Analyses of Off-Target Effects on Cardiac and Skeletal Muscles by Berberine, a Drug Used to Treat Cancers and Induce Weight Loss.

Previous reports from our laboratory describing the formation of myofibrils in cultured embryonic cardiac and skeletal muscle cells have proposed that myofibrillogenesis occurs in three steps of increasing protein organization: beginning with premyofibrils, followed by nascent myofibrils, and ending in mature myofibrils. Inhibitors of the ubiquitin proteasome system (UPS) prevented nascent myofibrils from progressing directly to mature myofibrils in cultured cardiac and skeletal muscle cells, supporting a three-step model of assembly in which some of the proteins in nascent myofibrils are proteolyzed to allow the assembly of mature myofibrils. Application of UPS inhibitors on cultured muscle cells suggests possible explanations for the off-target cardiac and skeletal muscle adverse effects of UPS drugs, which are used on cancer patients.

Sarcomeric tropomyosin expression during human iPSC differentiation into cardiomyocytes.

Tropomyosin (TPM) is an essential sarcomeric component, stabilizing the thin filament and facilitating actin's interaction with myosin. In mammals, including humans, there are four TPM genes (TPM1, TPM2, TPM3, and TPM4) each of which generates a multitude of TPM isoforms via alternative splicing and using different promoters. In this study, we have examined the expression of transcripts as well as proteins of various sarcomeric TPM isoforms during human inducible pluripotent stem cell differentiation into cardiomyocytes.

A-Band assembly in avian skeletal muscles observed with super-resolution microscopy.

Myofibrils in vertebrate skeletal muscle are organized in aligned arrays of filaments formed from multiple protein components. Despite considerable information describing individual proteins, how they assemble de novo into mature myofibrils is still a challenge. Studies in our lab of sarcomeric protein localization during myofibril assembly led us to propose a three-step progression: premyofibrils to nascent myofibrils, culminating in mature myofibrils.

Xiaoyaosan ameliorates CUMS-induced depressive-like and anorexia behaviors in mice via necroptosis related cellular senescence in hypothalamus.

Ethnopharmacological Relevance: Depression and anorexia often co-occur and share symptoms such as low mood, lack of energy, and weight loss. Xiaoyaosan is a classic formula comprising of a combination of eight herbs, possessing definitive therapeutic effects, minimal side effects, and economical benefits. It has been extensively employed in clinical treatment of ailments and symptoms such as depression, anxiety, and appetite problems.

STED analysis reveals the organization of nonmuscle muscle II, muscle myosin II, and F-actin in nascent myofibrils.

A three-step model has been proposed to describe myofibril assembly in vertebrate cardiac and skeletal muscle cells beginning with premyofibrils, followed by nascent myofibrils, and ending as mature myofibrils (reviewed in Sanger, Wang, et al. (2017). Assembly and maintenance of myofibrils in striated muscle.

Comparison of incorporation of wild type and mutated actins into sarcomeres in skeletal muscle cells: A fluorescence recovery after photobleaching study.

The α-actin mutation G15R in the nucleotide-binding pocket of skeletal muscle, causes severe actin myopathy in human skeletal muscles. Expressed in cultured embryonic quail skeletal myotubes, YFP-G15R-α-actin incorporates in sarcomeres in a pattern indistinguishable from wildtype YFP-α-actin. However, patches of YFP-G15R-α-actin form, resembling those in patients.

Inhibitors of the ubiquitin proteasome system block myofibril assembly in cardiomyocytes derived from chick embryos and human pluripotent stem cells.

Details of sarcomeric protein assembly during de novo myofibril formation closely resemble myofibrillogenesis in skeletal and cardiac myocytes in birds, rodents, and zebrafish. The arrangement of proteins during myofibrillogenesis follows a three-step process: beginning with premyofibrils, followed by nascent myofibrils, and concluding with mature myofibrils (reviewed in Sanger et al., 2017).

Effect of MG-132 on myofibrillogenesis and the ubiquitination of GAPDH in quail myotubes.

In the three-step myofibrillogenesis model, mature myofibrils are formed through two intermediate structures: premyofibrils and nascent myofibrils. We have recently reported that several inhibitors of the Ubiquitin Proteosome System, for example, MG-132, and DBeQ, reversibly block progression of nascent myofibrils to mature myofibrils. In this investigation, we studied the effects of MG132 and DBeQ on the expression of various myofibrillar proteins including actin, myosin light and heavy chains, tropomyosin, myomesin, and myosin binding protein-C in cultured embryonic quail myotubes by western blotting using two loading controls-α-tubulin and glyceraldehyde 3-phosphate dehydrogenase (GAPDH).

Identification of a novel TPM4 isoform transcript and comparison to the expression of other tropomyosin isoforms in bovine cardiac and skeletal muscles.

In mammals, there are four tropomyosin (TPM) genes (TPM1, TPM2, TPM3, and TPM4) each of which generate a multitude of alternatively spliced mRNAs. TPM isoform diversity in bovine unlike in humans are not well characterized. The purpose of this investigation is to perform an extensive analysis of the expression of both transcripts and corresponding protein of sarcomeric TPMs in bovine strated muscles.

Myofibril assembly and the roles of the ubiquitin proteasome system.

De novo assembly of myofibrils in vertebrate cross-striated muscles progresses in three distinct steps, first from a minisarcomeric alignment of several nonmuscle and muscle proteins in premyofibrils, followed by insertions of additional proteins and increased organization in nascent myofibrils, ending with mature contractile myofibrils. In a search for controls of the process of myofibril assembly, we discovered that the transition from nascent to mature myofibrils could be halted by inhibitors of three distinct functions of the ubiquitin proteasome system (UPS). First, inhibition of pathway to E3 Cullin ligases that ubiquitinate proteins led to an arrest of myofibrillogenesis at the nascent myofibril stage.

Wogonin preventive impact on hippocampal neurodegeneration, inflammation and cognitive defects in temporal lobe epilepsy.

Previous studies demonstrated that the pathophysiological changes after temporal lobe epilepsy (TLE) such as oxidative stress, inflammatory reaction contribute to cognitive defect and neuronal damage. The present study was conducted to evaluate the anticonvulsant effect of wogonin ameliorates kainate-induced TLE, and to investigate the mechanism underlying these effects. Rats were divided into control, wogonin, kainate, and wogonin-pretreated kainate groups.

Myofibril Assembly in Cultured Mouse Neonatal Cardiomyocytes.

The formation of myofibrils was analyzed in neonatal mouse cardiomyocytes grown in culture and stained with fluorescent antibodies directed against myofibrillar proteins. The cardiomyocyte cultures also were exposed to siRNA probes to test the role of nonmuscle myosin IIB expression in the formation of myofibrils. In culture, new myofibrils formed in the spreading cell margins surrounding contractile myofibrils previously assembled in utero.

Qualitative and quantitative evaluation of TPM transcripts and proteins in developing striated chicken muscles indicate TPM4α is the major sarcomeric cardiac tropomyosin from early embryonic life to adulthood.

The chicken has been used since the 1980s as an animal model for developmental studies regarding tropomyosin isoform diversity in striated muscles, however, the pattern of expression of transcripts as well as the corresponding TPM proteins of various tropomyosin isoforms in avian hearts are not well documented. In this study, using conventional and qRT-PCR, we report the expression of transcripts for various sarcomeric TPM isoforms in striated muscles through development. Transcripts of both TPM1α and TPM1κ, the two sarcomeric isoforms of the TPM1 gene, are expressed in embryonic chicken hearts but disappear in post hatch stages.

Simultaneous determination of 22 phthalate esters in polystyrene food-contact materials by ultra-performance convergence chromatography with tandem mass spectrometry.

A method for the determination of 22 phthalate esters in polystyrene food-contact materials has been established using ultraperformance convergence chromatography with tandem mass spectrometry. In this method, 22 phthalate esters were analyzed in <3.5 min on an ACQUITY Tours 1-AA column by gradient elution.

Nonmuscle myosin II in cardiac and skeletal muscle cells.

De novo assembly of contractile myofibrils begins with the formation of premyofibrils where filaments of non-muscle myosin (NM II), and actin organize in sarcomeric patterns with Z-Bodies containing muscle-specific alpha-actinin. Interactions of muscle specific myosin (MM II) with NM II occur in a nascent myofibril stage that precedes the assembly of mature myofibrils. By the final stage of myofibrillogenesis, the only myosin II present in the mature myofibrils is MM II.

Significant interaction of hypertension and homocysteine on neurological severity in first-ever ischemic stroke patients.

It is not known whether combination of hypertension and high homocysteine (HHcy) impacts on stroke-related neurological severity. Our aim was to determine whether there is an interaction of hypertension and HHcy on neurological severity in first-ever ischemic stroke patients. We analyzed neurological severity among 189 consecutive first-ever ischemic stroke patients with or without hypertension or HHcy.

Risk of glomerular filtration rate decline in patients with hypertrophic cardiomyopathy and obstructive sleep apnoea.

Sleep apnoea is associated with chronic kidney diseases. A high obstructive sleep apnoea (OSA) prevalence is shown in patients with hypertrophic cardiomyopathy (HCM). Whether the presence of OSA would affect the renal function of patients with HCM is unknown.

Sarcomeric TPM3α in developing chicken.

Cloning and sequencing of various tropomyosin isoforms expressed in chickens have been described since the early 1980s. However, to the best of our knowledge, this is the first report on the molecular characterization and the expression of the sarcomeric isoform of the TPM3 gene in cardiac and skeletal muscles from developing as well as adult chickens. Expression of TPM3α was performed by conventional RT-PCR as well as qRT-PCR using relative expression (by ΔC as well as ΔΔC methods) and by determining absolute copy number.

Identification, characterization, and expression of sarcomeric tropomyosin isoforms in zebrafish.

Tropomyosin is a component of thin filaments that constitute myofibrils, the contractile apparatus of striated muscles. In vertebrates, except for fish, four TPM genes TPM1, TPM2, TPM3, and TPM4 are known. In zebrafish, there are six TPM genes that include the paralogs of the TPM1 (TPM1-1 and TPM1-2), the paralogs of the TPM4 gene (TPM4-1 and TPM4-2), and the two single copy genes TPM2 and TPM3.

Assembly and Maintenance of Myofibrils in Striated Muscle.

In this chapter, we present the current knowledge on de novo assembly, growth, and dynamics of striated myofibrils, the functional architectural elements developed in skeletal and cardiac muscle. The data were obtained in studies of myofibrils formed in cultures of mouse skeletal and quail myotubes, in the somites of living zebrafish embryos, and in mouse neonatal and quail embryonic cardiac cells. The comparative view obtained revealed that the assembly of striated myofibrils is a three-step process progressing from premyofibrils to nascent myofibrils to mature myofibrils.

Hyperuricemia and the risk for coronary heart disease morbidity and mortality a systematic review and dose-response meta-analysis.

Considerable controversy exists regarding the association between hyperuricemia and coronary heart disease (CHD). Therefore, we performed a systematic review and dose-response meta-analysis of prospective studies to examine the controversy. Prospective cohort studies with relative risks (RRs) and 95% confidence intervals (CIs) for CHD according to serum uric acid levels in adults were eligible.

Fruit and vegetable intake and risk of type 2 diabetes mellitus: meta-analysis of prospective cohort studies.

Objective: To clarify and quantify the potential dose-response association between the intake of fruit and vegetables and risk of type 2 diabetes.

Design: Meta-analysis and systematic review of prospective cohort studies.

Data Source: Studies published before February 2014 identified through electronic searches using PubMed and Embase.

Jasplakinolide reduces actin and tropomyosin dynamics during myofibrillogenesis.

The premyofibril model proposes a three-stage process for the de novo assembly of myofibrils in cardiac and skeletal muscles: premyofibrils to nascent myofibrils to mature myofibrils. FRAP experiments and jasplakinolide, a drug that stabilizes F-actin, permitted us to determine how decreasing the dynamics of actin filaments affected the dynamics of tropomyosin, troponin-T, troponin-C, and two Z-Band proteins (alpha-actinin, FATZ) in premyofibrils versus mature myofibrils. Jasplakinolide reduced markedly the dynamics of actin in premyofibrils and in mature myofibrils in skeletal muscles.

Expression of myotilin during chicken development.

Several missense mutations in the Z-band protein, myotilin, have been implicated in human muscle diseases such as myofibrillar myopathy, spheroid body myopathy, and distal myopathy. Recently, we have reported the cloning of chicken myotilin cDNA. In this study, we have investigated the expression of myotilin in cross-striated muscles from developing chicken by qRT-PCR and in situ hybridizations.