MicroRNA-206 is highly expressed in newly formed muscle fibers: implications regarding potential for muscle regeneration and maturation in muscular dystrophy

miR-1, miR-133a, and miR-206 are muscle-specific microRNAs expressed in skeletal muscles and have been shown to contribute to muscle development. To gain insight into the pathophysiological roles of these three microRNAs in dystrophin-deficient muscular dystrophy, their expression in the tibialis anterior (TA) muscles of mdx mice and CXMD(J) dogs were evaluated by semiquantitative RT-PCR and in situ hybridization. Their temporal and spatial expression patterns were also analyzed in C2C12 cells during muscle differentiation and in cardiotoxin (CTX)-injured TA muscles to examine how muscle degeneration and regeneration affect their expression. In dystrophic TA muscles of mdx mice, miR-206 expression was significantly elevated as compared to that in control TA muscles of age-matched B10 mice, whereas there were no differences in miR-1 or miR-133a expression between B10 and mdx TA muscles. On in situ hybridization analysis, intense signals for miR-206 probes were localized in newly formed myotubes with centralized nuclei, or regenerating muscle fibers, but not in intact pre-degenerated fibers or numerous small mononucleated cells, possibly proliferating myoblasts and inflammatory infiltrates. Similar increased expression of miR-206 was also found in C2C12 differentiation and CTX-induced regeneration, in which differentiated myotubes or regenerating fibers showed abundant expression of miR-206. However, CXMD(J) TA muscles contained smaller amounts of miR-206, miR-1, and miR-133a than controls. They exhibited more severe and more progressive degenerative alterations than mdx TA muscles. Taken together, these observations indicated that newly formed myotubes showed markedly increased expression of miR-206, which might reflect active regeneration and efficient maturation of skeletal muscle fibers.     

Synthesis and characterization of the sweet protein brazzein

The sweet protein brazzein isolated from the fruit of the African plant, Pentadiplandra brazzeana Baillon is 2000-500 times sweeter than sucrose, and consists of 54 amino acid residues with four intramolecular disulfide bonds. Brazzein was prepared by the fluoren-9-yl-methoxycarbonyl solid-phase method, and was identical to natural brazzein by high performance liquid chromatography, mass spectroscopy, peptide mapping, and taste evaluation. The D enantiomer of brazzein was also synthesized, and was shown to be the mirror image of brazzein. The D enantiomer (ent-brazzein) was devoid of any sweetness and was essentially tasteless. © 1996 John Wiley & Sons, Inc.     

Diversity in the degree of sulfation and chain length of the glycosaminoglycan moiety of urinary trypsin inhibitor isomers

Five isomers with different electric charge were fractionated from human urinary trypsin inhibitor (UTI) by anion exchange HPLC. Intact low-sulfated chondroitin 4-sulfate chains from the isomers were analyzed by HPLC and mass spectrometry. Unsaturated disaccharide composition analysis of the chondroitin sulfate chain revealed that the five isomers differ in the numbers of 4-sulfated disaccharide units. Intriguingly, we detected the presence of multiple novel isomers with different numbers of non-sulfated disaccharide units even in the same charge isomer fraction. Our results demonstrate that UTI can vary in terms of both the degree of sulfation and the length of the low-sulfated chondroitin 4-sulfate chain.     

Impact of symptoms by gender and age in Japanese subjects with irritable bowel syndrome with constipation (IBS-C): a large population-based internet survey

Background

Irritable bowel syndrome with constipation (IBS-C) is a representative psychosomatic disorder. Several pathophysiological factors have been linked to IBS symptoms such as the modulation of gastrointestinal motility, visceral hypersensitivity, dysregulation of the gut-brain axis, genetic and environmental factors, sequelae of infection, and psychosocial disorders. It is likely that biopsychosocial aspects of IBS-C underlie its gender and age effects. However, the influence of each symptom of IBS-C by gender and age is not well understood. We hypothesized that the expression rate of each IBS-C symptom in females and in subjects aged 20–49 years was higher than that of subjects who were male and aged 50–79 years.

Methods

We conducted an internet survey of 30,000 adults from the general Japanese population. IBS-C subjects were asked to answer a questionnaire on the degree of anxiety, thoughts about bowel habits, and their dominant gastrointestinal symptoms together with exacerbation factors. The correlation between gender and age and IBS-C symptoms was analyzed.

Results

When analyzed by gender, the expression rate of abdominal discomfort, abdominal distention, and abdominal fullness was significantly higher in female than male IBS-C subjects (66.5% vs. 58.7%, p?<?0.05; 54.7% vs. 43.6%, p?<?0.01; 18.9% vs. 9.6%, p?<?0.01, respectively). When analyzed by age, the expression rate of abdominal distention and abdominal pain was significantly higher among IBS-C subjects aged 20–49 years than those aged 50–79 years (55.7% vs. 46.8%, p?<?0.05; 36.6% vs. 20.6%, p?<?0.001, respectively). In contrast, there was no gender or age differences with regard to the most common and bothersome symptom (abdominal bloating) among IBS-C subjects.

Conclusions

The expression rate of some IBS-C symptoms was higher among females and those aged 20–49 years than males and those aged 50–79 years, respectively. It is important to understand the impact of symptoms by gender and age to evaluate the pathology of IBS-C from a biopsychosocial perspective.

Trial registration

Although this survey was an anonymous internet survey, we obtained informed consent for the study as an online response. The disclosure of this study was approved by the Ethics Committee of Tohoku University Graduate School of Medicine (approval number: 2015–1-405).

     

Knockout of the SREBP system increases production of the polyketide FR901512 in filamentous fungal sp. No. 14919 and lovastatin in Aspergillus terreus ATCC20542

Applied Microbiology and Biotechnology - In the production of useful microbial secondary metabolites, the breeding of strains is generally performed by random mutagenesis. However, because random...     

Gene expression pattern analysis of the tight junction protein, Claudin, in the early morphogenesis of Xenopus embryos

To study how epithelial layers are formed during early development in Xenopus embryos, we have focused on Claudin, the major component of the tight junction. So far, 19 claudin genes have been found in the mouse, expressed in different epithelial tissues. However, though a number of cytological studies have been done for the roles of Claudins, their expression patterns and functions during early embryogenesis are largely unknown. We found three novel Xenopus claudin genes, which are referred to as claudin-4L1, -4L2, and -7L1. At the early gastrula stage, claudin-4L1, -4L2, and -7L1 mRNAs were detected in the ectoderm and in the mesoderm. At the late gastrula stage, claudin mRNAs were detected in the ectoderm through the involuting archenteron roof. At the neurula stage, claudin-4L1/4L2 and -7L1 mRNAs were differentially expressed in the neural groove and the epidermal ectoderm. At the tailbud stage, the claudin mRNAs were found in the branchial arches, the otic vesicles, the sensorial layer of the epidermis, and along the dorsal midline of the neural tube. In addition, claudin-4L1/4L2 mRNAs were detected in the pronephros and the endoderm, whereas claudin-7L1 mRNA was observed in the epithelial layer of the epidermis.     

Peroxisomes of the nematode Caenorhabditis elegans: distribution and morphological characteristics

We analyzed the distribution and morphological characteristics of peroxisomes in the nematode Caenorhabditis elegans by routine electron microscopy, immunoelectron microscopy, and morphometry. Peroxisomes were mainly contained in the epithelial cells of the digestive tract and pharyngeal gland, but some were observed in other cells. Their shape varied from round to twisted. The matrix of most peroxisomes was coarse and uneven, and contained electron-dense nucleoids and frequently tubular substructures. The diameter of peroxisomes in the gut (0.185 micro m) was smaller than that in pharyngeal gland (0.262 micro m). The volume density of peroxisomes per 100 micro m(2) of cytoplasm was 1.86 in the gut and 1.75 in the pharyngeal gland. After treatment with clofibrate, the diameter of peroxisomes increased approximately 1.11-fold in the gut and 1.2-fold in the pharyngeal gland. The volume density of peroxisomes also increased by 2.2-fold in the gut and 2.6-fold in the pharyngeal gland. The labeling density for catalase-2 was almost identical between gut and pharyngeal gland peroxisomes. The results show that in C. elegans peroxisomes mainly distribute in the epithelial cells of the gut and pharyngeal gland. Peroxisomes of the pharyngeal gland are larger than those of the gut, but peroxisomes of both tissues contain catalase-2 at similar concentrations.