Disease relevance of MYHC

• These findings indicate that the two antimyosins cross-react with a particular type of ventricular myosin heavy chain, whose distribution varies in different muscle cells and whose relative concentration changes during development and during cardiac hypertrophy induced by systemic hypertension [1].
• In the rat and the rabbit, hyperthyroidism induced a beta- to alpha-like myosin heavy chain transition, which was considerable in the right atria and complete in the left atria [2].
• Four months after repair, the MyHC expression in the PCA was near normal, suggesting that our model reduces the risk of synkinesis and ensures the accurate muscle reinnervation required for full functional recovery [3].
• We compared the localization patterns of myosin heavy chain isoforms in normal arteries and lesions of increasing severity and determined that TM4 expression was relegated mainly to SMC of the synthetic phenotype in the media and intima during atherogenesis [4].
• We therefore determined the impact of mild postnatal undernutrition on key markers of myofibre function: type I slow myosin heavy chain (MyHC) isoform, myosin ATPase, succinate dehydrogenase and alpha-glycerophosphate dehydrogenase [5].

High impact information on MYHC

• Rat, rabbit, pig, and bovine atrial myocardia were investigated with anti-alpha and anti-beta myosin heavy chain monoclonal antibodies [2].
• Fractional synthesis rate (FSR) of mitochondrial and cytoplasmic proteins in liver, heart, and skeletal muscle, as well as myosin heavy chain (MHC) in muscle, were measured using L-[1-(13)C]leucine as a tracer [6].
• Molecular characterization of a developmentally regulated porcine skeletal myosin heavy chain gene and its 5' regulatory region [7].
• Most BrdU-positive cells expressed myosin heavy chain beta [8].
• Gel electrophoresis revealed no difference in contractile protein composition, but a tendency towards a lower amount of alpha-MHC in the minoxidil-treated hearts was found in ELISA [9].

Biological context of MYHC

• This MyHC isoform was found exclusively in skeletal muscles from about the last quarter of gestation through to adulthood [7].
• This skeletal phenotype appeared to downregulate with time, and Mbs partially transdifferentiated into a cardiac phenotype as indicated by labeling for cardiac-specific troponin T and cardiac myosin heavy chain [10].
• Screening of the libraries with a human anti-alpha-MHC mAb (F8812F8) demonstrated the presence of positive MHC clones in both libraries; the nucleotide sequence of the 3'-untranslated region (3'-UTR) was identical in both libraries [11].
• The use of immunohistochemistry and heterologous monoclonal antibodies (mAb) directed against specific myosin heavy chain (MHC) isoforms revealed a different pattern of gene expression between the two portions of the ST muscle for both generations of fibers [12].
• Mitochondrial genes (16.2%), myosin heavy chain genes (9%) and the actin alpha skeletal muscle gene (9%) were the most abundant transcripts [13].

Anatomical context of MYHC

• The non-muscle myosin heavy chain comprised 63% of the smooth-muscle myosin [14].
• Transitory expression of alpha cardiac myosin heavy chain in a subpopulation of secondary generation muscle fibers in the pig [11].
• The greater stimulation of protein synthesis in colostrum-fed pigs was restricted entirely to the myofibrillar protein compartment and was associated with higher ribosome and myosin heavy chain mRNA abundance [15].
• Reinnervation of laryngeal muscles: a study of changes in myosin heavy chain expression [3].
• Moreover, cells cultured on LM show higher levels of expression of smooth muscle myosin heavy chain (a marker of smooth muscle cell differentiation) than cells cultured on FN [16].

Associations of MYHC with chemical compounds

• Parallel to the phosphorylation of MLC, thrombin increased the amounts of the 43- and 200-kDa proteins in the Triton-insoluble fraction; these proteins were identified as actin and myosin heavy chain, respectively [17].
• The affinity of cardiac myosin for immobilized salicylate was unique as myosin heavy chain from guinea pig leg muscle detergent extracts could not be purified by this procedure [18].
• Two topics are discussed in detail: polymorphism of cardiac myosin heavy chains in the mammalian heart, and effect of thyroid hormone on myosin heavy chain expression by thyroid hormone [19].
• The 18 peptides originate from 9 different proteins including the 3 structural proteins (actin, myosin heavy chain, and troponin T) and the 6 metabolic proteins glycogen phosphorylase, creatine kinase, phosphopyruvate hydratase, myokinase, pyruvate kinase, and dihydrolipoamide succinyltransferase [20].
• We show the IIa to IIb transition in the male involves a change in myosin heavy chain synthesis (Figure 39), a corresponding change in the mobility of native myosin isozymes run on pyrophosphate gels (Figure 43), and changes in the proportions of the alpha and beta subunits of tropomyosin (Figure 41) [21].

Other interactions of MYHC

• We studied the porcine myosin heavy chain 2B (MYH4) and the porcine skeletal muscle myosin regulatory light chain 2 (HUMMLC2B) genes [22].
• Versican was localized to myofibroblast-rich regions in the adventitia and neointima [positive for alpha-smooth muscle (SM) actin, negative for h-caldesmon and SM myosin heavy chain] [23].
• In conduit intrapulmonary elastic arteries alpha, beta and gamma actin, the 204, 200 and 196 kDa myosin heavy chain (MHC) isoforms and vinculin were localised by immunohistochemistry [24].

Analytical, diagnostic and therapeutic context of MYHC

• In the rat, thyroidectomy induced a moderate alpha- to beta-like myosin heavy chain transition, visible in the left atria [2].
• Using specific cRNA probes and mAbs against pig alpha-cardiac and beta/slow/type I MHC, we studied the expression of these MHCs in developing pig semitendinosus muscle by combining in situ hybridization and immunocytochemistry on serial sections at 90 days of gestation, and at 1, 6, 35 days and 6 months of age [11].
• We report on the novel use of combined TaqMan quantitative real-time RT-PCR and image analysis of serial porcine muscle sections, subjected to in situ hybridization (ISH) and immunocytochemistry (IHC), to quantify the mRNA expression of each MyHC isoform within its corresponding fiber type, termed relative fiber type-restricted expression [25].
• Somatic hybrids secreted an IgM monoclonal antibody (B7) that reacted with the myosin heavy chain of human platelets by immunoblotting [26].
• We conclude that pig muscles express high proportions of fast MHC isoforms, including MHC-2B, and that V(o) values are higher than expected on the basis of the scaling relationship between contractile parameters and body size [27].

References