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Optogenetics-enabled assessment of viral gene and cell therapy for restoration of cardiac excitability.

Ambrosi CM, Boyle PM, Chen K, Trayanova NA, Entcheva E - Sci Rep (2015)

Bottom Line: Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias).Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation.More generally, our findings can help optimize gene therapy for restoration of cardiac excitability.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY.

ABSTRACT
Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias). In addition to electronic device therapy (i.e. implantable pacemakers and cardioverter/defibrillators), biological approaches have recently been explored to restore pacemaking ability and to correct conduction slowing in the heart by delivering excitatory ion channels or ion channel agonists. Using optogenetics as a tool to selectively interrogate only cells transduced to produce an exogenous excitatory ion current, we experimentally and computationally quantify the efficiency of such biological approaches in rescuing cardiac excitability as a function of the mode of application (viral gene delivery or cell delivery) and the geometry of the transduced region (focal or spatially-distributed). We demonstrate that for each configuration (delivery mode and spatial pattern), the optical energy needed to excite can be used to predict therapeutic efficiency of excitability restoration. Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation. More generally, our findings can help optimize gene therapy for restoration of cardiac excitability.

No MeSH data available.


Related in: MedlinePlus

Patterned light-sensitive cardiac syncytia in vitro.(a–c) Binarized panoramic images (based on eYFP fluorescence) showing the island (I), uniform low (UL), and uniform high (UH) spatial distributions of light-sensitive (white) and non-transduced (black) myocytes in monolayers with light sensitivity inscribed by gene delivery (GD). (d–f) Same as (a–c) but showing distributions of ChR2-rich donor cells (white) and myocytes (black) in monolayers with light sensitivity inscribed by cell delivery (CD). (g) Fraction of monolayer (by area) consisting of light-sensitive cells for the six configurations shown in (a–f). Data are presented as mean ± standard error of the mean. Scale bars are 1 mm.
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f2: Patterned light-sensitive cardiac syncytia in vitro.(a–c) Binarized panoramic images (based on eYFP fluorescence) showing the island (I), uniform low (UL), and uniform high (UH) spatial distributions of light-sensitive (white) and non-transduced (black) myocytes in monolayers with light sensitivity inscribed by gene delivery (GD). (d–f) Same as (a–c) but showing distributions of ChR2-rich donor cells (white) and myocytes (black) in monolayers with light sensitivity inscribed by cell delivery (CD). (g) Fraction of monolayer (by area) consisting of light-sensitive cells for the six configurations shown in (a–f). Data are presented as mean ± standard error of the mean. Scale bars are 1 mm.

Mentions: Experimentally, gene patterning techniques and gene titration (see Ambrosi et al.18 and the Materials and Methods section) were used for both delivery modalities (GD and CD) to obtain three principal transgene configurations: a consolidated island (I; Fig. 2a,d); a spatially uniform, low-density distribution (UL; Fig. 2b,e); and a spatially uniform, high-density distribution (UH; Fig. 2c,f). These distributions represent a range of opsin densities (D), as quantified in two dimensions (Fig. S1 and Movie S1), with ratios ranging from 0.02 ± 0.002 (GD-I) to 0.71 ± 0.02 (GD-UL) based on binarized versions of the imaged eYFP intensities (Fig. 2g). In addition to the transgene intensity profiles of the cells (Fig. 1c,f), the fraction of transduced cells (from the binarized images) was similar (not significantly different) between GD and CD configurations (e.g. 0.36 ± 0.02, GD-UL; 0.23 ± 0.02, CD-UL), allowing for direct comparisons of optical excitability between delivery modes.


Optogenetics-enabled assessment of viral gene and cell therapy for restoration of cardiac excitability.

Ambrosi CM, Boyle PM, Chen K, Trayanova NA, Entcheva E - Sci Rep (2015)

Patterned light-sensitive cardiac syncytia in vitro.(a–c) Binarized panoramic images (based on eYFP fluorescence) showing the island (I), uniform low (UL), and uniform high (UH) spatial distributions of light-sensitive (white) and non-transduced (black) myocytes in monolayers with light sensitivity inscribed by gene delivery (GD). (d–f) Same as (a–c) but showing distributions of ChR2-rich donor cells (white) and myocytes (black) in monolayers with light sensitivity inscribed by cell delivery (CD). (g) Fraction of monolayer (by area) consisting of light-sensitive cells for the six configurations shown in (a–f). Data are presented as mean ± standard error of the mean. Scale bars are 1 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664892&req=5

f2: Patterned light-sensitive cardiac syncytia in vitro.(a–c) Binarized panoramic images (based on eYFP fluorescence) showing the island (I), uniform low (UL), and uniform high (UH) spatial distributions of light-sensitive (white) and non-transduced (black) myocytes in monolayers with light sensitivity inscribed by gene delivery (GD). (d–f) Same as (a–c) but showing distributions of ChR2-rich donor cells (white) and myocytes (black) in monolayers with light sensitivity inscribed by cell delivery (CD). (g) Fraction of monolayer (by area) consisting of light-sensitive cells for the six configurations shown in (a–f). Data are presented as mean ± standard error of the mean. Scale bars are 1 mm.
Mentions: Experimentally, gene patterning techniques and gene titration (see Ambrosi et al.18 and the Materials and Methods section) were used for both delivery modalities (GD and CD) to obtain three principal transgene configurations: a consolidated island (I; Fig. 2a,d); a spatially uniform, low-density distribution (UL; Fig. 2b,e); and a spatially uniform, high-density distribution (UH; Fig. 2c,f). These distributions represent a range of opsin densities (D), as quantified in two dimensions (Fig. S1 and Movie S1), with ratios ranging from 0.02 ± 0.002 (GD-I) to 0.71 ± 0.02 (GD-UL) based on binarized versions of the imaged eYFP intensities (Fig. 2g). In addition to the transgene intensity profiles of the cells (Fig. 1c,f), the fraction of transduced cells (from the binarized images) was similar (not significantly different) between GD and CD configurations (e.g. 0.36 ± 0.02, GD-UL; 0.23 ± 0.02, CD-UL), allowing for direct comparisons of optical excitability between delivery modes.

Bottom Line: Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias).Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation.More generally, our findings can help optimize gene therapy for restoration of cardiac excitability.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY.

ABSTRACT
Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias). In addition to electronic device therapy (i.e. implantable pacemakers and cardioverter/defibrillators), biological approaches have recently been explored to restore pacemaking ability and to correct conduction slowing in the heart by delivering excitatory ion channels or ion channel agonists. Using optogenetics as a tool to selectively interrogate only cells transduced to produce an exogenous excitatory ion current, we experimentally and computationally quantify the efficiency of such biological approaches in rescuing cardiac excitability as a function of the mode of application (viral gene delivery or cell delivery) and the geometry of the transduced region (focal or spatially-distributed). We demonstrate that for each configuration (delivery mode and spatial pattern), the optical energy needed to excite can be used to predict therapeutic efficiency of excitability restoration. Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation. More generally, our findings can help optimize gene therapy for restoration of cardiac excitability.

No MeSH data available.


Related in: MedlinePlus