Role of matrix metalloproteinases in delayed cortical responses after stroke

Zhao, Bing-Qiao,Wang, Sophia,Kim, Hahn-Young,Storrie, Hannah,Rosen, Bruce R,Mooney, David J,Wang, Xiaoying,Lo, Eng H Nature Publishing Group 2006 Nature medicine Vol.12 No.4

Matrix metalloproteinases (MMPs) are zinc-endopeptidases with multifactorial actions in central nervous system (CNS) physiology and pathology. Accumulating data suggest that MMPs have a deleterious role in stroke. By degrading neurovascular matrix, MMPs promote injury of the blood-brain barrier, edema and hemorrhage. By disrupting cell-matrix signaling and homeostasis, MMPs trigger brain cell death. Hence, there is a movement toward the development of MMP inhibitors for acute stroke therapy. But MMPs may have a different role during delayed phases after stroke. Because MMPs modulate brain matrix, they may mediate beneficial plasticity and remodeling during stroke recovery. Here, we show that MMPs participate in delayed cortical responses after focal cerebral ischemia in rats. MMP-9 is upregulated in peri-infarct cortex at 7–14 days after stroke and is colocalized with markers of neurovascular remodeling. Treatment with MMP inhibitors at 7 days after stroke suppresses neurovascular remodeling, increases ischemic brain injury and impairs functional recovery at 14 days. MMP processing of bioavailable VEGF may be involved because inhibition of MMPs reduces endogenous VEGF signals, whereas additional treatment with exogenous VEGF prevents MMP inhibitor–induced worsening of infarction. These data suggest that, contrary to MMP inhibitor therapies for acute stroke, strategies that modulate MMPs may be needed for promoting stroke recovery.

Transcriptome-Wide Analyses Provide Insights into Development of the Hedychium coronarium Flower, Revealing Potential Roles of PTL

Zhao Tong,Piñeyro-Nelson Alma,Yu Qianxia,Pan Xiaoping,Hu Xiaoying,Liu Huanfang,Liao Jingping 한국식물학회 2021 Journal of Plant Biology Vol.64 No.5

The flower of Hedychium coronarium possesses highly specialized floral organs: a synsepalous calyx, petaloid staminodes and a labellum. The formation of these organs is controlled by two gene categories: floral organ identity genes and organ boundary genes, which may function individually or jointly during flower development. Although the floral organogenesis of H. coronarium has been studied at the morphological level, the underlying molecular mechanisms involved in particular organ morphologies that emerge in flower development still remain poorly understood. Here, we used comparative transcriptomics combined with Real-time quantitative PCR to investigate gene expression patterns of ABC-class genes in H. coronarium flowers, as well as the homolog of PETAL LOSS (HcPTL). Our studies found that stamen/petal identity or stamen fertility in H. coronarium was not necessarily correlated with the differential expression of HcAP3 and HcAG. We also found a novel spatio-temporal expression pattern for HcPTL mRNA, suggesting it may have evolved a lineage-specific role in the morphogenesis of the Hedychium flower. Our study provides a new transcriptome reference and a functional hypothesis regarding the role of a boundary gene in organ fusion that should be further addressed through phylogenetic analyzes of this gene, as well as functional studies.

Model predictive pulse pattern control of permanent magnet synchronous motors for medium‑ and low‑speed optimization

Yueqing Zhao,Taiqiang Cao,Guangxu Pan,Jin Dai,Xiaoying Guo,Min Zheng,Xuan Lin 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.9

Taking the permanent magnet synchronous motor (PMSM) as the research object, the model prediction pulse pattern control (MP3C) of a PMSM running in the medium–low-speed zone is adopted to further reduce the torque ripple and phase current total harmonic distortion (THD) of a motor running in the medium–low-speed zone. First, the objective function of the predictive pulse control method is optimized. The objective function is intended to be the difference between the switching voltage vector and the equivalent reference voltage vector. At the same time, the integral of the difference between the d-axis current reference value and the actual value is compensated into the voltage reference vector. Thus, the pulse pattern control selected by the objective function is optimal when the motor is running in the medium–low-speed region. In addition, the PMSM can run stably and reliably. Simulation results show that the torque ripple is reduced by 1.3 Nm and 1.2 Nm, and that the phase current total harmonic distortion is reduced by 0.10% and 0.03% when the motor is running at 5 Nm and 10 Nm and at a speed of 100 rpm, respectively. When the rotation speed is 1000 rpm, the torque ripple is reduced by 0.74 Nm and 0.78 Nm respectively. In addition, the phase current total harmonic distortion is decreased by 0.44% and 0.54%, respectively.

Correlations of Fecal Bacterial Communities with Age and Living Region for the Elderly Living in Bama, Guangxi, China

Liang Zhao,Xuewei Qiao,Jun Zhu,Xiaoying Zhang,Jingli Jiang,Yanling Hao,Fazheng Ren 한국미생물학회 2011 The journal of microbiology Vol.49 No.2

Bama County (Guangxi, China) is famous for its longevous population. In this study, intestinal microflora of 17 healthy elderly subjects of different ages and from different regions (rural and urban) in Bama,were analyzed by denaturing gradient gel electrophoresis (DGGE). Significant effects of age and living region on the whole intestinal bacterial communities were observed by redundancy analysis (RDA). A total of 11 bacterial strains that were correlated with age and living region were identified using a t-value biplot combined with band sequencing. Four bacterial strains were correlated with both age and living region of the elderly in Bama. Two Bacteroides strains and one Ruminococcaceae strain were abundant in the rural, younger elderly; conversely, one Desulfovibrio strain was high in the urban, older elderly. Another Bacteroidetes strain was only correlated with the participant’s age, and its abundance increased with the age of the elderly. The richness of one Clostridium sordellii strain, which was only correlated with the elderly living region, was high in the urban elderly. The study also found five other novel bacterial strains that were correlated with the age or living region of the elderly in Bama. These results expand our understanding of age- and region-effects on the intestinal microflora of the elderly and raise the possibility of developing probiotics originating from centenarians.

Inactivation of epithelial sodium ion channel molecules serves as effective diagnostic biomarkers in clear cell renal cell carcinoma

Zheng Qian,Wang Yifang,Zhao Ran,Han Peipei,Zhao Jun,Li Limei,Zhou Xiaohui,Li Ping,Mo Yingxi,Pan Xinli,Luo Wenqi,Zhou Xiaoying 한국유전학회 2023 Genes & Genomics Vol.45 No.7

Background Non-voltage-gated sodium channel, also known as the epithelial sodium channel (ENaC), formed by heteromeric complexes consisting of SCNN1A, SCNN1B, and SCNN1G, is responsible for maintaining sodium ion and body fluid homeostasis in epithelial cells. However, no systematic study of SCNN1 family members has been conducted in renal clear cell carcinoma (ccRCC) to date. Objective To investigate the abnormal expression of SCNN1 family in ccRCC and its potential correlation with clinical parameters. Methods The transcription and protein expression levels of SCNN1 family members in ccRCC were analyzed based on the TCGA database, and were confirmed by quantitative RT-PCR and immunohistochemical staining assays, respectively. The area under curve (AUC) was used to evaluate the diagnostic value of SCNN1 family members for ccRCC patients. Results The mRNA and protein expression of SCNN1 family members was significantly downregulated in ccRCC compared with normal kidney tissues, which might be due to DNA hypermethylation in the promoter region. It is worth noting that the AUC of SCNN1A, SCNN1B, and SCNN1G were 0.965, 0.979, and 0.988 based on the TCGA database (p < 0.0001), respectively. The diagnostic value was even higher when combing these three members together (AUC = 0.997, p < 0.0001). Intriguingly, the mRNA level of SCNN1A was significantly lower in females compared with males, while SCNN1B and SCNN1G were increased with the progression of ccRCC and remarkably associated with a worse outcome for patients. Conclusion The aberrantly decrease of SCNN1 family members might serve as valuable biomarkers for the diagnosis of ccRCC.

Construction of a resequencing-based high-density genetic map for grape using an interspecific population (Vitis amurensis × Vitis vinifera)

Shi Guangli,Sun Dan,Wang Zhenxing,Liu Xiaoying,Guo Jianhui,Zhang Susu,Zhao Ying,Ai Jun 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.4

A high-density genetic map is a prerequisite for marker-assisted selection of crop species. Here, we developed a high-density genetic map of Vitis using 92 F1 progeny derived from the cross between two wine grape cultivars, ‘Shuanghong’ and ‘Italian Riesling’. Whole genome resequencing (WGS) technology was used to generate SNP markers for the map. The map consisted of 1351 recombination bin markers (210,873 SNPs), distributed on 19 linkage groups (LGs), with an average distance of 0.65 cM between adjacent bin markers and a map distance of 860.46 cM. The high levels of uniform coverage and collinearity between the 19 LGs and the grape reference genome indicated that the map is of high quality and can serve as a powerful platform for evaluating grapevines and deciphering the genetic mechanism of important economic and agronomic traits. Our findings will facilitate the process of mapping quantitative trait loci (QTL) that control important horticultural and economic traits of grape.

Epigenetic inactivation of ACAT1 promotes epithelial-mesenchymal transition of clear cell renal cell carcinoma

Han Peipei,Wu Shu,Li Limei,Li Danping,Zhao Jun,Zhang Haishan,Wang Yifang,Zhong Xuemin,Zhang Zhe,Li Ping,Matskova Liudmila,Zhou Xiaoying 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Acetyl-CoA acyltransferase 1 (ACAT1) is a key enzyme catalyzing the production of mitochondrial ketone bodies. We have shown that ACAT1 is down-regulated in kidney renal clear cell carcinoma (KIRC) previously. Objective: To investigate the reasons for downregulation of ACAT1 in KIRC and explore the underlying mechanisms involved in metastatic inhibition regulated by ACAT1. Methods: The Gene Expression Omnibus (GEO) database was queried for meta-analysis of ACAT1 mRNA expression in KIRC. The UALCAN website was used to compare the methylation levels of the ACAT1 promoter region in KIRC and normal tissues. RT-qPCR was used to quantitate ACAT1 transcription levels. The GCBI and Tarbase V.8 databases were used to predict miRNAs that may target the mRNA of ACAT1. The correlation between mRNA expression of ACAT1, MMP7 (matrix metallopeptidase 7), CDH1 (E-cadherin), EpCAM (epithelial cell adhesion molecule), and VIM (vimentin) was analyzed. Extracellular MMP7 protein was quantitated using an ELISA assay. Results: The methylation level of the ACAT1 promoter region in KIRC was significantly higher than that in the normal kidney tissues. The ACAT1 mRNA expression in the KIRC cell lines was restored after treatment with 5-aza-dC (p < 0.05). MiR-21-5p is a conserved microRNA targeting ACAT1. It is expressed at a significantly higher level in KIRC than in normal tissues (p < 0.001). MiR-21-5p miRNA expression negatively correlates with ACAT1 mRNA expression. The expression of miR-21-5p is higher at the T3-T4 stages and in the histologic grades G3-G4. Patients with high miR-21-5p expression tended to have lower overall survival, suggesting that miR-21-5p could serve as a potentially valuable diagnostic biomarker for KIRC (AUC = 0.957; p < 0.001). A mimetic of miR-21-5p inhibited the expression of ACAT1 mRNA and protein. In addition, ACAT1 mRNA expression positively correlates with CDH1 and EpCAM but is negatively correlated with VIM. Overexpression of ACAT1 suppresses the secretion of MMP7 in KIRC cells. Conclusion: Expression of ACAT1 in KIRC is controlled at two levels, firstly by the hypermethylation of the ACAT1 promoter region and secondly by overexpression of miR-21-5p. Downregulation of ACAT1 expression correlates with epithelial-mesenchymal transition (EMT).

A Defect in Zinc Finger Protein Double B-box 1a (DBB1a) Causes Abnormal Floral Development in Arabidopsis

Qiming Wang,Xiaoju Tu,Keqin Deng,Jianxin Zeng,Xiaoying Zhao,Dongying Tang,Xuanming Liu 한국식물학회 2009 Journal of Plant Biology Vol.52 No.6

The double B-box (DBB) type zinc finger protein has thus far been shown to be involved in photomorphegenesis in Arabidopsis thaliana. Here, we show that DBB1a is expressed in the embryo, cytolden, and flower. Misexpression of DBB1a in mutant plants resulted in abnormal numbers and patterns of floral organs. We further show that DBB1a could regulate expression of several floral homeotic genes, including APETALA 2, APETALA 3, PISTILLATA, and AGAMOUS. Interestingly, expression of the microRNA gene MiR172, which is involved in organ boundary establishment, was also misregulated in the dbb1a mutant plants. Our study identified a previously uncharacterized role of DDB1a in regulation of expression of floral homeotic genes and miR172, which is important for understanding of floral pattern formation.

A Lectin Receptor Kinase Positively Regulates ABA Response During Seed Germination and Is Involved in Salt and Osmotic Stress Response

Keqin Deng,Qiming Wang,Jianxin Zeng,Xinhong Guo,Xiaoying Zhao,Dongying Tang,Xuanming Liu 한국식물학회 2009 Journal of Plant Biology Vol.52 No.6

Lectin receptor-like kinases (LecRK) are widespread in higher plants; however, little is known about their physiological roles. In this study, At1g70130 (designated LecRK-b2), an Arabidopsis LecRK gene, has been investigated. LecRK-b2 was predominantly expressed during seed germination, and its expression was ceased following germination. The expression of LecRK-b2 was induced by abscisic acid (ABA), salt, and osmotic stress. LecRK-b2 lossof- function mutation slightly reduced the ABA sensitivity during seed germination, and this reduced sensitivity was demonstrated not due to lower ABA accumulation level in the seeds. Dual-luciferase transient expression assay confirmed that the transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3) could activate the luciferase under driving of LecRK-b2 promoter. LecRK-b2 transcription level was found to be down-regulated in abi3 during seed germination. Furthermore, LecRK-b2 loss-of-function mutation reduced the salt and osmotic sensitivity during early development stage of Arabidopsis. Taken together, these results suggest that LecRK-b2 functions as a positive regulator of the ABA response during the seed germination and is involved in salt and osmotic stress response in the early development stage.

Recent developments and challenges in welding of magnesium to titanium alloys

Auwal, S.T.,Ramesh, S.,Tan, Caiwang,Zhang, Zequn,Zhao, Xiaoye,Manladan, S.M. Techno-Press 2019 Advances in materials research Vol.8 No.1

Joining of Mg/Ti hybrid structures by welding for automotive and aerospace applications has attracted great attention in recent years due mainly to its potential benefit of energy saving and emission reduction. However, joining them has been hampered with many difficulties due to their physical and metallurgical incompatibilities. Different joining processes have been employed to join Mg/Ti, and in most cases in order to get a metallurgical bonding between them was the use of an intermediate element at the interface or mutual diffusion of alloying elements from the base materials. The formation of a reaction product (in the form of solid solution or intermetallic compound) along the interface between the Mg and Ti is responsible for formation of a metallurgical bond. However, the interfacial bonding achieved and the joints performance depend significantly on the newly formed reaction product(s). Thus, a thorough understanding of the interaction between the selected intermediate elements with the base metals along with the influence of the associated welding parameters are essential. This review is timely as it presents on the current paradigm and progress in welding and joining of Mg/Ti alloys. The factors governing the welding of several important techniques are deliberated along with their joining mechanisms. Some opportunities to improve the welding of Mg/Ti for different welding techniques are also identified.