Medium-chain triglyceride-specific appetite is regulated by the ß-oxidation of medium-chain fatty acids in the liver.

Most studies on fat appetite have focused on long-chain triglycerides (LCTs) due to their obesogenic properties. Medium-chain triglycerides (MCTs), conversely, exhibit antiobesogenic effects; however, the regulation of MCT intake remains elusive. Here, we demonstrate that mice can distinguish between MCTs and LCTs, and the specific appetite for MCTs is governed by hepatic ß-oxidation. We generated liver-specific medium-chain acyl-CoA dehydrogenase (MCAD)-deficient (MCADL-/-) mice and analyzed their preference for MCT and LCT solutions using glyceryl trioctanoate (C8-TG), glyceryl tridecanoate (C10-TG), corn oil, and lard oil in two-bottle choice tests conducted over 8 days. In addition, we used lick microstructure analyses to evaluate the palatability and appetite for MCT and LCT solutions. Finally, we measured the expression levels of genes associated with fat ingestion (Galanin, Qrfp, and Nmu) in the hypothalamus 2 h after oral gavage of fat. Compared with control mice, MCADL-/- mice exhibited a significantly reduced preference for MCT solutions, with no alteration in the preference for LCTs. Lick analysis revealed that MCADL-/- mice displayed a significantly decreased appetite for MCT solutions only while the palatability of both MCT and LCT solutions remained unaffected. Hypothalamic Galanin expression in control mice was elevated by oral gavage of C8-TG but not by LCTs, and this response was abrogated in MCADL-/- mice. In summary, our data suggest that hepatic ß-oxidation is required for MCT-specific appetite but not for LCT-specific appetite. The induction of hypothalamic galanin upon MCT ingestion, dependent on hepatic ß-oxidation, could be involved in the regulation of MCT-specific appetite.NEW & NOTEWORTHY Whether and how medium-chain triglyceride (MCT) intake is regulated remains unknown. Here, we showed that mice can discriminate between MCTs and LCTs. Hepatic ß-oxidation participates in MCT-specific appetite, and hypothalamic galanin may be one of the factors that regulate MCT intake. Because of the antiobesity effects of MCTs, studying MCT-specific appetite may help combat obesity by promoting the intake of MCTs instead of LCTs.

Potential treatment option of rivaroxaban for breastfeeding women: A case series.

The use of direct oral anticoagulants (DOACs) in breastfeeding women is currently challenging due to limited safety data for breastfeeding infants, and there have been no previous studies on the drug concentration in breastfeeding infants. We treated 2 patients (one case was twin pregnancy) with venous thromboembolisms in breastfeeding women administered rivaroxaban at our institution. Blood samples from the mothers and breastmilk samples were collected at time 0 and 2 h after the rivaroxaban administration, breastfeeding was conducted 2 h after the rivaroxaban administration, and blood samples from the infants were collected 2 h after breastfeeding (4 h after maternal rivaroxaban administration). The milk-to-plasma (M:P) ratios were 0.27 in Case 1 and 0.32 in Case 2. The estimated relative infant dose (RID) was 0.82 % in Case 1 Children 1 and 2, and 1.27 % in Case 2. The rivaroxaban concentration in the infant plasma was below the lower limit of quantification in all infants. In addition, even in the high-exposure case simulation based on 5 days of breastfeeding in Case 2, the infant plasma concentration level was below the lower limit of quantification. At 3 months of follow-up, breastfeeding was continued, and all infants grew and developed without any health problems including bleeding events. The current case series showed that there were no pharmacokinetic or clinical concerns for breastfeeding women or breastfed infants, and provides support for rivaroxaban as a safe treatment option for these patients.

Atrial fibrillation-induced cardiomyopathy presenting with bilateral intermittent claudication associated with intracardiac thrombi.

Systemic thromboembolism associated with atrial fibrillation (AF) is usually caused by thrombi in the left atrial appendage and acute onset. We experienced an unusual case of a woman in her 60s who presented to the outpatient district having bilateral intermittent claudication for more than 1 month, which turned out to be multiple thromboembolism from asymptomatic AF with tachycardia. She was also complicated with non-ischaemic dilated cardiomyopathy with reduced ejection fraction, consistent with arrhythmia-induced cardiomyopathy (AiCM), along with left atrial and left ventricular thrombi and thromboembolism in multiple organs. Rate control with beta-blockers was not effective. With the administration of amiodarone after adequate anticoagulation therapy, she returned to sinus rhythm, and the ejection fraction was restored. This case is instructive in that AiCM with AF can cause thrombosis in the left ventricle, and the patient may present with worsening intermittent claudication as a result of systemic embolism.

CRISPR-Cas9-guided amplification-free genomic diagnosis for familial hypercholesterolemia using nanopore sequencing.

Familial hypercholesterolemia is an inherited disorder that remains underdiagnosed. Conventional genetic testing methods such as next-generation sequencing (NGS) or target PCR are based on the amplification process. Due to the efficiency limits of polymerase and ligase enzymes, these methods usually target short regions and do not detect large mutations straightforwardly. This study combined the long-read nanopore sequencing and CRISPR-Cas9 system to sequence the target DNA molecules without amplification. We originally designed and optimized the CRISPR-RNA panel to target the low-density lipoprotein receptor gene (LDLR) and proprotein convertase subtilisin/kexin type 9 gene (PCSK9) from human genomic DNA followed by nanopore sequencing. The average coverages for LDLR and PCSK9 were 106× and 420×, versus 1.2× for the background genome. Among them, continuous reads were 52x and 307x, respectively, and spanned the entire length of LDLR and PCSK9. We identified pathogenic mutations in both coding and splicing donor regions in LDLR. We also detected an 11,029 bp large deletion in another case. Furthermore, using continuous long reads generated from the benchmark experiment, we demonstrated how a false-positive 670 bp deletion caused by PCR amplification errors was easily eliminated.

KUS121, a VCP modulator, has an ameliorating effect on acute and chronic heart failure without calcium loading via maintenance of intracellular ATP levels.

AIMS: As heart failure (HF) progresses, ATP levels in myocardial cells decrease, and myocardial contractility also decreases. Inotropic drugs improve myocardial contractility but increase ATP consumption, leading to poor prognosis. Kyoto University Substance 121 (KUS121) is known to selectively inhibit the ATPase activity of valosin-containing protein, maintain cellular ATP levels, and manifest cytoprotective effects in several pathological conditions. The aim of this study is to determine the therapeutic effect of KUS121 on HF models. METHODS AND RESULTS: Cultured cell, mouse, and canine models of HF were used to examine the therapeutic effects of KUS121. The mechanism of action of KUS121 was also examined. Administration of KUS121 to a transverse aortic constriction (TAC)-induced mouse model of HF rapidly improved the left ventricular ejection fraction and improved the creatine phosphate/ATP ratio. In a canine model of high frequency-paced HF, administration of KUS121 also improved left ventricular contractility and decreased left ventricular end-diastolic pressure without increasing the heart rate. Long-term administration of KUS121 to a TAC-induced mouse model of HF suppressed cardiac hypertrophy and fibrosis. In H9C2 cells, KUS121 reduced ER stress. Finally, in experiments using primary cultured cardiomyocytes, KUS121 improved contractility and diastolic capacity without changing peak Ca2+ levels or contraction time. These effects were not accompanied by an increase in cyclic adenosine monophosphate or phosphorylation of phospholamban and ryanodine receptors. CONCLUSIONS: KUS121 ameliorated HF by a mechanism totally different from that of conventional catecholamines. We propose that KUS121 is a promising new option for the treatment of HF.

Inhibition of microRNA-33b in humanized mice ameliorates nonalcoholic steatohepatitis.

Nonalcoholic steatohepatitis (NASH) can lead to cirrhosis and hepatocellular carcinoma in their advanced stages; however, there are currently no approved therapies. Here, we show that microRNA (miR)-33b in hepatocytes is critical for the development of NASH. miR-33b is located in the intron of sterol regulatory element-binding transcription factor 1 and is abundantly expressed in humans, but absent in rodents. miR-33b knock-in (KI) mice, which have a miR-33b sequence in the same intron of sterol regulatory element-binding transcription factor 1 as humans and express miR-33b similar to humans, exhibit NASH under high-fat diet feeding. This condition is ameliorated by hepatocyte-specific miR-33b deficiency but unaffected by macrophage-specific miR-33b deficiency. Anti-miR-33b oligonucleotide improves the phenotype of NASH in miR-33b KI mice fed a Gubra Amylin NASH diet, which induces miR-33b and worsens NASH more than a high-fat diet. Anti-miR-33b treatment reduces hepatic free cholesterol and triglyceride accumulation through up-regulation of the lipid metabolism-related target genes. Furthermore, it decreases the expression of fibrosis marker genes in cultured hepatic stellate cells. Thus, inhibition of miR-33b using nucleic acid medicine is a promising treatment for NASH.

Inhibition of microRNA-33b specifically ameliorates abdominal aortic aneurysm formation via suppression of inflammatory pathways.

Abdominal aortic aneurysm (AAA) is a lethal disease, but no beneficial therapeutic agents have been established to date. Previously, we found that AAA formation is suppressed in microRNA (miR)-33-deficient mice compared with wild-type mice. Mice have only one miR-33, but humans have two miR-33 s, miR-33a and miR-33b. The data so far strongly support that inhibiting miR-33a or miR-33b will be a new strategy to treat AAA. We produced two specific anti-microRNA oligonucleotides (AMOs) that may inhibit miR-33a and miR-33b, respectively. In vitro studies showed that the AMO against miR-33b was more effective; therefore, we examined the in vivo effects of this AMO in a calcium chloride (CaCl2)-induced AAA model in humanized miR-33b knock-in mice. In this model, AAA was clearly improved by application of anti-miR-33b. To further elucidate the mechanism, we evaluated AAA 1 week after CaCl2 administration to examine the effect of anti-miR-33b. Histological examination revealed that the number of MMP-9-positive macrophages and the level of MCP-1 in the aorta of mice treated with anti-miR-33b was significantly reduced, and the serum lipid profile was improved compared with mice treated with control oligonucleotides. These results support that inhibition of miR-33b is effective in the treatment for AAA.

microRNA-33 maintains adaptive thermogenesis via enhanced sympathetic nerve activity.

Adaptive thermogenesis is essential for survival, and therefore is tightly regulated by a central neural circuit. Here, we show that microRNA (miR)-33 in the brain is indispensable for adaptive thermogenesis. Cold stress increases miR-33 levels in the hypothalamus and miR-33-/- mice are unable to maintain body temperature in cold environments due to reduced sympathetic nerve activity and impaired brown adipose tissue (BAT) thermogenesis. Analysis of miR-33f/f dopamine-ß-hydroxylase (DBH)-Cre mice indicates the importance of miR-33 in Dbh-positive cells. Mechanistically, miR-33 deficiency upregulates gamma-aminobutyric acid (GABA)A receptor subunit genes such as Gabrb2 and Gabra4. Knock-down of these genes in Dbh-positive neurons rescues the impaired cold-induced thermogenesis in miR-33f/f DBH-Cre mice. Conversely, increased gene dosage of miR-33 in mice enhances thermogenesis. Thus, miR-33 in the brain contributes to maintenance of BAT thermogenesis and whole-body metabolism via enhanced sympathetic nerve tone through suppressing GABAergic inhibitory neurotransmission. This miR-33-mediated neural mechanism may serve as a physiological adaptive defense mechanism for several stresses including cold stress.

Overview of the 84th Annual Scientific Meeting of the Japanese Circulation Society　- Change Practice!

Due to the COVID-19 pandemic, the 84thAnnual Meeting of the Japanese Circulation Society (JCS) was held in a web-based format for the first time in its history as "The Week for JCS 2020" from Monday, July 27 to Sunday, August 2, 2020. All sessions, including general abstracts, were streamed live or on-demand. The main theme of the meeting was "Change Practice!" and the aim was to organize the latest findings in the field of cardiovascular medicine and discuss how to change practice. The total number of registered attendees was over 16,800, far exceeding our expectations, and many of the sessions were viewed by far more people than at conventional face-to-face scientific meetings. At this conference, the power of online information dissemination was fully demonstrated, and the evolution of online academic meetings will be a direction that cannot be reversed in the future. The meeting was completed with great success, and we express our heartfelt gratitude to all affiliates for their enormous amount of work, cooperation, and support.

Functional non-coding RNAs in vascular diseases.

Recently, advances in genomic technology such as RNA sequencing and genome-wide profiling have enabled the identification of considerable numbers of non-coding RNAs (ncRNAs). MicroRNAs have been studied for decades, leading to the identification of those with disease-causing and/or protective effects in vascular disease. Although other ncRNAs such as long ncRNAs have not been fully described yet, recent studies have indicated their important functions in the development of vascular diseases. Here, we summarize the current understanding of the mechanisms and functions of ncRNAs, focusing on microRNAs, circular RNAs and long ncRNAs in vascular diseases.

Lionheart LincRNA alleviates cardiac systolic dysfunction under pressure overload.

Recent high-throughput approaches have revealed a vast number of transcripts with unknown functions. Many of these transcripts are long noncoding RNAs (lncRNAs), and intergenic region-derived lncRNAs are classified as long intergenic noncoding RNAs (lincRNAs). Although Myosin heavy chain 6 (Myh6) encoding primary contractile protein is down-regulated in stressed hearts, the underlying mechanisms are not fully clarified especially in terms of lincRNAs. Here, we screen upregulated lincRNAs in pressure overloaded hearts and identify a muscle-abundant lincRNA termed Lionheart. Compared with controls, deletion of the Lionheart in mice leads to decreased systolic function and a reduction in MYH6 protein levels following pressure overload. We reveal decreased MYH6 results from an interaction between Lionheart and Purine-rich element-binding protein A after pressure overload. Furthermore, human LIONHEART levels in left ventricular biopsy specimens positively correlate with cardiac systolic function. Our results demonstrate Lionheart plays a pivotal role in cardiac remodeling via regulation of MYH6.

Utility of collagen-derived peptides as markers of organ injury in patients with acute heart failure.

Objective: This study aims to investigate the time-dependent prognostic utility of two fibrosis markers representing organ fibrogenesis (N-terminal propeptide of procollagen III (PIIINP) and type IV collagen 7S (P4NP 7S)) in patients with acute heart failure (HF). Methods: 390 patients with acute HF were dichotomised based on the median value of fibrosis markers at discharge. The primary outcome measure was a composite of cardiac death and HF hospitalisation. Results: P4NP 7S significantly declined during hospitalisation, whereas PIIINP did not. The cumulative 90-day and 365-day incidence of the primary outcome measure was 16.6% vs 16.0% (p=0.42) and 33.3% vs 28.4% (p=0.34) in the patients with high versus low PIIINP; 19.9% vs 13.0% (p=0.04) and 32.3% vs 29.0% (p=0.34) in the patients with high and low P4NP 7S, respectively. After adjusting for confounders, high P4NP 7S correlated with significant excess risk relative to low P4NP 7S for both 90-day and 365-day primary outcome measure (adjusted HR, 1.50; 95% CI, 1.02 to 2.21; p=0.04 and adjusted HR, 1.89; 95% CI, 1.11 to 3.26; p=0.02, respectively), which was driven by significant association of high P4NP 7S with higher incidence of HF hospitalisation. Furthermore, P4NP 7S exhibited an additive value to conventional prognostic factors for predicting 90-day outcome (p=0.038 for net reclassification improvement; p=0.0068 for integrated discrimination improvement). High PIIINP did not correlate with significant excess risk for both 90-day and 365-day outcome. Conclusions: This study suggests a possible role of P4NP 7S in the risk stratification of patients with acute HF.

Homeobox A4 suppresses vascular remodeling by repressing YAP/TEAD transcriptional activity.

The Hippo signaling pathway is involved in the pathophysiology of various cardiovascular diseases. Yes-associated protein (YAP) and transcriptional enhancer activator domain (TEAD) transcriptional factors, the main transcriptional complex of the Hippo pathway, were recently identified as modulators of phenotypic switching of vascular smooth muscle cells (VSMCs). However, the intrinsic regulator of YAP/TEAD-mediated gene expressions involved in vascular pathophysiology remains to be elucidated. Here, we identified Homeobox A4 (HOXA4) as a potent repressor of YAP/TEAD transcriptional activity using lentiviral shRNA screen. Mechanistically, HOXA4 interacts with TEADs and attenuates YAP/TEAD-mediated transcription by competing with YAP for TEAD binding. We also clarified that the expression of HOXA4 is relatively abundant in the vasculature, especially in VSMCs. In vitro experiments in human VSMCs showed HOXA4 maintains the differentiation state of VSMCs via inhibition of YAP/TEAD-induced phenotypic switching. We generated Hoxa4-deficient mice and confirmed the downregulation of smooth muscle-specific contractile genes and the exacerbation of vascular remodeling after carotid artery ligation in vivo. Our results demonstrate that HOXA4 is a repressor of VSMC phenotypic switching by inhibiting YAP/TEAD-mediated transcription.

Effects of Metformin on Left Ventricular Size and Function in Hypertensive Patients with Type 2 Diabetes Mellitus: Results of a Randomized, Controlled, Multicenter, Phase IV Trial.

BACKGROUND: Metformin is the most widely used oral antihyperglycemic agent for patients with type 2 diabetes mellitus (T2DM). Despite the possible benefits of metformin on diabetes mellitus (DM) and heart failure (HF), acute or unstable HF remains a precaution for its use. OBJECTIVE: The aim of the present prospective randomized controlled trial was to assess whether metformin treatment has beneficial effects on patients with T2DM with hypertension without overt HF. METHODS: A total of 164 patients (92 males, 72 females; median age 66 years) were included in this study. Patients with T2DM with a history of hypertension were randomized 1:1 to treatment for 1 year with either metformin (metformin-treated group) or other hypoglycemic agents (control group). The primary endpoints were changes in brain natriuretic peptide (BNP) levels, left ventricular (LV) mass index, and indicators of LV diastolic function. We also evaluated changes in both clinical findings and blood laboratory examination data. RESULTS: We observed no significant changes between baseline and 1-year post-treatment in LV mass index, BNP levels, or E/e' (early diastolic transmitral flow velocity/early diastolic mitral annular velocity; an indicator of LV diastolic function) in either the metformin-treated (n = 83) or the control (n = 81) groups. The metformin-treated group had a significant reduction of body mass index (BMI) and low-density lipoprotein cholesterol (LDL-C), but the control group did not. We determined that renal function, including serum creatinine and estimated glomerular filtration rate, deteriorated significantly in the control group but not in the metformin-treated group. CONCLUSION: LV mass and diastolic function were not affected after 1 year of metformin treatment in patients with T2DM. However, we observed benefits in terms of reductions in both BMI and LDL-C levels and preservation of renal function. TRIAL REGISTRATION: UMIN000006504. Registered 7 October 2011.

Cardioprotective Effects of VCP Modulator KUS121 in Murine and Porcine Models of Myocardial Infarction.

No effective treatment is yet available to reduce infarct size and improve clinical outcomes after acute myocardial infarction by enhancing early reperfusion therapy using primary percutaneous coronary intervention. The study showed that Kyoto University Substance 121 (KUS121) reduced endoplasmic reticulum stress, maintained adenosine triphosphate levels, and ameliorated the infarct size in a murine cardiac ischemia and reperfusion injury model. The study confirmed the cardioprotective effect of KUS121 in a porcine ischemia and reperfusion injury model. These findings confirmed that KUS121 is a promising novel therapeutic agent for myocardial infarction in conjunction with primary percutaneous coronary intervention.

Identification of Differential Roles of MicroRNA-33a and -33b During Atherosclerosis Progression With Genetically Modified Mice.

Background Micro RNA (miR)-33 targets cholesterol transporter ATP -binding cassette protein A1 and other antiatherogenic targets and contributes to atherogenic progression. Its inhibition or deletion is known to result in the amelioration of atherosclerosis in mice. However, mice lack the other member of the miR-33 family, miR-33b, which exists in humans and other large mammals. Thus, precise evaluation and comparison of the responsibilities of these 2 miRs during the progression of atherosclerosis has not been reported, although they are essential. Methods and Results In this study, we performed a comprehensive analysis of the difference between the function of miR-33a and miR-33b using genetically modified mice. We generated 4 strains with or without miR-33a and miR-33b. Comparison between mice with only miR-33a (wild-type mice) and mice with only miR-33b (miR-33a-/-/miR-33b+/+) revealed the dominant expression of miR-33b in the liver. To evaluate the whole body atherogenic potency of miR-33a and miR-33b, we developed apolipoprotein E-deficient/miR-33a+/+/miR-33b-/- mice and apolipoprotein E-deficient/miR-33a-/-/miR-33b+/+ mice. With a high-fat and high-cholesterol diet, the apolipoprotein E-deficient/miR-33a-/-/miR-33b+/+ mice developed increased atherosclerotic plaque versus apolipoprotein E-deficient/miR-33a+/+/miR-33b-/- mice, in line with the predominant expression of miR-33b in the liver and worsened serum cholesterol profile. By contrast, a bone marrow transplantation study showed no significant difference, which was consistent with the relevant expression levels of miR-33a and miR-33b in bone marrow cells. Conclusions The miR-33 family exhibits differences in distribution and regulation and particularly in the progression of atherosclerosis; miR-33b would be more potent than miR-33a.

MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons.

Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3'-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4.

Hepatokine α1-Microglobulin Signaling Exacerbates Inflammation and Disturbs Fibrotic Repair in Mouse Myocardial Infarction.

Acute cardiac rupture and adverse left ventricular (LV) remodeling causing heart failure are serious complications of acute myocardial infarction (MI). While cardio-hepatic interactions have been recognized, their role in MI remains unknown. We treated cultured cardiomyocytes with conditioned media from various cell types and analyzed the media by mass spectrometry to identify α1-microglobulin (AM) as an Akt-activating hepatokine. In mouse MI model, AM protein transiently distributed in the infarct and border zones during the acute phase, reflecting infiltration of AM-bound macrophages. AM stimulation activated Akt, NFκB, and ERK signaling and enhanced inflammation as well as macrophage migration and polarization, while inhibited fibrogenesis-related mRNA expression in cultured macrophages and cardiac fibroblasts. Intramyocardial AM administration exacerbated macrophage infiltration, inflammation, and matrix metalloproteinase 9 mRNA expression in the infarct and border zones, whereas disturbed fibrotic repair, then provoked acute cardiac rupture in MI. Shotgun proteomics and lipid pull-down analysis found that AM partly binds to phosphatidic acid (PA) for its signaling and function. Furthermore, systemic delivery of a selective inhibitor of diacylglycerol kinase α-mediated PA synthesis notably reduced macrophage infiltration, inflammation, matrix metalloproteinase activity, and adverse LV remodeling in MI. Therefore, targeting AM signaling could be a novel pharmacological option to mitigate adverse LV remodeling in MI.

Circulating markers of collagen types I, III, and IV in patients with dilated cardiomyopathy: relationships with myocardial collagen expression.

AIMS: Collagen-derived peptides such as collagen I C-terminal telopeptide (CITP) and procollagen III N-terminal propeptide (PIIINP) have been conventionally used as markers of cardiac fibrosis. Collagen IV 7S domain (P4NP 7S) has been recently reported to be correlated with haemodynamics in patients with acute heart failure. We investigated whether these markers reflect cardiac remodelling and myocardial collagen expression. METHODS AND RESULTS: In 80 patients with dilated cardiomyopathy, relationships of CITP, PIIINP, and P4NP 7S to clinical and echocardiographic variables were analysed. CITP and PIIINP were inversely correlated with estimated glomerular filtration rate (r = -0.41, P < 0.001 and r = -0.32, P = 0.004, respectively); P4NP 7S was positively correlated with B-type natriuretic peptide (r = 0.32, P = 0.003) and γ-glutamyltransferase (r = 0.38, P < 0.001). These correlations were significant even after adjustment by potential confounders, whereas all three collagen markers were not independently correlated with ejection fraction nor with left ventricular (LV) diastolic diameter. In 33 patients undergoing endomyocardial biopsy, myocardial collagen I and III mRNA expressions were correlated with LV end-diastolic volume index (r = 0.42, P = 0.02 and r = 0.54, P = 0.002, respectively), whereas myocardial collagen IV mRNA expression was not correlated with LV end-diastolic volume index nor with ejection fraction. Each collagen-derived peptide was not significantly correlated with the myocardial expression of their corresponding collagen mRNA. CONCLUSIONS: Our study shows that CITP, PIIINP, and P4NP 7S do not reflect myocardial collagen mRNA expression but presumably reflect extra-cardiac organ injury in heart failure.