We tested the hypothesis whether calcium preconditioning (CPC) reduces reoxygenation injury by inhibiting mitochondrial permeability transition (MPT). Cultured myocytes were preconditioned by a brief exposure to 1.5 mM calcium (CPC) and subjected to 3 h of anoxia followed by 2 h of reoxygenation (A-R). Myocytes were also treated with 0.2 microM/l cyclosporin A (CsA), an inhibitor of MPT, before A-R. A significant increase of viable cells and reduced lactate dehydrogenase release was observed both in CPC- and CsA-treated myocytes compared with the A-R group. Cytochrome c release was predominantly observed in the cytoplasm of myocytes in the A-R group in contrast with CPC- or CsA-treated groups, where it was restricted only to mitochondria. Similarly, the cell death by apoptosis was also markedly attenuated in these groups. Electron-dense Ca(2+) deposits in mitochondria were also less frequent. Atractyloside (20 microM/l), an adenine nucleotide translocase inhibitor, caused changes similar to those in the A-R group, suggesting a role of MPT in A-R injury. Protection by inhibition of MPT by CsA and CPC suggests that MPT plays an important role in reoxygenation/reperfusion injury. The data further suggest that preconditioning inhibits MPT by inhibiting Ca(2+) accumulation by mitochondria.
Neuropeptide Y (NPY) induced reentry of differentiated rat neonatal and adult cardiomyocytes into the cell cycle. NPY also induced differentiation of bone marrow-derived mesenchymal stem cells (MSC) into cardiomyocytes following transplantation into infarcted myocardium. Rat neonatal and adult cardiomyocytes were treated in vitro with vehicle, NPY, fibroblast growth factor (FGF; 100 ng/ml), or FGF plus NPY. DNA synthesis, mitosis, and cytokinesis were determined by immunocytochemistry. NPY-induced MSC gene expression, cell migration, tube formation, and endothelial cell differentiation were analyzed. Male rat green fluorescent protein-MSC (2 × 10 6 ), pretreated with either vehicle or NPY (10 −8 M) for 72 h, were injected into the border zone of the female myocardium following left anterior descending artery ligation. On day 30, heart function was assessed, and hearts were harvested for histological and immunohistochemical analyses. NPY increased 5-bromo-2′-deoxy-uridine incorporation and promoted both cytokinesis and mitosis in rat neonatal and adult myocytes. NPY also upregulated several genes required for mitosis in MSC, including aurora B kinase, FGF-2, cycline A2, eukaryotic initiation factor 4 E, and stromal cell-derived factor-1α. NPY directly induced neonatal and adult cardiomyocyte cell-cycle reentry and enhanced the number of differentiated cardiomyocytes from MSC in the infarcted myocardium, which corresponded to improved cardiac function, reduced fibrosis, ventricular remodeling, and increased angiomyogenesis. It is concluded that a combined treatment of NPY with MSC is a novel approach for cardiac repair.
Incorporation of transversus abdominis plane (TAP) block into multimodal analgesia has been emphasized in Enhanced Recovery protocols (ERPs). However, benefit is limited in clinical practice. A potential explanation is the short duration of analgesia of standard local anesthetics. Herein, this randomized, double-blind, controlled trial evaluated whether TAPB with long-acting compound lidocaine hydrochloride injection reduces postoperative pain.164 patients undergoing elective gynecological laparotomy under sevoflurane anesthesia randomly received ultrasound-guided TAP block with either saline, or ropivacaine, or compound lidocaine before anesthesia induction. The postoperative pain intensity (primary outcome) was evaluated by pain 11-point numerical rating scale. We also recorded sufentanil consumptions, time to first flatus, side-effects and hospital stay after surgery.We reported that pain scores at rest at postoperative 3h in group 0.375% ropivacaine was lower than that in group saline [mean 2.4 (SD 1.2) vs. 3.0 (1.0), p = 0.036]. Compared with saline, 0.4% and 0.6% compound lidocaine caused lower pain scores at rest at postoperative 12h [2.8 (0.9) vs. 2.1 (0.9) and 2.0 (0.9), p = 0.016 and p = 0.006]. Sufentanil usage for the first postoperative 48h was lower in group 0.6% compound lidocaine than group saline [24.2 (5.4) vs. 45.6 (7.5) µg, p < 0.001]. Time to first flatus and hospital stay after surgery was shortest and the incidence of postoperative nausea was lowest in patients receiving 0.6% compound lidocaine.TAP block with 0.6% compound lidocaine hydrochloride injection attenuates postoperative pain, reduces opioid consumption, accelerates gastrointestinal function recovery, and shortens length of hospital stay in patients after gynecological laparotomy.ClinicalTrials.gov, identifier: NCT04938882.
Mesenchymal stem cells (MSCs) have been found to benefit patients with a variety of ischemic diseases via promoting angiogenesis. It is also well established that exosomes secreted from MSCs deliver bioactive molecules, including microRNAs (miRs) to recipient cells. Therefore, we hypothesized that exosomes secreted from MSCs deliver miRs into endothelial cells and mediate angiogenesis. The pro-angiogenic stimulatory capacity of exosomes was investigated using tube-like structure formation and spheroid-based sprouting of human umbilical vein endothelial cells (HUVECs), and in vivo Matrigel plug assay. The secretion of pro-angiogenic miRs (pro-angiomiRs) from MSCs into culture medium and transfer of the miRs to HUVECs were confirmed using real-time quantitative PCR. Supplementation of the exosome secretion blocker GW4869 (10 μM) reduced the pro-angiomiRs in the MSC-derived conditioned medium (CdMMSC). Addition of exosomes isolated from CdMMSC could directly 1) promote HUVEC tube-like structure formation in vitro; 2) mobilize endothelial cells into Matrigel plug subcutaneously transplanted into mice; and 3) increase blood flow inside Matrigel plug. Fluorescence tracking showed that the exosomes were internalized rapidly by HUVECs causing an upregulated expression of pro-angiomiRs in HUVECs. Loss-and-gain function of the pro-angiomiRs (e.g., miR-30b) in MSCs significantly altered the pro-angiogenic properties of these MSC-derived exosomes, which could be associated with the regulation of their targets in HUVECs. These results suggest that exosomal transfer of pro-angiogenic miRs plays an important role in MSC mediated angiogenesis and stem cell-to-endothelial cell communication.
Introduction Coronary artery disease (CAD), i.e. myocardial infarction and ischemic cardiomyopathy, is the global leading cause of death. Ischemia leads to loss of functional cardiomyocytes, which contributes to a variety of types of heart failure. Although conventional treatments including pharmacological therapy and coronary revascularization procedures exist, novel therapeutic approaches are still needed. The prospect of stem‐cell‐based therapies might have considerable therapeutic potential. Induced pluripotent stem cells (iPSCs) can be generated from a variety of somatic cells as a potential resource of replacement cells, making them ideal cellular models to provide a renewable source of cardiomyocytes for cell‐based therapy. However, an ideal cell type with superior cardiomyocyte (CM) potential has yet to be identified. Masseter muscle cells (MMC) characterized as Isl‐1 + cells, a genetic marker associated with stem and progenitor states, also contribute to various cardiovascular lineages and have similar embryological origins. We postulate the regenerative potential of masseter muscle cell lineages may yield valuable developmental and clinical insights in the identification of a cell source capable of enhanced cardiomyocyte differentiation and may be used in cell‐based therapy. This study aims to study the role of epigenetic memory in the cardiogenic potential of different lineages of iPSC. Methods A variety of cell sources including masseter muscle cells (MMC), dermal fibroblasts (Fib), bone marrow mesenchymal cells (BMC), and Trunk skeletal muscle cells (TMC) from mouse were isolated. These cell sources were then transfected with Yamanaka's factors (Oct4, Sox2, c‐Myc, and Klf‐4) to generate four lineages of iPSCs. These four iPSC cell lineages were differentiated into iPSC‐CMs via 3‐D culture protocols and analyzed for differences in their differentiation potential as well as the efficiency of differentiation. Cardiomyocytes differentiation was analyzed by spontaneous contractions, immunostaining, flow cytometry test, and patch clamp. The epigenetic signatures of somatic cells, iPSCs, and derived Cardiomyocytes were analyzed by Real‐time PCR. Methylation study was used to evaluate epigenetic memory of four lineages of iPSCs. Results Spontaneous beating was observed in 80% colonies of MMC‐derived iPSC‐cardiomyocytes (MMC‐CM), which was significantly higher than other groups. Cardiac genes Isl‐1, Nkx2.5, and GATA4 were also significantly upregulated in MMC‐CM. MMC‐CM exerted robust cardiac functional phenotype, indicated by enhanced contractility and electrophysiological properties. Low methylation levels of the cardiac mesodermal gene (Isl‐1) in MMC and M‐iPSC were similar to neonatal cardiomyocytes and were maintained in MMC‐CM. Cardiac genes were epigenetically silenced in other somatic cells. Conclusion iPSCs derived from masseter muscle cell sources have better cardiogenic differentiation capabilities than other somatic cell sources. Epigenetic memory significantly contributes to the prominent cardiogenic potential of masseter‐derived iPSCs. Support or Funding Information National Institutes of Health grants (HL110740)
In this study, a passenger car was tested for its aerodynamic noise performance in terms of sound pressure level in the wind tunnel at Tongji University (Shanghai Automotive Wind Tunnel Center), where the phase microphone array was used along with sound surface microphones and artificial heads combining with the adhesive tape sealing method. The wind noise sources, the noise level on the exterior surface and the sealing influence on the interior noise level were evaluated. Based on datum of the tested subject, the potential design problem associated with the body structure and seals are identified, the main aerodynamic noise sources and their transfer path are located. The details about the setup of the experiment, data collection and processing method offered in this study can be used to not only help improve the tested vehicle aerodynamic noise performance, but also provide a long-term reference value for the aero-noise research community.
Survival of stem cells following transplantation in the infarcted myocardium is a critical issue for the cell‐based therapy and preconditioning (PC) of stem cells is a method for cytoprotection. In this study, we investigated the cytoprotective effect of PC with electrical stimulation (EleS) on cardiac stem cells (CSCs) survival. Sca‐1 + CSCs were isolated from male C57BL6 mice hearts. PC of CSCs with EleS ( EleS CSCs) was carried out for 3 h at 1.5 V followed by exposure to H 2 O 2 . Cytoprotective effects and cell adhesion ability were significantly increased by EleS as evaluated by TUNEL, lactate dehyrogenase release assay and adhesion assay as well as Sry gene analysis in vivo . EleS increased phosphorylation of AKT, FAK and GSK3β, and decreased pro‐apoptotic protein caspase‐3 cleavage. Pretreatment with Wortmannin, a PI3K inhibitor, and FAK inhibitor‐14 abolished the pro‐survival effects of EleS. Importantly, we found that connective tissue growth factor ( Ctgf ) is a key determinant for EleS‐induced CSC survival and adhesion. Furthermore, we identified miR‐378 is a potential negative regulator for Ctgf expression in EleS CSCs. In conclusion, EleS enhanced CSC survival in vitro and in vivo through AKT/FAK/CTGF/miR‐378 signaling cascade, being suggested as a novel preconditioining strategy. This work was supported by National Institutes of Health grant, [HL087246 to M.A.].
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)