UNASSIGNED: Lung cancer is one of the major cause of death globally. Crizotinib is a first-line drug used in treating non-small-cell lung cancer (NSCLC). However, the pathophysiological mechanisms underlying its cardiotoxicity are unknown. This study investigated the mechanisms of crizotinib-induced cardiotoxicity and explored whether this toxicity can be prevented by the angiotensin receptor/neprilysin inhibitor sacubitril/valsartan.
UNASSIGNED: Male C57BL/6 mice were randomly divided into three groups: control, crizotinib (40 mg ⋅ kg - 1 ⋅ d - 1 for four weeks), and crizotinib + sacubitril/valsartan (40 mg ⋅ kg - 1 ⋅ d - 1 /60 mg ⋅ kg - 1 ⋅ d - 1 for four weeks). Expression of genes in myocardial tissue were detected by transcriptomic sequencing, with verification of the differentially expressed genes (DEGs) using Real time-polymerase chain reaction (RT-PCR). Blood pressure (BP) and cardiac function of animals were measured using non-invasive monitoring and echocardiography approaches. Ventricular refractory period (RP), as well as the induction rate and score of ventricular arrhythmias (VAs) were detected by in vivo electrophysiology. Epicardial conductance was measured by mapping. Expression of Myh7 in myocardium was detected by western blot and RT-PCR.
UNASSIGNED: DEGs detected using transcriptomic sequencing included 10 up-regulated and 20 down-regulated genes. The first 5 DEGs identified were Myh7, Ngp, Lcn2, Ciart and Ptgds. Kyoto Encyclopedia of Genes and Genomes (KEGG) result indicated that Myh7 is involved in myocarditis, cardiomyopathy, and cardiac muscle contraction. Crizotinib treatment increased blood pressure, prolonged QTc interval, shortened ventricular RP, increased the incidence and score of right VAs, and increased Myh7 expression. Most of these responses were limited by sacubitril/valsartan.
UNASSIGNED: Crizotinib induced a range of cardiotoxic side effects in a mouse model and increased Myh7 expression represents a biomarker for this response. These cardiovascular toxic responses can be largely prevented by sacubitril/valsartan.

Myosin heavy chain gene 7 (MYH7), a sarcomeric gene encoding the myosin heavy chain (myosin-7), has attracted considerable interest as a result of its fundamental functions in cardiac and skeletal muscle contraction and numerous nucleotide variations of MYH7 are closely related to cardiomyopathy and skeletal muscle myopathy. These disorders display significantly inter- and intra-familial variability, sometimes developing complex phenotypes, including both cardiomyopathy and skeletal myopathy. Here, we review the current understanding on MYH7 with the aim to better clarify how mutations in MYH7 affect the structure and physiologic function of sarcomere, thus resulting in cardiomyopathy and skeletal muscle myopathy. Importantly, the latest advances on diagnosis, research models in vivo and in vitro and therapy for precise clinical application have made great progress and have epoch-making significance. All the great advance is discussed here.

BACKGROUND: MicroRNAs (miRNAs) are endogenous small non-coding RNAs (21-25 nucleotides) that act as essential components of several biological processes. Golden-back crucian carp (GBCrC, Carassius auratus) is a naturally mutant species of carp that has two distinct body skin color types (golden and greenish-grey), making it an excellent model for research on the genetic basis of pigmentation. Here, we performed small RNA (sRNA) analysis on the two different skin colors via Illumina sequencing.
RESULTS: A total of 679 known miRNAs and 254 novel miRNAs were identified, of which 32 were detected as miRNAs with significant differential expression (DEMs). 23,577 genes were projected to be the targets of 32 DEMs, primarily those involved in melanogenesis, adrenergic signaling in cardiomyocytes, MAPK signaling pathway and wnt signaling pathway by functional enrichment. Furthermore, we built an interaction module of mRNAs, proteins and miRNAs based on 10 up-regulated and 13 down-regulated miRNAs in golden skin. In addition to transcriptional destabilization and translational suppression, we discovered that miRNAs and their target genes were expressed in the same trend at both the transcriptional and translational levels. Finally, we discovered that miR-196d could be indirectly implicated in regulating melanocyte synthesis and motility in the skin by targeting to myh7 (myosin-7) gene through the luciferase reporter assay, antagomir silencing in vivo and qRT-PCR techniques.
CONCLUSIONS: Our study gives a systematic examination of the miRNA profiles expressed in the skin of GBCrC, assisting in the comprehension of the intricate molecular regulation of body color polymorphism and providing insights for C. auratus breeding research.

Left ventricular non-compaction cardiomyopathy (LVNC) is a rare congenital heart defect. Gene defections have been found in patients with LVNC and their family members; and MYH7 is the most frequent gene associated with LVNC.
We performed a complete prenatal ultrasound and echocardiographic examination on a fetus with cardiac abnormality and a parent-child trio whole-exome sequencing to identify the potential genetic causes. When the genetic abnormality in MYH7 was identified in the fetus, we performed echocardiography and genetic screening on its high-risk relatives.
Second trimester ultrasound and echocardiography showed several malformations in the fetus: Ebstein\'s anomaly (EA), heart dilatation, perimembranous ventricle septal defects, mild seroperitoneum, and single umbilical artery. Heterozygous genotyping of a splicing variant allele (NM_00025.3: c.732+G>A) was identified in this fetus and her mother, not her father, indicating a maternal inheritance. Subsequently, direct sequencing confirmed the presence of this splicing variant among her grandmother (mother of mother), mother, older sister, and herself in a heterozygous manner. No PCR products were amplified by qRT-PCR for the RNA samples extracted from peripheral blood cells. In addition to this proband who was diagnosed with EA, her older sister and grandmother (mother of mother) were diagnosed with isolated asymptomatic LVCN, but her mother was just a carrier with no marked clinical manifestations after family screening.
The presence of MYH7 splicing variant c.732+G>A can be inherited maternally, and its cardiac phenotypes are different from one carrier to another.

Inherited hypertrophic cardiomyopathy (HCM) is a common heart muscle disease that damages heart function and may cause the heart to suddenly stop beating. Genetic factors play an important role in HCM. Pedigree analysis is a good way to identify the genetic defects that cause disease.
An HCM pedigree was determined in Yunnan, China. Whole-exome sequencing was performed to identify the genetic variants of HCM. Another 30 HCM patients and 200 healthy controls were also used to investigate the frequency of the variants by customized TaqMan genotyping assay.
The variant NM_000257.4:c.3134G > A (NP_000248.2:p.Arg1045His, rs397516178, c.3134G > A in short) was found to cosegregate with the clinical phenotype of HCM. Moreover, the variant was not found in the 200 control subjects. After genotyping the variant in 30 HCM patients, there was one patient who carried the variant and had a family history.
Our findings suggest that this variant may be closely related to the occurrence of the disease. According the ACMG guidelines, the c.3134G > A variant should be classified as \"Likely pathogenic\".

Danon disease (DD) is a monogenic lysosomal storage disorder characterized by cardiomyopathy, skeletal myopathy, and variable degrees of intellectual disability. It is caused by a deficiency of lysosomal-associated membrane protein 2 (LAMP2). Two unrelated boys who presented with severe hypertrophic cardiomyopathy and elevated levels of liver enzymes, and were diagnosed with Danon disease at a very young age, were investigated. One boy was diagnosed at 4 months old and died soon after; his mother also died of hypertrophic cardiomyopathy shortly after his birth. Another developed hypertrophic cardiomyopathy at 3 months old but reported no significant cardiovascular symptoms during more than 5 years follow-up. Genetic screening found compound variants of LAMP2 and MYH7 in both of them. This report highlights the clinical heterogeneity in DD. The timely identification of LAMP2 mutation plays a critical role in their treatment and family counseling.

Laing distal myopathy is a rare autosomal dominant inherited distal myopathy caused by mutations of the MYH7 gene affecting mainly the rod region. We described the clinical features, muscle MRI and pathological changes as well as genetic mutations in a group of Chinese patients with Laing distal myopathy.
Six patients with the confirmed diagnoses of Laing distal myopathy were recruited. Ankle dorsiflexion and finger extension weakness, as well as neck flexion weakness were common in our patients. Myopathic as well as neurogenic lesions were suggested by electromyography in different patients. Respiratory abnormality of sleep apnea was detected in two of our patients stressing the necessity of close respiratory monitoring in this disease. Muscle MRIs showed similar features of concentric fatty infiltration of anterior thigh muscles together with early involvement of tibialis anterior and extensor hallucis longus. However, muscle pathological presentations were varied depending on the biopsied muscles and the severity of the disease. In-frame deletions of the MYH7 gene made up 3/4 of mutations in our patients, suggesting that these are common mutations of Laing distal myopathy.
Our study further expanded the phenotypes and genotypes of Laing distal myopathy. In-frame deletions of the MYH7 gene are common causes of Laing distal myopathy.

Myh7 is a classic biomarker for cardiac remodeling and a potential target to attenuate cardiomyocyte (CM) hypertrophy. This study aimed to identify the dominant function of Myh7 after birth and determine whether its removal would affect CM maturation or contribute to reversal of pathological hypertrophy phenotypes. The CASAAV (CRISPR/Cas9-AAV9-based somatic mutagenesis) technique was used to deplete Myh6 and Myh7, and an AAV dosage of 5 × 109 vg/g was used to generate a mosaic CM depletion model to explore the function of Myh7 in adulthood. CM hypertrophy was induced by transverse aortic constriction (TAC) in Rosa26Cas9-P2A-GFP mice at postnatal day 28 (PND28). Heart function was measured by echocardiography. Isolated CMs and in situ imaging were used to analyze the structure and morphology of CM. We discovered that CASAAV successfully silenced Myh6 and Myh7 in CMs, and early depletion of Myh7 led to mild adulthood lethality. However, the Myh7 PND28-knockout mice had normal heart phenotype and function, with normal cellular size and normal organization of sarcomeres and T-tubules. The TAC mice also received AAV-Myh7-Cre to produce Myh7-knockout CMs, which were also of normal size, and echocardiography demonstrated a reversal of cardiac hypertrophy. In conclusion, Myh7 has a role during the maturation period but rarely functions in adulthood. Thus, the therapeutic time should exceed the period of maturation. These results confirm Myh7 as a potential therapeutic target and indicate that its inhibition could help reverse CM hypertrophy.

Hypertrophic cardiomyopathy (HCM) is a group of myocardial diseases defined by cardiac hypertrophy which cannot be explained by secondary causes with a non-dilated left ventricle and preserved or increased ejection fraction. Sometimes it can be combined with restrictive cardiomyopathy. Here we describe a very rare case of a 12-year-old girl with non-obstructive hypertrophic cardiomyopathy accompanied by restrictive phenotype, complete left bundle branch block and intermittent third-degree atrioventricular block, who presented with recurrent syncope. Her father was also found to have hypertrophic cardiomyopathy and treated with implantable cardioverter defibrillator for ventricular tachycardia. Her younger brother is currently asymptomatic but echocardiogram showed hypertrophic cardiomyopathy. Genetic analysis identified a heterozygous missense mutation (c.2155C>T, p.R719W) of MYH7 in the proband girl, her father and her brother. The girl was treated with left bundle pacing and recovered well. The case we present further demonstrates the feasibility of left bundle pacing in children.

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