Vimentin modulates infectious porcine circovirus type 2 in PK-15 cells

Porcine circovirus type 2 (PCV2) is the pathogen that causes postweaning multisystemic wasting syndrome, which leads to significant economic losses for swine farms worldwide. However, the infection mechanism of PCV2 is not completely understood yet. Vimentin is a part of the cytoskeleton network and plays an important role in several virus infections. It is not clear whether vimentin has a role in PCV2 infection nor how it affects PCV2 infection. In this study, the function of vimentin in PK-15 cells infected with PCV2 has been elucidated. We found that vimentin had a restrictive effect on the replication of PCV2 in PK-15 cells. Overexpression of vimentin by transferred pCAGGS-vimentin and down-regulation by the respective scrambled small interfering RNA showed that vimentin restricted the replication and virion production of PCV2. A special interaction between vimentin and PCV2 Cap protein was observed using laser confocal microscopy and immunoprecipitation assay. Moreover, overexpression of vimentin could decrease NF-κB activity and increase PCV2-induced caspase-3 activity in PK-15 cells. These data suggest that vimentin is involved in the replication of PCV2 and has a restrictive effect on it, which is helpful in the study of the replication mechanism of PCV2.

Garcinone E induces apoptosis and inhibits migration and invasion in ovarian cancer cells

Ovarian cancer remains the most lethal gynecological malignant tumor. In this study, 24 xanthones were isolated and identified from the pericarps of mangosteen (Garcinia mangostana), and their anti-proliferative activities were tested in ovarian cancer cells. Garcinone E (GE) was found to exhibit excellent anti-proliferative effects among the tested xanthones. It significantly inhibited the proliferation in HEY, A2780, and A2780/Taxol cells as evidenced by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) release assay, Hoechst 33342 staining, annexin V/PI staining, and JC-1 staining. It induced endoplasmic reticulum (ER) stress and activated the protective inositol-requiring kinase (IRE)-1α pathway. Knocking down IRE-1α further activated the caspase cascade and caused an increase in cell death. Moreover, GE eliminated the migratory ability of HEY cells by reducing the expression of RhoA and Rac. It also blocked the invasion, which might be related to downregulation of matrix metalloproteinases (MMPs), i.e., MMP-9 and MMP-2, and upregulation of tissue inhibitors of metalloproteinase (TIMP) -1 and TIMP-2. In summary, GE exerts anticancer activities by inducing apoptosis and suppressing migration and invasion in ovarian cancer cells, which indicates its therapeutic potential for ovarian cancer.

Changes in the soil organic carbon balance on China's cropland during the last two decades of the 20th century

Agro-ecosystems play an important role in regulating global changes caused by greenhouse gas emissions. Restoration of soil organic carbon (SOC) in agricultural soils can not only improve soil quality but also influence climate change and agronomic productivity. With about half of its land area under agricultural use, China exhibits vast potential for carbon (C) sequestration that needs to be researched. Chinese cropland has experienced SOC change over the past century. The study of SOC dynamics under different bioclimatic conditions and cropping systems can help us to better understand this historical change, current status, the impacts of bioclimatic conditions on SOC and future trends. We used a simulation based on historical statistical data to analyze the C balance of Chinese croplands during the 1980s and 1990s, taking into account soil, climate and agricultural management. Nationwide, 77.6% of the national arable land is considered to be in good condition. Appropriate farm management practices should be adopted to improve the poor C balance of the remaining 22.4% of cropland to promote C sequestration.

Norditerpenoids and Dinorditerpenoids from the Seeds of Podocarpus nagi as Cytotoxic Agents and Autophagy Inducers

Nine new norditerpenoids and dinorditerpenoids, 2-oxonagilactone A (1), 7β-hydroxynagilactone D (2), nagilactones K and L (3 and 4), 3β-hydroxynagilactone L (5), 2β-hydroxynagilactone L (6), 3-epi-15-hydroxynagilactone D (7), 1α-chloro-2β,3β,15-trihydroxynagilactone L (8), and 15-hydroxynagilactone L (9), were isolated from the seeds of Podocarpus nagi, along with eight known analogues. The structures of the new compounds were established based on detailed NMR and HRESIMS analysis, as well as from their ECD spectra. The absolute configuration of the known compound 1-deoxy-2α-hydroxynagilactone A (16) was confirmed by single-crystal X-ray diffraction. All of the isolates were tested for their cytotoxic activities against cancer cells. The results indicated that compounds 4 and 6, as well as several known compounds, displayed cytotoxicity against A2780 and HEY cancer cells. Among the new compounds, 2β-hydroxynagilactone L (6) showed IC₅₀ values of less than 2.5 μM against the two cell lines used. Furthermore, compound 6 induced autophagic flux in A2780 cells, as evidenced by an enhanced expression level of the autophagy marker phosphatidylethanolamine-modified microtubule-associated protein light-chain 3 (LC3-II) and increased mRFP-GFP-LC3 puncta. Also, compound 6 activated the c-Jun N-terminal kinase (JNK) pathway, while pretreatment with the JNK inhibitor SP600125 decreased compound 6-induced autophagy.

[Association of the expression of leptin and leptin receptor with bone metastasis in pulmonary adenocarcinoma]

Objective: To explore the association of expression of leptin and leptin receptor (LR) with bone metastasis of pulmonary adenocarcinoma. Methods: One hundred and sixteen pulmonary adenocarcinoma patients who had complete clinicopathological data and definite pathological diagnosis in our hospital from January 2008 to January 2010 were selected. They were divided into the metastasis (n= 58) and non-metastasis (control, n=58) groups. The expressions of leptin and LR were identified by immunohistochemistry. The differences between expressions of leptin and LR in primary pulmonary adenocarcinoma tissues and metastasis, and between the groups with and without bone metastasis were analyzed. We also analyzed the correlation of leptin and LR expressed in primary adenocarcinoma and bone metastatic tissues, and the relationship between their expression levels and bone metastasis free survival (BMFS). Results: Among 58 patients of the metastasis group, the cases of high, moderate and low expressions of leptin were 36, 15 and 7, respectively, and the cases of high, moderate and low expressions of LR were 32, 17 and 9, respectively. Among the 58 patients of control group, the cases of high, moderate and low expressions of leptin were 19, 24 and 15, respectively, and those of LR were 17, 16 and 25, respectively. The expressions of leptin and LR in primary pulmonary adenocarcinoma tissues of metastasis group were significantly different from those of the control group (P=0.006, P=0.002, respectively). The expressions of leptin and LR in primary pulmonary adenocarcinoma tissues of the bone metastasis group were also significantly different from those of the non-bone metastasis group (P=0.029, P=0.032, respectively). The high/moderate expression rates of leptin and LR in the bone-metastatic tissues reached 91.4% (32/35) and 88.6% (31/35), respectively. The results showed that the expressions of leptin and LR in primary pulmonary adenocarcinoma tissues were positively related with their expressions in bone metastatic tissue (r = 0.612). The median bone metastasis free survival (BMFS) of the bone metastasis groups with high, moderate and low expressions of leptin were 14, 21 and 47 months, respectively, and the median BMFS of high, moderate and low expressions of LR in the bone metastasis group were 13, 19 and 27 months, respectively. The expressions of leptin and LR in pulmonary adenocarcinoma were significantly associated with BMFS (P<0.001, P=0.006, respectively). Conclusions: The expressions of leptin and LR are significantly up-regulated in primary pulmonary adenocarcinoma tissues and bone metastatic tissues, and are negatively correlated with BMFS. These two molecules may be used as effective predictors of bone metastasis in pulmonary adenocarcinoma.

[Progress of research in relation to the impact of climate change on children's health status]

Along with global warming, climate change has become one of the biggest public health challenges. The unique metabolism, behavior, physiology and development in children, will make them suffer more from the climate change. In the present review, we summarized the progress and situation of studies on the associations between climate change and children's health also trying to provide adaptation and mitigation strategies. The purpose of this study was to offer scientific evidence for prevention and control on the adverse effects as injuries, diseases and deaths among children that resulted from the changes of climate.

[Different meanings of Long(stranguria) in medicaland historical books in Han Dynasty]

The word "long (stranguria)" is seen both in historical and medical works in the Han Dynasty, but with much different meanings. In medical books, including Nei jing(Inner Canon), Wu shi er bing fang(Prescriptions for Fifty-two Diseases), and Wu wei yi jian(Medical Bamboo slips of Wuwei), Long refers to incontinence of urination. However, in historical books, Long is usually expressed as "pi long" , referring to different conditions, including lame, fatigue, and disability, all congenital or acquired renal deficient illness. It is also seen in unearthed documents as fei ji (disability) and "du long" , referring to congenital or postnatal severe diseases resulting in disability to do anything. Together with orphan, widow, widower, senility, and poverty without relatives for existence, all weak communities need to be supported and saved.

Effects of DNA methyltransferase inhibitor RG108 on methylation in buffalo adult fibroblasts and subsequent embryonic development following somatic cell nuclear transfer

Buffalo are characteristic livestock of the Guangxi Zhuang Autonomous Region of China, but their low reproductive capacity necessitates the use of somatic cell nuclear transfer (SCNT). We investigated the effects of RG108 on DNA methylation in buffalo adult fibroblasts, and on subsequent SCNT embryo development. RG108 treatment (0, 5, 10, 20, and 100 mM) had no effect on cell morphology, viability, or karyotype (2n = 48), and cell growth followed a typical "S" curve. Immunohistochemistry showed that relative DNA methylation gradually decreased as RG108 concentration increased, and was significantly lower in the 20 and 100 mM groups compared to the 0, 5, and 10 mM treatments (0.94 ± 0.03 and 0.92 ± 0.05 vs 1.0 ± 0.02, 0.98 ± 0.05, and 0.98 ± 0.09, respectively; P < 0.05). Quantitative polymerase chain reaction revealed that DNMT1 gene expression of fibroblasts administered 10, 20, and 100 mM RG108 was significantly lower than those in the 0 and 5 mM groups (0.2 ± 0.05, 0.18 ± 0.07, and 0.3 ± 0.09 vs 1.0 ± 0.12 and 1.4 ± 0.12, respectively; P < 0.05). Treatment with 20 mM RG108 resulted in the lowest expression levels. Fibroblasts incubated with 20 mM RG108 for 72 h were used as donor cells to generate SCNT embryos. A greater number of such embryos developed into blastocysts compared to the non-treated group (28.9 ± 3.9 vs 15.3 ± 3.4%; P < 0.05). RG108 treatment can modify DNA methylation in buffalo adult fibroblasts and promote development of subsequent SCNT embryos.

[Role of CMKLR1 on mouse vascular smooth muscle cells proliferation and related mechanism]

OBJECTIVE

To explore the proliferation property of vascular smooth muscle cells (VSMCs) in the stable CMKLR1 gene knock-down mouse VSMCs line and explore related mechanism.

METHODS

The short hairpin RNA sequence targeting to knockdown the coding regions of mouse CMKLR1 mRNA was synthesized and subsequently employed to construct recombinant lentivirus vector.Mouse VSMCs were cultured and infected with the recombinant lentivirus (knockdown VSMCs). mRNA and protein CMKLR1 expression in Knockdown VSMCs was measured by real-time PCR and Western blot and compared with those in normal VSMCs (vehicle VSMCs) and lentivirus control VSMCs (control VSMCs). The proliferation of normal, knockdown and control VSMCs was induced by platelet-derived growth factor-BB (PDGF VSMCs) and measured by cell number counting and BrdU.The phosphorylated c-Jun N-terminal kinase (p-JNK) protein was investigated by Western blot.

RESULTS

The relative level of CMKLR1 mRNA in knockdown VSMCs (0.23±0.04) was significantly downregulated compared with which in vehicle VSMCs (1.05±0.05) as well as control VSMCs (0.99±0.04) (P<0.01). The relative level of CMKLR1 protein in knockdown VSMCs (0.29±0.04) was also significantly decreased, compared with which in vehicle VSMCs (1.06±0.04) as well as control VSMCs (0.95±0.02) (P<0.01). The VSMCs number ((50.33±1.20)×10(3)/cm(2)) and BrdU A450 nm value (1.80±0.05) in PDGF VSMCs were significantly increased in vehicle VSMCs ((42.02±1.53)×10(3)/cm(2,) 1.55±0.04) (both P<0.05). Compared with those in vehicle VSMCs, the VSMCs number ((23.33±2.03)×10(3)/cm(2)) and BrdU A450 nm value (1.32±0.02) in knockdown VSMCs were significantly decreased.The proliferation property between PDGF VSMCs and control VSMCs was similar(P>0.05). Compared with the relative level of p-JNK protein (1.03±0.03) in vehicle VSMCs, the p-JNK protein level was significantly increased in PDGF VSMCs (1.36±0.02, P<0.05) and significantly downregulated in knockdown VSMCs (0.79±0.05, P<0.05).

CONCLUSION

Knockdowning CMKLR1 gene can reduce the proliferation of mouse vascular smooth muscle cells, which was related with the down-regulation of p-JNK expression.

[Novel biomarkers for latent tuberculosis infection by plasma proteomic profiling]

OBJECTIVE

To screen specific biomarkers for latent tuberculosis infection by comparing the plasma proteomic profiling between latent tuberculosis infection and healthy controls.

METHODS

The plasma proteins from 15 cases with latent tuberculosis infection and 15 healthy controls were detected by the label-free quantitative proteomic technology. Differential expressed proteins were analyzed by GO, KEGG, and BiNGO analysis. Student's t test was used to analyze the differential expression between 2 groups.

RESULTS

Twenty-three candidate proteins were identified, among which 15 proteins were downregulated (<0.5-fold at P<0.05) and 8 proteins were upregulated (>2.0-fold at P<0.05) in the latent tuberculosis infection group. Bioinformatic analysis revealed 3 proteins AAT, C3 and C4A to be the most significant.

CONCLUSION

There were differential plasma protein profiles between latent tuberculosis infection and healthy controls. Candidate proteins AAT, C3 and C4A were promising biomarkers for discriminating cases with latent tuberculosis infection from healthy persons.

Cytotoxic and Pro-Apoptotic Effects of Cassane Diterpenoids from the Seeds of Caesalpinia sappan in Cancer Cells

The chemical study on the seeds of Caesalpinia sappan led to the isolation of five new cassane diterpenoids, phanginins R‒T (1–3) and caesalsappanins M and N (4 and 5), together with seven known compounds 6–12. Their structures were elucidated on the basis of NMR and HRESIMS analyses. The absolute configurations of compounds 1 and 4 were determined by the corresponding CD spectra. All the isolated compounds were tested for their cytotoxicity against ovarian cancer A2780 and HEY, gastric cancer AGS, and non-small cell lung cancer A549 cells. Compound 1 displayed significant toxicity against the four cell lines with the IC₅₀ values of 9.9 ± 1.6 µM, 12.2 ± 6.5 µM, 5.3 ± 1.9 µM, and 12.3 ± 3.1 µM, respectively. Compound 1 induced G1 phase cell cycle arrest in A2780 cells. Furthermore, compound 1 dose-dependently induced A2780 cells apoptosis as evidenced by Hoechst 33342 staining, Annexin V positive cells, the up-regulated cleaved-PARP and the enhanced Bax/Bcl-2 ratio. What’s more, compound 1 also promoted the expression of the tumor suppressor p53 protein. These findings indicate that cassane diterpenoids might have potential as anti-cancer agents, and further in vivo animal studies and structural modification investigation are needed.

Subtraction suppressive hybridisation analysis of differentially expressed genes associated with puberty in the goat hypothalamus

The cost of developing replacement nanny goats could be reduced by decreasing the age at puberty because this way nanny goats could be brought into production at an earlier age. The aim of the present study was to screen genes related to puberty to investigate the molecular mechanisms of puberty. Subtracted cDNA libraries were constructed for hypothalami from juvenile (Group A), pubertal (Group B) and age-matched control pubertal (Group E) Jining grey (JG) and Liaoning cashmere (LC) goats using suppression subtractive hybridisation (SSH). Differentially expressed genes were analysed by bioinformatics methods. There were 203 expressed sequence tags (ESTs) in the subtracted cDNA libraries that were differentially expressed between JG and LC goats at the juvenile stage, 226 that were differentially expressed at puberty and 183 that were differentially expressed in the age-matched control group. The differentially expressed ESTs in each subtracted cDNA library were classified as known gene, known EST and unknown EST according to sequence homology in the GenBank non-redundant (NR) and EST database. According to gene function analysis in the COG (Cluster of Orthologous Groups) database, the known genes were grouped into 10 subdivisions in Group A, into seven subdivisions in Group E and into nine subdivisions in Group B under three categories: cellular processes and signalling, information storage and processing, and metabolism. Pathway analysis in the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway database of known genes revealed that the three pathways that most differentially expressed genes were involved in were metabolic pathways, Parkinson's disease and oxidative phosphorylation. Protein interaction analysis of the high homology genes revealed the most dominant network to be structure of ribosome/protein translation, oxidative phosphorylation and carbohydrate metabolism. The results reveal that the onset of puberty is a complex event involving multiple genes in multiple biological processes. The differentially expressed genes include genes related to both neuroendocrine and energy metabolism.

Evaluation of Virtual Noncontrast Images Obtained from Dual-Energy CTA for Diagnosing Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

The virtual noncontrast images generated with iodine subtraction from dual-energy CTA images are expected to replace the true noncontrast images for radiation-dose reduction. This study assessed the feasibility of virtual noncontrast images for diagnosing SAH.

MATERIALS AND METHODS

Eighty-four patients with or without SAH underwent true noncontrast brain CT (the criterion standard for diagnosing SAH). Among them, 37 patients underwent an additional head dual-energy angiography, and the other patients underwent head and neck dual-energy angiography. Virtual noncontrast images were produced on a dedicated dual-energy postprocessing workstation and reconstructed in orientation and section width identical to those in true noncontrast images. The findings on the virtual noncontrast and true noncontrast images were compared at both the individual level and the lesion level. Image noise of the virtual noncontrast and true noncontrast images was also measured and compared. The volume CT dose index and dose-length product were recorded for the radiation-dose analysis.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of virtual noncontrast images at the individual level and the lesion level were 94.5%, 100%, 100%, 90.6% and 86.7%, 96.9%, 91.8%, 94.8%, respectively. The agreement in the diagnosis of SAH on true noncontrast and virtual noncontrast images reached 92.3% at the individual level and 85.1% at the lesion level. The virtual noncontrast images showed a higher image noise level. The volume CT dose index and dose-length product were obviously reduced without the true noncontrast brain CT scan.

CONCLUSIONS

Virtual noncontrast images are a reliable tool for diagnosing SAH, with the advantage of reducing the radiation dose.

New insights into the anti-obesity activity of xanthones from Garcinia mangostana

This article reviews the anti-adipogenic, anti-inflammatory and antioxidant activities of xanthones from Garcinia mangostana.

Naturally occurring homoisoflavonoids and their pharmacological activities

Homoisoflavonoids, a special subclass of flavonoids, are rarely found in nature, mainly existing in Fabaceae and Asparagaceae families and being less common in Polygonaceae, Portulacaceae, Orchidaceae, and Gentianaceae families. Until now, approximately 240 natural occurring homoisoflavonoids have been identified from roots, barks, heartwood, bulbs, leaves, and seeds of the plants from the above mentioned families, which have often been used in traditional medicine. Homoisoflavonoids have been reported with a broad range of bioactivities, including anti-microbial, anti-mutagenic, anti-oxidant, immunomodulatory, anti-diabetic, cytotoxic, anti-angiogenic, vasorelaxant, and anti-inflammatory effects. To organize this review, the homoisoflavonoids were classified into five groups based on their structures: sappanin-type (I), scillascillin-type (II), brazilin-type (III), caesalpin-type (IV), and protosappanin-type (V). The structures of natural occurring homoisoflavonoids are described, and their proposed biosynthetic pathway and recent pharmacological studies are discussed. The main purpose of this review is to provide a comprehensive and up-to-date state of knowledge from phytochemical and pharmacological studies performed on homoisoflavonoids during the past decades. Homoisoflavonoids might have a large potential for further investigations of their bioactivities in order to identify important leads.

Photonic wire biosensor microarray chip and instrumentation with application to serotyping of Escherichia coli isolates

A complete photonic wire molecular biosensor microarray chip architecture and supporting instrumentation is described. Chip layouts with 16 and 128 independent sensors have been fabricated and tested, where each sensor can provide an independent molecular binding curve. Each sensor is 50 μm in diameter, and consists of a millimeter long silicon photonic wire waveguide folded into a spiral ring resonator. An array of 128 sensors occupies a 2 × 2 mm2 area on a 6 × 9 mm2 chip. Microfluidic sample delivery channels are fabricated monolithically on the chip. The size and layout of the sensor array is fully compatible with commercial spotting tools designed to independently functionalize fluorescence based biochips. The sensor chips are interrogated using an instrument that delivers sample fluid to the chip and is capable of acquiring up to 128 optical sensor outputs simultaneously and in real time. Coupling light from the sensor chip is accomplished through arrays of sub-wavelength surface grating couplers, and the signals are collected by a fixed two-dimensional detector array. The chip and instrument are designed so that connection of the fluid delivery system and optical alignment are automated, and can be completed in a few seconds with no active user input. This microarray system is used to demonstrate a multiplexed assay for serotyping E. coli bacteria using serospecific polyclonal antibody probe molecules.

Label-free biosensor array based on silicon-on-insulator ring resonators addressed using a WDM approach

We report a silicon-on-insulator ring resonator biosensor array with one output port, using wavelength division multiplexing as the addressing scheme. With the use of on-chip referencing for environmental drift cancellation, simultaneous monitoring of multiplexed molecular bindings is demonstrated, with a resolution of 0.3 pg/mm(2) (40 ag of total mass) for protein concentrations over 4 orders of magnitude down to 20 pM. Reactions are measured over time periods as long as 3 h with high stability.

Silicon photonic wire biosensor array for multiplexed real-time and label-free molecular detection

We demonstrate a silicon photonic wire waveguide biosensor array chip for the simultaneous monitoring of different molecular binding reactions. The chip is compatible with automated commercial spotting tools and contains a monolithically integrated microfluidic channel for sample delivery. Each array sensor element is a 1.8-mm-long spiral waveguide folded within a 130 microm diameter spot and is incorporated in a balanced Mach-Zehnder interferometer with a near temperature independent response. The sensors are arranged in a 400 microm spacing grid pattern and are addressed through cascaded 1x2 optical power splitters using light from a single input fiber. We demonstrate the real-time monitoring of antibody-antigen reactions using complementary and mismatched immunoglobulin G receptor-analyte pairs and bovine serum albumin. The measured level of detection for each sensor element corresponds to a surface coverage of less than 0.3 pg/mm(2).

Preparation and evaluation of a microemulsion for oral delivery of berberine

The principal aim of this study was to develop an oral microemulsion formulation of berberine in order to improve its bioavailability. The Microemulsion was prepared with pharmaceutically acceptable ingredients such as oleic acid, Tween 80 and PEG400. Phase diagrams were drawn to elucidate the phase behavior of systems, which were composed of Tween 80 as surfactant and PEG400 as cosurfactant. A single isotropic region, considered to be a bicontinuous microemulsion, was detected in the pseudo ternary phase diagrams. The berberine-loaded microemulsion was characterized by viscosity, refractive index, electrical conductivity and particle size. In vivo pharmacokinetic profile and oral bioavailability were also investigated in rats. The optimized formulation was as follows: 15 wt.% oleic acid, 17 wt.% Tween-80, 17 wt.% PEG400, and 51 wt.% water. The formulated microemulsion was found to be relatively uniform in size (24.0 nm). The in vivo study indicated that the bioavailability of the oral berberine-loaded microemulsion formulation was 6.47 times greater than that of the berberine tablet suspensions. The results suggest that the microemulsion is a promising oral drug delivery system for berberine.

Oxidative stress regulated expression of Ubiquitin Carboxyl-terminal Hydrolase-L1: Role in cell survival

The ubiquitin Carboxyl-terminal Hydrolase-L1 gene (UCHL1) is a key enzyme in the protein degradation pathway; however, its precise role in protecting cells under stress conditions is unclear. In the present study we investigated the activity of this gene in human NT2/D1 embryonal carcinoma cells subjected to oxygen-glucose deprivation (OGD) and reoxygenation. OGD/reoxygenation cause global metabolic changes due to energy withdrawal and the subsequent generation of reactive oxygen species which initiates either a stress-adaptation-survival response or cell death, depending on the severity of the insult. A bi-phasic change in UCHL1 expression was observed by Q-PCR, Western blotting and flow cytometry. Down regulation of UCHL1 was detected immediately after OGD treatment and its expression was subsequently restored and increased 6 h after OGD treatment as well as during reoxygenation. Furthermore, flow cytometry analysis detected a lower level of UCHL1 only in apoptotic cells that had severe loss of mitochondrial membrane potential. Accordingly, down-regulation of endogenous UCHL1 by antisense cDNA in mouse N2a neuroblastoma cells increased the cell's sensitivity to OGD treatment. This down-regulation of endogenous UCHL1 led to the accumulation of p27, suggesting that UCHL1 is an essential gene to maintain cell homeostasis under normal growth and oxidative stress conditions.