91 research outputs found
Use of signal sequences as an in situ removable sequence element to stimulate protein synthesis in cell-free extracts
This study developed a method to boost the expression of recombinant proteins in a cell-free protein synthesis system without leaving additional amino acid residues. It was found that the nucleotide sequences of the signal peptides serve as an efficient downstream box to stimulate protein synthesis when they were fused upstream of the target genes. The extent of stimulation was critically affected by the identity of the second codons of the signal sequences. Moreover, the yield of the synthesized protein was enhanced by as much as 10 times in the presence of an optimal second codon. The signal peptides were in situ cleaved and the target proteins were produced in their native sizes by carrying out the cell-free synthesis reactions in the presence of Triton X-100, most likely through the activation of signal peptidase in the S30 extract. The amplification of the template DNA and the addition of the signal sequences were accomplished by PCR. Hence, elevated levels of recombinant proteins were generated within several hours
Differential Association of Uncoupling Protein 2 Polymorphisms with Pattern Identification among Korean Stroke Patients: A Diagnostic System in Traditional Korean Medicine
Uncoupling protein 2 (UCP2), a mitochondrial protein present in many organs and cell types, is known to dissipate the proton gradient formed by the electron transport chain. Its function is correlated with predictive parameters, such as obesity, diabetes, and metabolic syndromes. We analyzed the distribution of UCP2 polymorphisms in stroke patients diagnosed with one of the following four stroke subtypes based on the TKM standard pattern identification (PI): Qi-deficiency (QD), Dampness and Phlegm (D&P), Yin-deficiency (YD), and Fire and Heat (F&D). We studied a total of 1,786 stroke patients (397/QD, 645/D&P, 223/YD, and 522/F&D, 586/normal). Genotyping for the G-1957A, G-866A and A55V UCP2 polymorphisms was performed using the TaqMan. G-866A and A55V were significantly associated with the D&P and H&F subtypes. The frequency of subjects with the A allele of G-866A was significantly lower than the frequency of subjects with the GG type. The A55V polymorphism was also shown similar effect with G-866A in the dominant model. In contrast, no SNPs were shown to be associated with the QD or YD subtypes in this study. These results showed that the G-866A and A55V UCP2 polymorphisms may be genetic factors for specific PI types among Korean stroke patients
Skin care benefits of bioactive compounds isolated from Zanthoxylum piperitum DC. (Rutaceae)
Purpose: To investigate skin care efficacies of Zanthoxylum pipetitum extract and isolated compounds.
Methods: Ethanol extracts of leaves, branches and fruits of what were partitioned into n-hexane, chloroform, ethyl acetate, n-butanol and aqueous layers and some fractions were further analyzed to isolate five compounds. The isolated compounds were identified based on the proton and carbon nuclear magnetic resonance (NMR) spectra. Cosmetic efficacy tests of the extracts and isolated compounds were evaluated by in vitro tests.
Results: Phytochemical studies of the chloroform and ethyl acetate layers led to the isolation of five compounds; quercitrin (1), afzelin (2), hydroxy-α-sanshool (3), α-sanshool (4) and hyperoside (5). In activity tests, the extracts showed inhibitory activity against inflammation response and melanin synthesis, and induction of procollagen type I C-peptide (PIP). Among the isolated compounds, hydroxy-α-sanshool (3) and α-sanshool (4) displayed significant anti-inflammatory activity.
Conclusion: The results demonstrate that Z. piperitum extract and its active compounds possess a significant potential as a cosmeeutical agent for enhancing skin quality
Human embryonic stem cells express a unique set of microRNAs.
Abstract Human embryonic stem (hES) cells are pluripotent cell lines established from the explanted inner cell mass of human blastocysts. Despite their importance for human embryology and regenerative medicine, studies on hES cells, unlike those on mouse ES (mES) cells, have been hampered by difficulties in culture and by scant knowledge concerning the regulatory mechanism. Recent evidence from plants and animals indicates small RNAs of approximately 22 nucleotides (nt), collectively named microRNAs, play important roles in developmental regulation. Here we describe 36 miRNAs (from 32 stem-loops) identified by cDNA cloning in hES cells. Importantly, most of the newly cloned miRNAs are specifically expressed in hES cells and downregulated during development into embryoid bodies (EBs), while miRNAs previously reported from other human cell types are poorly expressed in hES cells. We further show that some of the ES-specific miRNA genes are highly related to each other, organized as clusters, and transcribed as polycistronic primary transcripts. These miRNA gene families have murine homologues that have similar genomic organizations and expression patterns, suggesting that they may operate key regulatory networks conserved in mammalian pluripotent stem cells. The newly identified hES-specific miRNAs may also serve as molecular markers for the early embryonic stage and for undifferentiated hES cells
Release of SOS2 kinase from sequestration with GIGANTEA determines salt tolerance in Arabidopsis
Kim, Woe-Yeon et al.--Environmental challenges to plants typically entail retardation of vegetative growth
and delay or cessation of flowering. Here we report a link between the flowering time
regulator, GIGANTEA (GI), and adaptation to salt stress that is mechanistically based
on GI degradation under saline conditions, thus retarding flowering. GI, a switch in
photoperiodicity and circadian clock control, and the SNF1-related protein kinase SOS2
functionally interact. In the absence of stress, the GI:SOS2 complex prevents SOS2-
based activation of SOS1, the major plant Na+/H+-antiporter mediating adaptation to
salinity. GI over-expressing, rapidly flowering, plants show enhanced salt sensitivity,
whereas gi mutants exhibit enhanced salt tolerance and delayed flowering. Salt-induced
degradation of GI confers salt tolerance by the release of the SOS2 kinase. The GISOS2
interaction introduces a higher order regulatory circuit that can explain in
molecular terms, the long observed connection between floral transition and adaptive
environmental stress tolerance in Arabidopsis.This research was supported by the Next-Generation
BioGreen 21 Program (Systems and Synthetic Agrobiotech Center, no. PJ008025), a Cooperative Research Program for Agriculture Science & Technology Development
(Project No. PJ007850), and the Ministry of Education, Science and Technology for the
World Class University (WCU) program (R32-10148) from the Rural Development
Administration, Republic of Korea, and by grant BIO2009-08641 financed by the
Spanish Ministry of Science and Innovation and the FEDER program.Peer reviewe
Three cases of glycogenic hepatopathy mimicking acute and relapsing hepatitis in type I diabetes mellitus
Glycogenic hepatopathy (GH) is an uncommon cause of serum transaminase elevation in type I diabetes mellitus (DM). The clinical signs and symptoms of GH are nonspecific, and include abdominal discomfort, mild hepatomegaly, and transaminase elevation. In this report we describe three cases of patients presenting serum transaminase elevation and hepatomegaly with a history of poorly controlled type I DM. All of the cases showed sudden elevation of transaminase to more than 30 times the upper normal range (like in acute hepatitis) followed by sustained fluctuation (like in relapsing hepatitis). However, the patients did not show any symptom or sign of acute hepatitis. We therefore performed a liver biopsy to confirm the cause of liver enzyme elevation, which revealed GH. Clinicians should be aware of GH so as to prevent diagnostic delay and misdiagnosis, and have sufficient insight into GH; this will be aided by the present report of three cases along with a literature review
A Case of Hepatocellular Carcinoma with Pulmonary Metastases Treated Successfully with a Combination of Repeated Hepatic Arterial Infusion Epirubicin and Cisplatin Chemotherapy and Systemic Low-Dose Infusion of 5-Fluorouracil
We report a case of hepatocellular carcinoma (HCC) with pulmonary metastases treated with repeated hepatic arterial infusion chemotherapy (HAIC) comprising epirubicin and cisplatin, and systemic infusion of 5-fluorouracil (a modified EC/F protocol), which led to complete remission. A 49-year-old man with compensated liver cirrhosis experienced intrahepatic recurrence of HCC with extensive lung metastases. The modified EC/F therapeutic protocol, which was applied at the tenth cycle every 4-5 weeks, resulted in disappearance of the pulmonary metastases and normalization of serum α-fetoprotein levels. A single small HCC lesion was found in the left lobe of the liver 13 months after the final chemotherapy session. HAIC with the same regimen was conducted again, followed by percutaneous intratumoral chemoinjection therapy with 5-fluorouracil and interferon-γ. Thereafter, there was no evidence of recurrence in either the liver or the lung, as evidenced by image analysis and expression of tumor markers. The disease-free intervals for the liver and lung were 41 and 54 months, respectively
Apolipophorin-III Mediates Antiplasmodial Epithelial Responses in Anopheles gambiae (G3) Mosquitoes
Apolipophorin-III (ApoLp-III) is known to play an important role in lipid transport and innate immunity in lepidopteran insects. However, there is no evidence of involvement of ApoLp-IIIs in the immune responses of dipteran insects such as Drosophila and mosquitoes.We report the molecular and functional characterization of An. gambiae apolipophorin-III (AgApoLp-III). Mosquito ApoLp-IIIs have diverged extensively from those of lepidopteran insects; however, the predicted tertiary structure of AgApoLp-III is similar to that of Manduca sexta (tobacco hornworm). We found that AgApoLp-III mRNA expression is strongly induced in the midgut of An. gambiae (G3 strain) mosquitoes in response to Plasmodium berghei infection. Furthermore, immunofluorescence stainings revealed that high levels of AgApoLp-III protein accumulate in the cytoplasm of Plasmodium-invaded cells and AgApoLp-III silencing increases the intensity of P. berghei infection by five fold.There are broad differences in the midgut epithelial responses to Plasmodium invasion between An. gambiae strains. In the G3 strain of An. gambiae AgApoLp-III participates in midgut epithelial defense responses that limit Plasmodium infection
Single nucleotide polymorphisms in bone turnover-related genes in Koreans: ethnic differences in linkage disequilibrium and haplotype
<p>Abstract</p> <p>Background</p> <p>Osteoporosis is defined as the loss of bone mineral density that leads to bone fragility with aging. Population-based case-control studies have identified polymorphisms in many candidate genes that have been associated with bone mass maintenance or osteoporotic fracture. To investigate single nucleotide polymorphisms (SNPs) that are associated with osteoporosis, we examined the genetic variation among Koreans by analyzing 81 genes according to their function in bone formation and resorption during bone remodeling.</p> <p>Methods</p> <p>We resequenced all the exons, splice junctions and promoter regions of candidate osteoporosis genes using 24 unrelated Korean individuals. Using the common SNPs from our study and the HapMap database, a statistical analysis of deviation in heterozygosity depicted.</p> <p>Results</p> <p>We identified 942 variants, including 888 SNPs, 43 insertion/deletion polymorphisms, and 11 microsatellite markers. Of the SNPs, 557 (63%) had been previously identified and 331 (37%) were newly discovered in the Korean population. When compared SNPs in the Korean population with those in HapMap database, 1% (or less) of SNPs in the Japanese and Chinese subpopulations and 20% of those in Caucasian and African subpopulations were significantly differentiated from the Hardy-Weinberg expectations. In addition, an analysis of the genetic diversity showed that there were no significant differences among Korean, Han Chinese and Japanese populations, but African and Caucasian populations were significantly differentiated in selected genes. Nevertheless, in the detailed analysis of genetic properties, the LD and Haplotype block patterns among the five sub-populations were substantially different from one another.</p> <p>Conclusion</p> <p>Through the resequencing of 81 osteoporosis candidate genes, 118 unknown SNPs with a minor allele frequency (MAF) > 0.05 were discovered in the Korean population. In addition, using the common SNPs between our study and HapMap, an analysis of genetic diversity and deviation in heterozygosity was performed and the polymorphisms of the above genes among the five populations were substantially differentiated from one another. Further studies of osteoporosis could utilize the polymorphisms identified in our data since they may have important implications for the selection of highly informative SNPs for future association studies.</p
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