MRP1-Dependent Extracellular Release of Glutathione Induces Cardiomyocyte Ferroptosis After Ischemia-Reperfusion.

BACKGROUND: The membrane components of cardiomyocytes are rich in polyunsaturated fatty acids, which are easily oxidized. Thus, an efficient glutathione-based lipid redox system is essential for maintaining cellular functions. However, the relationship between disruption of the redox system during ischemia-reperfusion (IR), oxidized lipid production, and consequent cell death (ferroptosis) remains unclear. We investigated the mechanisms underlying the disruption of the glutathione-mediated reduction system related to ferroptosis during IR and developed intervention strategies to suppress ferroptosis. METHODS: In vivo fluctuations of both intra- and extracellular metabolite levels during IR were explored via microdialysis and tissue metabolome analysis. Oxidized phosphatidylcholines were assessed using liquid chromatography high-resolution mass spectrometry. The areas at risk following IR were assessed using triphenyl-tetrazolium chloride/Evans blue stain. RESULTS: Metabolomic analysis combined with microdialysis revealed a significant release of glutathione from the ischemic region into extracellular spaces during ischemia and after reperfusion. The release of glutathione into extracellular spaces and a concomitant decrease in intracellular glutathione concentrations were also observed during anoxia-reperfusion in an in vitro cardiomyocyte model. This extracellular glutathione release was prevented by chemical inhibition or genetic suppression of glutathione transporters, mainly MRP1 (multidrug resistance protein 1). Treatment with MRP1 inhibitor reduced the intracellular reactive oxygen species levels and lipid peroxidation, thereby inhibiting cell death. Subsequent in vivo evaluation of endogenously oxidized phospholipids following IR demonstrated the involvement of ferroptosis, as levels of multiple oxidized phosphatidylcholines were significantly elevated in the ischemic region 12 hours after reperfusion. Inhibition of the MRP1 transporter also alleviated intracellular glutathione depletion in vivo and significantly reduced the generation of oxidized phosphatidylcholines. Administration of MRP1 inhibitors significantly attenuated infarct size after IR injury. CONCLUSIONS: Glutathione was released continuously during IR, primarily in an MRP1-dependent manner, and induced ferroptosis. Suppression of glutathione release attenuated ferroptosis and reduced myocardial infarct size following IR.

Pathophysiological Involvement of Mast Cells and the Lipid Mediators in Pulmonary Vascular Remodeling.

Mast cells are responsible for IgE-dependent allergic responses, but they also produce various bioactive mediators and contribute to the pathogenesis of various cardiovascular diseases, including pulmonary hypertension (PH). The importance of lipid mediators in the pathogenesis of PH has become evident in recent years, as exemplified by prostaglandin I2, the most central therapeutic target in pulmonary arterial hypertension. New bioactive lipids other than eicosanoids have also been identified that are associated with the pathogenesis of PH. However, it remains largely unknown how mast cell-derived lipid mediators are involved in pulmonary vascular remodeling. Recently, it has been demonstrated that mast cells produce epoxidized n-3 fatty acid (n-3 epoxides) in a degranulation-independent manner, and that n-3 epoxides produced by mast cells regulate the abnormal activation of pulmonary fibroblasts and suppress the progression of pulmonary vascular remodeling. This review summarizes the role of mast cells and bioactive lipids in the pathogenesis of PH. In addition, we introduce the pathophysiological role and therapeutic potential of n-3 epoxides, a mast cell-derived novel lipid mediator, in the pulmonary vascular remodeling in PH. Further knowledge of mast cells and lipid mediators is expected to lead to the development of innovative therapies targeting pulmonary vascular remodeling.

Molecular Mechanism of Pathogenesis and Treatment Strategies for AL Amyloidosis.

In amyloid light-chain (AL) amyloidosis, small B-cell clones (mostly plasma cell clones) present in the bone marrow proliferate and secrete unstable monoclonal free light chains (FLCs), which form amyloid fibrils that deposit in the interstitial tissue, resulting in organ injury and dysfunction. AL amyloidosis progresses much faster than other types of amyloidosis, with a slight delay in diagnosis leading to a marked exacerbation of cardiomyopathy. In some cases, the resulting heart failure is so severe that chemotherapy cannot be administered, and death sometimes occurs within a few months. To date, many clinical studies have focused on therapeutics, especially chemotherapy, to treat this disease. Because it is necessary to promptly lower FLC, the causative protein of amyloid, to achieve a hematological response, various anticancer agents targeting neoplastic plasma cells are used for the treatment of this disease. In addition, many basic studies using human specimens to elucidate the pathophysiology of AL have been conducted. Gene mutations associated with AL, the characteristics of amyloidogenic LC, and the structural specificity of amyloid fibrils have been clarified. Regarding the mechanism of cellular and tissue damage, the mass effect due to amyloid deposition, as well as the toxicity of pre-fibrillar LC, is gradually being elucidated. This review outlines the pathogenesis and treatment strategies for AL amyloidosis with respect to its molecular mechanisms.

Therapeutic Targets for DOX-Induced Cardiomyopathy: Role of Apoptosis vs. Ferroptosis.

Doxorubicin (DOX) is the most widely used anthracycline anticancer agent; however, its cardiotoxicity limits its clinical efficacy. Numerous studies have elucidated the mechanisms underlying DOX-induced cardiotoxicity, wherein apoptosis has been reported as the most common final step leading to cardiomyocyte death. However, in the past two years, the involvement of ferroptosis, a novel programmed cell death, has been proposed. The purpose of this review is to summarize the historical background that led to each form of cell death, focusing on DOX-induced cardiotoxicity and the molecular mechanisms that trigger each form of cell death. Furthermore, based on this understanding, possible therapeutic strategies to prevent DOX cardiotoxicity are outlined. DNA damage, oxidative stress, intracellular signaling, transcription factors, epigenetic regulators, autophagy, and metabolic inflammation are important factors in the molecular mechanisms of DOX-induced cardiomyocyte apoptosis. Conversely, the accumulation of lipid peroxides, iron ion accumulation, and decreased expression of glutathione and glutathione peroxidase 4 are important in ferroptosis. In both cascades, the mitochondria are an important site of DOX cardiotoxicity. The last part of this review focuses on the significance of the disruption of mitochondrial homeostasis in DOX cardiotoxicity.

MITOL/MARCH5 determines the susceptibility of cardiomyocytes to doxorubicin-induced ferroptosis by regulating GSH homeostasis.

MITOL/MARCH5 is an E3 ubiquitin ligase that plays a crucial role in the control of mitochondrial quality and function. However, the significance of MITOL in cardiomyocytes under physiological and pathological conditions remains unclear. First, to determine the significance of MITOL in unstressed hearts, we assessed the cellular changes with the reduction of MITOL expression by siRNA in neonatal rat primary ventricular cardiomyocytes (NRVMs). MITOL knockdown in NRVMs induced cell death via ferroptosis, a newly defined non-apoptotic programmed cell death, even under no stress conditions. This phenomenon was observed only in NRVMs, not in other cell types. MITOL knockdown markedly reduced mitochondria-localized GPX4, a key enzyme associated with ferroptosis, promoting accumulation of lipid peroxides in mitochondria. In contrast, the activation of GPX4 in MITOL knockdown cells suppressed lipid peroxidation and cell death. MITOL knockdown reduced the glutathione/oxidized glutathione (GSH/GSSG) ratio that regulated GPX4 expression. Indeed, the administration of GSH or N-acetylcysteine improved the expression of GPX4 and viability in MITOL-knockdown NRVMs. MITOL-knockdown increased the expression of the glutathione-degrading enzyme, ChaC glutathione-specific γ-glutamylcyclotransferase 1 (Chac1). The knockdown of Chac1 restored the GSH/GSSG ratio, GPX4 expression, and viability in MITOL-knockdown NRVMs. Further, in cultured cardiomyocytes stressed with DOX, both MITOL and GPX4 were reduced, whereas forced-expression of MITOL suppressed DOX-induced ferroptosis by maintaining GPX4 content. Additionally, MITOL knockdown worsened vulnerability to DOX, which was almost completely rescued by treatment with ferrostatin-1, a ferroptosis inhibitor. In vivo, cardiac-specific depletion of MITOL did not produce obvious abnormality, but enhanced susceptibility to DOX toxicity. Finally, administration of ferrostatin-1 suppressed exacerbation of DOX-induced myocardial damage in MITOL-knockout hearts. The present study demonstrates that MITOL determines the cell fate of cardiomyocytes via the ferroptosis process and plays a key role in regulating vulnerability to DOX treatment. (288/300).

Imeglimin prevents heart failure with preserved ejection fraction by recovering the impaired unfolded protein response in mice subjected to cardiometabolic stress.

The pathogenesis of heart failure with preserved ejection fraction (HFpEF) in obese diabetic patients has been implicated in metainflammation. Increased expression of inducible nitric oxide synthase (iNOS) and dysfunction of the unfolded protein response (UPR), especially inositol-requiring enzyme 1α-X-box binding protein 1 (IRE1α-Xbp1s) signaling in the heart, have been associated with HFpEF. We investigated the effect of imeglimin, a potential new treatment for type 2 diabetes, on the pathogenesis of HFpEF. We induced obesity, impaired glucose tolerance, and cardiac hypertrophy with fibrosis, fat accumulation, and diastolic dysfunction in wild-type mice with a high-fat diet (HFD) and the nitric oxide synthase (NOS) inhibitor l-NAME for 16 weeks. Treatment with imeglimin starting at 10 weeks not only improved their abnormal systemic glucose metabolism and visceral obesity but also their cardiac abnormalities. We found that imeglimin suppressed the upregulation of iNOS, and restored the expression of Xbp1s and the expression of the E3 ubiquitin ligase STIP1 homology and U-box-containing protein 1 (STUB1), which is responsible for the degradation of Forkhead box protein O1 (FoxO1), a direct transcriptional target of Xbp1s. It also suppressed the excessive transcriptional activity of FoxO1, which is located downstream of Xbp1s and is involved in the form development of HFpEF and cardiac adipogenesis. Imeglimin also restored the expression of Glutathione peroxidase 4 (GPX4), which protects cells against excess lipid peroxidation and governs a novel form of programmed cell death, called ferroptosis.

Time-Series Transcriptome Analysis Reveals the miR-27a-5p-Ppm1l Axis as a New Pathway Regulating Macrophage Alternative Polarization After Myocardial Infarction.

BACKGROUND: Timely differentiation of monocytes into M2-like macrophages is important in the cardiac healing process after myocardial infarction (MI), but molecular mechanisms governing M2-like macrophage differentiation at the transcriptional level after MI have not been fully understood.Methods and Results:A time-series microarray analysis of mRNAs and microRNAs in macrophages isolated from the infarcted myocardium was performed to identify the microRNAs involved in regulating the process of differentiation to M2-like macrophages. Correlation analysis revealed 7 microRNAs showing negative correlations with the progression of polarity changes towards M2-like subsets. Next, correlation coefficients for the changes in expression of mRNAs and miRNAs over time were calculated for all combinations. As a result, miR-27a-5p was extracted as a possible regulator of the largest number of genes in the pathway for the M2-like polarization. By selecting mouse mRNAs and human mRNAs possessing target sequences of miR-27a-5p and showing expression patterns inversely correlated with that of miR-27a-5p, 8 potential targets of miR-27a-5p were identified, includingPpm1l. Using the mouse bone marrow-derived macrophages undergoing differentiation into M2-like subsets by interleukin 4 stimulation, we confirmed that miR-27a-5p suppressed M2-related genes by negatively regulatingPpm1lexpression. CONCLUSIONS: Ppm1land miR-27a-5p may be the key molecules regulating M2-like polarization, with miR-27a-5p inhibiting the M2-like polarization through downregulation ofPpm1lexpression.

Clinical Significance of Guanylate Cyclase Stimulator, Riociguat, on Right Ventricular Functional Improvement in Patients with Pulmonary Hypertension.

BACKGROUND: Riociguat is a soluble guanylate cyclase stimulator that improves hemodynamics in patients with pulmonary hypertension (PH). Accumulating evidence implicates the additional effect of riociguat on the increase in cardiac output. However, its mechanisms have not been fully understood. This study aimed to investigate whether riociguat could ameliorate right ventricular (RV) contraction as well as hemodynamics. METHODS: We studied 45 patients with pulmonary arterial hypertension (14) or chronic thromboembolic pulmonary hypertension (31) and evaluated hemodynamics, using right-sided heart catheterization, before and after the administration of riociguat. RV function was assessed by echocardiography, including speckle-tracking echocardiography. RESULTS: Riociguat significantly improved the WHO functional class and reduced the mean pulmonary arterial pressure and vascular resistance. In addition, the cardiac index increased. RV remodeling was ameliorated after riociguat administration as assessed by the echocardiographic parameters, such as RV diameter and RV area index. RV function, including RV fractional area change and RV global longitudinal strain, also significantly improved, and their improvement was even observed in patients with mild PH after pulmonary endarterectomy or balloon pulmonary angioplasty. Furthermore, covariance analysis revealed that RV global longitudinal strain and RV fractional area change improved after riociguat administration, even with the same mean pulmonary arterial pressure, implicating the improvement of RV contractile function by riociguat, regardless of RV loading. CONCLUSIONS: Riociguat not only improved the hemodynamics of patients with PH but also ameliorated the echocardiographic parameters with RV function. RV strain could detect the subtle improvement in mild PH, and riociguat may have a benefit even after intervention, as assessed by speckle-tracking echocardiography.

Palmitate induces cardiomyocyte death via inositol requiring enzyme-1 (IRE1)-mediated signaling independent of X-box binding protein 1 (XBP1).

Overloading of the saturated fatty acid (SFA) palmitate induces cardiomyocyte death. The purpose of this study is to elucidate signaling pathways contributing to palmitate-induced cardiomyocyte death. Palmitate-induced cardiomyocyte death was induced in Toll-like receptor 2/4 double-knockdown cardiomyocytes to a similar extent as wild-type cardiomyocytes, while cardiomyocyte death was canceled out by triacsin C, a long-chain acyl-CoA synthetase inhibitor. These results indicated that palmitate induced cytotoxicity after entry and conversion into palmitoyl-CoA. Palmitoyl-CoA is not only degraded by mitochondrial oxidation but also taken up as a component of membrane phospholipids. Palmitate overloading causes cardiomyocyte membrane fatty acid (FA) saturation, which is associated with the activation of endoplasmic reticulum (ER) unfolded protein response (UPR) signaling. We focused on the ER UPR signaling as a possible mechanism of cell death. Palmitate loading activates the UPR signal via membrane FA saturation, but not via unfolded protein overload in the ER since the chemical chaperone 4-phenylbutyrate failed to suppress palmitate-induced ER UPR. The mammalian UPR relies on three ER stress sensors named inositol requiring enzyme-1 (IRE1), PKR-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Palmitate loading activated only IRE1 and PERK. Knockdown of PERK did not affect palmitate-induced cardiomyocyte death, while knockdown of IRE1 suppressed palmitate-induced cardiomyocyte death. However, knockdown of X-box binding protein 1 (XBP1), the downstream effector of IRE1, did not affect palmitate-induced cardiomyocyte death. These results were validated by pharmacological inhibitor experiments. In conclusion, we identified that palmitate-induced cardiomyocyte death was triggered by IRE1-mediated signaling independent of XBP1.

Adrenal cortex hypoxia modulates aldosterone production in heart failure.

Plasma aldosterone concentration increases in proportion to the severity of heart failure, even during treatment with renin-angiotensin system inhibitors. This study investigated alternative regulatory mechanisms of aldosterone production that are significant in heart failure. Dahl salt-sensitive rats on a high-salt diet, a rat model of heart failure with cardio-renal syndrome, had high plasma aldosterone levels and elevated ß3-adrenergic receptor expression in hypoxic zona glomerulosa cells. In H295R cells (a human adrenocortical cell line), hypoxia-induced ß3-adrenergic receptor expression. Hypoxia-mediated ß3-adrenergic receptor expression augmented aldosterone production by facilitating hydrolysis of lipid droplets though ERK-mediated phosphorylation of hormone-sensitive lipase, also known as cholesteryl ester hydrolase. Hypoxia also accelerated the synthesis of cholesterol esters by acyl-CoA:cholesterol acyltransferase, thereby increasing the cholesterol ester content in lipid droplets. Thus, hypoxia enhanced aldosterone production by zona glomerulosa cells via promotion of the accumulation and hydrolysis of cholesterol ester in lipid droplets. In conclusion, hypoxic zona glomerulosa cells with heart failure show enhanced aldosterone production via increased catecholamine responsiveness and activation of cholesterol trafficking, irrespective of the renin-angiotensin system.

Pressure overload inhibits glucocorticoid receptor transcriptional activity in cardiomyocytes and promotes pathological cardiac hypertrophy.

Glucocorticoid receptor (GR) is abundantly expressed in cardiomyocytes. However, the role of GR in regulating cardiac hypertrophy and heart failure in response to pressure overload remains unclear. Cardiomyocyte-specific GR knockout (GRcKO) mice, mineralocorticoid receptor (MR) knockout (MRcKO), and GR and MR double KO (GRMRdcKO) mice were generated using the Cre-lox system. In response to pressure overload, GRcKO mice displayed worse cardiac remodeling compared to control (GRf/f) mice, including a greater increase in heart weight to body weight ratio with a greater increase in cardiomyocytes size, a greater decline in left ventricular contractility, and higher reactivation of fetal genes. MRcKO mice showed a comparable degree of cardiac remodeling compared to control (MRf/f) mice. The worse cardiac remodeling in pressure overloaded GRcKO mice is not due to compensatory activation of cardiomyocyte MR, since pressure overloaded GRMRdcKO mice displayed cardiac remodeling to the same extent as GRcKO mice. Pressure overload suppressed GR-target gene expression in the heart. Although plasma corticosterone levels and subcellular localization of GR (nuclear/cytoplasmic GR) were not changed, a chromatin immunoprecipitation assay revealed that GR recruitment onto the promoter of GR-target genes was significantly suppressed in response to pressure overload. Rescue of the expression of GR-target genes to the same extent as sham-operated hearts attenuated adverse cardiac remodeling in pressure-overloaded hearts. Thus, GR works as a repressor of adverse cardiac remodeling in response to pressure overload, but GR-mediated transcription is suppressed under pressure overload. Therapies that maintain GR-mediated transcription in cardiomyocytes under pressure overload can be a promising therapeutic strategy for heart failure.

Sirt1 counteracts decrease in membrane phospholipid unsaturation and diastolic dysfunction during saturated fatty acid overload.

BACKGROUND: The fatty acid (FA) composition of membrane phospholipid reflects at least in part dietary fat composition. Saturated FA (SFA) suppress Sirt1 activity, while monounsaturated FA (MUFA) counteract this effect. OBJECTIVE: We explored a role of Sirt1 in homeostatic control of the fatty acid composition of membrane phospholipid in the presence of SFA overload. METHODS AND RESULTS: Sirt1 deficiency in cardiomyocytes decreased the expression levels of liver X receptor (LXR)-target genes, particularly stearoyl-CoA desaturase-1 (Scd1), a rate-limiting enzyme in the cellular synthesis of MUFA from SFA, increased membrane SFA/MUFA ratio, and worsened left ventricular (LV) diastolic function in mice fed an SFA-rich high fat diet. In cultured cardiomyocytes, Sirt1 knockdown (KD) exacerbated the palmitate overload-induced increase in membrane SFA/MUFA ratio, which was associated with decrease in the expression of LXR-target genes, including Scd1. Forced overexpression of Scd1 in palmitate-overloaded Sirt1KD cardiomyocytes lowered the SFA/MUFA ratio. Nicotinamide mononucleotide (NMN) increased Sirt1 activity and Scd1 expression, thereby lowering membrane SFA/MUFA ratio in palmitate-overloaded cardiomyocytes. These effects of NMN were not observed for Scd1KD cardiomyocytes. LXRα/ßKD exacerbated palmitate overload-induced increase in membrane SFA/MUFA ratio, while LXR agonist T0901317 alleviated it. NMN failed to rescue Scd1 protein expression and membrane SFA/MUFA ratio in palmitate-overloaded LXRα/ßKD cardiomyocytes. The administration of NMN or T0901317 showed a dramatic reversal in membrane SFA/MUFA ratio and LV diastolic function in SFA-rich HFD-fed mice. CONCLUSION: Cardiac Sirt1 counteracted SFA overload-induced decrease in membrane phospholipid unsaturation and diastolic dysfunction via regulating LXR-mediated transcription of the Scd1 gene.

Endothelial-Mesenchymal Transition Drives Expression of CD44 Variant and xCT in Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) pathogenesis shares similarities with carcinogenesis. One CD44 variant (CD44v) isoform, CD44v8-10, binds to and stabilizes the cystine transporter subunit (xCT), producing reduced glutathione and thereby enhancing the antioxidant defense of cancer stem cells. Pharmacological inhibition of xCT by sulfasalazine suppresses tumor growth, survival, and resistance to chemotherapy. We investigated whether the CD44v-xCT axis contributes to PAH pathogenesis. CD44v was predominantly expressed on endothelial-to-mesenchymal transition (EndMT)-like cells in the neointimal layer of PAH affected pulmonary arterioles. In vitro, CD44 standard form and CD44v were induced as a result of EndMT. Among human pulmonary artery endothelial cells that have undergone EndMT, CD44v+ cells showed high levels of xCT expression on their cell surfaces and high concentrations of glutathione for survival. This made CD44v+ cells the most vulnerable target for sulfasalazine. CD44v+xCThi cells showed the highest expression levels of proinflammatory cytokines, antioxidant enzymes, antiapoptotic molecules, and cyclin-dependent kinase inhibitors. In the Sugen5416/hypoxia mouse model, CD44v+ cells were present in the thickened pulmonary vascular wall. The administration of sulfasalazine started either at the same time as "Sugen5416" administration (a prevention model) or after the development of pulmonary hypertension (a reversal model) attenuated the muscularization of the pulmonary vessels, decreased the expression of markers of inflammation, and reduced the right ventricular systolic pressure, while reducing CD44v+ cells. In conclusion, CD44v+xCThi cells appear during EndMT and in pulmonary hypertension tissues. Sulfasalazine is expected to be a novel therapeutic agent for PAH, most likely targeting EndMT-derived CD44v+xCThi cells.

IL (Interleukin)-10-STAT3-Galectin-3 Axis Is Essential for Osteopontin-Producing Reparative Macrophage Polarization After Myocardial Infarction.

BACKGROUND: Both osteopontin (OPN) and galectin-3 have been implicated in phagocytic clearance of dead cells and reparative fibrosis during wound healing. CD206+ macrophages are involved in tissue repair through phagocytosis and fibrosis after myocardial infarction (MI). However, the relationship among OPN, galectin-3, and macrophage polarization in the context of MI remains unclear. METHODS: The time course of Spp1 (encoding OPN) expression in the heart after MI showed a strong activation of Spp1 on day 3 after MI. To identify where in the body and in which cells the transcriptional activity of Spp1 increased after MI, we analyzed EGFP (enhanced green fluorescent protein)- Spp1 knockin reporter mice on day 3 after MI. RESULTS: The transcriptional activity of Spp1 increased only in CD206+ macrophages in the infarct myocardium, and most of CD206+ macrophages have strong transcriptional activation of Spp1 after MI. The temporal expression pattern of Lgal3 (encoding galectin-3) in cardiac macrophages after MI was similar to that of Spp1, and OPN is almost exclusively produced by galectin-3hiCD206+ macrophages. Although both interleukin (IL)-4 and IL-10 were reported to promote CD206+ macrophage-mediated cardiac repair after MI, IL-10- but not IL-4-stimulated CD11b+Ly6G- cells could differentiate into OPN-producing galectin-3hiCD206+ macrophages and showed enhanced phagocytic ability. Inhibition of STAT3 tyrosine phosphorylation suppressed IL-10-induced expression of intracellular galectin-3 and transcriptional activation of Spp1. Knockdown of galectin-3 suppressed their ability to differentiate into OPN-producing cells, but not STAT3 activation. The tyrosine phosphorylation of STAT3 and the appearance rate of galectin-3hiCD206+ cells on cardiac CD11b+Ly6G- cells in Spp1 knockout mice were the same as those in wild-type mice. Spp1 knockout mice showed vulnerability to developing post-MI left ventricular chamber dilatation and the terminal deoxynucleo-tidyltransferase 2'-Deoxyuridine-5'-triphosphate nick-end labeling (TUNEL)-positive cells in the infarcted myocardium after MI remained higher in number in Spp1 knockout mice than in wild-type mice. CONCLUSIONS: OPN is almost exclusively produced by galectin-3hiCD206+ macrophages, which specifically appear in the infarct myocardium after MI. The IL-10-STAT3-galectin-3 axis is essential for OPN-producing reparative macrophage polarization after myocardial infarction, and these macrophages contribute to tissue repair by promoting fibrosis and clearance of apoptotic cells. These results suggest that galectin-3 may contribute to reparative fibrosis in the infarct myocardium by controlling OPN levels.

Length of hospital stay and its impact on subsequent early readmission in patients with acute heart failure: a report from the WET-HF Registry.

Heart failure (HF) is characterized by frequent rehospitalization and prolonged hospital stay. Although length of stay has been used as a surrogate marker for hospital performance, its association with early rehospitalization remains unknown. We investigated their precise association using contemporary Japanese HF registry. We analyzed the 2785 acute HF patients who were registered in the West Tokyo Heart Failure registry and discharged or transferred to the recuperation facilities (mean age, 73.8 ± 13.5 years; 60.8% were men). Median length of stay was 15 days (interquartile range, 10-23 days). One-hundred and fourteen patients (4.1%) were readmitted for worsening HF within 30 days after discharge. Thirty-day risk-adjusted HF readmission after a shorter length of stay (1-12 days; the lower tertile within the cohort) was higher than those after intermediate (13-19 days; the middle tertile) [HR 1.71, 95% confidence interval (CI) 1.05-2.77]. Even after a longer length of stay, there tended to be a higher risk of 30-day HF readmission (HR 1.59, 95% CI 0.96-2.65). In conclusion, the Japanese acute HF patients had low rates of early-HF readmission after quite a long length of stay at urban tertiary care centers. Shorter length of stay was associated with increased rates of 30-day HF readmission, while longer length of stay also the same trended.Clinical Trial Registration: https://www.umin.ac.jp/icdr/index-j.html . Unique identifier: UMIN000001171.

Obesity in elementary school children after the Great East Japan Earthquake.

BACKGROUND: Rikuzentakata was one of the cities most devastated by the Great East Japan Earthquake on 11 March 2011. Many buildings were swept away or destroyed and affected families were placed into temporary housing. The aim of this study was to determine the impact of long-term temporary housing on the body mass index (BMI) of elementary school children living in Rikuzentakata City. METHODS: A retrospective cohort study of was carried out of students attending 1st-3rd grade in 2010, and 4th-6th grade in 2013, in eight elementary schools in Rikuzentakata City. Height and weight were measured annually. We compared changes in BMI between children in temporary housing and those in permanent housing. Separately, parents of students attending one of the elementary schools were surveyed in 2013. RESULTS: Of 526 children in the present study, 32% were living in temporary housing. The prevalence of obesity climbed from 5.3% in 2010 to 7.8% in 2013 in the temporary housing group, and from 7.6% to 7.8% in the permanent housing group. BMI z-score in the temporary housing group increased by 0.102 points between 2010 and 2013 (P < 0.02). Children in temporary housing spent more time reading comic books and their walking commute time had decreased by 2 min compared with before the disaster. CONCLUSION: Obesity prevalence and BMI z-score increased in children in temporary housing compared with permanent housing. A more sedentary lifestyle may explain this trend. It is important for policy makers and health-care providers to recognize potential consequences of long-term residence in temporary housing.

Recent Progress of Antisense Oligonucleotide Therapy for Superoxide-Dismutase-1-Mutated Amyotrophic Lateral Sclerosis: Focus on Tofersen.

Amyotrophic lateral sclerosis (ALS) is a refractory neurodegenerative disease characterized by the degeneration and loss of motor neurons, typically resulting in death within five years of onset. There have been few effective treatments, making the development of robust therapies an urgent challenge. Genetic mutations have been identified as contributors to ALS, with mutations in superoxide dismutase 1 (SOD1), which neutralizes the harmful reactive oxygen species superoxide, accounting for approximately 2% of all ALS cases. To counteract the toxic gain of function caused by SOD1 mutations, therapeutic strategies aimed at suppressing SOD1 gene expression have shown promise. Antisense oligonucleotide (ASO) is an artificially synthesized, short, single-stranded DNA/RNA molecule that binds to target RNA to alter gene expression, representing a next-generation therapeutic approach. In 2023, tofersen became the first ASO drug approved by the FDA for ALS. Administered intrathecally, tofersen specifically binds to SOD1 mRNA, inhibiting the production of toxic SOD1 protein, thereby improving biomarkers of ALS. The long-term efficacy and safety of tofersen require further validation, and the development of more optimized treatment protocols is essential. A series of studies and therapeutic developments related to SOD1 mutations have advanced the understanding of ALS pathophysiology and significantly contributed to treatment strategies for central nervous system disorders. This review focuses on an overview of SOD1 mutations and the development process of tofersen, aiming to deepen the understanding of advancements in ALS research and discuss future challenges and directions for ASO therapy.

De-escalation of Oxygen Therapy and Medication in Patients With Chronic Thromboembolic Pulmonary Hypertension After Balloon Pulmonary Angioplasty.

BACKGROUND: There is no consensus on the adjustment of home oxygen therapy (HOT) and pulmonary hypertension (PH)-specific medications after balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to examine the status of de-escalation and discontinuation of HOT and PH-specific medications post-BPA and clarify its effect on hemodynamics, biomarkers, and long-term outcomes. METHODS: From November 2012 to May 2018, 135 consecutive patients with CTEPH who underwent BPA at a single university hospital were enrolled (age, 63.5 ± 13.5 years; World Health Organization functional class (WHO-FC) II, III, IV; 34, 92, 9). RESULTS: The mean pulmonary arterial pressure decreased from 37.7 ± 11.3 to 20.4 ± 5.1 mm Hg 1 year post-BPA (P < 0.01). The proportion of patients who required HOT and combination medical therapy (≥ 2 PH-specific medications) decreased 1 year post-BPA (from 58.5% to 7.4% and from 40.0% to 10.4%, respectively). Baseline factors influencing the requirement of HOT and combination medical therapy post-BPA were almost identical (ie, lower exercise capacity and pulmonary diffusion capacity and worse hemodynamics). Regardless of their discontinuation, the improved hemodynamics, functional capacity (WHO-FC), and biomarkers (B-type natriuretic peptide and high-sensitivity troponin T) were almost maintained, and no adverse 1-year clinical outcomes (all-cause death and PH-related hospitalization) were observed. CONCLUSIONS: Most patients with CTEPH discontinued HOT and PH-specific combination medical therapy post-BPA, which was not associated with the deterioration of hemodynamics, functional capacity, or biomarkers. No long-term adverse outcomes were observed.

Treatment of transthyretin His88Arg amyloidosis with RNA interference therapy: A case report.

A new class of medicines called small interfering RNA molecule has demonstrated beneficial effects in patients with amyloidosis associated with mutations in transthyretin genes (ATTRv), but therapeutic effects towards His88Arg mutation were unknown. Here, we present two challenging cases of patisiran treatment for His88Arg variant. The first case is a 50-year-old male patient diagnosed with transthyretin amyloidosis cardiomyopathy with His88Arg mutation. Administration of patisiran 0.3 mg/kg every three weeks did not show any change in his symptoms. Echocardiography performed 1-year after drug initiation revealed progression of LV hypertrophy and systolic dysfunction with increased pleural effusion. The second case was a 63-year-old woman with heart failure (HF) caused by ATTRv cardiomyopathy with a His88Arg mutation. The patient began patisiran treatment 0.3 mg/kg every three weeks. Eleven months after beginning patisiran, her HF signs worsened with exacerbation of lung congestion and pleural effusion, resulting in hospitalization for decompensated HF. The two cases showed that treatment with patisiran for the patients with advanced stage of His88Arg ATTRv cardiomyopathy was unable to stop the progression of HF. Since the therapeutic response for each variant in ATTRv cardiomyopathy is unknown, further assessment of clinical efficacy for each individual variant is needed. .

Step-by-step typing for the accurate diagnosis of concurrent light chain and transthyretin cardiac amyloidosis.

While 99m Tc-pyrophosphate scintigraphy is clearly useful in diagnosing transthyretin amyloid cardiomyopathy (ATTR-CM), it is necessary to know the pitfalls of this test for proper use. We present a rare case of concurrent ATTR-CM and amyloid light chain (AL) cardiomyopathy. The patient showed congestive heart failure with left ventricular hypertrophy. 99m Tc-pyrophosphate scintigraphy revealed abnormal cardiac uptake of Grade 3, a typical feature for ATTR-CM. However, the patient showed renal impairment with proteinuria and the presence of monoclonal gammopathy, which rather suggested AL amyloidosis. Endomyocardial biopsy, immunohistochemistry, and proteomic analysis by laser microdissection with liquid chromatography-coupled tandem mass spectrometry were performed, which finally confirmed both ATTR-CM and AL cardiomyopathy. This case implicates the importance of combining examinations and precisely interpreting the results to diagnose cardiac amyloidosis accurately.