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ABSTRACT The potential liability to hypercatabolism in lipodystrophy remains to be fully elucidated. Here we report a 28‐year‐old Japanese woman with acquired generalized lipodystrophy, who presented with recurrence of panniculitis and anemia. After corticosteroid treatment was started, she showed rapid reductions in body weight and lean mass by 15% at maximum, accompanied by an elevated urea nitrogen/creatinine ratio, which recovered almost fully as the corticosteroid treatment was tapered and discontinued. She had multiple risk factors for hypercatabolism: lack of metabolic reserves, insulin resistance, and hyperglycemia due to lipodystrophy, lowered daily activity due to anemia, persistent inflammation, and wasting associated with panniculitis, and relatively insufficient energy and protein intake during hospitalization. More attention should be paid to the potential liability to hypercatabolism in patients with lipodystrophy, and to skeletal muscle loss as an adverse effect of corticosteroid treatment in patients at high risk, such as those with diabetes or decreased metabolic reserves.

BackgroundHereditary angioedema (HAE), a rare genetic disease, induces acute attacks of swelling in various regions of the body. Its prevalence is estimated to be 1 in 50,000 people, with no reported bias among different ethnic groups. However, considering the estimated prevalence, the number of patients in Japan diagnosed with HAE remains approximately 1 in 250,000, which means that only 20% of potential HAE cases are identified. ObjectiveThis study aimed to develop an artificial intelligence (AI) model that can detect patients with suspected HAE using medical history data (medical claims, prescriptions, and electronic medical records [EMRs]) in the United States. We also aimed to validate the detection performance of the model for HAE cases using the Japanese dataset. MethodsThe HAE patient and control groups were identified using the US claims and EMR datasets. We analyzed the characteristics of the diagnostic history of patients with HAE and developed an AI model to predict the probability of HAE based on a generalized linear model and bootstrap method. The model was then applied to the EMR data of the Kyoto University Hospital to verify its applicability to the Japanese dataset. ResultsPrecision and sensitivity were measured to validate the model performance. Using the comprehensive US dataset, the precision score was 2% in the initial model development step. Our model can screen out suspected patients, where 1 in 50 of these patients have HAE. In addition, in the validation step with Japanese EMR data, the precision score was 23.6%, which exceeded our expectations. We achieved a sensitivity score of 61.5% for the US dataset and 37.6% for the validation exercise using data from a single Japanese hospital. Overall, our model could predict patients with typical HAE symptoms. ConclusionsThis study indicates that our AI model can detect HAE in patients with typical symptoms and is effective in Japanese data. However, further prospective clinical studies are required to investigate whether this model can be used to diagnose HAE.

The object of this paper is to develop numerical procedures for creep-fatigue-oxidation life prediction and damage assessments based on engineering damage approach, in response to high-reliability and long-life design requirement that supports low-carbon and new-energy technologies. In order to achieve the prediction results in terms of cycle-dependent stress–strain responses, crack initiation life prediction and multi-damage evolutions, the generalized creep-fatigue loading conditions including tension-hold-only, compression-hold-only and tension-compression-hold-both, which are abbreviated as CP, PC, and CC types, are conducted for IN 718 at 650 °C. Results show that creep-fatigue deformation behaviors are well depicted through the evolutions of hysteresis loops, cyclic softening curves and stress responses. With incorporating into oxidation damage especially under long-life conditions, both error band and probability density function for life prediction are quantitatively improved. In addition, the cycle-dependent roles in multi-damage evolutions are clearly observed in a set of radar graphs, where fatigue, creep and oxidation damage are manifested as different evolutionary features. Finally, the technical route in the transition from deterministic to probabilistic multi-damage assessments is discussed based on the established creep-fatigue-oxidation diagram.

Tomofuji et al. perform non-targeted metabolomics on serum samples from people with type 2 diabetes with or without complications. The authors identify metabolites associated with retinal and renal complications.

Intracranial germ cell tumors (IGCTs) are rare brain tumors mainly diagnosed in children and young adults. Here, the authors conduct a genome-wide association study for IGCTs, identify a risk locus at BAK1, and characterize its functional consequences.

Peritoneal adhesions are a major cause of complications after abdominal surgery. Here the authors use a post-operative abdominal adhesion model in mice to show that resident F4/80HighCD206− macrophages form a protective barrier that can be enhanced by IL-4 administration or adoptive transfer of these cells.

The pathological consequences leading to primary storage, autophagy impairment, impaired mitochondrial dynamics, and endoplasmic reticulum (ER) stress on neural cell dysfunction and apoptosis in metachromatic leukodystrophy (MLD) have been poorly elucidated. In the present study, we generated 2 cell lines of patient-specific-induced pluripotent stem cells (iPSCs) and modeled the progression of pathological events during the differentiation of iPSCs to motor neuron progenitors (MNPs) and mature motor neurons (MNs). The iPS cells were generated from two late-infantile MLD patient-derived skin fibroblasts using electroporation or the Sendai virus. Olig2+ MNPs were generated from both iPSC lines using a combination of small molecules in a chemically defined neural medium. Furthermore, the MNPs could be differentiated into mature MNs, which was confirmed by RT–PCR and MN markers, including SMI32 and ChAT. The population of MNs was approximately 50% under the culture conditions. Pathological observation of MLD patient-derived iPSCs revealed lysosomal accumulation and impaired autophagy. In addition, both MNPs and MNs derived from MLD-iPSCs showed increased lysosomal accumulation, dysfunctional autophagy, impaired mitophagy, endoplasmic reticulum (ER) stress or unfolded protein response (UPR) activation, and premature cellular death.

We applied photoreflectance (PR) spectroscopy for contactless determination of the electric field strength at buried interfaces in metal–insulator–semiconductor (MIS) structures. The PR is an all-optical version of an electromodulated reflectance spectroscopy. The tradeoff of this adoption is that this requires an additional feedback system to eliminate background problems induced by scattered pump light and/or photoluminescence. A microcomputer-based feedback system has been developed for this elimination. Despite the very tiny signal intensity, we successfully attained a sufficiently good signal–noise ratio to determine the electric field strength in oxide-based MIS interfaces that exhibits a large, unwanted photoluminescence signal. The field strength was evaluated to be ca. 0.25 kV/cm.

Human leukocyte antigen (HLA) genes contribute to risk of many complex traits, yet understanding inter-ethnic heterogeneity is computationally challenging. Here, the authors develop DEEP*HLA for imputation of HLA genotypes and show its ability to disentangle HLA variant risk effects in diverse populations.

Autoimmune pulmonary alveolar proteinosis (aPAP) is a complex lung disease caused by abnormal surfactant homeostasis. Here, the authors carry out a genome-wide association study of aPAP in a Japanese cohort, finding variants in the MHC and suggesting predisposition to abnormal antibody production.

Abstract Recently, we conducted genome-wide association studies of type 2 diabetes (T2D) in a Japanese population, which identified 20 novel T2D loci that were not associated with T2D in Europeans. Moreover, nine novel missense risk variants, such as those of PAX4, were not rare in the Japanese population, but rare in Europeans. We report in silico structural analysis of ethnic-specific variants of PAX4, which suggests the pathogenic effect of these variants.

Previous genome-wide association studies have identified risk loci for pancreatic cancer but were centered on individuals of European ancestry. Here the authors identify GP2 gene variants associated with pancreatic cancer susceptibility in populations of East Asian ancestry.

Population structure, even subtle differences within seemingly homogenous populations, can have an impact on the accuracy of polygenic prediction. Here, Sakaue et al. use dimensionality reduction methods to reveal fine-scale structure in the Biobank Japan cohort and explore the performance of polygenic risk scores.

Niemann−Pick disease type C (NPC) is a rare neurodegenerative disorder caused by a recessive mutation in the NPC1 or NPC2 gene, in which patients exhibit lysosomal accumulation of unesterified cholesterol and glycolipids. Most of the research on NPC has been done in patient-derived skin fibroblasts or mouse models. Therefore, we developed NPC patient neurons derived from induced pluripotent stem cells (iPSCs) to investigate the neuropathological cause of the disease. Although an accumulation of cholesterol and glycolipids, which is characteristic of NPC, was observed in both undifferentiated iPSCs and derived neural stem cells (NSCs), we could not observed the abnormalities in differentiation potential and autophagic activity in such immature cells. However, definite neuropathological features were detected in mature neuronal cells generated from NPC patient-derived iPSCs. Abnormal accumulation of cholesterol and other lipids identified by lipid droplets and number of enlarged lysosomes was more prominent in mature neuronal cells rather than in iPSCs and/or NSCs. Thin-sectioning electron microscopic analysis also demonstrated numerous typical membranous cytoplasmic bodies in mature neuronal cells. Furthermore, TUJ1-positive neurite density was significantly reduced in NPC patient-derived neuronal cells. In addition, disruption of the p62/SQSTM1−KEAP1−NRF2 axis occurred in neurons differentiated from NPC patient-derived iPSCs. These data indicate the impairment of neuronal network formation associated with neurodegeneration in mature neuronal cells derived from patients with NPC.

Abstract Background The spectrum of classical and non-classical HLA genes related to the risk of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) in the Japanese population has not been studied in detail. We conducted a case-control analysis of classical and non-classical HLA genes. Methods We used next-generation sequencing (NGS)-based HLA genotyping methods for mapping risk for 45 MS patients, 31 NMOSD patients, and 429 healthy controls. We evaluated the association of the HLA variants with the risk of MS and NMOSD using logistic regression analysis and Fisher’s exact test. Results We confirmed that HLA-DRB1*15:01 showed the strongest association with MS (P = 2.1 × 10−5; odds ratio [OR] = 3.44, 95% confidence interval [95% CI] = 1.95–6.07). Stepwise conditional analysis identified HLA-DRB1*04:05, HLA-B*39:01, and HLA-B*15:01 as being associated with independent MS susceptibility (P Conditional

Abstract The phylloplane yeast Pseudozyma antarctica secretes an esterase, named PaE, and xylanase when cultivated with xylose. We previously observed that the lipophilic layer of Micro-Tom tomato leaves became thinner after the culture filtrate treatment. The leaves developed reduced water-holding ability and became wilted. In this study, the purified enzymes were spotted on Micro-Tom leaves. PaE, but not xylanase, thinned the lipophilic layer of leaves and decreased leaf resistance to the phytopathogenic fungus Botrytis cinerea. Disease severity increased significantly in detached leaves and potted plants treated with the culture filtrate and B. cinerea spores compared with those treated with inactivated enzyme and B. cinerea alone. Spore germination ratios, numbers of penetrating fungal hyphae in the leaves, and fungal DNA contents also increased significantly on the detached leaves. Japanese knotweed (Fallopia japonica), a serious invasive alien weed in Europe and North America, also became susceptible to infection by the rust pathogen Puccinia polygoni-amphibii var. tovariae following the culture filtrate treatment. The culture filtrate treatment increased disease development in plants induced by both phytopathogenic fungi. Our results suggest that P. antarctica culture filtrate could be used as an adjuvant for sustainable biological weed control using phytopathogenic fungi.

Biodegradable plastics must be sufficiently stable to maintain functionality during use but need to be able to degrade rapidly after use. We previously reported that treatment with an enzyme named PaE, secreted by the basidiomycete yeast Pseudozyma antarctica can speed up this degradation. To facilitate the production of large quantities of PaE, here, we aimed to elucidate the optimal conditions of ethanol treatment for sterilization of the culture supernatant and for concentration and stabilization of PaE. The results showed that Pseudozyma antarctica completely lost its proliferating ability when incubated in ≥20% (v/v) ethanol. When the ethanol concentration was raised to 90% (v/v), PaE formed a precipitate; however, its activity was restored completely when the precipitate was dissolved in water. To reduce ethanol use, PaE was successfully concentrated and recovered by sequential ammonium sulfate precipitation and ethanol precipitation steps. Over 90% of the activity in the original culture supernatant was recovered and the specific activity was increased 3.4-fold. By preparing the enzyme solution at a final concentration of 20% (v/v) ethanol, about 60% of the initial activity was maintained at ambient temperature for over 6 months without growth of microbes. We conclude that ethanol treatment is effective for sterilization, concentration, and stabilization of PaE, and that concentrating PaE by sequential ammonium sulfate precipitation and ethanol precipitation substantially increases the PaE purity and decreases ethanol use.

While microbiome plays key roles in the etiology of multiple sclerosis (MS), its mechanism remains elusive. Here, we conducted a comprehensive metagenome-wide association study (MWAS) of the relapsing-remitting MS gut microbiome (ncase = 26, ncontrol = 77) in the Japanese population, by using whole-genome shotgun sequencing. Our MWAS consisted of three major bioinformatic analytic pipelines (phylogenetic analysis, functional gene analysis, and pathway analysis). Phylogenetic case-control association tests showed discrepancies of eight clades, most of which were related to the immune system (false discovery rate [FDR] < 0.10; e.g., Erysipelatoclostridium_sp. and Gemella morbillorum). Gene association tests found an increased abundance of one putative dehydrogenase gene (Clo1100_2356) and one ABC transporter related gene (Mahau_1952) in the MS metagenome compared with controls (FDR < 0.1). Molecular pathway analysis of the microbiome gene case-control comparisons identified enrichment of multiple Gene Ontology terms, with the most significant enrichment on cell outer membrane (P = 1.5 × 10−7). Interaction between the metagenome and host genome was identified by comparing biological pathway enrichment between the MS MWAS and the MS genome-wide association study (GWAS) results (i.e., MWAS-GWAS interaction). No apparent discrepancies in alpha or beta diversities of metagenome were found between MS cases and controls. Our shotgun sequencing-based MWAS highlights novel characteristics of the MS gut microbiome and its interaction with host genome, which contributes to our understanding of the microbiome’s role in MS pathophysiology.

In this study, a basic design of area-arrayed graphene nanoribbon (GNR) strain sensors was proposed to realize the next generation of strain sensors. To fabricate the area-arrayed GNRs, a top-down approach was employed, in which GNRs were cut out from a large graphene sheet using an electron beam lithography technique. GNRs with widths of 400 nm, 300 nm, 200 nm, and 50 nm were fabricated, and their current-voltage characteristics were evaluated. The current values of GNRs with widths of 200 nm and above increased linearly with increasing applied voltage, indicating that these GNRs were metallic conductors and a good ohmic junction was formed between graphene and the electrode. There were two types of GNRs with a width of 50 nm, one with a linear current–voltage relationship and the other with a nonlinear one. We evaluated the strain sensitivity of the 50 nm GNR exhibiting metallic conduction by applying a four-point bending test, and found that the gauge factor of this GNR was about 50. Thus, GNRs with a width of about 50 nm can be used to realize a highly sensitive strain sensor.

Abstract Recent research has shown that reparative (alternatively activated or M2) macrophages play a role in repair of damaged tissues, including the infarcted hearts. Administration of IL-4 is known to augment M2 macrophages. This translational study thus aimed to investigate whether IL-4 administration is useful for the treatment of myocardial infarction. Long-acting IL-4 complex (IL-4c; recombinant IL-4 mixed with anti-IL-4 monoclonal antibody as a stabilizer) was administered after coronary artery ligation in mice. It was observed that IL-4c administration increased accumulation of CD206+F4/80+ M2-like macrophages predominantly in the injured myocardium, compared to the control. Sorted cardiac M2-like macrophages highly expressed wide-ranging tissue repair-related genes. Indeed, IL-4c administration enhanced cardiac function in association with reduced infarct size and enhanced tissue repair (strengthened connective tissue formation, improved microvascular formation and attenuated cardiomyocyte hypertrophy). Experiments using Trib1 −/− mice that had a depleted ability to develop M2 macrophages and other in-vitro studies supported that these IL-4-mediated effects were induced via M2-like macrophages. On the other hand, when administered at Day 28 post-MI, the effects of IL-4c were diminished, suggesting a time-frame for IL-4 treatment to be effective. These data represent proof-of-concept of efficacy of IL-4 treatment for acute myocardial infarction, encouraging its further development.

A surface marker that distinctly identifies cardiac progenitors (CPs) is essential for the robust isolation of these cells, circumventing the necessity of genetic modification. Here, we demonstrate that a Glycosylphosphatidylinositol-anchor containing neurotrophic factor receptor, Glial cell line-derived neurotrophic factor receptor alpha 2 (Gfra2), specifically marks CPs. GFRA2 expression facilitates the isolation of CPs by fluorescence activated cell sorting from differentiating mouse and human pluripotent stem cells. Gfra2 mutants reveal an important role for GFRA2 in cardiomyocyte differentiation and development both in vitro and in vivo. Mechanistically, the cardiac GFRA2 signaling pathway is distinct from the canonical pathway dependent on the RET tyrosine kinase and its established ligands. Collectively, our findings establish a platform for investigating the biology of CPs as a foundation for future development of CP transplantation for treating heart failure.

Here, Imamuraet al. conduct meta-analysis of genome-wide association studies to identify novel susceptibility loci for type 2 diabetes (T2D) in the Japanese population. By doing so, this study shows that both ethnicity-specific and ethnically-shared genetic loci can contribute to T2D risk.

BackgroundTransplantation of allogeneic mesenchymal stromal cells (MSCs) is a promising treatment for heart failure. We have shown that epicardial placement of cell sheets markedly increases donor cell survival and augments therapeutic effects compared with the current methods. Although immune rejection of intramyocardially injected allogeneic MSCs have been suggested, allogeneic MSCs transplanted on the heart surface (virtual space) may undergo different courses. This study aimed to elucidate immunologic response against epicardially placed allogeneic MSCs, rejection or acceptance of these cells, and their therapeutic effects for heart failure. Methods and ResultsAt 4 weeks after coronary artery ligation, Lewis rats underwent epicardial placement of MSC sheets from syngeneic Lewis or allogeneic Fischer 344 rats or sham treatment. At days 3 and 10 after treatment, similar ratios (≈50% and 30%, respectively) of grafted MSCs survived on the heart surface in both MSC sheet groups. By day 28, survival of syngeneic MSCs was substantially reduced (8.9%); survival of allogeneic MSCs was more extensively reduced (0.2%), suggesting allorejection. Correspondingly, allogeneic MSCs were found to have evoked an immunologic response, albeit low level, as characterized by accumulation of CD4+ T cells and upregulation of interleukin 6. Despite this alloimmune response, the allogeneic MSC sheet achieved myocardial upregulation of reparative factors, enhanced repair of the failing myocardium, and improved cardiac function to the equivalent degree observed for the syngeneic MSC sheet. ConclusionsAllogeneic MSCs placed on the heart surface evoked an immunologic response; however, this allowed sufficient early phase donor cell survival to induce equivalent therapeutic benefits to syngeneic MSCs. Further development of this approach toward clinical application is warranted.

Intracoronary injection of bone marrow mononuclear cells (BMMNC) is an emerging treatment for heart failure. Initial donor cell retention in the heart is the key to the success of this approach, but this process remains insufficiently characterized. Although it is assumed that cell size of injected cells may influence their initial retention, no scientific evidence has been reported. We developed a unique model utilizing an ex-vivo rat heart perfusion system, enabling quantitative assessment of retention of donor cells after intracoronary injection. The initial (5 minutes after intracoronary injection) retention rate of BMMNC was as low as approximately 20% irrespective of donor cell doses injected (1×106, 8×106, 4×107). Quantitative cell-size assessment revealed a positive relationship between the size of BMMNC and retention ratio; larger subpopulations of BMMNC were more preferentially retained compared to smaller ones. Furthermore, a larger cell type-bone marrow-derived mesenchymal stromal cells (median size = 11.5μm versus 7.0μm for BMMNC)-had a markedly increased retention rate (77.5±1.8%). A positive relationship between the cell size and retention ratio was also seen in mesenchymal stromal cells. Flow-cytometric studies showed expression of cell-surface proteins, including integrins and selectin-ligands, was unchanged between pre-injection BMMNC and those exited from the heart, suggesting that biochemical interaction between donor cells and host coronary endothelium is not critical for BMMNC retention. Histological analyses showed that retained BMMNC and mesenchymal stromal cells were entrapped in the coronary vasculature and did not extravasate by 60 minutes after transplantation. Whilst BMMNC did not change coronary flow after intracoronary injection, mesenchymal stromal cells reduced it, suggesting coronary embolism, which was supported by the histological finding of intravascular cell-clump formation. These data indicate that cell-size dependent, passive (mechanical), intravascular entrapment is responsible for the initial donor cell retention after intracoronary injection of BMMNC in the heart having normal vasculatures (at least).

When a radial strain is applied to a carbon nanotube (CNT), the increase in local curvature induces orbital hybridization. The effect of the curvature-induced orbital hybridization on the electronic properties of CNTs, however, has not been evaluated quantitatively. In this study, the strength of orbital hybridization in CNTs under homogeneous radial strain was evaluated quantitatively. Our analyses revealed the detailed procedure of the change in electronic structure of CNTs. In addition, the dihedral angle, the angle between π-orbital axis vectors of adjacent atoms, was found to effectively predict the strength of local orbital hybridization in deformed CNTs.

In the early vertebrate embryo, cardiac progenitor/precursor cells (CPs) give rise to cardiac structures. Better understanding their biological character is critical to understand the heart development and to apply CPs for the clinical arena. However, our knowledge remains incomplete. With the use of single-cell expression profiling, we have now revealed rapid and dynamic changes in gene expression profiles of the embryonic CPs during the early phase after their segregation from the cardiac mesoderm. Progressively, the nascent mesodermal gene Mesp1 terminated, and Nkx2-5+/Tbx5+ population rapidly replaced the Tbx5low+ population as the expression of the cardiac genes Tbx5 and Nkx2-5 increased. At the Early Headfold stage, Tbx5-expressing CPs gradually showed a unique molecular signature with signs of cardiomyocyte differentiation. Lineage-tracing revealed a developmentally distinct characteristic of this population. They underwent progressive differentiation only towards the cardiomyocyte lineage corresponding to the first heart field rather than being maintained as a progenitor pool. More importantly, Tbx5 likely plays an important role in a transcriptional network to regulate the distinct character of the FHF via a positive feedback loop to activate the robust expression of Tbx5 in CPs. These data expands our knowledge on the behavior of CPs during the early phase of cardiac development, subsequently providing a platform for further study.

We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth.

Transplantation of unfractionated bone marrow mononuclear cells (BMCs) repairs and/or regenerates the damaged myocardium allegedly due to secretion from surviving BMCs (paracrine effect). However, donor cell survival after transplantation is known to be markedly poor. This discrepancy led us to hypothesize that dead donor BMCs might also contribute to the therapeutic benefits from BMC transplantation. High mobility group box 1 (HMGB1) is a nuclear protein that stabilizes nucleosomes, and also acts as a multi-functional cytokine when released from damaged cells. We thus studied the role of extracellular HMGB1 in the effect of BMC transplantation for heart failure. Four weeks after coronary artery ligation in female rats, syngeneic male BMCs (or PBS only as control) were intramyocardially injected with/without anti-HMGB1 antibody or control IgG. One hour after injection, ELISA showed that circulating extracellular HMGB1 levels were elevated after BMC transplantation compared to the PBS injection. Quantitative donor cell survival assessed by PCR for male-specific sry gene at days 3 and 28 was similarly poor. Echocardiography and catheterization showed enhanced cardiac function after BMC transplantation compared to PBS injection at day 28, while this effect was abolished by antibody-neutralization of HMGB1. BMC transplantation reduced post-infarction fibrosis, improved neovascularization, and increased proliferation, while all these effects in repairing the failing myocardium were eliminated by HMGB1-inhibition. Furthermore, BMC transplantation drove the macrophage polarization towards alternatively-activated, anti-inflammatory M2 macrophages in the heart at day 3, while this was abolished by HMGB1-inhibition. Quantitative RT-PCR showed that BMC transplantation upregulated expression of an anti-inflammatory cytokine IL-10 in the heart at day 3 compared to PBS injection. In contrast, neutralizing HMGB1 by antibody-treatment suppressed this anti-inflammatory expression. These data suggest that extracellular HMGB1 contributes to the effect of BMC transplantation to recover the damaged myocardium by favorably modulating innate immunity in heart failure.

BACKGROUND:Intramyocardial injection of skeletal myoblasts (SMB) has been shown to be a promising strategy for treating post-infarction chronic heart failure. However, insufficient therapeutic benefit and occurrence of ventricular arrhythmias are concerns. We hypothesised that the use of a retrograde intracoronary route for SMB-delivery might favourably alter the behaviour of the grafted SMB, consequently modulating the therapeutic effects and arrhythmogenicity. METHODS AND RESULTS:Three weeks after coronary artery ligation in female wild-type rats, 5x10(6) GFP-expressing SMB or PBS only (control) were injected via either the intramyocardial or retrograde intracoronary routes. Injection of SMB via either route similarly improved cardiac performance and physical activity, associated with reduced cardiomyocyte-hypertrophy and fibrosis. Grafted SMB via either route were only present in low numbers in the myocardium, analysed by real-time PCR for the Y-chromosome specific gene, Sry. Cardiomyogenic differentiation of grafted SMB was extremely rare. Continuous ECG monitoring by telemetry revealed that only intramyocardial injection of SMB produced spontaneous ventricular tachycardia up to 14 days, associated with local myocardial heterogeneity generated by clusters of injected SMB and accumulated inflammatory cells. A small number of ventricular premature contractions with latent ventricular tachycardia were detected in the late-phase of SMB injection regardless of the injection-route. CONCLUSION:Retrograde intracoronary injection of SMB provided significant therapeutic benefits with attenuated early-phase arrhythmogenicity in treating ischaemic cardiomyopathy, indicating the promising utility of this route for SMB-delivery. Late-phase arrhythmogenicity remains a concern, regardless of the delivery route.