Background In acute decompensated heart failure (ADHF), noninvasive markers that predict morbidity and mortality are limited. Liver stiffness measurement (LSM) increases with hepatic fibrosis; however, it may be falsely elevated in patients with ADHF in the absence of liver disease. We investigated whether elevated LSM predicts cardiac outcomes in ADHF. Methods In a prospective study, we examined 52 ADHF patients without liver disease between 2016 and 2017. Patients underwent liver 2D shear wave elastography (SWE) and were followed for 12 months to assess the outcomes of left ventricular assist device (LVAD), heart transplant (HT) or death. Results The median LSM was elevated in patients who received an LVAD or HT within 30-days compared to those who did not (median [IQR]: 55.6 [22.5 - 63.4] vs 13.8 [9.5 - 40.3] kPa, p = .049). Moreover, the risk of composite outcome was highest in the 3rd tertile (> 39.8 kPa compared to 1(st) and 2(nd) combined, HR 2.83, 95% CI 1.20- 6.67, p = .02). Each 1-kPa increase in LSM was associated with a 1%-increase in the incidence rate of readmissions (IRR 1.01, 95% CI 1.00-1.02, p = .01). Conclusions LSM may serve as a novel noninvasive tool to determine LVAD, HT, or death in patients with ADHF.

Using endogenous mesenchymal stem cells for treating myocardial infarction and other cardiovascular conditions typically results in poor efficacy, in part owing to the heterogeneity of the harvested cells and of the patient responses. Here, by means of high-throughput screening of the combinatorial space of mechanical-strain level and of the presence of particular kinase inhibitors, we show that human mesenchymal stem cells can be mechanically and pharmacologically conditioned to enhance vascular regeneration in vivo. Mesenchymal stem cells conditioned to increase the activation of signalling pathways mediated by Smad2/3 (mothers against decapentaplegic homolog 2/3) and YAP (Yes-associated protein) expressed markers that are associated with pericytes and endothelial cells, displayed increased angiogenic activity in vitro, and enhanced the formation of vasculature in mice after subcutaneous implantation and after implantation in ischaemic hindlimbs. These effects were mediated by the crosstalk of endothelial-growth-factor receptors, transforming-growth-factor-beta receptor type 1 and vascular-endothelial-growth-factor receptor 2. Mechanical and pharmacological conditioning can significantly enhance the regenerative properties of mesenchymal stem cells.

Mechanical forces are important in the regulation of physiological homeostasis and the development of disease. The application of mechanical forces to cultured cells is often performed using specialized systems that lack the flexibility and throughput of other biological techniques. In this study, we developed a high throughput platform for applying complex dynamic mechanical forces to cultured cells. We validated the system for its ability to accurately apply parallel mechanical stretch in a 96 well plate format in 576 well simultaneously. Using this system, we screened for optimized conditions to stimulate increases in Oct-4 and other transcription factor expression in mouse fibroblasts. Using high throughput mechanobiological screening assays, we identified small molecules that can synergistically enhance the increase in reprograming-related gene expression in mouse fibroblasts when combined with mechanical loading. Taken together, our findings demonstrate a new powerful tool for investigating the mechanobiological mechanisms of disease and performing drug screening in the presence of applied mechanical load.

Differentiation of mesenchymal stem cells (MSCs) towards vascular cell types would provide improved cell therapies for cardiovascular disease. However, studies of differentiation of MSCs into endothelial cells or vascular muscle cells have had mixed or contradictory results. We developed a high throughput device capable of applying mechanical strain to cells in multiwell format that allow mechanobiological screening of cultured cells. Using this device, we screened for mechanical conditions that maximally increased signaling through the Hippo and TGF-β signaling pathways (7.5% strain at 0.1 Hz). Detailed phenotypic analysis of the cells under these conditions revealed increased expression of markers for both endothelial cells and pericytes (confirmed by flow cytometry, immunostaining, and RNAseq gene expression analysis). These conditioned cells had increased tube formation in culture and pericyte-like activity in supporting tube formation by endothelial cells. A drug screen under the optimal mechanical conditions identified several compounds that enhanced this effect further including inhibitors to the EGFR/ErbB pathways. RNASeq analysis of these cells demonstrated increased expression of endothelial and pericyte-related genes. When these conditioned MSCs were implanted into ischemic models of nu/nu mice, we observed significantly higher blood perfusion recovery compared to the control groups (Figure 1A). Tissue immunohistochemistry also identified increased level of blood vessel formation and PECAM expression, indicative of angiogenesis (Figure 1B). Our results demonstrate a practical technique to quickly optimize mechanical and pharmacological conditioning for improving MSC-based therapies for to enhance therapeutic angiogenesis in peripheral ischemia.

Introduction: Induced pluripotent stem cells (iPSC) have great promise for providing new models of disease and generating novel cell types from patient derived samples. However, studies on iPSC der...

Introduction: Stem cell therapies have immense potential for the treatment of cardiovascular disease. However, their full potential has not yet been realized in clinical trials due to limited effic...

Purpose While induction immunosuppression is commonly employed by heart transplant (HT) centers, its impact on patient survival remains controversial. Optimal use of a risk stratification methodology balancing risk versus benefit to determine induction is also unknown. Our team sought to analyze the impact of a risk stratified approach to induction on outcomes after HT. Methods Historically, our program has utilized basiliximab routinely on HT recipients. In 2017, we implemented a risk stratified approach to induction categorized into four groups. Stratification was based on age, race, re-transplant status, virtual crossmatch data, pre-transplant C1q data, panel reactive antibodies, and need for pre-transplant desensitization. Low risk patients received no induction, moderate risk basiliximab, specialty risk anti-thymocyte globulin and high risk plasmapheresis/bortezomib/IVIG/anti-thymocyte globulin. We performed a retrospective analysis of adult HTs performed in 2016 (historical cohort) and 2017 (risk stratified cohort). One-year outcomes compared included mortality, biopsy proven ACR and AMR, DSA, graft dysfunction, and infectious complications. Results Baseline demographics were similar between groups. The low risk category represented 91% of the risk stratified cohort. Use of basiliximab decreased by 65.2% in risk stratified group. Incidence of acute cellular rejection (ACR) was similar in both cohorts and there were no cases of antibody mediated rejection (AMR). There was a trend towards higher DSA development in the historical cohort. While the trend for treated CMV was higher in the risk-stratified cohort, there was no difference in rate of infections requiring hospitalizations. There was no significant difference in survival. Conclusion This personalized approach to induction in HT led to similar rejection, mortality and infectious outcomes, in addition to cost savings from decreased overall use of induction therapy. While induction immunosuppression is commonly employed by heart transplant (HT) centers, its impact on patient survival remains controversial. Optimal use of a risk stratification methodology balancing risk versus benefit to determine induction is also unknown. Our team sought to analyze the impact of a risk stratified approach to induction on outcomes after HT. Historically, our program has utilized basiliximab routinely on HT recipients. In 2017, we implemented a risk stratified approach to induction categorized into four groups. Stratification was based on age, race, re-transplant status, virtual crossmatch data, pre-transplant C1q data, panel reactive antibodies, and need for pre-transplant desensitization. Low risk patients received no induction, moderate risk basiliximab, specialty risk anti-thymocyte globulin and high risk plasmapheresis/bortezomib/IVIG/anti-thymocyte globulin. We performed a retrospective analysis of adult HTs performed in 2016 (historical cohort) and 2017 (risk stratified cohort). One-year outcomes compared included mortality, biopsy proven ACR and AMR, DSA, graft dysfunction, and infectious complications. Baseline demographics were similar between groups. The low risk category represented 91% of the risk stratified cohort. Use of basiliximab decreased by 65.2% in risk stratified group. Incidence of acute cellular rejection (ACR) was similar in both cohorts and there were no cases of antibody mediated rejection (AMR). There was a trend towards higher DSA development in the historical cohort. While the trend for treated CMV was higher in the risk-stratified cohort, there was no difference in rate of infections requiring hospitalizations. There was no significant difference in survival. This personalized approach to induction in HT led to similar rejection, mortality and infectious outcomes, in addition to cost savings from decreased overall use of induction therapy.

Induced pluripotent stem cells (iPSC) have great promise for providing new models of disease and generating novel cell types from patient derived samples. However, studies on iPSC derivation often involve viral genetic manipulation, which causes concerns in terms of using the derived cells for cellular therapeutics. To that end, we propose a methodology to induce pluripotent phenotypes in mouse embryonic fibroblasts (MEFs) through the use of mechanical conditioning, and without viral gene editing. To achieve this goal, we have developed a high-throughput biaxial stretching device that is capable of inducing dynamic mechanical strain to 576 cell culture wells simultaneously. We applied varying levels of mechanical strain to an MEFs and found that Oct-4 expression increased 2.5-fold in MEFs stretched at 17.5% strain at 0.1 Hz. Under these conditions we also found a five-fold increase in Sox2 and a three-fold increase in SSEA1 in MEFs. We used the high throughput mechanical loading system to perform drug screening in the presence of mechanical loads and found several compounds that synergistically increased Oct-4 expression with mechanical load. Combined treatment with mechanical load and the candidate compounds led to further increases in Sox2, SSEA1, Nanog, and some pluripotency related genes. Taken together, our work suggests optimized mechanical conditions can prime MEFs for developing pluripotency and this effect can be increased with co-treatment with small molecule inhibitors.

Stem cell therapies have great promise for revolutionizing treatments for cardiovascular disease and other disorders but have not yet achieved their potential due to poor efficacy and heterogeneity in patient response. Here, we used a novel high throughput screening system to optimize the conditioning of mesenchymal stem cells using a combinatorial set of biochemical factors, pharmacological inhibitors and biomechanical forces. Our studies revealed that a combination of specific kinase inhibitors and a complex mechanical strain waveform dramatically increased the population of mesenchymal stem cells that express markers for both pericytes and endothelial cells. These mechanically and pharmacologically conditioned mesenchymal stem cells had superior properties in enhancing endothelial tube formation, production of angiogenic growth factors and induction of angiogenesis following implantation. Overall, our work supports that combinatorial optimization of mechanical conditioning and pharmacological treatments can significantly enhance the regenerative properties of mesenchymal stem cells.

Transgenic methods for direct reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) are effective in cell culture systems but ultimately limit the utility of iPSCs due to concerns of mutagenesis and tumor formation. Recent studies have suggested that some transgenes can be eliminated by using small molecules as an alternative to transgenic methods of iPSC generation. We developed a high throughput platform for applying complex dynamic mechanical forces to cultured cells. Using this system, we screened for optimized conditions to stimulate the activation of Oct-4 and other transcription factors to prime the development of pluripotency in mouse fibroblasts. Using high throughput mechanobiological screening assays, we identified small molecules that can synergistically enhance the priming of pluripotency of mouse fibroblasts in combination with mechanical loading. Taken together, our findings demonstrate the ability of mechanical forces to induce reprograming factors and support that biophysical conditioning can act cooperatively with small molecules to priming the induction pluripotency in somatic cells.

Stem cell therapies have great promise for revolutionizing treatments for cardiovascular disease and other disorders. However, these therapies have not yet achieved their potential due to poor effi...