XCR1+ conventional dendritic cell-induced CD4+ T helper 1 cell activation exacerbates cardiac remodeling after ischemic myocardial injury.

Cardiac remodeling has no established therapies targeting inflammation. CD4+ T-cell subsets have been reported to play significant roles in healing process after ischemic myocardial injury, but their detailed mechanisms of activation remain unknown. To explore immune reactions during cardiac remodeling, we applied a non-surgical model of coronary heart disease (CHD) induced by a high-fat diet (HFD-CHD) in SR-BI-/-/ApoeR61h/h mice. Flow cytometry analyses throughout the period of progressive cardiac dysfunction revealed that CD4+ T Helper 1 (Th1) cells were predominantly activated in T-cell subsets. Probucol was reported to attenuate cardiac dysfunction after coronary artery ligation model (ligation-MI) in rats. To determine whether probucol suppress cardiac remodeling after HFD-CHD, we treated SR-BI-/-/ApoeR61h/h mice with probucol. We found treatment with probucol in HFD-CHD mice reduced cardiac dysfunction, with attenuated activation of Th1 cells. RNA-seq analyses revealed that probucol suppressed the expression of CXCR3, a Th1-related chemokine receptor, in the heart. XCR1+ cDC1 cells, which highly expresses the CXCR3 ligands CXCL9 and CXCL10, were predominantly activated after HFD-CHD. XCR1+ cDC1 lineage skewing of pre-DC progenitors was observed in bone marrow, with subsequent systemic expansion of XCR1+ cDC1 cells after HFD-CHD. Activation of CXCR3+ Th1 cell and XCR1+ cDC1 cells was also observed in ligation-MI. Notably, post-MI depletion of XCR1+ cDC1 cells suppressed CXCR3+ Th1 cell activation and prevented cardiac dysfunction. In patient autopsy samples, CXCR3+ Th1 and XCR1+ cDC1 cells infiltrated the infarcted area. In this study, we identified a critical role of XCR1+ cDC1-activated CXCR3+ Th1 cells in ischemic cardiac remodeling.

TTC39B deficiency stabilizes LXR reducing both atherosclerosis and steatohepatitis.

Cellular mechanisms that mediate steatohepatitis, an increasingly prevalent condition in the Western world for which no therapies are available, are poorly understood. Despite the fact that its synthetic agonists induce fatty liver, the liver X receptor (LXR) transcription factor remains a target of interest because of its anti-atherogenic, cholesterol removal, and anti-inflammatory activities. Here we show that tetratricopeptide repeat domain protein 39B (Ttc39b, C9orf52) (T39), a high-density lipoprotein gene discovered in human genome-wide association studies, promotes the ubiquitination and degradation of LXR. Chow-fed mice lacking T39 (T39(-/-)) display increased high-density lipoprotein cholesterol levels associated with increased enterocyte ATP-binding cassette transporter A1 (Abca1) expression and increased LXR protein without change in LXR messenger RNA. When challenged with a high fat/high cholesterol/bile salt diet, T39(-/-) mice or mice with hepatocyte-specific T39 deficiency show increased hepatic LXR protein and target gene expression, and unexpectedly protection from steatohepatitis and death. Mice fed a Western-type diet and lacking low-density lipoprotein receptor (Ldlr(-/-)T39(-/-)) show decreased fatty liver, increased high-density lipoprotein, decreased low-density lipoprotein, and reduced atherosclerosis. In addition to increasing hepatic Abcg5/8 expression and limiting dietary cholesterol absorption, T39 deficiency inhibits hepatic sterol regulatory element-binding protein 1 (SREBP-1, ADD1) processing. This is explained by an increase in microsomal phospholipids containing polyunsaturated fatty acids, linked to an LXRα-dependent increase in expression of enzymes mediating phosphatidylcholine biosynthesis and incorporation of polyunsaturated fatty acids into phospholipids. The preservation of endogenous LXR protein activates a beneficial profile of gene expression that promotes cholesterol removal and inhibits lipogenesis. T39 inhibition could be an effective strategy for reducing both steatohepatitis and atherosclerosis.

A Dietary Oxysterol, 7-Ketocholesterol, Exacerbates Imiquimod-Induced Psoriasis-like Dermatitis in Steatohepatitic Mice.

Patients with psoriasis are at a higher risk of developing nonalcoholic fatty liver disease. We previously identified an oxidized derivative of cholesterol, 7-ketocholesterol (7KC), in diet-induced steatohepatitic mice. Here, we investigated whether 7KC exacerbates psoriasis-like dermatitis by accelerating steatohepatitis in mice. A high-fat/high-cholesterol/high-sucrose/bile salt diet (nonalcoholic steatohepatitis (NASH) diet) with or without 0.0125% 7KC was fed to C57BL/6 mice (7KC or control group) for three weeks to induce steatohepatitis. A 5% imiquimod cream was then applied to the ears and dorsal skin for four days to induce psoriasis-like dermatitis. Hepatic lipid accumulation and inflammatory cell infiltration were exacerbated in the 7KC group compared with the control group after three weeks. Serum tumor necrosis factor-α (TNF-α) levels were also elevated in the 7KC group (108.5 ± 9.8 vs. 83.1 ± 13.1 pg/mL, p < 0.005). Imiquimod cream increased the psoriasis area severity index (PASI) score in mice in the 7KC group (9.14 ± 0.75 vs. 5.17 ± 1.17, p < 0.0001). Additionally, Tnfa, Il23a, Il17a, and Il22 mRNA levels in the dorsal lesion were significantly upregulated. Finally, Th17 cell differentiation and the TNF signaling pathway were enhanced in the dorsal lesions and liver of mice in the 7KC group. These data suggest that steatohepatitis and psoriasis are linked by a potent, diet-related factor.

MAFLD better predicts the progression of atherosclerotic cardiovascular risk than NAFLD: Generalized estimating equation approach.

AIM: Metabolic associated fatty liver disease (MAFLD) partly overlaps with non-alcoholic fatty liver disease (NAFLD). Thus, using a generalized estimating equation (GEE) approach, we aimed to investigate the difference in worsening of atherosclerotic cardiovascular disease (ASCVD) risk between patients with MAFLD and NAFLD. We also investigated factors related to the difference between the two groups. METHODS: We enrolled 2306 subjects with fatty liver (MAFLD 80.7%, NAFLD 63.4%). Subjects with MAFLD/NAFLD were sub-classified into three groups: NAFLD with no metabolic dysfunction (non-Met NAFLD), overlapping, and MAFLD with moderate alcohol consumption (mod-Alc MAFLD). ASCVD risk was estimated by non-invasive tests, including the Suita score. An event was defined as worsening of these scores from the low-risk to the high-risk group. Independent factors for the event were analyzed by Cox regression analysis with the GEE. RESULTS: In Cox regression analysis, MAFLD (HR 1.08, 95% CI 1.02-1.15, p = 0.014) and alcohol consumption (20-39 g/day; HR 1.73, 95% CI 1.26-2.36, p = 0.001) were independently associated with worsening of the Suita score. In a subanalysis, the incidence of the event was significantly lower in non-Met NAFLD than in the overlapping group (HR 0.70, 95% CI 0.50-0.98, p = 0.042). However, no significant difference was observed in the incidence between the overlapping and mod-Alc MAFLD group (HR 1.19, 95% CI 0.89-1.58, p = 0.235). CONCLUSIONS: The GEE approach demonstrates that MAFLD better identifies patients with worsening of ASCVD risk than NAFLD. Moreover, the superiority of MAFLD over NAFLD was due to the presence of metabolic dysfunction rather than moderate alcohol consumption.

Progranulin deficiency leads to enhanced age-related cardiac hypertrophy through complement C1q-induced ß-catenin activation.

AIMS: Age-related cardiac hypertrophy and subsequent heart failure are predicted to become increasingly serious problems in aging populations. Progranulin (PGRN) deficiency is known to be associated with accelerated aging in the brain. We aimed to evaluate the effects of PGRN deficiency on cardiac aging, including left ventricular hypertrophy. METHODS AND RESULTS: Echocardiography was performed on wild-type (WT) and PGRN-knockout (KO) mice every 3 months from 3 to 18 months of age. Compared to that of WT mice, PGRN KO mice exhibited age-dependent cardiac hypertrophy and cardiac dysfunction at 18 months. Morphological analyses showed that the heart weight to tibia length ratio and cross-sectional area of cardiomyocytes at 18 months were significantly increased in PGRN KO mice relative to those in WT mice. Furthermore, accumulation of lipofuscin and increases in senescence markers were observed in the hearts of PGRN KO mice, suggesting that PGRN deficiency led to enhanced aging of the heart. Enhanced complement C1q (C1q) and activated ß-catenin protein expression levels were also observed in the hearts of aged PGRN KO mice. Treatment of PGRN-deficient cardiomyocytes with C1q caused ß-catenin activation and cardiac hypertrophy. Blocking C1q-induced ß-catenin activation in PGRN-depleted cardiomyocytes attenuated hypertrophic changes. Finally, we showed that C1 inhibitor treatment reduced cardiac hypertrophy and dysfunction in old KO mice, possibly by reducing ß-catenin activation. These results suggest that C1q is a crucial regulator of cardiac hypertrophy induced by PGRN ablation. CONCLUSION: The present study demonstrates that PGRN deficiency enhances age-related cardiac hypertrophy via C1q-induced ß-catenin activation. PGRN is a potential therapeutic target to prevent cardiac hypertrophy and dysfunction.

Loss of core fucosylation reduces low-density lipoprotein receptor expression in hepatocytes by inducing PCSK9 production.

Fucosylation is a type of glycosylation, a form of post-transcriptional regulation of proteins, involved in cancer and inflammation. It involves the attachment of a fucose residue to N-glycans, O-glycans, and glycolipids, which is catalyzed by a family of enzymes called fucosyltransferases (Futs). Among the many Futs, α-1,6-fucosyltransferase (Fut8) is the only enzyme that produces α-1,6-fucosylated oligosaccharides (core fucose). In the human liver, the expression and activity of Fut8 are frequently elevated during progression of chronic liver diseases. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a well-known negative regulator of the low-density lipoprotein receptor (LDLR). Here, we found that loss of core fucose in immortalized hepatocytes led to LDLR downregulation through a dramatic induction of PCSK9. We used the immortalized hepatocytes derived from Fut8 knockout mice or a Fut8 knockdown AML12 hepatocyte cell line. Using these cells, we investigated the effects of Fut8 on hepatocyte cholesterol influx. Both cell lines had reduced LDLR protein levels, resulting from marked increases in PCSK9 expression. Intracellular cholesterol levels were significantly lower and LDL cholesterol uptake was suppressed in Fut8-KO cells. Hepatocyte nuclear factor 1α accumulated in nuclei of Fut8-KO hepatocytes, which mediated increases in PCSK9 mRNA expression. Our findings demonstrated that loss of core fucosylation promoted degradation of LDLR and impaired cholesterol uptake, which is a novel mechanism that regulates cholesterol influx, suggesting that Fut8 might be a novel causative gene for familial hypercholesterolemia.

Marked effects of novel selective peroxisome proliferator-activated receptor α modulator, pemafibrate in severe hypertriglyceridemia: preliminary report.

BACKGROUND: Currently available treatments have only been partly successful in patients with severe hypertriglyceridemia, including those with high serum triglycerides above 1,000 mg/dL (11.3 mmol/L), who often suffer from acute pancreatitis. Pemafibrate is a novel selective peroxisome proliferator-activated receptor α modulator (SPPARMα) which has been developed as an affordable oral tablet in Japan. We herein report the first three patients with severe hypertriglyceridemia who were successfully treated with pemafibrate. METHODS: Three patients with fasting serum triglyceride (TG) levels above 1,000 mg/dL (11.3 mmol/L) were treated with pemafibrate (0.2-0.4 mg/day, 0.1-0.2 mg BID). RESULTS: Serum TGs decreased from 2,000-3,000 mg/dL (22.6-33.9 mmol/L) to < 250 mg/dL (2.8 mmol/L) without adverse effects in all three patients. Serum TGs in Patient 1 and 2 decreased from 1,326 mg/dL (15.0 mmol/L) to 164 mg/dL (1.9 mmol/L) and from 2,040 mg/dL (23.1 mmol/L) to 234 mg/dL (2.6 mmol/L), respectively. Patient 3 with type 2 diabetes and 12.1% (109 mmol/mol) hemoglobin A1c had a TG level of 2,300 mg/dL (26.0 mmol/L). Even after glycemic control improved, TG remained high. After pemafibrate administration, TG decreased to 200 mg/dL (2.3 mmol/L). All patients showed no serious adverse events. CONCLUSIONS: Pemafibrate demonstrated potential efficacy and safety for severe hypertriglyceridemia which may contribute to the prevention of acute pancreatitis, in a manner that can be easily prescribed and used as an oral tablet.

Antidiabetic Therapy in the Treatment of Nonalcoholic Steatohepatitis.

Liver-related diseases are the third-leading causes (9.3%) of mortality in type 2 diabetes (T2D) in Japan. T2D is closely associated with nonalcoholic fatty liver disease (NAFLD), which is the most prevalent chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to hepatocellular carcinoma (HCC) and hepatic failure. No pharmacotherapies are established for NASH patients with T2D. Though vitamin E is established as a first-line agent for NASH without T2D, its efficacy for NASH with T2D recently failed to be proven. The effects of pioglitazone on NASH histology with T2D have extensively been established, but several concerns exist, such as body weight gain, fluid retention, cancer incidence, and bone fracture. Glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors are expected to ameliorate NASH and NAFLD (LEAN study, LEAD trial, and E-LIFT study). Among a variety of SGLT2 inhibitors, dapagliflozin has already entered the phase 3 trial (DEAN study). A key clinical need is to determine the kinds of antidiabetic drugs that are the most appropriate for the treatment of NASH to prevent the progression of hepatic fibrosis, resulting in HCC or liver-related mortality without increasing the risk of cardiovascular or renal events. Combination therapies, such as glucagon receptor agonist/GLP-1 or gastrointestinal peptide/GLP-1, are under development. This review focused on antidiabetic agents and future perspectives on the view of the treatment of NAFLD with T2D.

Pressure Overload Impairs Cardiac Function in Long-Chain Fatty Acid Transporter CD36-Knockout Mice.

CD36 is one of the important transporters of long-chain fatty acids (LCFAs) in the myocardium. We previously reported that CD36-deficient patients demonstrate a marked reduction of myocardial uptake of LCFA, while myocardial glucose uptake shows a compensatory increase, and are often accompanied by cardiomyopathy. However, the molecular mechanisms and functional role of CD36 in the myocardium remain unknown.The current study aimed to explore the pathophysiological role of CD36 in the heart. Methods: Using wild type (WT) and knockout (KO) mice, we generated pressure overload by transverse aortic constriction (TAC) and analyzed cardiac functions by echocardiography. To assess cardiac hypertrophy and fibrosis, histological and molecular analyses and measurement of ATP concentration in mouse hearts were performed.By applying TAC, the survival rate was significantly lower in KO than that in WT mice. After TAC, KO mice showed significantly higher heart weight-to-tibial length ratio and larger cross-sectional area of cardiomyocytes than those of WT. Although left ventricular (LV) wall thickness in the KO mice was similar to that in the WT mice, the KO mice showed a significant enlargement of LV cavity and reduced LV fractional shortening compared to the WT mice with TAC. A tendency for decreased myocardial ATP concentration was observed in the KO mice compared to the WT mice after TAC operation.These data suggest that the LCFA transporter CD36 is required for the maintenance of energy provision, systolic function, and myocardial structure.

Biological, clinical and population relevance of 95 loci for blood lipids.

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD.

Changes in Body Weight in Severely Obese Patients Treated with the Anorexiant Mazindol.

(1) Background: The number of severely obese patients worldwide is rapidly increasing. Recently, novel therapeutic approaches, such as bariatric surgery or GLP-1 receptor agonists, have emerged, bringing about a paradigm shift in this field. However, these therapies sometimes face challenges, such as peri-surgical complications or supply shortages. Mazindol, which is an appetite suppressant approved decades ago in Japan, remains a valuable option. In this study, we investigated the effectiveness of mazindol in reducing body weight in 147 patients, and we examined the factors influencing said effectiveness. (2) Methods: The patients were divided into four groups based on the treatment cycles they underwent: 1 cycle, 2 cycles, 3-5 cycles, and over 6 cycles. We compared the changes in body weight before and after the treatment among these four groups. Additionally, we sought to identify the factors correlated to the effectiveness of mazindol. (3) Results: The change in body weight was more pronounced in the group which underwent 3-5 cycles compared to the groups which underwent 1 cycle and 2 cycles; this change was also more pronounced in the group which underwent over 6 cycles compared to those which underwent 1 cycle. Furthermore, we observed a significant correlation between the initial body weight and the extent of body weight change. (4) Conclusions: Mazindol demonstrated effectiveness in reducing the body weight of patients in a cycle-dependent manner.

A Man with Primary Hyperchylomicronemia with Triglyceride Levels Exceeding 11,000 mg/dL was Well Controlled by Pemafibrate Combined with Dietary Therapy: A Case Report.

A 50-year-old man with a triglyceride (TG) level of 11,397 mg/dL was admitted to our hospital. He consumed a high-fat and high-carbohydrate diet as well as more than 100 g of alcohol per day. He had type 2 diabetes and obesity and had previously suffered from severe acute pancreatitis twice. A genetic analysis revealed compound heterozygous mutations in APOA5 (c.56C>G and c.553G>T). In addition to low-fat meals and alcohol cessation, administration of pemafibrate lowered his triglyceride levels to <150 mg/dL.

Stronger positive correlation of the left ventricular mass index and extracellular volume fraction with diastolic function in diabetic patients without myocardial infarction.

BACKGROUND: The structural and functional characteristics of the heart in patients with diabetes mellitus (DM) and without myocardial infarction (MI) are not fully understood. METHODS: We retrospectively analysed the data of patients with left ventricular ejection fraction (LVEF) ≥ 40% who underwent contrast-enhanced cardiac magnetic resonance imaging (CMR), which was also used to exclude MI, at two hospitals. Volumetric data and extracellular volume fraction (ECVf) of the myocardium evaluated using CMR were compared between patients with and without DM, and their association with diastolic function was evaluated. RESULTS: Among 322 analysed patients, 53 had DM. CMR revealed that the left ventricular mass index (LVMi) and ECVf were increased while LVEF was decreased in patients with DM after adjusting for patient characteristics (all P < 0.05). A stronger positive correlation was observed between LVMi and the early diastolic transmitral flow velocity to early diastolic mitral annular velocity ratio (E/e') in patients with DM than in those without DM (correlation coefficient [R] = 0.46, p = 0.001; R = 0.15, p = 0.021, respectively; p for interaction = 0.011). ECVf correlated with E/e' only in patients with DM (R = 0.61, p = 0.004). CONCLUSIONS: Patients with DM have increased LVMi and ECVf. Importantly, there was a difference between patients with and without DM in the relationship between these structural changes and E/e', with a stronger relationship in patients with DM. Furthermore, DM is associated with mildly reduced LVEF even in the absence of MI.

Twin Study: The Factors Affecting the Serum LDL-C and HDL-C Levels and an RNA-Seq Analysis in Mononuclear Cells in Monozygotic Twins.

AIM: A twin study is a valuable tool for elucidating the acquired factors against lifestyle diseases such as dyslipidemia, diabetes mellitus, and obesity. We aimed 1. to investigate the factors that affect low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in monozygotic (MZ) twins, and 2. to identify genes which expression levels changed in pairs with large differences in LDL-C or HDL-C levels. METHODS: The registered database at the Center for Twin Research, Osaka University, containing 263 pairs of MZ twins, was analyzed. 1. The effects of smoking, exercise, nutritional factors, and anthropometric and biochemical parameters on LDL-C or HDL-C levels were examined in MZ twins. 2. RNA sequencing in the peripheral blood mononuclear cells of 59 pairs was analyzed for large differences of LDL-C or HDL-C groups. RESULTS: 1. The ΔLDL-C levels were significantly associated with an older age, the ΔTG levels, and ΔBMI. ΔHDL-C levels were associated with the ΔBMI, ΔTG, ΔTP, and ΔLDL-C levels. The HDL-C levels were affected by smoking and exercise habits. The intakes of cholesterol and saturated fatty acids were not associated with the LDL-C or HDL-C levels. 2. An RNA sequencing analysis revealed that the expression of genes related to the TLR4 and IFNG pathways was suppressed in accordance with the HDL-C levels in the larger ΔHDL-C group among the 59 pairs. CONCLUSION: We identified the factors affecting the LDL-C or HDL-C levels in monozygotic twins. In addition, some types of inflammatory gene expression in peripheral blood mononuclear cells were suppressed in accordance with the HDL-C levels, thus suggesting the importance of weight management and exercise habits in addition to dietary instructions to control the LDL-C or HDL-C levels.

Genetic and Functional Analyses of Patients with Marked Hypo-High-Density Lipoprotein Cholesterolemia.

AIM: This study aimed to analyze two cases of marked hypo-high-density lipoprotein (HDL) cholesterolemia to identify mutations in ATP-binding cassette transporter A1 (ABCA1) and elucidate the molecular mechanism by which these novel pathological mutations contribute to hypo-HDL cholesterolemia in Tangier disease. METHODS: Wild type and mutant expression plasmids containing a FLAG tag inserted at the C-terminus of the human ABCA1 gene were generated and transfected into HEK293T cells. ABCA1 protein expression and cholesterol efflux were evaluated via Western blotting and efflux assay. The difference in the rate of change in protein expression was evaluated when proteolytic and protein-producing systems were inhibited. RESULTS: In case 1, a 20-year-old woman presented with a chief complaint of gait disturbance. Her HDL-C level was only 6.2 mg/dL. Tangier disease was suspected because of muscle weakness, decreased nerve conduction velocity, and splenomegaly. Whole-exome analysis showed compound heterozygosity for a W484* nonsense mutation and S1343I missense mutation, which confirmed Tangier disease. Cholesterol efflux decreased by a mixture of W484* and S1343I mutations. The S1343I mutation decreased the protein production rate but increased the degradation rate, decreasing the protein levels. This patient also had Krabbe disease. The endogenous ABCA1 protein level of macrophage cell decreased by knocking down its internal galactocerebrosidase.Case 2, a 51-year-old woman who underwent tonsillectomy presented with peripheral neuropathy, corneal opacity, and HDL-C of 3.4 mg/dL. Whole-exome analysis revealed compound heterozygosity for R579* and R1572* nonsense mutations, which confirmed Tangier disease. CONCLUSION: Case 1 is a new ABCA1 mutation with complex pathogenicity, namely, a W484*/S1343I compound heterozygote with marked hypo-HDL cholesterolemia. Analyses of the compound heterozygous mutations indicated that decreases in ABCA1 protein levels and cholesterol efflux activity caused by the novel S1343I mutation combined with loss of W484* protein activity could lead to marked hypo-HDL cholesterolemia. Galactocerebrosidase dysfunction could also be a potential confounding factor for ABCA1 protein function.

Application of Magnetic Resonance Strain Analysis Using Feature Tracking in a Myocardial Infarction Model.

This study validates the usefulness of myocardial strain analysis with cardiac cine magnetic resonance imaging (MRI) by evaluating the changes in the cardiac function and myocardial strain values longitudinally in a myocardial disease model. Six eight-week-old male Wistar rats were used as a model of myocardial infarction (MI). Cine images were taken in the short axis, two-chamber view longitudinal axis, and four-chamber view longitudinal axis directions in rats 3 and 9 days after MI and in control rats, with preclinical 7-T MRI. The control images and the images on days 3 and 9 were evaluated by measuring the ventricular ejection fraction (EF) and the strain values in the circumferential (CS), radial (RS), and longitudinal directions (LS). The CS decreased significantly 3 days after MI, but there was no difference between the images on days 3 and 9. The two-chamber view LS was -9.7 ± 2.1% at 3 days and -13.9 ± 1.4% at 9 days after MI. The four-chamber view LS was -9.9 ± 1.5% at 3 days and -11.9 ± 1.3% at 9 days after MI. Both the two- and four-chamber LS values were significantly decreased 3 days after MI. Myocardial strain analysis is, therefore, useful for assessing the pathophysiology of MI.

Anti-GPIHBP1 Antibody-Positive Autoimmune Hyperchylomicronemia and Immune Thrombocytopenia.

Primary hyperchylomicronemia is characterized by marked hypertriglyceridemia exceeding 1,000 mg/dL. It is caused by dysfunctional mutations in specific genes, namely those for lipoprotein lipase (LPL), glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1), apolipoprotein C2 (ApoC-II), lipase maturation factor 1 (LMF1), or apolipoprotein A5 (ApoA-V). Importantly, antibodies against LPL or GPIHBP1 have also been reported to induce autoimmune hyperchylomicronemia. The patient was a 46-year-old man diagnosed with immune thrombocytopenia (ITP) at 41 years. At the time, he was administered prednisolone (PSL) and eltrombopag, a thrombopoietin receptor agonist. At 44 years, he suffered from acute myocardial infarction, and PSL was discontinued to avoid enhancing atherogenic risks. He was maintained on eltrombopag monotherapy. After discontinuing PSL, marked hypertriglyceridemia (＞3,000 mg/dL) was observed, which did not improve even after a few years of pemafibrate therapy. Upon referral to our clinic, the triglyceride (TG) level was 2,251 mg/dL, ApoC-II was 19.8 mg/dL, LPL was 11.1 ng/mL (0.02-1.5 ng/mL), GPIHBP1 was 47.7 pg/mL (740.0-1,014.0 pg/mL), and anti-GPIHBP1 antibody was detected. The patient was diagnosed to have anti-GPIHBP1 antibody-positive autoimmune hyperchylomicronemia. He was administered PSL 15 mg/day, and TG levels were controlled at approximately 200 mg/dL. Recent studies have reported that patients with anti-GPIHBP1 antibody-induced autoimmune hyperchylomicronemia had concomitant rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, Hashimoto's disease, and Graves' disease. We report a rare case of anti-GPIHBP1 antibody-positive autoimmune hyperchylomicronemia with concomitant ITP, which became apparent when PSL was discontinued due to the onset of steroid-induced acute myocardial infarction.

The Long-Term Efficacy and Safety of Evinacumab in Patients With Homozygous Familial Hypercholesterolemia.

Background: Homozygous familial hypercholesterolemia (HoFH) is characterized by early-onset atherosclerotic cardiovascular disease due to the high low-density lipoprotein cholesterol (LDL-C) burden. Patients with null-null low-density lipoprotein receptor (LDLR) variants respond poorly, if at all, to statins and proprotein convertase subtilisin/kexin type 9 inhibitors, which act by upregulating LDLR expression. The 24-week double-blind treatment period (DBTP) of the phase 3 ELIPSE HoFH (Evinacumab Lipid Studies in Patients with Homozygous Familial hypercholesterolemia; NCT03399786) study demonstrated significant LDL-C reductions in patients with HoFH; LDL-C reductions were also observed in those with null-null LDLR mutations. Objectives: The purpose of this study was to evaluate longer-term efficacy and safety of evinacumab in patients with HoFH from the ELIPSE HoFH study. Methods: Patients with HoFH on stable lipid-lowering therapies (LLTs) ± lipoprotein apheresis and screening LDL-C ≥70 mg/dL who completed the DBTP entered the 24-week open-label treatment period (OLTP) and received intravenous evinacumab 15 mg/kg every 4 weeks. OLTP results were summarized descriptively. Results: A total of 64 patients completed the DBTP and received open-label evinacumab. Despite multiple LLTs, the mean baseline LDL-C at DBTP entry was 250.5 ± 162.3 mg/dL. From baseline to week 48 (end of OLTP), evinacumab reduced mean LDL-C by 46.3% (mean reduction, 134.3 ± 117.3 mg/dL), with similar mean LDL-C reductions for patients with null-null (47.2%) and non-null variants (45.9%). Adverse events occurred in 47 (73.4%) patients; 4 (6.3%) patients experienced adverse events considered evinacumab-related (drug hypersensitivity, infusion-related reaction and asthenia, generalized pruritis, and muscle spasms). Conclusions: In patients with HoFH, evinacumab demonstrated substantial and sustained LDL-C reduction regardless of LDLR function, and was generally well tolerated.

A Resuscitated Case of Acute Myocardial Infarction with both Familial Hypercholesterolemia Phenotype Caused by Possibly Oligogenic Variants of the PCSK9 and ABCG5 Genes and Type I CD36 Deficiency.

A 56-year-old postmenopausal woman with out-of-hospital cardiac arrest caused by acute myocardial infraction was successfully resuscitated by intensive treatments and recovered without any neurological disability. She was diagnosed as having familial hypercholesterolemia (FH) based on a markedly elevated low-density lipoprotein cholesterol (LDL-C) level and family history of premature coronary artery disease. Genetic testing in her family members showed that a variant of the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene (c.2004C＞A, p.S668R), which had been previously reported as having uncertain significance, was associated with FH, indicating that the variant is a potential candidate for the FH phenotype. Next-generation sequencing analysis for the proband also showed that there was a heterozygous mutation of the ATP-binding cassette sub-family G member 5 ( ABCG5) gene (c.1166G＞A, R389H), which has been reported to increase LDL-C level and the risk of cardiovascular disease. She was also diagnosed as having type 1 CD36 deficiency based on a lack of myocardial uptake of 123I-labeled 15-(p-iodophenyl)-3-R,S-methyl-pentadecanoic acid in scintigraphy and the absence of CD36 antigen in both monocytes and platelets in flow cytometry. She had a homozygous mutation of the CD36 gene (c.1126-5_1127delTTTAGAT), which occurs in a canonical splice site (acceptor) and is predicted to disrupt or distort the normal gene product. To our knowledge, this is the first report of a heterozygous FH phenotype caused by possibly oligogenic variants of the PCSK9 and ABCG5 genes complicated with type I CD36 deficiency caused by a novel homozygous mutation. Both FH phenotype and CD36 deficiency might have caused extensive atherosclerosis, leading to acute myocardial infarction in the present case.

Pemafibrate suppresses NLRP3 inflammasome activation in the liver and heart in a novel mouse model of steatohepatitis-related cardiomyopathy.

Although patients with nonalcoholic fatty liver disease have been reported to have cardiac dysfunction, and appropriate model has not been reported. We established a novel mouse model of diet-induced steatohepatitis-related cardiomyopathy and evaluated the effect of pemafibrate. C57Bl/6 male mice were fed a (1) chow diet (C), (2) high-fat, high-cholesterol, high-sucrose, bile acid diet (NASH diet; N), or (3) N with pemafibrate 0.1 mg/kg (NP) for 8 weeks. In the liver, macrophage infiltration and fibrosis in the liver was observed in the N group compared to the C group, suggesting steatohepatitis. Free cholesterol accumulated, and cholesterol crystals were observed. In the heart, free cholesterol similarly accumulated and concentric hypertrophy was observed. Ultrahigh magnetic field magnetic resonance imaging revealed that the left ventricular (LV) ejection fraction (EF) was attenuated and LV strain was focally impaired. RNA sequencing demonstrated that the NOD-like receptor and PI3 kinase-Akt pathways were enhanced. mRNA and protein expression of inflammasome-related genes, such as Caspase-1, NLRP3, and IL-1ß, were upregulated in both the liver and heart. In the NP compared to the N group, steatohepatitis, hepatic steatosis, and cardiac dysfunction were suppressed. Sequential administration of pemafibrate after the development of steatohepatitis-related cardiomyopathy recovered hepatic fibrosis and cardiac dysfunction.