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1.
Front Neurol ; 15: 1442613, 2024.
Article in English | MEDLINE | ID: mdl-39022737

ABSTRACT

In recent years, substantial advancements have been made in understanding the pathophysiology of ischemic stroke. Despite these developments, therapeutic options for cerebral ischemia remain limited due to stringent time windows and various contraindications. Consequently, there has been a concentrated effort to elucidate the underlying mechanisms of cerebral ischemic injury. Emerging research indicates that neutrophil extracellular traps (NETs) exacerbate inflammation and damage in ischemic brain tissue, contributing to neuronal cell death. The inhibition of NETs has shown potential in preventing thrombosis and the infiltration of immune cells. Central to the formation of NETs are P-selectin and its ligand, P-selectin glycoprotein ligand-1 (PSGL-1), which represent promising therapeutic targets. This review explores the detrimental impact of P-selectin, PSGL-1, and NETs on cerebral ischemia. Additionally, it delineates the processes by which P-selectin and PSGL-1 stimulate NETs production and provides evidence that blocking these molecules reduces NETs formation. This novel insight highlights a potential therapeutic avenue that warrants further investigation by researchers in the field.

2.
Behav Neurol ; 2023: 8537296, 2023.
Article in English | MEDLINE | ID: mdl-38058356

ABSTRACT

MicroRNAs (miRNAs) are the smallest class of noncoding RNAs, which widely exist in animals and plants. They can inhibit translation or overexpression by combining with mRNA and participate in posttranscriptional regulation of genes, resulting in reduced expression of target proteins, affecting the development, growth, aging, metabolism, and other physiological and pathological processes of animals and plants. It is a powerful negative regulator of gene expression. It mediates the information exchange between different cellular pathways in cellular homeostasis and stress response and regulates the differentiation, plasticity, and neurotransmission of neurons. In neurodegenerative diseases, in addition to the complex interactions between genetic susceptibility and environmental factors, miRNAs can serve as a promising diagnostic tool for diseases. They can also increase or reduce neuronal damage by regulating the body's signaling pathways, immune system, stem cells, gut microbiota, etc. They can not only affect the occurrence of diseases and exacerbate disease progression but also promote neuronal repair and reduce apoptosis, to prevent and slow down the development of diseases. This article reviews the research progress of miRNAs on the mechanism and treatment of neurodegenerative diseases in the nervous system. This trial is registered with NCT01819545, NCT02129452, NCT04120493, NCT04840823, NCT02253732, NCT02045056, NCT03388242, NCT01992029, NCT04961450, NCT03088839, NCT04137926, NCT02283073, NCT04509271, NCT02859428, and NCT05243017.


Subject(s)
MicroRNAs , Neurodegenerative Diseases , Animals , MicroRNAs/genetics , MicroRNAs/metabolism , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/therapy , RNA, Messenger , Signal Transduction , Clinical Trials as Topic , Humans
3.
Front Genet ; 14: 1163464, 2023.
Article in English | MEDLINE | ID: mdl-37359383

ABSTRACT

Sheath rot disease (SRD) is one of the most devastating diseases of Manchurian wild rice (MWR) (Zizania latifolia Griseb). Pilot experiments in our laboratory have shown that an MWR cultivar "Zhejiao NO.7"exhibits signs of SRD tolerance. To explore the responses of Zhejiao No. 7 to SRD infection, we used a combined transcriptome and metabolome analysis approach. A total of 136 differentially accumulated metabolites (DAMs, 114 up- and 22 down-accumulated in FA compared to CK) were detected. These up-accumulated metabolites were enriched in tryptophan metabolism, amino acid biosynthesis, flavonoids, and phytohormone signaling. Transcriptome sequencing results showed the differential expression of 11,280 genes (DEGs, 5,933 up-, and 5,347 downregulated in FA compared to CK). The genes expressed in tryptophan metabolism, amino acid biosynthesis, phytohormone biosynthesis and signaling, and reactive oxygen species homeostasis confirmed the metabolite results. In addition, genes related to the cell wall, carbohydrate metabolism, and plant-pathogen interaction (especially hypersensitive response) showed changes in expression in response to SRD infection. These results provide a basis for understanding the response mechanisms in MWR to FA attack that can be used for breeding SRD-tolerant MWR.

4.
Biomedicines ; 11(2)2023 Jan 26.
Article in English | MEDLINE | ID: mdl-36830903

ABSTRACT

Glycogen storage disease type IV (GSD IV) is an ultra-rare autosomal recessive disease caused by variants in the GBE1 gene, which encodes the glycogen branching enzyme (GBE). GSD IV accounts for approximately 3% of all GSD. The phenotype of GSD IV ranges from neonatal death to mild adult-onset disease with variable hepatic, muscular, neurologic, dermatologic, and cardiac involvement. There is a paucity of literature and clinical and dietary management in GSD IV, and liver transplantation (LT) is described to correct the primary hepatic enzyme defect. Objectives: We herein describe five cases of patients with GSD IV with different ages of onset and outcomes as well as a novel GBE1 variant. Methods: This is a descriptive case series of patients receiving care for GSD IV at Reference Centers for Rare Diseases in Brazil and in the United States of America. Patients were selected based on confirmatory GBE1 genotypes performed after strong clinical suspicion. Results: Pt #1 is a Latin male with the chief complaints of hepatosplenomegaly, failure to thrive, and elevated liver enzymes starting at the age of 5 months. Before LT at the age of two, empirical treatment with corn starch (CS) and high protein therapy was performed with subjective improvement in his overall disposition and liver size. Pt #2 is a 30-month-old Afro-American descent patient with the chief complaints of failure to gain adequate weight, hypotonia, and hepatosplenomegaly at the age of 15 months. Treatment with CS was initiated without overall improvement of the symptoms. Pt #3.1 is a female Latin patient, sister to pt #3.2, with onset of symptoms at the age of 3 months with bloody diarrhea, abdominal distention, and splenomegaly. There was no attempt of treatment with CS. Pt #4 is an 8-year-old male patient of European descent who had his initial evaluation at 12 months, which was remarkable for hepatosplenomegaly, elevated ALT and AST levels, and a moderate dilatation of the left ventricle with normal systolic function that improved after LT. Pt #1, #3.2 and #4 presented with high levels of chitotriosidase. Pt #2 was found to have the novel variant c.826G > C p.(Ala276Pro). Conclusions: GSD IV is a rare disease with different ages of presentation and different cardiac phenotypes, which is associated with high levels of chitotriosidase. Attempts of dietary intervention with CS did not show a clear improvement in our case series.

5.
J Phys Chem B ; 126(46): 9705-9714, 2022 11 24.
Article in English | MEDLINE | ID: mdl-36356196

ABSTRACT

A new subtype of nano-impacts by emulsion droplets via reorganization of the electric double layer (EDL) at the liquid/liquid interface (LLI) is reported. This subtype shows anodic, bipolar, and cathodic transient currents with a potential of zero charge (PZC) dependence, revealing the non-faradic characteristic of single fusion impacts. In addition, the absolute integrated mean charge is proportional to the Galvani potential at the ITIES, indicating that the EDL at the LLI may obey the discrete Helmholtz model. The exact PZC point is interpolated from the fitting curve, and the droplet size distribution is estimated from the integrated charge distribution. Moreover, the different values of Epzc between single fusion impacts of MgCl2 droplets and pure water droplets is due to the specific absorption between Mg2+ and antagonistic anion in the organic phase. The influence of the concentration of the supporting electrolyte is also investigated. The above work gives physicochemical insights into the EDL at the micropipette-supported LLI and provides potential application to measure micro/nanoscale heterogeneous media without catalytic, reactive, or charge-transfer activity via impact experiments at LLI.


Subject(s)
Electrolytes , Water , Electrodes , Emulsions , Anions
6.
Anal Chem ; 94(3): 1850-1858, 2022 01 25.
Article in English | MEDLINE | ID: mdl-35023726

ABSTRACT

A strategy for the fast analysis of ion transfer/facilitated ion transfer toward a tiny (femtoliter) water-in-oil droplet has been established. This scenario is embodied by the fusion of a w/o microdroplet at the micro liquid/liquid (L/L) interface, with the use of Fourier transform fast-scan cyclic voltammetry (FT-FSCV) to express the apparent half-wave potentials of anions or cations encapsulated inside the w/o microdroplet. First, the half-wave potential is in strict accordance with the transfer Gibbs free energy of either cations or anions. Second, the half-wave potential has been found to be positively proportional to the logarithmic concentration of ions, shedding thermodynamic insight into ion transfer. Third, as an instance of multivalent biopolymers, the transfer of protamine inside the single w/o microdroplet has been investigated. Obvious discrepancies in the behaviors of the fusion impacts at different pH, as well as in the absence and presence of the cationic surfactant DNNS-, are revealed. The internal mechanism of protamine transfer has been thoroughly investigated. This work proposes a strategy to sensitively and quickly determine the transfer Gibbs energy and the concentration of ions encapsulated in a single microdroplet, and it provides the possibility of analyzing the interfacial transfer properties of trace biomacromolecules inside an aqueous micro- or nanoscale droplet.


Subject(s)
Surface-Active Agents , Water , Anions/chemistry , Electrochemistry , Ions/chemistry , Water/chemistry
7.
Ecotoxicol Environ Saf ; 230: 113129, 2022 Jan 15.
Article in English | MEDLINE | ID: mdl-34979310

ABSTRACT

The large-scale commercial cultivation of genetically modified (GM) cotton has brought significant economic and environmental benefits. However, GM crops must undergo strict environmental monitoring and long-term observation. An important natural enemy insect in cotton fields, Geocoris pallidipennis, can ingest the Bt protein expressed in GM cotton by feeding on herbivorous insects that feed on the cotton. However, the potential risk of GM cotton to G. pallidipennis is still unclear. We here evaluated the effects of Bt cotton expressing the Cry1Ac/1Ab protein on nymphs and adults G. pallidipennis. Cry1Ac protein was detected in the midgut of the cotton bollworm, Helicoverpa armigera, after it ingested Bt cotton, and in the midgut of G. pallidipennis nymphs and adults preying on Bt-fed H. armigera. However, the survival rate, growth, development, and fecundity of G. pallidipennis were not adversely affected. Furthermore, G. pallidipennis cadherins, and those genes related to detoxification, antioxidant activity, nutrient utilization, and immune function were not differentially expressed in response to Cry1Ac exposure. Finally, we showed that Cry1Ac could not bind to brush border membrane vesicles (BBMV) proteins in G. pallidipennis nymphs or adults. In summary, these results indicate that the potential negative effect of transgenic Cry1Ac/1Ab cotton on the insect redator G. pallidipennis is negligible.

8.
World J Stem Cells ; 13(9): 1278-1292, 2021 Sep 26.
Article in English | MEDLINE | ID: mdl-34630862

ABSTRACT

Brain diseases, including brain tumors, neurodegenerative disorders, cerebrovascular diseases, and traumatic brain injuries, are among the major disorders influencing human health, currently with no effective therapy. Due to the low regeneration capacity of neurons, insufficient secretion of neurotrophic factors, and the aggravation of ischemia and hypoxia after nerve injury, irreversible loss of functional neurons and nerve tissue damage occurs. This damage is difficult to repair and regenerate the central nervous system after injury. Neural stem cells (NSCs) are pluripotent stem cells that only exist in the central nervous system. They have good self-renewal potential and ability to differentiate into neurons, astrocytes, and oligodendrocytes and improve the cellular microenvironment. NSC transplantation approaches have been made for various neurodegenerative disorders based on their regenerative potential. This review summarizes and discusses the characteristics of NSCs, and the advantages and effects of NSCs in the treatment of brain diseases and limitations of NSC transplantation that need to be addressed for the treatment of brain diseases in the future.

9.
Plants (Basel) ; 10(9)2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34579377

ABSTRACT

Zizania latifolia is a perennial plant native to East Asia. The swollen culm of Z. latifolia is a popular vegetable and traditional herbal medicine consumed in China and some other Asian countries. From 2019 to 2021, a sheath rot disease was found in Zhejiang Province of China. Symptoms mainly occurred in the leaf sheath showing as brown necrotic lesions surrounded by yellow halos. The pathogen fungal isolates were isolated from the affected sheaths. Ten representative isolates were selected for morphological and molecular identification by phylogenetic analyses of the translation elongation factor 1-α (TEF1) and the RNA polymerase II subunit beta (RPB2) gene regions. Based on the combined datasets, the fungal isolates were identified as Fusarium andiyazi. Koch's postulates were confirmed by pathogenicity test, re-isolation and re-identification of the fungal isolates. To the best of our knowledge, this is the first report of sheath rot caused by F. andiyazi in Z. latifolia in China.

10.
Transfusion ; 60(7): 1536-1543, 2020 07.
Article in English | MEDLINE | ID: mdl-32588918

ABSTRACT

BACKGROUND: The PLASMIC score is a rapid and inexpensive tool for predicting severe ADAMTS13 deficiency (activity <10%) in patients with suspected thrombotic thrombocytopenic purpura (TTP) by analyzing seven parameters (platelet count; combined hemolysis variable; absence of active neoplasia; absence of an organ or stem-cell transplant; mean corpuscular value; international normalized ratio; and serum creatinine). The purpose of this study was to validate the PLASMIC score at a large multi-institutional academic medical center. METHODS: An internal database of consultations to the transfusion medicine service, which oversees therapeutic apheresis at our institution, was reviewed to identify patients who were evaluated for and/or received plasma exchange for suspected TTP. These consultations covered the time period of January 2012 to February 2019. PLASMIC scoring criteria and ADAMTS13 assay results were abstracted from the electronic medical record, the PLASMIC score was calculated, and cases stratified into risk categories (low, intermediate, high risk) based on the score value. RESULTS: Of 58 patients identified, 46 met inclusion criteria, and 27 demonstrated ADAMTS13 activity <10%. Correlation of severe ADAMTS13 deficiency with risk-stratified groups resulted in 78% sensitivity, 63% specificity, 75% positive predictive value (PPV), and 67% negative predictive value (NPV). DISCUSSION: These findings paralleled those from validation studies performed at other institutions. They provided insufficient evidence to recommend routine use of the PLASMIC score to rule out TTP among patients at our hospitals. Nonetheless, these results reinforce the importance of early ADAMTS13 testing as a diagnostic triage tool for patients with suspected TTP.


Subject(s)
ADAMTS13 Protein/blood , Academic Medical Centers , Databases, Factual , Electronic Health Records , Plasma Exchange , Purpura, Thrombotic Thrombocytopenic , Adult , Female , Humans , Male , Middle Aged , Platelet Count , Purpura, Thrombotic Thrombocytopenic/blood , Purpura, Thrombotic Thrombocytopenic/therapy , Retrospective Studies
11.
Front Cell Dev Biol ; 8: 18, 2020.
Article in English | MEDLINE | ID: mdl-32154244

ABSTRACT

Obesity is characterized by low-grade chronic inflammation. As an acute-phase reactant to inflammation and infection, C-reactive protein (CRP) has been found to be the strongest factor associated with obesity. Here we show that chronic elevation of human CRP at baseline level causes the obesity. The obesity phenotype is confirmed by whole-body magnetic resonance imaging (MRI), in which the total fat mass is 6- to 9- fold higher in the CRP rats than the control rats. Univariate linear regression analysis showed different growth rates between the CRP rats and the control rats, and that the difference appears around 11 weeks old, indicating that they developed adult-onset obesity. We also found that chronic elevation of CRP can prime molecular changes broadly in the innate immune system, energy expenditure systems, thyroid hormones, apolipoproteins, and gut flora. Our data established a causal role of CRP elevation in the development of adult-onset obesity.

12.
J Chromatogr Sci ; 54(10): 1727-1734, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27729338

ABSTRACT

Poly(N-isopropylacrylamide-co-hexanediol diacrylate-co-ethylene dimethacrylate) [poly(NIPAAm-co-HDDA-co-EDMA)] monolithic column was prepared via in situ polymerization reaction. In order to investigate the porous properties of the monoliths prepared, the morphology was characterized by the scanning electron microscopy; the chemical group of the monolithic column was confirmed by a Fourier transform infrared spectroscopy method. The surface area was 39.1 m2/g by the nitrogen adsorption-desorption experiment. With methanol as the mobile phase, the permeability of the monolithic column was calculated as 3.2330 × 10-14 m2 Then it was used as the stationary phase of high performance liquid chromatography. The results indicted that poly(NIPAAm-co-HDDA-co-EDMA) monolithic column was good to separate small molecules by controlling the temperature. Column efficiency for p-chloronitrobenzene was 4,680 plates/m. Repeatability was defined by determining run-to-run and column-to-column variation of the retention times of aromatic compounds, expressed as relative standard deviation (RSD = standard deviation/mean × 100%), and the values were <0.58% and 3.1%, respectively.

13.
Am J Clin Pathol ; 146(4): 496-502, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27686176

ABSTRACT

OBJECTIVES: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer, and there is no approved targeted therapy. We studied the expression of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) in TNBC. METHODS: Full-face sections from 136 TNBC cases without neoadjuvant therapy between 2004 and 2013 were stained and evaluated for immune cell PD-1 staining and stromal or tumoral PD-L1 staining using the H-score (staining percentage × intensity). Nottingham histologic grade, lymphovascular invasion (LVI), mitotic count, and tumor-infiltrating lymphocytes (TILs) were evaluated. Tumor size, lymph node status, Ki-67 score, metastasis, overall survival (OS), and disease-free survival (DFS) were retrieved from medical records. RESULTS: Of the 136 TNBC cases, 69 (51%) had any PD-L1 staining and 35 (26%) had PD-L1 staining with an H-score of 5 or more; 117 (86%) had any PD-1 staining and 68 (50%) had PD-1 staining with an H-score of 5 or more. Tumor size and LVI were significantly associated with worse OS and DFS, and TILs and LVI were significantly associated with metastasis in univariate analysis. Stromal PD-L1 expression was significantly associated with better DFS in multivariate analysis. PD-1 expression was not associated with DFS, OS, or metastasis. CONCLUSIONS: PD-L1 expression is seen in a high proportion of TNBCs and associated with better DFS.


Subject(s)
B7-H1 Antigen/metabolism , Lymphatic Metastasis/pathology , Programmed Cell Death 1 Receptor/metabolism , Stromal Cells/metabolism , Triple Negative Breast Neoplasms/metabolism , Disease-Free Survival , Female , Humans , Neoplasm Grading , Prognosis , Stromal Cells/pathology , Survival Rate , Triple Negative Breast Neoplasms/mortality , Triple Negative Breast Neoplasms/pathology
14.
J Sep Sci ; 38(12): 2101-8, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25864707

ABSTRACT

An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography.

15.
Sci Rep ; 5: 8292, 2015 Feb 06.
Article in English | MEDLINE | ID: mdl-25659774

ABSTRACT

Epigenetic heritability is an important issue in the field of genetics and also in the development of many human diseases. In this study, we created a transgenic rat model and investigated the transgenerational methylation patterns in these animals. The transgene DNA fragment was unmethylated before it was injected into the pronucleus, so it is a good model to study the inheritance of DNA methylation patterns. We performed bisulfite sequencing on 23 CpG dinucleotides on the transgene across three generations in two tissues. We observed that the transgene was heavily methylated in the liver (87.53%) from the founder generation, whereas its methylation rate was much lower in the kidney (70.47%). Spearman correlation analysis showed that there was a strong correlation on the methylation status between different generations in the same tissue, which was observed in both liver and kidney, and among all individuals in this pedigree. This study provided some evidence that DNA methylation patterns acquired in the founder animal can be passed to the offspring.


Subject(s)
DNA Methylation , Transgenes , Animals , CpG Islands , Epigenomics , Kidney/metabolism , Liver/metabolism , Rats , Rats, Transgenic
16.
Biochem Biophys Res Commun ; 453(1): 138-42, 2014 Oct 10.
Article in English | MEDLINE | ID: mdl-25264203

ABSTRACT

SecA is an essential multifunctional protein for the translocation of proteins across bacterial membranes. Though SecA is known to function in the membrane, the detailed mechanism for this process remains unclear. In this study we constructed a series of SecA N-terminal deletions and identified two specific domains crucial for initial SecA/membrane interactions. The first small helix, the linker and part of the second helix (Δ2-22) were found to be dispensable for SecA activity in complementing the growth of a SecA ts mutant. However, deletions of N-terminal aminoacyl residues 23-25 resulted in severe progressive retardation of growth. Moreover, a decrease of SecA activity caused by N-terminal deletions correlated to the loss of SecA membrane binding, formation of lipid-specific domains and channel activity. All together, the results indicate that the N-terminal aminoacyl residues 23-25 play a critical role for SecA binding to membranes and that the N-terminal limit of SecA for activity is at the 25th amino acid.


Subject(s)
Adenosine Triphosphatases/chemistry , Adenosine Triphosphatases/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/metabolism , Membrane Transport Proteins/chemistry , Membrane Transport Proteins/metabolism , Adenosine Triphosphatases/genetics , Amino Acid Sequence , Bacterial Proteins/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Escherichia coli Proteins/genetics , Genes, Bacterial , Genetic Complementation Test , Ion Channels/chemistry , Ion Channels/genetics , Ion Channels/metabolism , Lipid-Linked Proteins/chemistry , Lipid-Linked Proteins/genetics , Lipid-Linked Proteins/metabolism , Membrane Lipids/metabolism , Membrane Transport Proteins/genetics , Membranes/metabolism , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Protein Binding , Protein Stability , Protein Structure, Tertiary , Protein Transport , SEC Translocation Channels , SecA Proteins , Sequence Deletion
17.
Sci Rep ; 4: 5800, 2014 Jul 23.
Article in English | MEDLINE | ID: mdl-25052506

ABSTRACT

Population stratification is a growing concern in genetic-association studies. Averaged ancestry at the genome level (global ancestry) is insufficient for detecting the population substructures and correcting population stratifications in association studies. Local and phase stratification are needed for human genetic studies, but current technologies cannot be applied on the entire genome data due to various technical caveats. Here we developed a novel approach (aMAP, ancestry of Modern Admixed Populations) for inferring local phased ancestry. It took about 3 seconds on a desktop computer to finish a local ancestry analysis for each human genome with 1.4-million SNPs. This method also exhibits the scalability to larger datasets with respect to the number of SNPs, the number of samples, and the size of reference panels. It can detect the lack of the proxy of reference panels. The accuracy was 99.4%. The aMAP software has a capacity for analyzing 6-way admixed individuals. As the biomedical community continues to expand its efforts to increase the representation of diverse populations, and as the number of large whole-genome sequence datasets continues to grow rapidly, there is an increasing demand on rapid and accurate local ancestry analysis in genetics, pharmacogenomics, population genetics, and clinical diagnosis.


Subject(s)
Genealogy and Heraldry , Genetic Association Studies , Genetics, Population , Genome, Human , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA/methods , Algorithms , Chromosome Mapping , Computer Simulation , Genome-Wide Association Study , Humans , Software
18.
Biochem Biophys Res Commun ; 447(2): 250-4, 2014 May 02.
Article in English | MEDLINE | ID: mdl-24704204

ABSTRACT

SecA is an essential ATPase in bacterial Sec-dependent protein translocation pathway, and equilibrates between monomers and dimers in solution. The question of whether SecA functions as monomers or dimers in membranes during the protein translocation is controversial. We previously constructed a tail-to-head SecAA tandem dimer, and showed it is fully functional by complementation in vivo and protein translocation in vitro, indicating that SecA can function at least as a dimer in the membrane without dissociating into monomers. In this study, we further constructed genetically a tail-to-head SecAAA trimer, which is functional in complementing a temperature-sensitive secA mutant. The purified SecAAA trimer per protomer is fully active as SecAA tandem dimers in ATPase activity, in protein translocation in vitro and in ion channel activities in the oocytes. With these functional tail-to-head trimer SecAAA and tandem SecAA, we examined their surface topology in the presence of liposomes using AFM. As expected, the soluble SecAAA without lipids are larger than SecAA. However, the ring/pore structures of SecAAA trimers were, surprisingly, almost identical to the SecA 2-monomers and SecAA dimers, raising the intriguing possibility that the SecA may exist and function as hexamer ring-structures in membranes. Cross-linking with formaldehyde showed that SecA, SecAA and SecAAA could form larger oligomers, including the hexamers. The molecular modeling simulation shows that both tail-to-head and tail-to-tail hexamers in the membranes are possible.


Subject(s)
Adenosine Triphosphatases/chemistry , Bacterial Proteins/chemistry , Membrane Transport Proteins/chemistry , Protein Multimerization , Adenosine Triphosphatases/genetics , Animals , Bacterial Proteins/genetics , Cross-Linking Reagents/chemistry , Membrane Transport Proteins/genetics , Microscopy, Atomic Force , Oocytes , SEC Translocation Channels , SecA Proteins , Xenopus
19.
Transgenic Res ; 23(2): 341-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24338332

ABSTRACT

Gender-preferential gene expression is a widespread phenomenon in humans. It is important to study how gender differences influence the pathogenesis of various diseases and response to specific drugs. The aim of this study is to determine if the mouse albumin enhancer/promoter may serve as the promoter to introduce gender-preferential gene expression in transgenic animals. We created four independent transgenic rat lines in which the human C-reactive protein transgene was under the control of mouse albumin enhancer/promoter. Quantitative real time RT-PCR analysis showed that transgene expression in the liver of male rats was significantly higher than transgene expression in the female rats (P < 0.05).There was a 5.3-fold (male/female) difference in line-519, and a 12.2-fold (male/female) difference in line-488. Enzyme-linked immunosorbent assay showed that the serum of male transgenic rats had a 13- to 679-fold difference at the protein level on transgene production compared with female transgenic rats. The male-to-female difference in gene expression was 10- to 17-fold in the liver of transgenic rats. Orchiectomy dramatically reduced protein production from the transgene in the liver. Testosterone administration into female rats did not increase the transgene expression, but estrogen administration into the male rats reduced transgene expression. This study provides a valuable tool for investigating the pathological roles of genes that are expressed in a gender-preferential manner in human disease.


Subject(s)
Albumins/genetics , C-Reactive Protein/metabolism , Gene Expression Regulation/genetics , Promoter Regions, Genetic/genetics , Transgenes/genetics , Animals , Animals, Genetically Modified , Blotting, Western , C-Reactive Protein/genetics , DNA Primers/genetics , Enzyme-Linked Immunosorbent Assay , Estrogens/administration & dosage , Estrogens/pharmacology , Female , Humans , Injections, Subcutaneous , Liver/metabolism , Male , Mice , Orchiectomy , Ovariectomy , Rats , Real-Time Polymerase Chain Reaction , Sex Factors , Testosterone/administration & dosage , Testosterone/pharmacology
20.
PLoS One ; 8(3): e58094, 2013.
Article in English | MEDLINE | ID: mdl-23516433

ABSTRACT

BACKGROUND: C-reactive protein (CRP) is a marker of inflammation and a risk predictor of cardiovascular disease. Current CRP assays are focused on the quantification of the CRP levels as pentamers. However, CRP can be present as other multimeric forms. There will be a market need to measure the CRP multimeric structure in addition to the levels in human populations. To meet this need, we investigated whether the long-term archived samples could be used instead of freshly collected samples. METHODOLOGY/PRINCIPAL FINDINGS: The specimens of serum, plasma and tissues were collected from transgenic rats expressing the human CRP. These samples were stored at 4°C, -20°C and -80°C for different periods. Non-denaturing Western blot analysis was used to observe the influence of storage conditions to multimeric structures of human CRP. Our results showed that there was no difference on multimeric structures of human CRP between samples stored at 4°C, -20°C and -80°C, between samples stored at -80°C for twenty-four hours and three months, and between plasma and serum. CONCLUSIONS/SIGNIFICANCE: This study implicated that archived samples stored at these conditions in those large longitudinal studies could be used for investigating the multimeric structures of CRP. Our report may speed up these researches and save labors and budget by enabling them to use currently available archived samples rather than freshly collected samples.


Subject(s)
C-Reactive Protein/metabolism , Animals , Biomarkers/metabolism , C-Reactive Protein/chemistry , Cryopreservation , Humans , Protein Conformation , Protein Multimerization , Protein Stability , Rats , Rats, Transgenic , Temperature , Time Factors , Tissue Preservation
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