas Wietek ◽  
Rodrigo Gaston Fernandez Lahore ◽  
Ruth-Anne Sandaa ◽  
...  

ABSTRACTChannelrhodopsins (ChRs) are algal light-gated ion channels widely used as optogenetic tools for manipulating neuronal activity 1,2. Four ChR families are currently known. Green algal 3–5 and cryptophyte 6 cation-conducting ChRs (CCRs), cryptophyte anion-conducting ChRs (ACRs) 7, and the MerMAID ChRs 8. Here we report the discovery of a new family of phylogenetically distinct ChRs encoded by marine giant viruses and acquired from their unicellular green algal prasinophyte hosts. These previously unknown viral and green algal ChRs act as ACRs when expressed in cultured neuroblastoma-derived cells and are likely involved in behavioral responses to light.


Oncoscience ◽  
2017 ◽  
Vol 4 (11-12) ◽  
pp. 199-214 ◽  
Author(s):  
Lucrecia Agnetti ◽  
Chiara Fondello ◽  
Marcela S. Villaverde ◽  
Gerardo C. Glikin ◽  
Liliana M.E. Finocchiaro

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Lisa M Tilemann ◽  
Kiyotake Ishikawa ◽  
Changwon Kho ◽  
Ahyoung Lee ◽  
Jaime Aguero ◽  
...  

Recently, small ubiquitin-related modifier 1 (SUMO1) was found to enhance the activity and stability of the cardiac sarcoplasmic reticulum Ca2+ ATPase, SERCA2a. In both, human and rodent models of heart failure (HF), the total amount of myocardial SUMO1 is decreased and its knock down results in severe HF. Adeno-associated vector (AAV) mediated SUMO1 gene transfer significantly improves cardiac function in murine models of HF. As a critical step towards clinical translation, we evaluated the effects of SUMO1 gene transfer in a swine model of ischemic heart failure. One month after balloon occlusion of the proximal LAD, 21 animals were randomized to receive either AAV1.SUMO1 at two doses, AAV1.SERCA2a, AAV1.SUMO1+AAV1.SERCA2a, or saline via antegrade coronary infusion. In addition, three pigs served as controls and underwent sham procedures. The ejection fraction and the maximum dP/dt significantly increased after gene transfer of SUMO1 at both doses, SERCA2a and the combination of SUMO1 and SERCA2a (p=0.034, p=0.028) compared to saline infusion. The increase in maximum dP/dt was most pronounced in the group that received both SUMO1 and SERCA2a. Furthermore, the increase in end-systolic and end-diastolic volumes was normalized in the treatment groups, while they further deteriorated in the saline group (p=0.001, p=0.022). SUMO1 and SERCA2a gene transfer significantly improved cardiac function and concomitant gene delivery of SUMO1 and SERCA2a had a synergistic effect on improving these parameters in the HF animals. These results strongly support the critical role of SUMO1 for SERCA2a function and underline the therapeutic potential in heart failure patients.


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