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Published on: October 18, 2014
Evaluation of Tyrosine Kinase Inhibitors Loaded Injectable Hydrogels for Improving Connexin43 Gap Junction
Li Zheng1, Wen Shi2,3, Bo Liu2,3
1Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.
Abstract:
Myocardial infarction (MI) is one of the leading causes of death in the developed world, and the loss of cardiomyocytes plays a critical role in the pathogenesis of heart failure. Implicated in this process is a decrease in gap junction intercellular communication due to remodeling of Connexin43 (Cx43). We previously identified that intraperitoneal injection of the Pyk2 inhibitor PF4618433 reduced infarct size, maintained Cx43 at the intercalated disc in left ventricle hypertrophic myocytes, and improved cardiac function in an MI animal model of heart failure. With the emergence of injectable hydrogels as a therapeutic toward the regeneration of cardiac tissue after MI, here, we provide proof of concept that the release of tyrosine kinase inhibitors from hydrogels could have beneficial effects on cardiomyocytes. We developed an injectable hydrogel consisting of thiolated hyaluronic acid and P123-maleimide micelles that can incorporate PF4618433 as well as the Src inhibitor Saracatinib and achieved sustained release (of note, Src activates Pyk2). Using neonatal rat ventricular myocytes in the presence of a phorbol ester, endothelin-1, or phenylephrine to stimulate cardiac hypertrophy, the release of PF4618433 from the hydrogel had the same ability to decrease Cx43 tyrosine phosphorylation and maintain Cx43 localization at the plasma membrane as when directly added to the growth media. Additional beneficial effects included decreases in apoptosis, the hypertrophic marker atrial natriuretic peptide (ANP), and serine kinases upregulated in hypertrophy. Finally, the presence of both PF4618433 and Saracatinib further decreased the level of ANP and apoptosis than each inhibitor alone, suggesting that a combinatorial approach may be most beneficial. These findings provide the groundwork to test if tyrosine kinase inhibitor release from hydrogels will have a beneficial effect in an animal model of MI-induced heart failure.
Insights
Injectable hydrogels releasing tyrosine kinase inhibitors show promise for treating heart failure after myocardial infarction (MI). This approach maintains critical proteins and reduces cell death, offering a new therapeutic avenue.
Area of Science:
- Cardiovascular Research
- Biomaterials Science
- Pharmacology
Background:
- Myocardial infarction (MI) leads to cardiomyocyte loss and heart failure, partly due to reduced gap junction communication from Connexin43 (Cx43) remodeling.
- Previous studies showed Pyk2 inhibitor PF4618433 reduced infarct size and improved cardiac function in MI models.
- Injectable hydrogels offer a promising platform for cardiac tissue regeneration post-MI.
Purpose of the Study:
- To provide proof of concept for using injectable hydrogels to deliver tyrosine kinase inhibitors for treating MI-induced heart failure.
- To investigate the effects of sustained release of PF4618433 and Saracatinib from a hyaluronic acid-based hydrogel on cardiomyocytes.
Main Methods:
- Developed an injectable hydrogel incorporating PF4618433 (Pyk2 inhibitor) and Saracatinib (Src inhibitor).
- Utilized neonatal rat ventricular myocytes stimulated to induce cardiac hypertrophy.
- Assessed Cx43 phosphorylation, plasma membrane localization, apoptosis, and atrial natriuretic peptide (ANP) levels.
Main Results:
- Hydrogel-released PF4618433 effectively decreased Cx43 tyrosine phosphorylation and maintained its plasma membrane localization, similar to direct addition.
- The hydrogel formulation reduced apoptosis and ANP levels, key markers of cardiac hypertrophy and damage.
- A combination of PF4618433 and Saracatinib demonstrated superior reduction in ANP and apoptosis compared to individual inhibitors.
Conclusions:
- Sustained release of tyrosine kinase inhibitors from injectable hydrogels is a viable strategy to protect cardiomyocytes and mitigate hypertrophy.
- Combinatorial therapy with PF4618433 and Saracatinib shows enhanced efficacy, suggesting a promising approach for MI treatment.
- These findings lay the foundation for future in vivo studies of hydrogel-based tyrosine kinase inhibitor delivery in MI models.
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