An Optical-Density-Based Feedback Feeding Method for Ammonium Concentration Control in Spirulina platensis Cultivation

( Yi Lu Bao ),( Shu Mei Wen ),( Wei Cong ),( Xia Wu ),( Xiang Ning Zheng ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.7

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium- N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l·d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.

Common Variants in the PALB2 Gene Confer Susceptibility to Breast Cancer: a Meta-analysis

Zhang, Yi-Xia,Wang, Xue-Mei,Kang, Shu,Li, Xiang,Geng, Jing Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Objective: Increasing scientific evidence suggests that common variants in the PALB2 gene may confer susceptibility to breast cancer, but many studies have yielded inconclusive results. This meta-analysis aimed to derive a more precise estimation of the relationship between PALB2 genetic variants and breast cancer risk. Methods: An extensive literary search for relevant studies was conducted in PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CNKI and CBM databases from their inception through September 1st, 2013. A meta-analysis was performed using the STATA 12.0 software and crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: Six case-control studies were included with a total of 4,499 breast cancer cases and 6,369 healthy controls. Our meta-analysis reveals that PALB2 genetic variants may increase the risk of breast cancer (allele model: OR>1.36, 95%CI: 1.20~1.52, P < 0.001; dominant model: OR>1.64, 95%CI: 1.42~1.91, P < 0.001; respectively). Subgroup analyses by ethnicity indicated PALB2 genetic variants were associated with an increased risk of breast cancer among both Caucasian and Asian populations (all P < 0.05). No publication bias was detected in this meta-analysis (all P > 0.05). Conclusion: The current meta-analysis indicates that PALB2 genetic variants may increase the risk of breast cancer. Thus, detection of PALB2 genetic variants may be a promising biomarker approach.

Hsa-let-7c controls the committed differentiation of IGF-1-treated mesenchymal stem cells derived from dental pulps by targeting IGF-1R via the MAPK pathways

Gen-Xia Liu,Shu Ma,Yao Li,Yan Yu,Yi-Xiang Zhou,Ya-Die Lu,Lin Jin,Zi-Lu Wang,Jin-Hua Yu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

The putative tumor suppressor microRNA let-7c is extensively associated with the biological properties of cancer cells. However, the potential involvement of let-7c in the differentiation of mesenchymal stem cells has not been fully explored. In this study, we investigated the influence of hsa-let-7c (let-7c) on the proliferation and differentiation of human dental pulp-derived mesenchymal stem cells (DPMSCs) treated with insulin-like growth factor 1 (IGF-1) via flow cytometry, CCK-8 assays, alizarin red staining, real-time RT-PCR, and western blotting. In general, the proliferative capabilities and cell viability of DPMSCs were not significantly affected by the overexpression or deletion of let-7c. However, overexpression of let-7c significantly inhibited the expression of IGF-1 receptor (IGF-1R) and downregulated the osteo/odontogenic differentiation of DPMSCs, as indicated by decreased levels of several osteo/odontogenic markers (osteocalcin, osterix, runt-related transcription factor 2, dentin sialophosphoprotein, dentin sialoprotein, alkaline phosphatase, type 1 collagen, and dentin matrix protein 1) in IGF-1-treated DPMSCs. Inversely, deletion of let- 7c resulted in increased IGF-1R levels and enhanced osteo/odontogenic differentiation. Furthermore, the ERK, JNK, and P38 MAPK pathways were significantly inhibited following the overexpression of let-7c in DPMSCs. Deletion of let-7c promoted the activation of the JNK and P38 MAPK pathways. Our cumulative findings indicate that Let-7c can inhibit the osteo/odontogenic differentiation of IGF-1-treated DPMSCs by targeting IGF-1R via the JNK/P38 MAPK signaling pathways.

Development of a Serum-Free Culture Method for Endothelial Cells of the Stria Vascularis and Their Pro-inflammatory Secretome Changes Induced by Oxidative Stress

Ying Yi,Shu-Bin Fang,Guan-Xia Xiong,Xian-Ren Wang,Hui-Ting Chen,Wan-Yi Huang,Li-Xuan Feng 대한이비인후과학회 2023 Clinical and Experimental Otorhinolaryngology Vol.16 No.1

Objectives. Reactive oxygen species in the stria vascularis (SV) of the cochlea may be involved in the pathogenesis of sen-sorineural hearing loss. However, the effects of oxidative stress on SV endothelial cells (SV-ECs) remain largely un-known, and no feasible in vitro cell culture model exists for the functional study of SV-ECs. Methods. We isolated primary SV-ECs from the SV of neonatal mice. The apoptosis-reducing effects of fibronectin in SV-ECs cultured with serum-free medium were determined using β-galactosidase staining and flow cytometry. SV-ECsincubated in serum-free medium were treated with various H2O2 concentrations to evaluate the effects of H2O2 ontheir viability. The secretome of SV-ECs treated with or without H2O2 (100 μM or 500 μM) was analyzed using high-resolution mass spectrometry. The function of the SV-EC secretome was evaluated by a macrophage assay. Results. We successfully isolated and characterized the SV-ECs. Treatment with H2O2 at concentrations up to 500 μM for2 hours and further incubation with serum-free medium in plates precoated with fibronectin showed no significanteffect on apoptosis. Compared to the control SV-ECs, the amount of differential proteins in the secretome of SV-ECsstimulated with 500 μM H2O2 was much higher than in those treated with 100 μM H2O2. Kyoto Encyclopedia ofGenes and Genomes and Gene Ontology analyses suggested that the proteins differentially expressed in SV-ECstreated with 500 μM H2O2 were involved in the regulation of multiple signaling pathways and cellular processes. Thesecretome of H2O2-stimulated SV-ECs exhibited significant pro-inflammatory effects on macrophages. Conclusion. We successfully established an in vitro serum-free culture method, identified the differential proteins releasedby oxidative stress-induced ECs and their functions, and revealed the pro-inflammatory effects of the secretome ofH2O2-stimulated SV-ECs. Therefore, SV-ECs might elicit immunoregulatory effects on bystander cells in the microen-vironment of oxidative stress-induced cochlea, especially cochlear macrophages.

<i>Yersinia pseudotuberculosis</i> Exploits CD209 Receptors for Promoting Host Dissemination and Infection

He, Ying-Xia,Ye, Cheng-Lin,Zhang, Pei,Li, Qiao,Park, Chae Gyu,Yang, Kun,Jiang, Ling-Yu,Lv, Yin,Ying, Xiao-Ling,Ding, Hong-Hui,Huang, Hong-Ping,Mambwe Tembo, John,Li, An-Yi,Cheng, Bing,Zhang, Shu-Sheng American Society for Microbiology 2019 Infection and immunity Vol.87 No.1

<P><I>Yersinia pseudotuberculosis</I> is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals.</P><P><I>Yersinia pseudotuberculosis</I> is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals. Although the molecular mechanisms for dissemination and infection are unclear, many Gram-negative enteropathogens presumably invade the small intestine via Peyer’s patches to initiate dissemination. In this study, we demonstrate that <I>Y. pseudotuberculosis</I> utilizes its lipopolysaccharide (LPS) core to interact with CD209 receptors, leading to invasion of human dendritic cells (DCs) and murine macrophages. These <I>Y. pseudotuberculosis</I>-CD209 interactions result in bacterial dissemination to MLNs, spleens, and livers of both wild-type and Peyer’s patch-deficient mice. The blocking of the <I>Y. pseudotuberculosis</I>-CD209 interactions by expression of O-antigen and with oligosaccharides reduces infectivity. Based on the well-documented studies in which HIV-CD209 interaction leads to viral dissemination, we therefore propose an infection route for <I>Y. pseudotuberculosis</I> where this pathogen, after penetrating the intestinal mucosal membrane, hijacks the <I>Y. pseudotuberculosis</I>-CD209 interaction antigen-presenting cells to reach their target destinations, MLNs, spleens, and livers.</P>

Insights into the Nutritional Physiology of Nickel

Chang Bai,Shu-Xia Yi,Charles C. Reilly,Bruce W. Wood 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

EBV-miR-BHRF1-1 Targets p53 Gene: Potential Role in Epstein-Barr Virus Associated Chronic Lymphocytic Leukemia

Dan-Min Xu,Yi-Lin Kong,Li Wang,Hua-Yuan Zhu,Jia-Zhu Wu,Yi Xia,Yue Li,Shu-Chao Qin,Lei Fan,Jian-Yong Li,Jin-Hua Liang,Wei Xu 대한암학회 2020 Cancer Research and Treatment Vol.52 No.2

Purpose The purpose of this study was to investigate the prognostic impact of Epstein-Barr virus (EBV)–microRNA (miRNA, miR)-BHRF1-1 with chronic lymphocytic leukemia (CLL) as well as role of EBV-miR-BHRF1-1 in p53 gene. Materials and Methods Quantitative reverse transcription–polymerase chain reaction and western blotting were used to quantify EBV-miR-BHRF1-1 and p53 expression in cultured CLL. Results p53 aberration was associated with the higher expression level of EBV-miR-BHRF1-1 (p < 0.001) which was also an independent prognostic marker for overall survival (p=0.028; hazard ratio, 5.335; 95% confidence interval, 1.193 to 23.846) in 97 newly-diagnosed CLL patients after adjusted with International Prognostic Index for patients with CLL. We identified EBV-miR-BHRF1-1 as a viral miRNA regulator of p53. EBV-miR-BHRF1-1 repressed luciferase reporter activity by specific interaction with the seed region within the p53 3- untranslated region. Discordance of p53 messenger RNA and protein expression was associated with high EBV-miR-BHRF1-1 levels in CLL patients and cell lines. EBV-miR-BHRF1- 1 inhibition upregulated p53 protein expression, induced cell cycle arrest and apoptosis and decreased cell proliferation in cell lines. EBV-miR-BHRF1-1 mimics downregulated p53 protein expression, decreased cell cycle arrest and apoptosis, and induced cell proliferation in cell lines. Conclusion This study supported the role of EBV-miR-BHRF1-1 in p53 regulation in vitro. Our results support the potential of EBV-miR-BHRF1-1 as a therapeutic target in EBV-associated CLL with p53 gene aberration.

Appropriate nitrogen application enhances saponin synthesis and growth mediated by optimizing root nutrient uptake ability

Wei, Wei,Ye, Chen,Huang, Hui-Chuan,Yang, Min,Mei, Xin-Yue,Du, Fei,He, Xia-Hong,Zhu, Shu-Sheng,Liu, Yi-Xiang The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.4

Background: Cultivation of medicinal crops, which synthesize hundreds of substances for curative functions, was focused on the synthesis of secondary metabolites rather than biomass accumulation. Nutrition is an important restrict factor for plant growth and secondary metabolites, but little attention has been given to the plasticity of nutrient uptake and secondary metabolites synthesis response to soil nitrogen (N) change. Methods: Two year-field experiments of Sanqi (Panax notoginseng), which can synthesize a high level of saponin in cells, were conducted to study the effects of N application on the temporal dynamics of biomass, nutrient absorption, root architecture and the relationships between these parameters and saponin synthesis. Results: Increasing N fertilizer rates could improve the dry matter yields and nutrient absorption ability through increasing the maximum daily growth (or nutrient uptake) rate. Under suitable N level (225 kg/ha N), Sanqi restricted the root length and surface and enhanced the root diameter and N uptake rate per root length (NURI) to promote nutrient absorption, but the opposite status of Sanqi root architecture and NURI was found when soil N was deficient. Furthermore, increasing N rates could promote the accumulation of saponin in roots through improving the NURI, which showed a significant positive relationship with the content of saponin in the taproots. Conclusion: Appropriate N fertilizer rates could optimize both root architecture and nutrient uptake efficiency, then promote both the accumulation of dry matter and the synthesis of saponins.