Engineered biological pacemakers
Inventors
Maltsev, Victor • Lakatta, Edward G. • Zahanich, Ihor • Sirenko, Syevda • Mikheev, Maxim • Vodovotz, Yoram
Assignees
University of Pittsburgh • US Department of Health and Human Services
Publication Number
US-9506032-B2
Publication Date
2016-11-29
Expiration Date
2030-05-21
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Biological pacemakers engineered to intrinsically generate rhythmic excitations are disclosed. In addition, methods of producing the biological pacemakers are disclosed. Methods of treating or preventing arrhythmia and heart disease associated with a defective pacemakers are also disclosed.
Core Innovation
The invention relates to biological pacemakers engineered to intrinsically generate rhythmic electric excitations that are sustained and rhythmic, similar to natural pacemakers. These biological pacemakers comprise electrically excitable cells, such as cardiac cells derived in vitro from embryonic stem cells, mesenchymal stem cells, or induced pluripotent stem cells (iPS cells), with elevated intracellular cAMP levels, increased PKA activity, or increased CaMK II activity. The invention uses genes expressing regulatory proteins that modulate intracellular cAMP and CaMK II activity to enhance the functional coupling of intracellular Ca2+ clocks and membrane clocks to produce spontaneous rhythmic excitations.
The problem being solved is the limitation of existing electronic pacemakers and prior biological approaches. Electronic pacemakers have limited lifetime due to battery dependency, lack physiological response characteristics, risk infection, and may be affected by other device interference. Prior biological methods, including gene targeting of ion channels or implantation of cells expressing HCN channels, either failed to produce sustained rhythmicity or depended on extrinsic stimulation. Embryonic stem cell-derived pacemaker cells generate irregular or arrhythmogenic action potentials and lack reliable rhythmicity, limiting their therapeutic use.
The invention addresses these problems by characterizing the integrative function of intracellular Ca2+ cycling (Ca2+ clock) and surface membrane voltage clocks (membrane clock) in embryonic stem cell-derived cardiomyocytes, showing that elevated basal cAMP/PKA and/or CaMK II activities enhance coupling of these clocks. This coupling produces consistent, rhythmic, and sustained spontaneous action potentials, enabling the production of biological pacemakers that operate autonomously and mimic natural sinoatrial node pacemaker cells. The approach includes genetic engineering of cells with genes encoding Ca2+-activated adenylyl cyclases (e.g., type 1 or 8) or CaMK II to maintain this elevated signaling.
Claims Coverage
The patent includes one independent claim focused on a method of producing a biological pacemaker in vivo by gene delivery to cardiomyocytes.
In vivo gene delivery of adenylyl cyclase to cardiomyocytes
Administering a viral vector comprising nucleic acid encoding an adenylyl cyclase into electrically excitable cardiomyocytes of a patient's heart to induce expression of the adenylyl cyclase protein sufficient to produce rhythmic local Ca2+ releases resulting in sustained rhythmic beating of those cardiomyocytes.
Targeting specific cardiac regions
The cardiomyocytes targeted are located in the right ventricle, right atrium, sinoatrial node, or atrioventricular node.
Expression of Ca2+-activated adenylyl cyclases
The adenylyl cyclase protein expressed is selected from Ca2+-activated adenylyl cyclase type 1, type 8, or their combination, which modulates Ca2+ clock and membrane clock activities in the cardiomyocytes.
Use of viral vectors with control sequences
Employing viral vectors such as adenoviral associated, herpes, or retroviral vectors containing control sequences including transcription initiation regions, termination regions, inverted terminal repeats, promoters, and optionally cardiac-specific promoters or cardiac enhancers to drive gene expression.
The claims focus on methods for producing sustained rhythmic biological pacemakers via in vivo gene delivery of Ca2+-activated adenylyl cyclases to electrically excitable cardiac cells, targeting key cardiac regions, and employing appropriate viral vectors with regulatory elements for controlled expression.
Stated Advantages
Biological pacemakers are engineered to generate rhythmic, sustained intrinsic electric excitations similar to natural pacemakers without reliance on external power sources.
The engineered pacemakers address limitations of electronic pacemakers, such as battery life, lack of physiological response, risk of infection, and interference from other devices.
Elevated intracellular cAMP/PKA and CaMK II activity ensure strong coupling of Ca2+ clock and membrane clock mechanisms, producing stable and rhythmic pacemaker activity.
The invention enables conversion of irregular or nonrhythmic electrically excitable cells into highly efficient biological pacemakers.
Documented Applications
Methods of treating or preventing arrhythmia and heart diseases associated with defective cardiac pacemakers by administering engineered biological pacemakers into the heart.
Implantation or gene delivery of biological pacemakers into cardiac regions including the left or right atrial muscle, sinoatrial node, atrioventricular junctional region, and components of the conduction system such as Bachman's bundle, His bundle, bundle branches, or Purkinje fibers for restoration of rhythmic cardiac pacing.
Interested in licensing this patent?