Jumonji domain containing 2A (JMJD2A) is a potential cancer-associated gene that may be involved in human breast cancer. The present study aimed to investigate suppressive effects on the MCF-7 human breast cancer cell line by transfection with JMJD2A-specific siRNA. Quantitative real-time PCR and western blot analysis were used to detect the expression levels of JMJD2A. Flow cytometric (FCM) analysis and WST-8 assay were used to evaluate cell proliferation. Boyden chambers were used in cell migration and invasion assays to evaluate the cell exercise capacity. Expression levels of JMJD2A mRNA and protein in the siRNA group were both downregulated successfully by transfection. FCM results showed that the percentage of cells in the G0/G1 phase in the siRNA group was significantly greater than that in the blank (P<0.05) and negative control groups (P<0.05). Additionally, the mean absorbance in the siRNA group was significantly lower (P<0.05), as observed by WST-8 assay. Moreover, a decreased number of migrated cells in the siRNA group was observed (P<0.05) using a cell migration and invasion assay. These data indicated that knockdown of JMJD2A may cause inhibition of proliferation, migration and invasion of MCF-7 cells. This study provides a new perspective in understanding the molecular mechanisms underlying the progression of breast cancer and offers a potential therapeutic target for breast cancer.
jumonji domain containing 2A; transfection; invasion; proliferation; migration
Previous data demonstrate that JMJD2A is a cancer-associated gene and may be involved in human breast cancer by demethylation of H3K9me3. The aim of this study was to investigate depressive effects on JMJD2A by transfection with JMJD2A-sepcific siRNA in human breast cancer cell line MDA-MB-231 and effects on cell proliferation, invasion and migration. JMJD2A-specific siRNA was chemically synthesised and transfected into human breast cancer cell line MDA-MB-231. Expression levels of JMJD2A were detected by quantitative real-time PCR and Western blot analysis. Cells proliferation was evaluated by using flow cytometric anlysis and MTT assay. The abilities of invasion and migration were evaluated by cell migration and invasion assay with Boyden chambers. The results showed that the transfection was successful and expression levels of JMJD2A mRNA and protein in siRNA group were both down-regulated. By MTT assay, the mean actual absorbance in siRNA group was significantly lower than that in blank control group (P < 0.05) and negative control group (P < 0.05). In addition, the percentage of cells in G0/G1 phase in siRNA group was significantly more than that in blank control group (P < 0.05) and negative control group (P < 0.05). Furthermore, by cell invasion and migration assay, the decreased number of migrated cells in siRNA group was observed (P < 0.05). These data imply that silencing JMJD2A gene could result in cell cycle change and proliferation inhibition, and lead to suppress tumor cell invasion and migration. It provides a new perspective in understanding the pleiotropic functions of JMJD2A and its contribution to human breast cancer.
JMJD2A; transfection; proliferation; invasion; migration
TAL (transcriptional activator-like) effectors (TALEs) are DNA-binding proteins, containing a modular central domain that recognizes specific DNA sequences. Recently, the crystallographic studies of TALEs revealed the structure of DNA-recognition domain. In this article, molecular dynamics (MD) simulations are employed to study two crystal structures of an 11.5-repeat TALE, in the presence and absence of DNA, respectively. The simulated results indicate that the specific binding of RVDs (repeat-variable diresidues) with DNA leads to the markedly reduced fluctuations of tandem repeats, especially at the two ends. In the DNA-bound TALE system, the base-specific interaction is formed mainly by the residue at position 13 within a TAL repeat. Tandem repeats with weak RVDs are unfavorable for the TALE-DNA binding. These observations are consistent with experimental studies. By using principal component analysis (PCA), the dominant motions are open-close movements between the two ends of the superhelical structure in both DNA-free and DNA-bound TALE systems. The open-close movements are found to be critical for the recognition and binding of TALE-DNA based on the analysis of free energy landscape (FEL). The conformational analysis of DNA indicates that the 5′ end of DNA target sequence has more remarkable structural deformability than the other sites. Meanwhile, the conformational change of DNA is likely associated with the specific interaction of TALE-DNA. We further suggest that the arrangement of N-terminal repeats with strong RVDs may help in the design of efficient TALEs. This study provides some new insights into the understanding of the TALE-DNA recognition mechanism.
Sucrose isomerase NX-5 from Erwiniarhapontici efficiently catalyzes the isomerization of sucrose to isomaltulose (main product) and trehalulose (by-product). To investigate the molecular mechanism controlling sucrose isomer formation, we determined the crystal structures of native NX-5 and its mutant complexes E295Q/sucrose and D241A/glucose at 1.70 Å, 1.70 Å and 2.00 Å, respectively. The overall structure and active site architecture of NX-5 resemble those of other reported sucrose isomerases. Strikingly, the substrate binding mode of NX-5 is also similar to that of trehalulose synthase from Pseudomonasmesoacidophila MX-45 (MutB). Detailed structural analysis revealed the catalytic RXDRX motif and the adjacent 10-residue loop of NX-5 and isomaltulose synthase PalI from Klebsiella sp. LX3 adopt a distinct orientation from those of trehalulose synthases. Mutations of the loop region of NX-5 resulted in significant changes of the product ratio between isomaltulose and trehalulose. The molecular dynamics simulation data supported the product specificity of NX-5 towards isomaltulose and the role of the loop330-339 in NX-5 catalysis. This work should prove useful for the engineering of sucrose isomerase for industrial carbohydrate biotransformations.
In the title compound, C27H22N2O4, the two indole ring systems are approximately perpendicular to each other, with a dihedral angle of 84.5 (5)° between their planes; the benzene ring is twisted with respect to the two indole ring systems at angles of 78.5 (5) and 86.5 (3)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, weak C—H⋯O and C—H⋯N hydrogen bonds, and C—H⋯π interactions into a three-dimensional supramolecular architecture.
Background. To investigate the specific link between lung and large intestine. Methods. Rat COPD-like model was prepared. Mirabilite or Chinese rhubarb was administrated intragastrically to stimulate the large intestine. Histological analysis of lung inflammation was assessed. The tissues levels of SP, VIP, NK1R, VIPR1, and VIPR2 were measured by using ELISA kits. In addition, mouse model of allergic asthma was prepared. Mirabilite was administrated intragastrically to stimulate the large intestine. Airway responsiveness and lung inflammation were assessed. The tissues levels of SP, VIP, NKA, NKB, NK1R, VIPR1, and VIPR2 were measured by using ELISA kits. Results. Stimulating the intestine with Mangxiao or Dahuang, SP, NK-1R, VIP, VIPR1, and VIPR2 were significantly increased in intestine tissues of rats with COPD and mice with asthma. Meanwhile, the SP and NK1R were significantly decreased, while VIP, VIPR1, and VIPR2 were significantly increased in lung tissues. An abnormal secretion of SP and VIP can be observed in other tissues; however, no marked changes were found in the receptors. The NKA and NKB levels were similar in lung tissues of mice with asthma among groups. Conclusions. Stimulating intestine with Mangxiao or Dahuang can specifically regulate the secretion of SP, VIP, and the receptors in lung tissues.
STAT is the backward position of cytokine and growth factor receptors in the nucleus, STAT dimers could bind to DNA and induce transcription of specific target genes. Several lines of evidence support the important roles of STAT, especially STAT5, in carcinogenesis. The overexpression of STAT 5 is related to the differentiation and apoptosis of tumor cells. However, the role of STAT5 in esophageal squamous cell carcinoma remains unclear.
The siRNA vectors aiming to STAT5 gene were constructed. STAT5 siRNA was transfected into Eca-109 cells by Lipofectamine™2000. Expression of STAT5、Bcl-2 and Cyclin D1 were analyzed by Western blot and RT-PCR. Eca-109 cells proliferation was determined by MTT. Eca-109 cell cycle and apoptosis were detected by the flow cytometry. Boyden chamber was used to evaluate the invasion and metastasis capabilities of Eca-109 cells.
The double strands oligonucleotide of siRNA aiming to STAT5 was successfully cloned into the pRNAT-U6.1 vector, and the target sequence coincided with the design. RT-PCR and Western blotting detection demonstrated that the expression levels of STAT5、Bcl-2 and Cyclin D1 gene were obviously decreased in Eca-109 cells transfected with STAT5 siRNA. STAT5 siRNA could suppress the proliferation of Eca-109 cells. The proportion of S and G2/M period frequency was significantly decreased (p < 0.05). The proportion of G0/G1 period frequency was significantly increased (p < 0.05). The average amount of cells penetrating Matrigel was significantly decreased (p < 0.05).
STAT5 silenced by siRNA could induce the apoptosis and suppress the proliferation、invasion and metastasis of esophageal carcinoma cell line Eca-109, which indicated STAT5 might be a novel therapeutic strategy for the human ESCC.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1351913072103000
STAT5; siRNA; Proliferation; Cell cycle; Apoptosis
The main purpose of this paper is to study the exceptional values of meromorphic function and its derivative on annulus. We also give some theorems and corollaries about exceptional values of meromorphic function on the annulus, which are the improvement of the previous results given by Chen and Wu.
We previously reported that Axin1 (Axin) is down-regulated in many cases of lung cancer, and X-ray irradiation increased Axin expression and inhibited lung cancer cells. The mechanisms, however, were not clear.
Four lung cancer cell lines were used to detect the methylation status of Axin with or without X-ray treatment. Real-time PCR was used to quantify the expression of Axin, and western blot analysis was applied to measure protein levels of Axin, β-catenin, Cyclin D1, MMP-7, DNMTS, MeCP2 and acetylated histones. Flow cytometric analysis, colony formation assay, transwell assay and xenograft growth experiment were used to study the biological behavior of the cells with hypermethylated or unmethylated Axin gene after X-ray treatment.
Hypermethylated Axin gene was detected in 2 of 4 cell lines, and it correlated inversely with Axin expression. X-ray treatment significantly up-regulated Axin expression in H446 and H157 cells, which possess intrinsic hypermethylation of the Axin gene (P<0.01), but did not show up-regulation in LTE and H460 cells, which have unmethylated Axin gene. 2Gy X-ray significantly reduced colony formation (from 71% to 10.5%) in H157 cells, while the reduction was lower in LTE cells (from 71% to 20%). After X-ray irradiation, xenograft growth was significantly decreased in H157 cells (from 1.15 g to 0.28 g) in comparison with LTE cells (from 1.06 g to 0.65 g). Significantly decreased cell invasiveness and increased apoptosis were also observed in H157 cells treated with X-ray irradiation (P<0.01). Down-regulation of DNMTs and MeCP2 and up-regulation of acetylated histones could be detected in lung cancer cells.
X-ray-induced inhibition of lung cancer cells may be mediated by enhanced expression of Axin via genomic DNA demethylation and histone acetylation. Lung cancer cells with a different methylation status of the Axin gene showed different radiosensitivity, suggesting that the methylation status of the Axin gene may be one important factor to predict radiosensitivity of the tumor.
Axin; Methylation; Proliferation; Invasiveness; Radiosensitivity
The silkworm, Bombyx mori, is one of the major insect model organisms, and its draft and fine genome sequences became available in 2004 and 2008, respectively. Transposable elements (TEs) constitute ∼40% of the silkworm genome. To better understand the roles of TEs in organization, structure and evolution of the silkworm genome, we used a combination of de novo, structure-based and homology-based approaches for identification of the silkworm TEs and identified 1308 silkworm TE families. These TE families and their classification information were organized into a comprehensive and easy-to-use web-based database, BmTEdb. Users are entitled to browse, search and download the sequences in the database. Sequence analyses such as BLAST, HMMER and EMBOSS GetORF were also provided in BmTEdb. This database will facilitate studies for the silkworm genomics, the TE functions in the silkworm and the comparative analysis of the insect TEs.
Database URL: http://gene.cqu.edu.cn/BmTEdb/.
Inflammatory mediators, many of which activate the signaling of nuclear factor kappa B (NFκB), have received increasing attention in the field of neurogenesis. NFκB signaling regulates neurite outgrowth and neural plasticity as well as the proliferation/apoptosis and terminal differentiation of neural stem cells (NSCs). Early neurogenesis from NSCs produces identical progeny through symmetric division and committed daughter cells through asymmetric division. Here, we show that NFκB signaling is required for NSC initial differentiation. The canonical IKKβ/IκBα/ p65 pathway is activated during the initial stages of neural differentiation induced by treatment with TNFα or with- drawal of epidermal growth factor/basic fibroblast growth factor. NSC-specific inhibition of NFκB in transgenic mice causes an accumulation of Nestin+/Sox2+/glial fibrillary acidic protein+ NSCs. Inhibition of NFκB signaling in vitro blocks differentiation and asymmetric division and maintains NSCs in an undifferentiated state. The induction of initial differentiation and asymmetry by NFκB signaling occurs through the inhibition of C/EBPβ expression. Our data reveal a novel function of NFκB signaling in early neurogenesis and provide insight into the molecular mechanisms underlying neurodevelopmental disorders and neurodegenerative diseases.
Neural stem cells; Nuclear factor kappa B; Neurogenesis; C/EBPβ; Glial fibrillary acidic protein; Cell division
♦ Background, Objectives, and Methods: The number of patients on chronic peritoneal dialysis (CPD) is increasing rapidly on a global scale. We analyzed the International Pediatric Peritoneal Dialysis Network (IPPN) registry, a global database active in 33 countries spanning a wide range in gross national income (GNI), to identify the impact of economic conditions on CPD practices and outcomes in children and adolescents.
♦ Results: We observed close associations of GNI with the fraction of very young patients on dialysis, the presence and number of comorbidities, the prevalence of patients with unexplained causes of end-stage kidney disease, and the rate of culture-negative peritonitis. The prevalence of automated PD increased with GNI, but was 46% even in the lowest GNI stratum. The GNI stratum also affected the use of biocompatible peritoneal dialysis fluids, enteral tube feeding, calcium-free phosphate binders, active vitamin D analogs, and erythropoiesis-stimulating agents (ESAs). Patient mortality was strongly affected by GNI (hazard ratio per $10 000: 3.3; 95% confidence interval: 2.0 to 5.5) independently of young patient age and the number of comorbidities present. Patients from low-income countries tended to die more often from infections unrelated to CPD (5 of 9 vs 15 of 61, p = 0.1). The GNI was also a strong independent predictor of standardized height (p < 0.0001), adding to the impact of congenital renal disease, anuria, age at PD start, and dialysis vintage. Patients from the lower economic strata (GNI < $18 000) had higher serum parathyroid hormone (PTH) and lower serum calcium, and achieved lower hemoglobin concentrations. No impact of GNI was observed with regard to CPD technique survival or peritonitis incidence.
♦ Conclusions: We conclude that CPD is practiced successfully, albeit with major regional variation related to economic differences, in children around the globe. The variations encompass the acceptance of very young patients and those with associated comorbidities to chronic dialysis programs, the use of automated PD and expensive drugs, and the diagnostic management of peritonitis. These variations in practice related to economic difference do not appear to affect PD technique survival; however, economic conditions seem to affect mortality on dialysis and standardized height, a marker of global child morbidity.
Children; economics; developing countries; patient survival; technique survival; growth; registry
Noninvasive imaging techniques have been considered important strategies in the clinic to monitor tumor early response to therapy. In the present study, we applied RGD peptides conjugated to iron oxide nanoparticles (IONP-RGD) as contrast agents in magnetic resonance imaging (MRI) to noninvasively monitor the response of a vascular disrupting agent VEGF121/rGel in an orthotopic glioblastoma model. RGD peptides were firstly coupled to IONPs coated with a crosslinked PEGylated amphiphilic triblock copolymer. In vitro binding assays confirmed that cellular uptake of particles was mainly dependent on the interaction between RGD and integrin αvβ3 of human umbilical vein endothelial cells (HUVEC). The tumor targeting of IONP-RGD was observed in an orthotopic U87 glioblastoma model. Finally, noninvasive monitoring of the tumor response to VEGF121/rGel therapy at early stages of treatment was successfully accomplished using IONP-RGD as a contrast agent for MRI, a superior method over common anatomical approaches which are based on tumor size measurements. This preclinical study can accelerate anticancer drug development and promote clinical translation of nanoprobes.
Magnetic resonance imaging (MRI); Iron oxide nanoparticles (IONPs); RGD peptides; Tumor targeting; Therapy response
To identify risk factors for HIV infection among men who have sex with men (MSM) and to provide a theoretical basis for prevention interventions. Between December 2011 and August 2012, a case–control study was conducted among MSM who underwent voluntary counselling and testing for HIV. Confirmed HIV-positive MSM were included in the case group, and HIV-negative MSM were included in the control group. Information on possible risk factors was collected by a survey questionnaire and a qualitative interview. The results of a conditional logistic regression showed that the following were influencing factors for HIV infection: average monthly income between 2001 and 3000 Yuan (odds ratio (OR)=6.341, 95% CI: 1.714–12.544), only sometimes using condoms when having anal sex with men in the last 6 months (OR=7.601, 95% CI: 1.359–23.083), having HIV-positive sex partners (OR=5.273, 95% CI: 1.572–17.691), rectal trauma with bleeding in the last 6 months (OR=2.947, 95% CI: 1.308–6.638), not using condoms at last sexual encounter (OR=1.278, 95% CI: 1.012–5.595), engaging in commercial sex (OR=5.925, 95% CI: 1.923–13.890) and having more than 16 sex partners in the last 6 months (OR=1.175, 95% CI: 1.021–1.353). These seven factors were the risk factors of HIV infection (OR>1). However, having anal sex less than 10 times in the previous 1 month (OR=0.002, 95% CI: 0.000–0.287) was a protective factor against HIV infection among MSM (OR<1), and insertive (OR=0.116, 95% CI: 0.000–0.236) (OR<1) anal intercourse influenced HIV infection. Interventions should be targeted at MSM whose average monthly income is between 2001 and 3000 Yuan, and who engage in commercial sex. In addition, the importance of using condoms at every sexual encounter should be emphasised in health education, as should the treatment of rectal trauma with bleeding. Finally, MSM should decrease the number of sex partners and frequency of anal sex to decrease the rate of HIV infection.
case–control study; HIV infection; influencing factors; men who have sex with men (MSM)
Adenocarcinoma of the rete testis is very rare. There is still little knowledge about its etiology and pathogenesis. Herein, we present a case of rete testis adenocarcinoma in a 36-year-old Chinese male. The tumor was predominantly composed of irregular small tubules and papillary structures with cuboidal or polygonal cells. In peripheral area of the tumor, the remaining normal rete testis and adenomatous hyperplasia of the rete testis could also be seen, indicating the possible relationship between adenomatous hyperplasia and adenocarcinoma. In addition, the patient underwent a left hydrocelectomy because of the existence of hydrocele 3 years ago. But, it is unclear whether hydrocele and hydrocelectomy is its cause or just the early clinical presentation of the adenocarcinoma.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6757609119625499
Adenocarcinoma; Rete testis; Adenomatous hyperplasia
CXC chemokine receptor 4 was found to be expressed by many different types of human cancers and its expression has been correlated with tumor aggressiveness, poor prognosis and resistance to chemotherapy. However the effect of CXCR4 on the esophageal carcinoma cells remains unclear, the present study explored the effects of CXCR4 siRNA on proliferation and invasion of esophageal carcinoma KYSE-150 and TE-13 cells. Two siRNA sequence targeting CXCR4 gene were constructed and then were transfected into KYSE-150 and TE-13 cells by Lipofectamine™2000. Changes of CXCR4 mRNA and protein were analyzed by qRT-PCR and Western blot. Effect of CXCR4 siRNA on KYSE-150 and TE-13 cells proliferation was determined by MTT. Transwell invasion assay was used to evaluate the invasion and metastasis of KYSE-150 and TE-13 cells. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. qRT-PCR and Western blot demonstrate that the expression level of CXCR4 gene were obviously decreased in KYSE-150 and TE-13 cells transfected with CXCR4 targeting siRNA expression vectors. The average amount of cells transfected with CXCR4 siRNA penetrating Matrigel was significantly decreased (p<0.05). Injection of CXCR4 siRNA transfected cells inhibited tumor growth in a xenograft model compared with blank and negative control groups (p <0.05). CXCR4 silenced by siRNA could suppress the proliferation, invasion and metastasis of esophageal carcinoma cell lines KYSE-150 and TE-13 in vitro and in vivo. The results provide a theoretical and experimental basis for the gene therapy of ESCC using RNAi technology based on CXCR4 target site.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3502376691001138
Esophageal carcinoma; CXCR4; Proliferation; Invasion
Epithelioid hemangioendothelioma is a relatively uncommon lesion usually presenting in soft tissues. The occurrence in the mediastinum is exceptional rare. Histologically, this tumor is characterized by epithelioid cells with intracytoplasmic vacuoles in a hyalinized or mucinous stroma. Occasionally, spindle cells or osteoclast-like giant cells can be observed. Herein, we present a case of epithelioid hemangioendothelioma in a 38 year-old Chinese male. The tumor was predominantly composed of abundant spindle cells with marked atypia and scattered osteoclast-like giant cells reminiscent of malignant fibrous histiocytoma. The unusual histological appearance can pose a great diagnostic challenge. It may be easily misdiagnosed, especially if the specimen is limited or from fine-needle aspiration.
Epithelioid hemangioendothelioma; Mediastinum; Osteoclast-like giant cells; Malignant fibrous histiocytoma
Etravirine (ETR) is an expanded-spectrum nonnucleoside reverse transcriptase inhibitor (NNRTI) approved for use as an antiretroviral agent in treatment-experienced patients. Y181C and E138K in HIV-1 RT are among 20 different drug resistance mutations associated with ETR. However, E138K can be consistently selected by ETR when wild-type viruses but not viruses containing Y181C are grown in tissue culture. This study was carried out to evaluate any possible mechanisms that might explain antagonism between the Y181C and E138K mutations. Accordingly, we performed tissue culture studies to investigate the evolutionary dynamics of E138K in both a wild-type (WT) and a Y181C background. We also generated recombinant enzymes containing Y181C and E138K alone or in combination in order to study enzyme processivity, rates of processive DNA synthesis, enzyme kinetics, and susceptibility to ETR. We now show that the presence of the Y181C mutation prevented the emergence of E138K in cell culture and that the simultaneous presence of E138K and Y181C impaired each of enzyme activity, processivity, rate of processive DNA synthesis, and deoxynucleoside triphosphate (dNTP) affinity. The addition of E138K to Y181C also decreased the level of resistance to ETR compared to that obtained with Y181C alone.
Evidence suggests that cytoglobin (Cygb) may function as a tumor suppressor gene.
We immunohistochemically evaluated the expression of Cygb, phosphatidylinositol-3 kinase (PI-3K), phosphorylated (p)-Akt, Interleukin-6 (IL-6), tumor necrosis factor-α (TNFα) and vascular endothelial growth factor (VEGF) in 88 patients with 41 high-grade gliomas and 47 low-grade gliomas. Intratumoral microvessel density (IMD) was also determined and associated with clinicopathological factors.
Low expression of Cygb was significantly associated with the higher histological grading and tumor recurrence. A significant negative correlation emerged between Cygb expression and PI3K, p-Akt, IL-6, TNFα or VEGF expression. Cygb expression was negatively correlated with IMD. There was a positive correlation between PI3K, p-Akt, IL-6, TNFα and VEGF expression with IMD.High histologic grade, tumor recurrence, decreased Cygb expression, increased PI3K expression, increased p-Akt expression and increased VEGF expression correlated with patients’ overall survival in univariate analysis. However, only histological grading and Cygb expression exhibited a relationship with survival of patients as independent prognostic factors of glioma by multivariate analysis.
Cygb loss may contribute to tumor recurrence and a worse prognosis in gliomas. Cygb may serve as an independent predictive factor for prognosis of glioma patients.
Glioma; Cytoglobin; Phosphatidylinositol-3 kinase; Recurrence; Prognosis
The unique structural hallmark of the intervertebral disc has made its central composition, the nucleus pulposus (NP), excluded from the immunologic tolerance. Consequently, the intervertebral disc is identified as an immune-privileged organ. Traditionally, local detrimental immune activities caused by NP at the lesion sites of the disc are noted as a significant factor contributing to disc degeneration. However, given the beneficial activities of immune cells in other immune-privileged sites on basis of current evidence, the degenerate disc might need the assistance of a subpopulation of immune cells to restore its structure and lessen inflammation. In addition, the beneficial impact of immune cells can be seen in the absorption of the herniated NP, which is an important factor causes the mechanical compression of nerve roots. Consequently, a modulated immune network in degenerate disc is essential for the restoration of this immune-privileged organ. Until now, the understandings of immune response in disc degeneration still rest on the harmful aspect. Further studies are needed to explore its beneficial influence. Accordingly, there are no absolutely the pros and cons in terms of immune reactions caused by NP.
Intervertebral disc degeneration; nucleus pulposus; immune privilege; immune reaction
Arabidopsis cryptochrome 2 (CRY2) is a blue-light receptor mediating blue-light inhibition of hypocotyl elongation and photoperiodic promotion of floral initiation. CRY2 is a constitutive nuclear protein that undergoes blue-light-dependent phosphorylation, ubiquitination, photobody formation, and degradation in the nucleus, but the relationship between these blue-light-dependent events remains unclear. It has been proposed that CRY2 phosphorylation triggers a conformational change responsible for the subsequent ubiquitination and photobody formation, leading to CRY2 function and/or degradation. We tested this hypothesis by a structure-function study, using mutant CRY2–GFP fusion proteins expressed in transgenic Arabidopsis. We show that changes of lysine residues of the NLS (Nuclear Localization Signal) sequence of CRY2 to arginine residues partially impair the nuclear importation of the CRY2K541R and CRY2K554/5R mutant proteins, resulting in reduced phosphorylation, physiological activities, and degradation in response to blue light. In contrast to the wild-type CRY2 protein that forms photobodies exclusively in the nucleus, the CRY2K541R and CRY2K554/5R mutant proteins form protein bodies in both the nucleus and cytosol in response to blue light. These results suggest that photoexcited CRY2 molecules can aggregate to form photobody-like structure without the nucleus-dependent protein modifications or the association with the nuclear CRY2-interacting proteins. Taken together, the observation that CRY2 forms photobodies markedly faster than CRY2 phosphorylation in response to blue light, we hypothesize that the photoexcited cryptochromes form oligomers, preceding other biochemical changes of CRY2, to facilitate photobody formation, signal amplification, and propagation, as well as desensitization by degradation.
protein phosphorylation; signal transduction; fluorescence imaging; protein degradation; photobody
Currently, the donor-recipient matching process for vascularized composite tissue allotransplantation (VCTA) closely follows the standard practices for solid organ transplantation. Sensitization is considered a contraindication to VCTA. However, the role of sensitization in VCTA rejection is largely unstudied.
Major histocompatibility-mismatched ACI (RT1a) donors and WF (RT1u) recipients were used to determine if sensitization would lead to hyperacute rejection in VCTA as in other organs, such as kidneys. WF rats were presensitized to ACI antigens by skin transplantation and received heterotopic osteomyocutaneous VCTA flaps. Kidney transplants served as controls.
Production of anti-donor antibody was detected in WF recipients after rejection of the ACI skin grafts. Sensitized WF rats rejected VCTA grafts from ACI rats significantly faster (P < 0.05) than unsensitized recipients, but not hyperacutely. Rejection in the sensitized recipients was not prevented by immunosuppression with FK506 and mycophenolate mofetil. In contrast, kidney allografts from ACI rats were hyperacutely rejected within 30 minutes by sensitized recipients. To confirm the role of antibody-mediated rejection in the sensitized recipients, serum from presensitized rats was adoptively transferred into naïve WF rats. Hyperacute rejection occurred only in transplanted kidneys but not VCTA. Histological examination of tissues from acceleratedly rejected VCTA showed dense lymphocytic infiltrates, and no antibody deposition.
VCTA are rejected in an accelerated fashion but not hyperacutely in the presence of allosensitization and preformed anti-donor antibody. The rejection of VCTA in sensitized recipients is mainly cell-mediated and differs mechanistically from that for renal transplants.
sensitization; vascularized composite tissue allotransplantation; rejection
APOE4 allele is a major risk factor for late-onset Alzheimer disease (AD). The mechanism of action of APOE in AD remains unclear. To study the effects of APOE alleles on gene expression in AD, we have analyzed the gene transcription patterns of human hippocampus from APOE3/3, APOE3/4, APOE4/4 AD patients and normal control using Serial Analysis of Gene Expression (SAGE). Using SAGE, we found gene expression patterns in hippocampus of APOE3/4 and APOE4/4 AD patients differ substantially from those of APOE3/3 AD patients. APOE3/4 and APOE4/4 allele expression may activate similar genes or gene pools with associated functions. APOE4 AD alleles activate multiple tumor suppressors, tumor inducers and negative regulator of cell growth or repressors that may lead to increased cell arrest, senescence and apoptosis. In contrast, there is decreased expression of large clusters of genes associated with synaptic plasticity, synaptic vesicle docking and fusing and axonal/neuronal outgrowth. In addition, reduction of neurotransmitter receptors and Ca++ homeostasis, disruption of multiple signal transduction pathways, loss of cell protection, and perhaps most notably, mitochondrial oxidative phosphorylation/energy metabolism are associated with APOE3/4 and APOE4/4 AD alleles. These findings may help define the mechanisms that APOE4 contribute increased risk for AD and identify new candidate genes conferring susceptibility to AD.
Apolipoprotein E; Alzheimer disease; Serial Analysis of Gene Expression (SAGE); apoptosis; signal pathways
This work introduces a coordinate-independent method to analyse movement variability of tasks performed with hand-held tools, such as a pen or a surgical scalpel. We extend the classical uncontrolled manifold (UCM) approach by exploiting the geometry of rigid body motions, used to describe tool configurations. In particular, we analyse variability during a static pointing task with a hand-held tool, where subjects are asked to keep the tool tip in steady contact with another object. In this case the tool is redundant with respect to the task, as subjects control position/orientation of the tool, i.e. 6 degrees-of-freedom (dof), to maintain the tool tip position (3dof) steady. To test the new method, subjects performed a pointing task with and without arm support. The additional dof introduced in the unsupported condition, injecting more variability into the system, represented a resource to minimise variability in the task space via coordinated motion. The results show that all of the seven subjects channeled more variability along directions not directly affecting the task (UCM), consistent with previous literature but now shown in a coordinate-independent way. Variability in the unsupported condition was only slightly larger at the endpoint but much larger in the UCM.
Daily motor tasks typically involve more degrees-of-freedom than strictly required. For instance, pressing a button in the elevator only requires positioning the fingertip at a three-dimensional location in space. However, to move the arm we need to control many more degrees-of-freedom (at least seven, only considering the shoulder, elbow and wrist) than required by the task, each with its own variability due to physiological factors such as tremor. Variability at proximal joints (e.g. shoulder or elbow) is expected to be amplified and projected at the distal end (fingertip). Remarkably, inter-joint coordination reduces the final variability at the fingertip position. Recent theories, such as the uncontrolled manifold (UCM), distinguished between inter-joint variability that would not affect the finger position and variability that would affect the final task. A major issue is that traditional UCM methods rely on the coordinate system chosen to analyse the arm motion. Therefore, we introduce a coordinate independent UCM method for tasks performed with handheld tools, e.g. surgery. This paper describes a new method and demonstrates that it enables an accurate analysis of static pointing. The results clearly show that the subjects can channel variability in dimensions that do not affect the task outcome.