MondoA Is Required for Normal Myogenesis and Regulation of the Skeletal Muscle Glycogen Content in Mice

Hui Ran,Yao Lu,Qi Zhang,Qiuyue Hu,Junmei Zhao,Kai Wang,Xuemei Tong,Qing Su 대한당뇨병학회 2021 Diabetes and Metabolism Journal Vol.45 No.3

Background: Skeletal muscle is the largest tissue in the human body, and it plays a major role in exerting force and maintaining metabolism homeostasis. The role of muscle transcription factors in the regulation of metabolism is not fully understood. MondoA is a glucose-sensing transcription factor that is highly expressed in skeletal muscle. Previous studies suggest that MondoA can influence systemic metabolism homeostasis. However, the function of MondoA in the skeletal muscle remains unclear. Methods: We generated muscle-specific MondoA knockout (MAKO) mice and analyzed the skeletal muscle morphology and glycogen content. Along with skeletal muscle from MAKO mice, C2C12 myocytes transfected with small interfering RNA against MondoA were also used to investigate the role and potential mechanism of MondoA in the development and glycogen metabolism of skeletal muscle. Results: MAKO caused muscle fiber atrophy, reduced the proportion of type II fibers compared to type I fibers, and increased the muscle glycogen level. MondoA knockdown inhibited myoblast proliferation, migration, and differentiation by inhibiting the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K)/Akt pathway. Further mechanistic experiments revealed that the increased muscle glycogen in MAKO mice was caused by thioredoxin-interacting protein (TXNIP) downregulation, which led to upregulation of glucose transporter 4 (GLUT4), potentially increasing glucose uptake. Conclusion: MondoA appears to mediate mouse myofiber development, and MondoA decreases the muscle glycogen level. The findings indicate the potential function of MondoA in skeletal muscle, linking the glucose-related transcription factor to myogenesis and skeletal myofiber glycogen metabolism.

Investigation on Preparation of Ge Quantum Dots in $SiO_2$ Thin Films

Chen, Jing,Wu, Xuemei,Jin, Zongming,Yao, Weiguo The Korean Vacuum Society 1998 Applied Science and Convergence Technology Vol.7 No.1

Ge quantum dots in $SiO_2$ thin films were prepared by r.f. magnetron co-sputtering using a Ge, $SiO_2$ composite target. The size of quantum dots was modulated by controlling of substrate temperature during depositing and annealing of samples deposited at certain substrate temperature. A series of work was done on the influence of preparing parameters on the growth of quantum dots, and a discussion on the formation and growth of quantum dots under different preparation parameters is given.

INVESTIGATION OF HOMOLOGOUS SERIES AS PRECURSORY HYDROCARBONS FOR ALIGNED CARBON NANOTUBE FORMATION BY THE SPRAY PYROLYSIS METHOD

ZHI YANG,HUAGUI NIE,XUEMEI ZHOU,ZHEN YAO,SHAOMING HUANG,XIAOHUA CHEN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.3

The precursory carbon source is one of the key parameters which govern the formation of carbon nanotubes (CNTs). In this work, by selecting four homologous series, namely n-pentane, n-hexane, n-heptane and n-octane, as investigated targets, we comparatively study the relationship between thermodynamic properties of the precursory carbon source and formation of aligned CNTs. We find that all of these alkanes are favored for the growth of aligned CNTs in a suitable growth environment. But only n-heptane can yield the aligned CNTs with relatively high quality, high yield and narrow diameter distribution. Furthermore, after considering the link between thermodynamic properties of the precursory carbon source and the morphology characteristic of the nanotube samples, we find that the Gibbs free energy and formation enthalpy of precursory carbon sources play critical roles in the nanotube formation. In additions some possible explanations are proposed to better understand these phenomena. These rules will be very helpful in making clearer the formation mechanism from the precursory carbon sources to the CNTs, and preparing large-scale aligned CNTs with diameter control at low cost.

SYNTHESIZING A WELL-ALIGNED CARBON NANOTUBE FOREST WITH HIGH QUALITY VIA THE NEBULIZED SPRAY PYROLYSIS METHOD BY OPTIMIZING ULTRASONIC FREQUENCY

ZHI YANG,HUAGUI NIE,XUEMEI ZHOU,ZHEN YAO,SHAOMING HUANG,XIAOHUA CHEN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.4

Nebulized spray pyrolysis (NSP) offers ease of scaling into an industrial scale process method for large-scale CNT synthesis. In the method, ultrasonic frequency plays an important role in the formation of well-aligned carbon nanotubes (CNTs). In this work, we obtain well-aligned CNTs with high quality by optimizing ultrasonic frequency via the NSP method. SEM, TEM and HRTEM results show that the aligned CNTs obtained under an ultrasonic frequency of 1.8 MHz have good alignment, uniform nanotube length (~200 μm), high density and no trace of other carbon nanoparticles. The Raman spectra result further confirms that the aligned CNTs have a high graphitization degree. Furthermore, we find that ultrasonic frequency is an important factor in determining the nanotube diameter. The higher the ultrasonic frequency, the smaller the nanotube diameter. This rule may be very helpful in the preparation of large-scale well-aligned CNTs with high quality and diameter-controlled at low cost.

Characterization of Ribose-5-Phosphate Isomerase B from Newly Isolated Strain Ochrobactrum sp. CSL1 Producing L-Rhamnulose from L-Rhamnose

( Min Shen ),( Xin Ju ),( Xinqi Xu ),( Xuemei Yao ),( Liangzhi Li ),( Jiajia Chen ),( Cuiying Hu ),( Jiaolong Fu ),( Lishi Yan ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.7

In this study, we attempted to find new and efficient microbial enzymes for producing rare sugars. A ribose-5-phosphate isomerase B (OsRpiB) was cloned, overexpressed, and preliminarily purified successfully from a newly screened Ochrobactrum sp. CSL1, which could catalyze the isomerization reaction of rare sugars. A study of its substrate specificity showed that the cloned isomerase (OsRpiB) could effectively catalyze the conversion of L-rhamnose to L-rhamnulose, which was unconventional for RpiB. The optimal reaction conditions (50oC, pH 8.0, and 1 mM Ca²⁺) were obtained to maximize the potential of OsRpiB in preparing L-rhamnulose. The catalytic properties of OsRpiB, including K_m, K_cat, and catalytic efficiency (K_cat/K_m), were determined as 43.47 mM, 129.4 sec^-1, and 2.98 mM/sec. The highest conversion rate of L-rhamnose under the optimized conditions by OsRpiB could reach 26% after 4.5 h. To the best of our knowledge, this is the first successful attempt of the novel biotransformation of L-rhamnose to L-rhamnulose by OsRpiB biocatalysis.

SP0454, A Putative Threonine Dehydratase, Is Required For Pneumococcal Virulence In Mice

WenJuan Yan,Hong Wang,WenChun Xu,KaiFeng Wu,Run Yao,XiuYu Xu,Jie Dong,YanQing Zhang,Wen Zhong,XueMei Zhang 한국미생물학회 2012 The journal of microbiology Vol.50 No.3

Increasing pressure in antibiotic resistance and the requirement for the design of new vaccines are the objectives of clarifying the putative virulence factors in pneumococcal infection. In this study, the putative threonine dehydratase sp0454 was inactivated by erythromycin-resistance cassette replacement in Streptococcus pneumoniae CMCC 31203 strain. The sp0454 mutant was tested for cell growth, adherence, colonization, and virulence in a murine model. The Δsp0454 mutant showed decreased ability for colonization and impaired ability to adhere to A549 cells. However, the SP0454 polypeptide or its antiserum did not affect pneumococcal CMCC 31203 adhesion to A549 cells. The sp0454 deletion mutant was less virulent in a murine intranasal infection model. Real-time RT-PCR analysis revealed significant decrease of the pneumococcal surface antigen A expression in the sp0454 mutant. These results suggest that SP0454 contributes to virulence and colonization, which could be explained in part by modulating the expression of other virulence factors, such as psaA in pneumococcal infection.

Nutrigenomics reveals potential genetic underpinning of diverse taste preference of Chinese men

Zhouhai Zhu,Junpu Mei,Silong Sun,Sheming Lu,Meng Li,Ying Guan,Ying Chen,Yuqiong Xu,Tao Zhang,Fengxue Shi,Xuemei Li,Mingming Miao,Shancen Zhao,Qian Gao,Qili Mi,Ping Tang,Jianhua Yao 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background Taste preference varies geographically in China. However, studies on Chinese people’s taste preference in different regions of China are limited, and are lack of research on the mechanism of diferences in taste preference, especially in genetics. Objective This study aims to investigate the characteristics of taste preference of Chinese men, and estimate whether diverse taste preference in Chinese have genetic underpinning. Methods We conducted a questionnaire survey on taste preferences on 1076 males from 10 regions of China, and collected another 1427 males from the same regions which genotyped by microarray. We compared the correlation between diferent taste preference, and evaluated the correlation between the mutation frequency of inhouse database and diferent taste preference. The putative taste-preference-related genes were further utilized to estimate the candidate relationship on gene and gene network in diferent taste preference. Results There was a correlation between diferent taste preferences in Chinese men. We found 31 SNPs associated with 6 kind of taste preferences. These SNPs located within or nearby 36 genes, and the tastes associated with 4 of these genes (TRPV1, AGT, ASIC2 and GLP1R) are consistent with the previous studies. Moreover, in diferent tastes which were suggested to be associated with each other, some putative related genes were the same or in the same gene network, such as pathways related with blood pressure, response to stimulus and nervous system. Conclusions This study indicates that the diverse taste preference of Chinese men may have genetic underpinning.