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Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been widely used in therapy of ischemic heart disease. However, there are still remaining issues that limit the therapeutic efficacy, such as immune rejection and low retention of hiPSC-CMs. Human adipose mesenchymal stromal cells (hADSCs) have been reported to be able to regulate the immune response, promote angiogenesis and promote the maturation of hiPSC-CMs. In this study, we co-cultured these two types of cells on fiber scaffold made of biodegradable poly (D,L-lactic-co-glycolic acid) (PLGA) polymer for several days to develop a composited 3D cardiac tissue sheet. As expected, the cells formed 231.00 ± 15.14 μm thickness tissue, with improved organization, alignment, ECM condition, contractile ability, and paracrine function compared to culture hiPSC-CMs only on PLGA fiber. Furthermore, the composited 3D cardiac tissue sheet significantly promoted the engraftment and survival after transplantation. The composited 3D cardiac tissue sheet also increased cardiac function, attenuated ventricular remodeling, decreased fibrosis, and enhanced angiogenesis in rat myocardial infarction model, indicating that this strategy wound be a promising therapeutic option in the clinical scenario.

Purpose: The impact of preoperative patent inferior mesenteric artery (IMA) on late outcomes following endovascular aneurysm repair (EVAR) remains unclear. This study aimed to investigate the specific influence of IMA patency on 7-year outcomes after EVAR.Materials and Methods: In this retrospective cohort study, 556 EVARs performed for true abdominal aortic aneurysm cases between January 2006 and December 2019 at our institution were reviewed. Endovascular aneurysm repairs performed using a commercially available device with no type I or type III endoleak (EL) during follow-up and with follow-up ≥12 months were included. A total of 336 patients were enrolled in this study. The cohort was divided into the patent IMA group and the occluded IMA group according to preoperative IMA status. The late outcomes, including aneurysm sac enlargement, reintervention, and mortality rates, were compared between both groups using propensity-score-matched data.Results: After propensity score matching, 86 patients were included in each group. The median follow-up period was 56 months (interquartile range: 32–94 months). The incidence of type II EL at discharge was 50% in the patent IMA group and 19% in the occluded IMA group (p<0.001). The type II EL from IMA and lumbar arteries was significantly higher in the patent IMA group than in the occluded IMA group (p<0.001 and p=0.002). The rate of freedom from aneurysm sac enlargement with type II EL was significantly higher in the occluded IMA group than in the patent IMA group (94% vs 69% at 7 years; p<0.001). The rate of freedom from reintervention was significantly higher in the occluded IMA group than in the patent IMA group (90% vs 74% at 7 years; p=0.007). Abdominal aortic aneurysm–related death and all-cause mortality did not significantly differ between groups (p=0.32 and p=0.34).Conclusions: Inferior mesenteric artery patency could affect late reintervention and aneurysm sac enlargement but did not have a significant impact on mortality. Preoperative assessment and embolization of IMA might be an important factor for improvement in late EVAR outcomes.Clinical Impact The preoperative patency of the inferior mesenteric artery was significantly associated with a higher incidence of sac enlargement and reintervention with type II endoleak following endovascular aneurysm repair, even after adjustment for patient background. Preoperative assessment and embolization of inferior mesenteric artery might be an important factor for improvement in late EVAR outcomes.

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection.

In patients with ischemic cardiomyopathy, coronary artery bypass grafting ensures better survival than medical therapy. However, the long-term clinical impact of complete revascularization remains unclear. This observational study aimed to evaluate the effects of complete revascularization on long-term survival and left ventricular functional recovery in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting.

Fulminant myocarditis (FM) requiring temporary mechanical circulatory support (t-MCS) has a high mortality rate. Peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pump (IABP) are sometimes insufficient to induce cardiac recovery. For patients with FM refractory to VA-ECMO with IABP, we have applied a biventricular assist device (BIVAD) or Impella to unload the left ventricle and to fully support the systemic circulation. In the last 10 years, 37 refractory FM patients histologically diagnosed with myocarditis and who did not recover with VA-ECMO were treated with BIVAD (n = 19) or Impella (n = 18). No significant difference was found between the Impella and BIVAD groups in preoperative findings other than serum creatinine level. Seventeen of 18 patients in the Impella group were successfully weaned from t-MCS in 9 (6–12) days. Conversely, the temporary BIVAD was removed in 21 (11–38) days in 10 of 19 patients. Six patients died while on temporary BIVAD because of multiple organ failure and cerebral bleeding, and three patients required conversion to implantable VAD. Compared with BIVAD, left ventricular unloading with Impella could be less invasive and could promote cardiac recovery in refractory FM patients. The Impella has the potential to provide effective temporary MCS for FM patients.

Anomalous origin of a left coronary artery from the right sinus of Valsalva with a single coronary orifice is a rare congenital anomaly, which has been associated with myocardial ischemia and sudden death. Surgical repair is recommended upon its detection. A 14-year-old boy was diagnosed with anomalous origin of a left coronary artery from the right sinus of valsalva with a single coronary orifice after a syncope attack. The patient underwent relocation of the left coronary orifice. The postoperative course was uneventful, with no ventricular arrhythmia or syncope. The patient did not develop cardiac ischemia or infarction on exercise Tc-99 m myocardial scintigraphy 8 months after the procedure.

Human-induced pluripotent stem cell (hiPSC)-derived cardiac patches have been extensively used for treating myocardial infarction and have shown potential for clinical application. However, the limited patch thickness can hamper its therapeutic effect. We previously developed a fibrous scaffold that allowed the formation of well-organized cardiac tissue constructs. In the present study, based on the above technology, we developed a three-dimensional multilayer fibrous scaffold with dynamic perfusion, on which approximately 20 million hiPSC-derived cardiomyocytes (CMs) could be seeded in a single step and organized into 1 mm thick and viable tissue. The multilayer cardiac tissue demonstrated enhanced contractile properties and upregulated cytokine secretion compared with the control group. Notably, when used on the myocardial infarction model, the multilayer group showed improved functional recovery and less fibrosis. These results indicated that the appropriate hiPSC-CM dose requires careful evaluation in developing clinical therapy. The multilayer cardiac tissue group demonstrated significant improvement than the control group, indicating that higher doses of transplanted cells may have improved therapeutic effects in treating myocardial infarction.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jtcvs.2005.02.024 Byline: Imran A. Memon, Yoshiki Sawa, Shigeru Miyagawa, Satoshi Taketani, Hikaru Matsuda Abstract: Cellular cardiomyoplasty with isolated skeletal myoblasts and bone marrow mononuclear cells is an encouraging therapeutic strategy for heart failure. We investigated the achievements accomplished with combined cell therapy of skeletal myoblast and bone marrow mononuclear cell transplantation to the ischemic canine myocardium. Author Affiliation: Osaka University Graduate School of Medicine, Department of Surgery E1, Division of Cardiovascular Surgery, Osaka, Japan Article History: Received 17 August 2004; Revised 4 January 2005; Accepted 4 February 2005 Article Note: (footnote) Supported by the 1st Department of Surgery, Osaka University.

We made a big mistake three hundred years ago when we separated technology and humanism. It's time to put the two back together. --Michael Dertouzos, former director of the Laboratory […]

We evaluated the cardiac function recovery following skeletal myoblast cell-sheet transplantation and the long-term outcomes after applying this treatment in 23 patients with ischemic cardiomyopathy. We defined patients as “responders” when their left ventricular ejection fraction remained unchanged or improved at 6 months after treatment. At 6 months, 16 (69.6%) patients were defined as responders, and the average increase in left ventricular ejection fraction was 4.9%. The responders achieved greater improvement degrees in left ventricular and hemodynamic function parameters, and they presented improved exercise capacity. During the follow-up period (56 ± 28 months), there were four deaths and the overall 5-year survival rate was 95%. Although the responders showed higher freedom from mortality and/or heart failure admission (5-year, 81% versus 0%; p = 0.0002), both groups presented an excellent 5-year survival rate (5-year, 93% versus 100%; p = 0.297) that was higher than that predicted using the Seattle Heart Failure Model. The stepwise logistic regression analysis showed that the preoperative estimated glomerular filtration rate and the left ventricular end-systolic volume index were independently associated with the recovery progress. Approximately 70% of patients with “no-option” ischemic cardiomyopathy responded well to the cell-sheet transplantation. Preoperative renal and left ventricular function might predict the patients’ response to this treatment.

Various surgical techniques have been developed for coarctation of the aorta. However, coarctation repair in neonates with arch hypoplasia remains challenging. We herein report a case in which a premature neonate under 1500 g with coarctation of the aorta and arch hypoplasia underwent an extra-anatomical bypass at 18 days old. A second extra-anatomical bypass was performed at 3 years of age, and a third extra-anatomic bypass for recurrent coarctation was performed in adulthood. By increasing the size of the graft as the patient grows, extra-anatomic bypass can be a useful surgical option for premature neonates with coarctation and arch hypoplasia.

This article was originally published under Nature Research’s License to Publish, but has now been made available under a [CC BY 4.0] license. The PDF and HTML versions of the article have been modified accordingly.

Purpose: Hybrid thoracic endovascular aortic repair (TEVAR) for aortic arch aneurysms is a minimally invasive procedure with improved results. This study aimed to clarify the effectiveness and expand the possibilities of zone 1 and 2 landing TEVAR for type B aortic dissection (TBAD) using our treatment strategy.Methods: This retrospective, single-center, observational cohort study included 213 patients (TBAD, n=69; thoracic arch aneurysm [TAA], n=144; median age, 72 years; median follow-up period, 6 years) from May 2008 to February 2020. The following conditions were satisfied before performing zone 1 and 2 landing TEVAR: TBAD; proximal landing zone (LZ): diameter <37 mm, length >15 mm, and nondissection area, proximal stent-graft: size ≤40 mm and oversizing rate: 10% to 20%, and TAA; proximal LZ: diameter ≤42 mm and length >15 mm, proximal stent-graft: size ≤46 mm and oversizing rate: 10% to 20%. Of the 69 patients in the TBAD group, 34 (49.3%) had patent false lumen (PFL), and 35 (50.7%) had false lumen partial thrombosis (FLPT), including ulcer-like projections. Emergency procedures were performed in 33 (15.5%) patients.Results: There were no significant differences in the in-hospital mortality (TBAD: 1.5% vs TAA: 0.7%, p=0.544) or the in-hospital aortic complications (TBAD: n=1 vs TAA: n=5, p=0.666). Retrograde type A dissection was not observed in the TBAD group. The aortic event-free rates at 10 years were 89.7% (95% confidence interval [CI]: 78.7%–95.3%) and 87.9% (95% CI: 80.3%–92.8%) in the TBAD and TAA groups, respectively (log-rank p=0.636). In the TBAD group, the early and late outcomes were not significantly different between the PFL and FLPT groups.Conclusion: Satisfactory early and long-term results were obtained with zone 1 and 2 landing TEVAR. The TBAD cases had the same good results as the TAA cases. Using our strategy, we especially might reduce complications and be an effective treatment for acute complicated TBAD.Clinical Impact This study aimed to clarify the effectiveness and expand the possibilities of zones 1 and 2 landing TEVAR for type B aortic dissection (TBAD) using our treatment strategy. Satisfactory early and long-term results in the TBAD and thoracic arch aneurysm (TAA) groups were obtained with zones 1 and 2 landing TEVAR. The TBAD cases had the same good results as the TAA cases. Using our strategy, we especially might reduce complications and be an effective treatment for acute complicated TBAD.

Purpose: The effectiveness of thoracic endovascular aortic repair (TEVAR) for chronic aortic dissection (AD) with aneurysmal degeneration remains controversial. We retrospectively investigated clinical outcomes and assessed predictors of aortic shrinkage after TEVAR for chronic aneurysmal AD.Materials and Methods: Between January 2010 and December 2021, 70 patients with double-barrel-type chronic AD were enrolled. Major intimal tears in thoracic aorta were covered by stent graft. Early and late clinical outcomes, and diameter change of downstream aorta during follow-up period were reviewed. Subsequently, factors associated with aortic shrinkage were assessed by logistic regression analysis.Results: Mean age was 63 (interquartile range [IQR]: 54–68) years, 54 (80%) men, median duration from AD onset was 4 (IQR: 1–10) years, and maximum aortic diameter was 53 (IQR: 49–58) mm. Supra-aortic debranching procedure was required in 57 (81%) patients. Early aorta-related death occurred in 2 (3%) patients. Both stroke and spinal cord ischemia occurred in 1 (2%) patient. Five-year freedom rates from aorta-related death and reintervention were 96% and 51%, respectively. Sixty-four patients underwent follow-up computed tomography (84%) 1 year after TEVAR, with 33 (52%) achieving aortic shrinkage. In multivariable analysis, duration from AD onset (per year) (odds ratio [OR]: 0.82, 0.70–0.97; p=0.017) and maximum aortic-diameter ratio between aortic arch and descending aorta (per 0.1) (morphologic index; OR: 1.34, 1.04–1.74; p=0.023) were independent aortic shrinkage predictors.Conclusions: Thoracic endovascular aortic repair for chronic AD with aneurysmal degeneration achieved satisfactory survival outcomes, but with a considerable reintervention rate. Duration from AD onset and preoperative aortic morphology could affect post-TEVAR aortic shrinkage. Earlier intervention could lead to better aortic shrinkage.Clinical Impact Thoracic endovascular aortic repair for chronic aortic dissection with aneurysmal degeneration showed low incidence of early and late aorta-related death. By contrast, aortic shrinkage rate was low with high incidence of reintervention to the residual downstream aorta. According to the assessment of preoperative variables, chronicity and aortic morphology could predict postoperative aortic shrinkage.

A volume combining two special issues of "Papers in Linguistics" contains 10 papers concerning Japanese language use and 12 concerning languages of the U.S.S.R. The papers on Japanese include: "Intrusion in Japanese Conversation,""Japanese Use of English Loans,""Some Discourse Principles and Lengthy Sentences in Japanese,""On the Two Forms of Negative Gerund in Japanese,""Some Politeness Strategies in Japanese,""Pragmatics of Causation in Japanese,""The Status of Kobuji: Usage of Ideographs Unique to Japan,""Subject Ellipsis and Topic in Japanese,""Variation and Change in Japanese Honorific Forms,""Presuppositional Culture Spaces: Language Use in Everyday Life." The papers concerning languages in the U.S.S.R. include "Predicate Instrumental and Agreement in Lithuanian: A Contrastive Analysis,""A Sketch of Vowel Harmony in the Tungus Languages,""Universal and Particular Properties of the Ewenki Case System,""On the Penumbra of Questions Surrounding the Internal Reconstruction of Gilyak,""The Phonology of Chukchee Consonants,""The Genetic Affiliation of Kamchadal: Some Morphological Evidence,""N-Agreement in Old Georgian,""On Derived Inceptives in Georgian,""The Causative: Daghestanian Variations on a Theme,""Subject Marking in Some Languages of Daghestan,""The Organization of a Voice-Neutral Verb: An Example in Avar;" and "Grammatical Subject and the Problem of the Ergative Construction in Lezgian." (MSE)

Mesenchymal stem/stromal cells (MSCs) are cultured adult stem cells that originally reside in virtually all tissues, and the gain of MSCs by transplantation has become the leading form of cell therapy in various diseases. However, there is limited knowledge on the alteration of its efficacy by factors in recipients. Here, we report that the cardioprotective properties of intravenously injected MSCs in a mouse model of pressure-overload heart failure largely depend on circulating adiponectin, an adipocyte-secreted factor. The injected MSCs exert their function through exosomes, extracellular vesicles of endosome origin. Adiponectin stimulated exosome biogenesis and secretion through binding to T-cadherin, a unique glycosylphosphatidylinositol-anchored cadherin, on MSCs. A pharmacological or adenovirus-mediated genetic increase in plasma adiponectin enhanced the therapeutic efficacy of MSCs. Our findings provide novel insights into the importance of adiponectin in mesenchymal-progenitor-mediated organ protections.

Genetic cardiomyopathy is a group of intractable cardiovascular disorders involving heterogeneous genetic contribution. This heterogeneity has hindered the development of life-saving therapies for this serious disease. Genetic mutations in dystrophin and its associated glycoproteins cause cardiomuscular dysfunction. Large animal models incorporating these genetic defects are crucial for developing effective medical treatments, such as tissue regeneration and gene therapy. In the present study, we knocked out the δ-sarcoglycan (δ-SG) gene (SGCD) in domestic pig by using a combination of efficient de novo gene editing and somatic cell nuclear transfer. Loss of δ-SG expression in the SGCDknockout pigs caused a concomitant reduction in the levels of α-, β-, and γ-SG in the cardiac and skeletal sarcolemma, resulting in systolic dysfunction, myocardial tissue degeneration, and sudden death. These animals exhibited symptoms resembling human genetic cardiomyopathy and are thus promising for use in preclinical studies of next-generation therapies.

3D printing in a microgel‐based supporting bath enables the construction of complex structures with soft and watery biomaterials but the low print resolution is usually an obstacle to its practical application in tissue engineering. Herein, high‐resolution printing of a 3D collagen organ scaffold is realized by using an engineered Gellan gum (GG) microgel bath containing trisodium citrate (TSC). The introduction of TSC into the bath system not only mitigates the aggregation of GG microgels, leading to a more homogeneous bath morphology but also suppresses the diffusion of the collagen ink in the bath due to the dehydration effect of TSC, both of which contribute to the improvement of print resolution. 3D collagen organ structures such as hand, ear, and heart are successfully constructed with high shape fidelity in the developed bath. After printing, the GG and TSC can be easily removed by washing with water, and the obtained collagen product exhibits good cell affinity in a tissue scaffold application. This work offers an easy‐to‐operate strategy for developing a microgel bath for high‐resolution printing of collagen, providing an alternative path to in vitro 3D organ construction. An easy‐to‐operate strategy based on Hofmeister effect is developed to prepare microgel bath for high‐resolution 3D printing of collagen scaffolds. The introduction of TSC in the bath leads to a good dispersion state of the microgels in the bath and suppresses the ink diffusion by speeding up the gelation by a salt‐out effect. Both contribute to enhancing print resolution.

Supplemental Digital Content is available in the text.

The authors compare the therapeutic effects among human induced pluripotent stem cell-derived cardiomyocytes, skeletal myoblasts stem cells and mesenchymal stem cells on promoting cardiac functional recovery including regional contractile function and cardiac bioenergetic efficiency in a porcine model of myocardial infarction. Supplemental digital content is available in the text.

The authors investigate a new method for cell therapy to treat ischemic cardiomyopathy and demonstrate that the spray method implantation of mesenchymal stem cells improves recovery of cardiac function in a porcine infarction model. Supplemental digital content is available in the text.

In this study, we proposed that the functionality or phenotype of differentiated cardiomyocytes derived from human induced pluripotent stem cells (iPSC-CMs) might be modified by co-culture with mesenchymal stem cells (MSCs), resulting in an improved therapeutic potential for failing myocardial tissues. Structural, motility, electrophysiological, and metabolic analyses revealed that iPSC-CMs co-cultured with MSCs displayed aligned myofibrils with A-, H-, and I-bands that could contract and relax quickly, indicating the promotion of differentiation and the establishment of the iPSC-CM structural framework, and showed clear gap junctions and an electric pacing of >2 Hz, indicating enhanced cell-cell interactions. In addition, soluble factors excreted by MSCs, including several cytokines and exosomes, enhanced cardiomyocyte-specific marker production, produced more energy under normal and stressed conditions, and reduced reactive oxygen species production by iPSC-CMs under stressed condition. Notably, gene ontology and pathway analysis revealed that microRNAs and proteins in the exosomes impacted the functionality and maturation of iPSC-CMs. Furthermore, cell sheets consisting of a mixture of iPSC-CMs and MSCs showed longer survival and enhanced therapeutic effects compared with those consisting of iPSC-CMs alone. This may lead to a new type of iPSC-based cardiomyogenesis therapy for patients with heart failure.

In adult patients, after a Fontan procedure, high central venous pressure (CVP) is a hemodynamic risk factor associated with poor prognosis. High liver stiffness (LS) on transient elastography (TE) is associated with high CVP in patients with heart failure without liver disease. Here, we investigated whether LS assessment using TE is a reliable method to noninvasively evaluate CVP in adult patients after a Fontan procedure, who can present varying degrees of liver fibrosis as a complication.

Although engineered cardiac tissues (ECTs) derived from induced pluripotent stem cells (iPSCs) are promising for myocardial regenerative therapy, the appropriate ratio of cardiomyocytes to non-cardiomyocytes is not fully understood. Here, we determined whether ECT-cell content is a key determinant of its structure/function, thereby affecting ECT therapeutic potential for advanced heart failure. Scaffold-free ECTs containing different ratios (25%, 50%, 70%, or 90%) of iPSC-derived cardiomyocytes were generated by magnetic-activated cell sorting by using cardiac-specific markers. Notably, ECTs showed synchronized spontaneous beating when cardiomyocytes constituted ≥50% of total cells, with the electrical-conduction velocity increasing depending on cardiomyocyte ratio; however, ECTs containing 90% cardiomyocytes failed to form stable structures. ECTs containing 25% or 50% cardiomyocytes predominantly expressed collagen and fibronectin, whereas ECTs containing 70% cardiomyocytes predominantly expressed laminin and exhibited the highest contractile/relaxation properties. Furthermore, transplantation of ECTs containing 50% or 70% cardiomyocytes into a rat chronic myocardial infarction model led to a more profound functional recovery as compared with controls. Notably, transplanted ECTs showed electrical synchronization with the native heart under Langendorff perfusion. Collectively, these results indicate that the quantity of non-cardiomyocytes is critical in generating functional iPSC-derived ECTs as grafts for cardiac-regeneration therapy, with ECTs containing 50–70% cardiomyocytes exhibiting stable structures and increased cardiotherapeutic potential.

An in vitrodrug-induced cardiotoxicity assay is a critical step in drug discovery for clinical use. The use of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) is promising for this purpose. However, single hiPSC-CMs are limited in their ability to mimic native cardiac tissue structurally and functionally, and the generation of artificial cardiac tissue using hiPSC-CMs is an ongoing challenging. We therefore developed a new method of constructing three-dimensional (3D) artificial tissues in a short time by coating extracellular matrix (ECM) components on cell surfaces. We hypothesized that 3D cardiac tissues derived from hiPSC-CMs (3D-hiPSC-CT) could be used for an in vitrodrug-induced cardiotoxicity assay. 3D-hiPSC-CT were generated by fibronectin and gelatin nanofilm coated single hiPSC-CMs. Histologically, 3D-hiPSC-CT exhibited a sarcomere structure in the myocytes and ECM proteins, such as fibronectin, collagen type I/III, and laminin. The administration of cytotoxic doxorubicin at 5.0 μM induced the release of lactate dehydrogenase, while that at 2.0 μM reduced the cell viability. E-4031, human ether-a-go-go related gene (hERG)-type potassium channel blocker, and isoproterenol induced significant changes both in the Ca transient parameters and contractile parameters in a dose-dependent manner. The 3D-hiPSC-CT exhibited doxorubicin-sensitive cytotoxicity and hERG channel blocker/isoproterenol-sensitive electrical activity in vitro, indicating its usefulness for drug-induced cardiotoxicity assays or drug screening systems for drug discovery.

Although mesenchymal stem cell transplantation has been successful in the treatment of ischemic cardiomyopathy, the underlying mechanisms remain unclear. Herein, we investigated whether mitochondrial transfer could explain the success of cell therapy in ischemic cardiomyopathy. Mitochondrial transfer in co-cultures of human adipose-derived mesenchymal stem cells and rat cardiomyocytes maintained under hypoxic conditions was examined. Functional recovery was monitored in a rat model of myocardial infarction following human adipose-derived mesenchymal stem cell transplantation. We observed mitochondrial transfer in vitro, which required the formation of cell-to-cell contacts and synergistically enhanced energy metabolism. Rat cardiomyocytes exhibited mitochondrial transfer 3 days following human adipose-derived mesenchymal stem cell transplantation to the ischemic heart surface post-myocardial infarction. We detected donor mitochondrial DNA in the recipient myocardium concomitant with a significant improvement in cardiac function. Mitochondrial transfer is vital for successful cell transplantation therapies and improves treatment outcomes in ischemic cardiomyopathy.

For ischemic cardiomyopathy (ICM) with limited therapeutic options, the induction of arteriogenesis has the potential to improve cardiac function through major restoration of blood flow. We hypothesized that transplantation of a Notch signaling-modified mesenchymal stem cell (SB623 cell) patch would induce angiogenesis and arteriogenesis in ischemic lesions, leading to improvement of left ventricular (LV) function in a rat ICM model. Two weeks after the induction of ischemia, SB623 cell patch transplantation into ICM rats (SB group, n= 10) or a sham operation (no-treatment group, n= 10) was performed. The LV ejection fraction was significantly improved at 6 weeks after SB623 cell patch transplantation (P< 0.001). Histological findings revealed that the number of von Willebrand factor (vWF)-positive capillary vessels (P< 0.01) and alpha smooth muscle actin (αSMA)- and vWF-positive arterioles with a diameter greater than 20 µm (P= 0.002) was significantly increased in the SB group, suggesting the induction of angiogenesis and arteriogenesis. Moreover, rat cardiomyocytes treated with SB623 cell patch transplantation showed upregulation of ephrin-B2 (P= 0.03) and EphB4 (P= 0.01) gene expression, indicating arteriogenesis induction. In conclusion, SB623 cell patch transplantation improved LV function by inducing angiogenesis and arteriogenesis in a rat ICM model.

Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

Atrial arrhythmias are a significant cause of late morbidity and mortality in patients after tetralogy of Fallot repair. However, reports on their recurrence following atrial arrhythmia surgery are limited. We aimed to identify the risk factors for atrial arrhythmia recurrence after pulmonary valve replacement (PVR) and arrhythmia surgery.

The study objectives were to determine the incidence, predictors, and clinical impact of ventricular arrhythmias after coronary artery bypass grafting and to evaluate the impact of implantable cardioverter defibrillators on the survival of patients with ventricular arrhythmias.

Introduction:Human iPSC derived cardiomyocytes (iPSC-CMs) have been proved to be a promising method to treat the heart failure. Multiple clinical studies including one in our group are ongoing around the world. Due to the diffusion limit, so far it is difficult to prepare viable cardiac tissue with high thickness. We hypothesized that by using multilayer fiber sheets and enhanced perfusion system, viable and thick cardiac tissue could be obtained for improved therapeutic effect for treating myocardial infarction. Method and Results:PLGA fiber sheet with multilayer and high porosity (30.61% ± 1.85%, n = 4) was fabricated for iPSC-CMs penetration and organization. A low-shear stress perfusion system was developed to promote the oxygen diffusion in the thick tissue. At day 5, multilayer cardiac tissue showed compact structure with thickness of 878.64 ± 193.45 μm (n = 4) and viability of 85.32 % ± 6.75 % (n = 4). Compared with the single layer tissues, the multilayer cardiac tissues demonstrated improved contractile properties and secretion of angiogenesis factors: VEGF, HGF and TGF-β1. When used for treating rat with myocardial infarction, multilayer group showed significantly improved left ventricular ejection fraction (0 vs. 4 week: 39.1 ± 4.6 % vs. 52.3 ± 7.8 %, n=8, p = 0.0029), whereas the control group showed no significant change (0 vs. 4 week: 40.6 ± 5.4 % vs. 44.9 ± 4.1 %, n=8, p = 0.37). The staining on sliced heart confirmed the survival of transplanted cells in large area. Moreover, the multilayer group showed significantly lower fibrosis at the border zone than the control group (10.8 % ± 3.1 % vs. 16.4 % ± 5.9 %, n=7, p=0.024). There are no significant differences in cell diameter and capillary density in border zone between two groups. Both groups showed no significant inflammatory reactions (CD68).Conclusion:By using multilayers fiber sheet and enhanced perfusion system, viable and thick iPSC-cardiac tissue could be obtained with enhanced features over the single layer cardiac tissue such as contractility and secretion. While used for transplantation, the multilayers cardiac tissue demonstrated improved therapeutic effect for treating myocardial infarction, holding high potential for future clinical applications.

Background:Patients with improved left ventricular ejection fraction (LVEF) after coronary artery bypass grafting (CABG) are known to have a better prognosis. In patients whose LVEF does not improved, the next alternative is cardiac regenerative therapy. However, surgeons cannot establish an appropriate surgical strategy because it is unpredictable what improvement will be achieved for the patient before CABG. Recently, it has been reported that high-quality medical data and machine learning (ML) can be used to predict diseases.Hypothesis:A ML model with preoperative values of patients could predict functional recovery of LVEF after CABG.Patients and Methods:Three hundred forty-two patients with reduced LVEF who underwent isolated CABG in Osaka University Medical Hospital were included. Reduced LVEF was defined as less than 50% by preoperative echocardiography. Functional recoveryof LVEF was defined as the condition with a 5% improvement of LVEF after CABG. Seventy percent of the patients’ data was used as a training dataset, and the other 30 percent was used as a test dataset for ML. Eighty preoperative features, such as creatinine level, were used for ML model construction.Results:Two hundred fifteen patients got functional recovery after CABG. Our unique ML model found five important preoperative features; histories of hypertension, chronic obstructive pulmonary disease, diabetes mellitus, cerebrovascular disease, and hemodialysis. The trained Extra Trees Classification model with these five features could predict the patients’ functional recovery with 70.7% accuracy in the test data. The predictive model had the area under the curve was 60.9 in the receiver operating characteristic curve.Conclusion:Machine learning-based prediction could work to sort patients with ischemic heart disease into recovery or non-recovery groups after CABG. This algorism may contribute to future precision medicine.

Introduction:Regenerative therapy for heart failure (HF) points to bone marrow mesenchymal stem cell (BM-MSC) as a promising cell source. High mobility group box 1 (HMGB1) is a nuclear protein involved in tissue homeostasis. In this study, we developed an HMGB1 fragment containing a BM-MSC mobilization domain.Hypothesis:We hypothesize that the HMGB1 fragment improves cardiac function by activating a tissue healing pathway of BM-MSC within a porcine ischemic cardiomyopathy (ICM) model as a pre-clinical study.Methods:Gottingen mini pigs weighing 15-25 kg were used. An ICM model was generated by placing an ameroid constrictor ring (internal diameter; 3.5 mm) on the left anterior descending artery (LAD). After 4 weeks, either the HMGB1 fragment (HMGB1 group; 3 mg/kg, n=6) or normal saline (control group; n=5) was administered intravenously with one dose every 48 h for five times. We examined cardiac function before and 8 weeks post treatment through echocardiography, cardiac magnetic resonance imaging (cMRI) with late gadolinium enhancement (LGE), and a fluoroscopy-guided pressure wire study. Then, histological analysis was performed.Results:In echocardiography, ejection fraction significantly improved in the HMGB1 group compared with the control (+11.1% vs -4.8%, p=0.0003). cMRI with LGE demonstrated that the areas of damaged myocardium (core infarct zone + border zone) in the LAD region was reduced in the HMGB1 group compared with the control group (-11.9% vs +17.9%, p=0.0090). Coronary flow reserve (CFR) and resistive reserve ratio (RRR) were evaluated through pressure wire study; they improved in the HMGB1 group compared with the control group (ΔCFR; +0.38 vs +0.01, p=0.0249, ΔRRR; +0.42 vs +0.07, p=0.0275). Histological analysis showed that cardiomyocyte size (26.6 μm vs 38.0 μm, p=0.0339) and areas of fibrosis were smaller (9.8% vs 11.6%, p=0.1649), and the density of CD31-positive endothelial cells was higher (1033/mm2vs 640/mm2, p=0.0339) in the HMGB1 group than in the control group.Conclusions:Systemic administration of the HMGB1 fragment improved cardiac function, coronary flow reserve, and reduced cardiac fibrosis in an ICM model. This drug-induced activation of inner tissue repair and regeneration is a novel approach to treat HF.

Introduction:Due to the serious shortage of cardiac donors in Japan, there is a strong demand for an effective alternative treatment to heart transplantation (HTx) and left ventricular assist device for end-stage severe heart failure. We have conducted induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM) sheet transplantation for ischemic cardiomyopathy as first in human clinical trial (jRCT2053190081), based on several pre-clinical studies suggesting both of angiogenic effects and mechanical contribution of iPSC-CMs. Then, we are next aiming to expand the indication for dilated cardiomyopathy (DCM), which is the most common indication for HTx worldwide. In this study, we established a cynomolgus macaque model of Doxorubicin (Dox)-induced DCM and performed the iPSC-CM sheet transplantation.Methods:Twelve male cynomolgus macaques were treated with Dox to induce DCM every two weeks for three consecutive days in three different doses. The cardiac function was assessed over time by transthoracic echocardiography (TTE) and the effect of doxorubicin on the myocardium was investigated with histological analysis.After the establishment of animal model, we performed the iPSC-CM sheet transplantation and assessed the postoperative cardiac function by TTE and cardiac computed tomography (CT).Results:Each Two macaques treated with high (1.2 kg/mg/day) and medium (1.0 kg/mg/day) dose of Dox died before the establishment of animal model. Of the remaining eight macaques in the low dose (0.8 kg/mg/day) group, six had progressively decreased cardiac function. Histology revealed vacuolization in the left ventricle of the Dox-treated heart. Postoperative evaluation two weeks after iPSC-CM sheet transplantation revealed the improvement in cardiac function on TTE and cardiac CT (left ventricular ejection fraction: from 22 % to 31%, and from 19 % to 31 %, respectively).Conclusions:Three-month administration of low-dose Dox was able to create a cynomolgus macaque model of Dox-induced DCM with relatively high reproducibility. IPSC-CM sheet transplantation may have the possibility for improving cardiac function of DCM.

Introduction:Many prediction algorithms for warfarin maintenance dose (WD) were constructed based on the clinical and genetic information of the patients without extracorporeal circulation devices (ECDs). However, it is unclear whether might be useful for the patients with ECD, such as left ventricular assist devices (LVAD), who still require warfarin.Hypothesis:The WD algorithms constructed using non-ECD patients could be useful for LVAD patients.Methods:An observational study, the Human Genome Research Ethics Committee of OU approved (#756), was conducted at the Osaka University (OU) Hospital on 108 LVAD patients receiving warfarin therapy. Genetic polymorphisms of CYP2C9*1, *3, and VKORC1-1639G>A were tested using TaqMan genotyping assay kits. WD was defined as the administered dose during the periods when the PT-INR value was within its target range. We investigated the difference between the actual warfarin dose (AWD) and the calculated warfarin dose (CWD) using an algorithm proposed by the International Warfarin Pharmacogenetics Consortium (IWPC), which we verified with 125 Japanese non-ECD patients previously (Eur J Clin Pharmacol, 75:901).Results:The percentage of patients whose difference between CWD and AWD was within 20% of AWD showed no significant difference between the LVAD and the non-ECD (%; I, LVAD, 41.7, non-ECD, 49.6, p=0.23). The root mean squared percentage error (RMSPE) to the AWD was similar between the groups (%; LVAD, 42, non-ECD, 37). As the algorithm requires if amiodarone is concomitant with warfarin, we probed the effect of the amiodarone dose on the CWD. Interestingly, RMSPE of the LVAD with ≥ 200 mg/day of amiodarone (≥ 200A) was higher compared to those with < 200 mg/day (<200A) and without amiodarone (%; 85.5, 25.9, 36.8). The difference between AWD and CWD of ≥ 200A was significantly higher than <200A (mg/day; 0.87, -0.07; p=0.012). We verified similar tendencies using other algorithms published before.Conclusions:The WD algorithm with the information on genotype and concomitant use of amiodarone for the non-ECD could be beneficial for the LVAD. Besides them, extra careful attention should be required for patients with ≥ 200 mg/day of amiodarone not to have warfarin overdosed.

Advanced cardiac failure is a progressive intractable disease and is the main cause of mortality and morbidity worldwide. Since this pathology is represented by a definite decrease in cardiomyocyte number, supplementation of functional cardiomyocytes into the heart would hypothetically be an ideal therapeutic option. Recently, unlimited in vitro production of human functional cardiomyocytes was established by using induced pluripotent stem cell (iPSC) technology, which avoids the use of human embryos. A number of basic studies including ours have shown that transplantation of iPSCderived cardiomyocytes (iPSC-CMs) into the damaged heart leads to recovery of cardiac function, thereby establishing “proof-of-concept” of this iPSC-transplantation therapy. However, considering clinical application of this therapy, its feasibility, safety, and therapeutic efficacy need to be further investigated in the pre-clinical stage. This review summarizes up-to-date important topics related to safety and efficacy of iPSC-CMs transplantation therapy for cardiac disease and discusses the prospects for this treatment in clinical studies.

Therapeutic effects of skeletal myoblast transplantation into the myocardium are mediated via paracrine factors. We investigated the ability of myoblast-derived soluble mediators to protect cardiomyocytes from oxidative stress. Fetal rat cardiac cells were treated with conditioned medium from cultures of myoblasts or cardiac fibroblasts, and oxidative stress was induced with H2O2. Myoblast-derived factors effectively prevented oxidative stress-induced cardiac cell death and loss of mitochondrial membrane potential. This protective effect was mediated via epidermal growth factor (EGF) receptor and c-Met signaling, and mimicked by neuregulin 1 but not EGF. Microarray analysis of cardiac cells treated with myoblast versus cardiac fibroblast-derived mediators revealed differential regulation of genes associated with antioxidative effects: cystathionine-γ-lyase (est), xanthine oxidase, and thioredoxin-interacting protein as well as nibbles homolog 3 (trib3). Cardiac cell pretreatment with tunicamycin, an inducer of trib3, also protected them against H2O2-induced cell death. Epicardial transplantation of myoblast sheets in a rat model of acute myocardial infarction was used to evaluate the expression of CST and trib3 as markers of myoblasts' paracrine effect in vivo. Myoblast sheets induced expression of the CST as well as trib3 in infarcted myocardium. CST localized around blood vessels, suggesting smooth muscle cell localization. Our results provide a deeper molecular insight into the therapeutic mechanisms of myoblast-derived paracrine signaling in cardiac cells and suggest that myoblast transplantation therapy may prevent oxidative stress-induced cardiac deterioration and progression of heart failure.

In vitro expanded beating cardiac myocytes derived from induced pluripotent stem cells (iPSC-CMs) are a promising source of therapy for cardiac regeneration. Meanwhile, the cell sheet method has been shown to potentially maximize survival, functionality, and integration of the transplanted cells into the heart. It is thus hypothesized that transplanted iPSC-CMs in a cell sheet manner may contribute to functional recovery via direct mechanical effects on the myocardial infarction (MI) heart. F344/NJcl-rnu/rnu rats were left coronary artery ligated (n= 30), followed by transplantation of Dsred-labeled iPSC-CM cell sheets of murine origin over the infarct heart surface. Effects of the treatment were assessed, including in vivo molecular/cellular evaluations using a synchrotron radiation scattering technique. Ejection fraction and activation recovery interval were significantly greater from day 3 onward after iPSC-CM transplantation compared to those after sham operation. A number of transplanted iPSC-CMs were present on the heart surface expressing cardiac myosin or connexin 43 over 2 weeks, assessed by immunoconfocal microscopy, while mitochondria in the transplanted iPSC-CMs gradually showed mature structure as assessed by electron microscopy. Of note, X-ray diffraction identified 1,0 and 1,1 equatorial reflections attributable to myosin and actin–myosin lattice planes typical of organized cardiac muscle fibers within the transplanted cell sheets at 4 weeks, suggesting cyclic systolic myosin mass transfer to actin filaments in the transplanted iPSC-CMs. Transplantation of iPSC-CM cell sheets into the heart yielded functional and electrical recovery with cyclic contraction of transplanted cells in the rat MI heart, indicating that this strategy may be a promising cardiac muscle replacement therapy.

There exists a substantial body of work describing cardiac support devices to mechanically support the left ventricle (LV); however, these devices lack biological effects. To remedy this, we implemented a cell sheet engineering approach utilizing chondrocytes, which in their natural environment produce a relatively elastic extracellular matrix (ECM) for a cushioning effect. Therefore, we hypothesized that a chondrocyte cell sheet applied to infarcted and borderzone myocardium will biologically enhance the ventricular ECM and increase elasticity to augment cardiac function in a model of ischemic cardiomyopathy (ICM). Primary articular cartilage chondrocytes of Wistar rats were isolated and cultured on temperature-responsive culture dishes to generate cell sheets. A rodent ICM model was created by ligating the left anterior descending coronary artery. Rats were divided into two groups: cell sheet transplantation (1.0 × 107cells/dish) and no treatment. The cell sheet was placed onto the surface of the heart covering the infarct and borderzone areas. At 4 weeks following treatment, the decreased fibrotic extension and increased elastic microfiber networks in the infarct and borderzone areas correlated with this technology's potential to stimulate ECM formation. The enhanced ventricular elasticity was further confirmed by the axial stretch test, which revealed that the cell sheet tended to attenuate tensile modulus, a parameter of stiffness. This translated to increased wall thickness in the infarct area, decreased LV volume, wall stress, mass, and improvement of LV function. Thus, the chondrocyte cell sheet strengthens the ventricular biomechanical properties by inducing the formation of elastic microfiber networks in ICM, resulting in attenuated myocardial stiffness and improved myocardial function.

Introduction:Bone marrow-derived autologous human mesenchymal stem cells (MSCs) are one of the most promising cell sources for cell therapy to treat heart failure. The cell sheet technique has allowed transplantation of a large number of cells and enhanced the efficacy of cell therapy. We hypothesized that the transplantation of MSC sheets may be a feasible, safe, and effective treatment for ischemic cardiomyopathy (ICM).Methods and Results:Human MSCs acquired from bone marrow were positive for CD73, CD90, and CD105 and negative for CD11b and CD45 by flow cytometry. Ten MSC sheets were created from a total cell number of 1×108MSCs using temperature-responsive culture dishes. These were successfully transplanted over the infarct myocardium of porcine ICM models induced by placing an ameroid constrictor on the left anterior descending coronary artery without any procedural-related complications (MSC group=6: sheet transplantation; sham group=6, oral intake of tacrolimus in both groups). Premature ventricular contractions were rarely detected by Holter electrocardiogram (ECG) in the MSC group in the first week after transplantation. On echocardiography, the cardiac performance of the MSC group was significantly better than that of the sham group at 8 weeks after transplantation. On histological examination 8 weeks after transplantation, left ventricular (LV) remodeling was significantly attenuated compared with the sham group (cardiomyocyte size and interstitial fibrosis were measured). Immunohistochemistry of the von Willebrand factor showed that the vascular density in the infarct border area was significantly greater in the MSC group than the sham group. Expression of angiogenesis-related factors in the infarct border area of the MSC group was significantly greater than that of the sham group, as measured by real-time polymerase chain reaction.Conclusions:Bone marrow-derived MSC sheets improved cardiac function and attenuated LV remodeling in ICM without major complications, indicating that this strategy would be applicable in clinical settings.

In ischemic heart disease, cardiomyocyte death results from both necrosis and apoptosis, and the area of infarction gradually increases. The induction of therapeutic angiogenesis is a promising therapy for this condition. In the present study, we investigated the actions of SV peptide—a 7-amino-acid sequence with angiogenic properties derived from osteopontin in the extracellular matrix—in a rat model of myocardial ischemia. We examined the angiogenesis activity of SV ex vivo using ring assay and dorsal air sac assay and in ischemic myocardium. We also conducted histological evaluations of left-ventricle remodeling and evaluated left ventricular (LV) function by echocardiography. The SV peptide had strong angiogenic effects both ex vivoand in vivo. In the experimental rats, this peptide stimulated the formation of new blood vessels in ischemic myocardium. Histological evaluation of the left ventricle in the SV-treated group showed a significant decrease in the size of the infarction, rate of myocardial fibrosis, and cardiomyocyte hypertrophy. Moreover, administration of the SV peptide significantly improved LV function. These results indicate that SV peptide induced angiogenesis in ischemic myocardium and improved cardiac function. Thus, it could serve as a potentially useful new therapy for ischemic heart disease.

The transplantation of cardiac stem cell sheets (CSC sheets) is a promising therapeutic strategy for ischemic cardiomyopathy, although potential ischemia in the transplanted area remains a problem. Injected endothelial progenitor cells (EPCs) can reportedly induce angiogenesis in the injected area. We hypothesized that concomitant CSC sheet transplantation and EPC injection might show better therapeutic effects for chronic ischemic injury model than the transplantation of CSC sheets alone. Scaffold-free CSC sheets were generated from human c-kit-positive heart-derived cells. A porcine chronic ischemic injury model was generated by placing an ameroid constrictor around the left coronary artery for 4 weeks. The animals then underwent a sham operation, epicardial transplantation of CSC sheet over the ischemic area, intramyocardial injection of EPCs into the ischemic and peri-ischemic area, or CSC sheet transplantation plus EPC injection. The efficacy of each treatment was then assessed for 2 months. Speckle-tracking echocardiography was used to dissect the layer-specific regional systolic function by measuring the radial strain (RS). The epicardial RS in the ischemic area was similarly greater after treatment with the CSC-derived cell sheets alone (19 ± 5%) or in combination with EPC injection (20 ± 5%) compared with the EPC only (9 ± 4%) or sham (7 ± 1%) treatment. The endocardial RS in the ischemic area was greatest after the combined treatment (14 ± 1%), followed by EPC only (12 ± 1%), compared to the CSC only (11 ± 1%) and sham (9 ± 1%) treatments. Consistently, either epicardial CSC sheet implantation or intramyocardial EPC injection yielded increased capillary number and reduced cardiac fibrosis in the ischemic epicardium or endocardium, respectively. Concomitant EPC injection induced the migration of transplanted CSCs into the host myocardium, leading to further neovascularization and reduced fibrosis in the ischemic endocardium, compared to the CSC sole therapy. Transplantation of CSC sheets induced significant functional recovery of the ischemic epicardium, and concomitant EPC transplantation elicited transmural improvement in chronic ischemic injury.

Introduction:Functional skeletal myoblasts (SMBs) are transplanted into the heart effectively and safely as cell sheets, which induce functional recovery in myocardial infarction (MI) patients without lethal arrhythmia. However, their therapeutic effect is limited by ischemia. Mesenchymal stem cells (MSCs) have prosurvival/proliferation and antiapoptotic effects on co-cultured cells in vitro. We hypothesized that adding MSCs to the SMB cell sheets might enhance SMB survival post-transplantation and improve their therapeutic effects.Methods and Results:Cell sheets of primary SMBs of male Lewis rats (r-SMBs), primary MSCs of human female fat tissues (h-MSCs), and their co-cultures were generated using temperature-responsive dishes. The levels of candidate paracrine factors, rat hepatocyte growth factor and vascular endothelial growth factor, in vitrowere significantly greater in the h-MSC/r-SMB co-cultures than in those containing r-SMBs only, by real-time PCR and enzyme-linked immunosorbent assay (ELISA). MI was generated by left-coronary artery occlusion in female athymic nude rats. Two weeks later, co-cultured r-SMB or h-MSC cell sheets were implanted or no treatment was performed (n=10 each). Eight weeks later, systolic and diastolic function parameters were improved in all three treatment groups compared to no treatment, with the greatest improvement in the co-cultured cell sheet transplantation group. Consistent results were found for capillary density, collagen accumulation, myocyte hypertrophy, Akt-signaling, STAT3 signaling, and survival of transplanted cells of rat origin, and were related to poly (ADP-ribose) polymerase-dependent signal transduction.Conclusions:Adding MSCs to SMB cell sheets enhanced the sheets' angiogenesis-related paracrine mechanics and, consequently, functional recovery in a rat MI model, suggesting a possible strategy for clinical applications.

The low survival rate of administered cells due to ischemic and inflammatory environments limits the efficacy of the current regenerative cell therapy in peripheral artery disease (PAD). This study aimed to develop a new method to enhance the efficacy of cell therapy in PAD using cell sheet technology. Clustered cells (CCs) from myoblast cell sheets obtained from C57/BL6 mice were administered into ischemic mouse muscles 7 days after induction of ischemia (defined as day 0). Control groups were administered with single myoblast cells (SCs) or saline. Cell survival, blood perfusion of the limb, angiogenesis, muscle regeneration, and inflammation status were evaluated. The survival of administered cells was markedly improved in CCs compared with SCs at days 7 and 28. CCs showed significantly improved blood perfusion, augmented angiogenesis with increased density of CD31+/α-smooth muscle actin+arterioles, and accelerated muscle regeneration, along with the upregulation of associated genes. Additionally, inflammation status was well regulated by CCs administration. CCs administration increased the number of macrophages and then induced polarization into an anti-inflammatory phenotype (CD11c−/CD206+), along with the increased expression of genes associated with anti-inflammatory cytokines. Our findings suggest clinical potential of rescuing severely damaged limbs in PAD using CCs.

Information regarding patient selection for mitral valve repair for chronic kidney disease or end-stage renal disease (ESRD) with severe heart failure (HF) as well as outcome is limited.

Human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) are a promising source of cells for regenerating myocardium. However, several issues, especially the large-scale preparation of hiPS-CMs and elimination of undifferentiated iPS cells, must be resolved before hiPS cells can be used clinically. The cell-sheet technique is one of the useful methods for transplanting large numbers of cells. We hypothesized that hiPS-CM-sheet transplantation would be feasible, safe, and therapeutically effective for the treatment of ischemic cardiomyopathy.