Induced pluripotent stem cells (iPSCs) constitute a potential source of autologous patient-specific cardiomyocytes for cardiac repair, providing a major benefit over other sources of cells in terms ...of immune rejection. However, autologous transplantation has substantial challenges related to manufacturing and regulation. Although major histocompatibility complex (MHC)-matched allogeneic transplantation is a promising alternative strategy, few immunological studies have been carried out with iPSCs. Here we describe an allogeneic transplantation model established using the cynomolgus monkey (Macaca fascicularis), the MHC structure of which is identical to that of humans. Fibroblast-derived iPSCs were generated from a MHC haplotype (HT4) homozygous animal and subsequently differentiated into cardiomyocytes (iPSC-CMs). Five HT4 heterozygous monkeys were subjected to myocardial infarction followed by direct intra-myocardial injection of iPSC-CMs. The grafted cardiomyocytes survived for 12 weeks with no evidence of immune rejection in monkeys treated with clinically relevant doses of methylprednisolone and tacrolimus, and showed electrical coupling with host cardiomyocytes as assessed by use of the fluorescent calcium indicator G-CaMP7.09. Additionally, transplantation of the iPSC-CMs improved cardiac contractile function at 4 and 12 weeks after transplantation; however, the incidence of ventricular tachycardia was transiently, but significantly, increased when compared to vehicle-treated controls. Collectively, our data demonstrate that allogeneic iPSC-CM transplantation is sufficient to regenerate the infarcted non-human primate heart; however, further research to control post-transplant arrhythmias is necessary.
Aims/hypothesis
Previously, we demonstrated that myristic acid (14:0) increases levels of diacylglycerol kinase (DGK) δ, a key enzyme involved in type 2 diabetes exacerbation, and enhances glucose ...uptake in C2C12 myotube cells. Moreover, results from a population-based cohort study suggest that consumption of high-fat dairy products, which contain high amounts of myristic acid, is associated with a lower risk of developing type 2 diabetes. Taken together, we hypothesised that intake of myristic acid reduces type 2 diabetes risk in vivo. The aim of this study was to examine the glucose-lowering effect of myristic acid in Nagoya–Shibata–Yasuda (NSY) mice, a spontaneous model for studying obesity-related type 2 diabetes.
Methods
Male NSY mice were orally administered vehicle (
n
= 9), 300 mg/kg of myristic acid (
n
= 14) or 300 mg/kg of palmitic acid (16:0) (
n
= 9) every other day from 4 weeks of age. Glucose and insulin tolerance tests were performed at weeks 18, 24 and 30, and weeks 20 and 26, respectively. DGKδ levels were measured in skeletal muscle from 32–36-week-old NSY mice via western blot.
Results
Chronic oral administration of myristic acid ameliorated glucose tolerance (24–28% decrease in blood glucose levels during glucose tolerance tests) and reduced insulin-responsive blood glucose levels (~20% decrease) in male NSY mice compared with vehicle and palmitic acid groups at 24–30 weeks of age (the age at which the severity of type 2 diabetes is exacerbated in NSY mice). Myristic acid also attenuated the increase in body weight seen in NSY mice. Furthermore, the fatty acid increased DGKδ levels (~1.6-fold) in skeletal muscle of NSY mice.
Conclusions/interpretation
These results suggest that the chronic oral administration of myristic acid improves hyperglycaemia by decreasing insulin-responsive glucose levels and reducing body weight, and that the fatty acid accounts for the diabetes protective properties of high-fat dairy products. Myristic acid is a potential candidate for the prevention and treatment of type 2 diabetes mellitus and its related diseases.
Metabotropic glutamate receptor 6, mGluR6, interacts with scaffold proteins and Gβγ subunits via its intracellular C‐terminal domain (CTD). The mGluR6 pathway is critically involved in the retinal ...processing of visual signals. We herein investigated whether the CTD (residues 840–871) was necessary for mGluR6 cell surface localization and G‐protein coupling using mGluR6‐CTD mutants with immunocytochemistry, surface biotinylation assays, and electrophysiological approaches. We used 293T cells and primary hippocampal neurons as model systems. We examined C‐terminally truncated mGluR6 and showed that the removal of up to residue 858 did not affect surface localization or glutamate‐induced G‐protein‐mediated responses, whereas a 15‐amino acid deletion (Δ857‐871) impaired these functions. However, a 21‐amino acid deletion (Δ851‐871) restored surface localization and glutamate‐dependent responses, which were again attenuated when the entire CTD was removed. The sequence alignment of group III mGluRs showed conserved amino acids resembling an ER retention motif in the CTD. These results suggest that the intracellular CTD is required for the cell surface transportation and receptor function of mGluR6, whereas it may contain regulatory elements for intracellular trafficking and signaling.
The intracellular C‐terminal domain (CTD) of G‐protein‐coupled receptors generally interacts with PDZ domain‐containing scaffold proteins and Gβγ subunits. We herein investigated whether mGluR6 CTD contributes to receptor cell surface localization and G‐protein coupling. Using 293T cells and hippocampal neuron cultures, we demonstrate that the deletions of the distal half of CTD attenuated mGluR6 surface localization and G‐protein coupling. However, these functions were restored by further deletions of the distal two‐thirds encoding an RXR‐type ER retention motif, which may be masked by the distal half of CTD. The results provide insights into the mechanisms underlying intracellular trafficking and signaling of mGluR6.
Biophysical mechanisms underlying collective cell migration of eukaryotic cells have been studied extensively in recent years. One mechanism that induces cells to correlate their motions is contact ...inhibition of locomotion, by which cells migrating away from the contact site. Here, we report that tail-following behavior at the contact site, termed contact following locomotion (CFL), can induce a non-trivial collective behavior in migrating cells. We show the emergence of a traveling band showing polar order in a mutant
cell that lacks chemotactic activity. We find that CFL is the cell-cell interaction underlying this phenomenon, enabling a theoretical description of how this traveling band forms. We further show that the polar order phase consists of subpopulations that exhibit characteristic transversal motions with respect to the direction of band propagation. These findings describe a novel mechanism of collective cell migration involving cell-cell interactions capable of inducing traveling band with polar order.
Self-incompatibility (SI) is conserved among members of the Brassicaceae plant family. This trait is controlled epigenetically by the dominance hierarchy of the male determinant alleles. We ...previously demonstrated that a single small RNA (sRNA) gene is sufficient to control the linear dominance hierarchy in Brassica rapa and proposed a model in which a homology-based interaction between sRNAs and target sites controls the complicated dominance hierarchy of male SI determinants. In Arabidopsis halleri, male dominance hierarchy is reported to have arisen from multiple networks of sRNA target gains and losses. Despite these findings, it remains unknown whether the molecular mechanism underlying the dominance hierarchy is conserved among Brassicaceae. Here, we identified sRNAs and their target sites that can explain the linear dominance hierarchy of Arabidopsis lyrata, a species closely related to A. halleri. We tested the model that we established in Brassica to explain the linear dominance hierarchy in A. lyrata. Our results suggest that the dominance hierarchy of A. lyrata is also controlled by a homology-based interaction between sRNAs and their targets.
The effects of acute intratracheal administration of electrolyzed reduced water (ERW; alkaline electrolyzed water) were investigated in rats. In this study, no deaths or near-deaths were recorded in ...either group, namely those treated with ERW or purified water (maximum doses of 900 mg/kg). The main symptoms observed in the rats were decreased spontaneous movements and abnormal breath sounds, which were considered to be transient symptoms caused by intratracheal administration. In addition, low values of alkaline phosphatase, total protein and lactate dehydrogenase were found in BALF tests, but these values were considered to be of low toxicological significance, since they are usually high in the presence of lung inflammation or cellular damage. This suggests that the alkalinity of ERW partially contributes to broken peptide bonds in proteins. There were no significant increases in bronchoalveolar lavage fluid protein in either group. ERW did not cause an increase in the influx of neutrophils, eosinophils, basophils, or lymphocytes, suggesting that intratracheal administration of ERW did not cause lung inflammation. ERW did not cause abnormalities in the body or pathological changes in the lungs. Aggregates of alveolar macrophages, as a measure of inflammation, were observed in both groups. These may be transient symptoms due to intratracheal administration, not due to ERW toxicity. This study confirmed the safety of intratracheal ERW infusion and demonstrated the low risk of acute toxicity for inhalation exposure to ERW aerosol or vapor. Therefore, ERW may be an effective air purifier against viruses or bacteria.
Although frailty is used to predict morbidity and mortality, its effect on the outcomes of acute type A aortic dissection has not been examined. Therefore, the objective of this study was to evaluate ...the role of frailty in predicting postoperative morbidity and mortality of patients with acute type A aortic dissection.
A retrospective analysis of a prospectively maintained database was undertaken for all patients (n = 310) undergoing aortic surgery between May 2004 and March 2017. Frailty was evaluated using an index consisting of age more than 70 years, body mass index less than 18.5 kg/m
, serum creatinine greater than 1.2 mg/dL, anemia, history of stroke, hypoalbuminemia, and the psoas muscle area index. One point was given for each criterion met, for a frailty score between 0 and 7. Frailty was defined as a score of 3 or more.
Of all patients, 106 (34.2%) were defined as frail. Inhospital mortality rates of frail versus nonfrail patients were not significantly different (10.4% versus 8.3%, respectively; p = 0.54). Incidences of postoperative major morbidities without reexploration for bleeding were also not statistically different. Five-year survival rates were significantly worse for frail patients than for nonfrail patients (57.7% versus 85.1%, respectively; p = 0.0001). A frailty score of 3 or greater was associated with late mortality, and long-term outcomes were clearly stratified by frailty score.
Frailty, as defined using a seven-component frailty index, can serve as an independent predictor of the risk of late mortality for patients undergoing surgery for acute type A aortic dissection. Such frailty markers, all of which are easily assessed preoperatively, may provide valuable information for patient counseling and risk stratification before aortic surgery.
An aortic valve with a coronary cusp adherent to the aortic wall is a rare anomaly. Furthermore, an adherent coronary cusp with fenestration is even rarer. Here, we report a case of aortic valve ...regurgitation with an adherent and fenestrated left coronary cusp. A 45-year-old man with complaints of dyspnea on exertion was hospitalized. Clinical examination revealed severe aortic valve regurgitation associated with poor cardiac function. He had a history of cardiac murmur present since childhood; however, the details of his cardiac history are unknown. During surgery, a fenestrated left coronary cusp adherent to the aortic wall was observed. Following resection of all aortic cusps, we performed an aortic valve replacement with a mechanical valve. The postoperative recovery was uneventful. In this case, the left coronary artery was perfused by a small fenestration in the adherent coronary cusp. In such cases, the adherent coronary cusp should be released to alleviate the possibility of sudden death and ischemic myocarditis.
The inhibitory activity of electrolyzed reduced water (ERW) against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which is the etiological agent responsible for coronavirus disease ...2019 (COVID-19), was tested in vitro on Vero E6 cells using a plaque assay. Infectious virus titers of cells treated with ERW 100%, 50% and 33.3% solutions and phosphate buffered saline (PBS, negative control) and exposed to the virus suspension for 60 seconds were 2.25, 2.65, 3.21 and 7.38, respectively. ERW has a high pH and low surface tension. It is considered that the alkaline property of ERW breaks down phospholipids and proteins of envelopes. The role of pH and reducibility on the virucidal effect of ERW should be further evaluated. This study provides a foundation for utilizing ERW as an effective antiviral aqueous solution in a variety of applications.
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