or alignment is a critical feature of functional soft
materials in living organisms, but it remains a challenge for spontaneously
generating anisotropic gel materials. Here we report a molecular design
that increases intermolecular aromatic–aromatic interactions
of hydrogelators during enzymatic hydrogelation for spontaneously
forming an anisotropic hydrogel. This process, relying on both aromatic–aromatic
interactions and enzyme catalysis, results in spontaneously aligned
supramolecular nanofibers as the matrices of a monodomain hydrogel
that exhibits significant birefringence. This work, as the first example
of monodomain hydrogels formed via an enzymatic reaction, illustrates
a new biomimetic approach for generating aligned anisotropic soft
Arthritis self-management education has demonstrated significant improvements in health distress, self-reported global health, and activity limitation, with trends toward improvement in self efficacy and mental stress management. Consequently, numerous national agencies have recommended arthritis self-management education to complement medical care. Despite these recommendations, arthritis self-management education has reached only a limited number of people. Compliance is also a persistent problem in standardized programs. As part of the Balancing Lupus Experiences with Stress Strategies (BLESS) Study, a validated psychosocial stress intervention was piloted among a cohort of African American lupus patients participating in an SLE database project at the Medical University of South Carolina (MUSC). Recruitment attempts were made with the 330 database participants who met eligibility requirements for the study. While enrollment was limited to 30 participants (n=15 controls and n=15 intervention), two of the participants assigned to the intervention group did not attend any intervention sessions and several participants did not complete post-intervention questionnaires. Therefore, data were analyzed on 30 participants at baseline, 25 (n=13 controls and n=12 intervention) at post-intervention, and 22 (n=12 controls and n=10 intervention) at four months post-intervention. In an effort to characterize those who fully participated in the study and those who were non-compliant or non-responsive to recruitment attempts, we obtained descriptive data from African-American Lupus patients participating in the SLE Clinic Database Project. This information can be used to develop and refine future intervention activities.
Toxoplasma gondii, an obligate intracellular pathogen, has a strong affinity for the nervous system. TgCtwh3, a representative Chinese 1 Toxoplasma strain prevalent in China, has the polymorphic features of the effectors ROP16I/III with type I and GRA15II with type II Toxoplasma strains. The interaction of this atypical strain with host cells remains extremely elusive.
Using a transwell system, neural stem cells C17.2 were co-cultured with the tachyzoites of TgCtwh3 or standard type I RH strain. The apoptosis levels of C17.2 cells and the expression levels of related proteins in the endoplasmic reticulum stress (ERS)-mediated pathway were detected by flow cytometry and Western blotting.
The apoptosis level of C17.2 cells co-cultured with TgCtwh3 had a significant increase compared to the negative control group; however, the apoptosis level in the TgCtwh3 group was significantly lower than that in the RH co-culture group. Western blotting analyses reveal that, after the C17.2 cells were co-cultured with TgCtwh3 and RH tachyzoites, the expression levels of caspase-12, CHOP and p-JNK in the cells increased significantly when compared to the control groups. After the pretreatment of Z-ATAD-FMK, an inhibitor of caspase-12, the apoptosis level of the C17.2 cells co-cultured with TgCtwh3 or RH tachyzoites had an apparent decline, and correspondingly, the expression levels of those related proteins were notably decreased.
Our findings suggest that TgCtwh3 may induce the apoptosis of the C17.2 cells by up-regulation of caspase-12, CHOP, and p-JNK, which are associated with ERS signaling pathways. This work contributes to better understanding the possible mechanism of brain pathology induced by T. gondii Chinese 1 isolates prevalent in China, and also reveals the potential value of ERS inhibitors to treat such related diseases in the future.
Toxoplasma gondii; TgCtwh3; C17.2; Apoptosis
Genetic efficiency in higher organisms depends on mechanisms to create multiple functions from single genes. To investigate this question for an enzyme family, we chose aminoacyl tRNA synthetases (AARSs). They are exceptional in their progressive and accretive proliferation of noncatalytic domains as the Tree of Life is ascended. Here we report discovery of a large number of natural catalytic nulls (CNs) for each human AARS. Splicing events retain noncatalytic domains while ablating the catalytic domain (CD) to create CNs with diverse functions. Each synthetase is converted into several new signaling proteins with biological activities ‘orthogonal’ to that of the catalytic parent. We suggest that splice variants with non-enzymatic functions may be more general, as evidenced by recent findings of other catalytically inactive splice-variant enzymes.
Self-assembly of small molecules, as a more common phenomenon than one previously thought, can be either beneficial or detrimental to cells. Despite its profound biological implications, how the self-assembly of small molecules behave in cellular environment is largely unknown and barely explored. This work studies four fluorescent molecules that consist of the same peptidic backbone (e.g., Phe-Phe-Lys) and enzyme trigger (e.g., a phosphotyrosine residue), but bear different fluorophores on the side chain of the lysine residue of the peptidic motif. These molecules, however, exhibit different ability of self-assembly before and after enzymatic transformation (e.g., dephosphorylation). Fluorescent imaging reveals that self-assembly directly affects the distribution of these small molecules in cellular environment. Moreover, cell viability tests suggest that the states and the location of the molecular assemblies in the cellular environment control the phenotypes of the cells. For example, the molecular nanofibers of one of the small molecules apparently stabilize actin filaments and alleviate the insult of an F-actin toxin (e.g., latrunculin A). Combining fluorescent imaging and enzyme-instructed self-assembly of small peptidic molecules, this work not only demonstrates that self-assembly as a key factor for dictating the spatial distribution of small molecules in cellular environment. In addition, it illustrates a useful approach, based on enzyme-instructed self-assembly of small molecules, to modulate spatiotemporal profiles of small molecules in cellular environment, which allows the use of the emergent properties of small molecules to control the fate of cells.
Human adenoviruses (HAdVs) are highly contagious pathogens causing acute respiratory disease (ARD), among other illnesses. Of the ARD genotypes, HAdV-7 presents with more severe morbidity and higher mortality than the others. We report the isolation and identification of a genome type HAdV-7d (DG01_2011) from a recent outbreak in Southern China. Genome sequencing, phylogenetic analysis, and restriction endonuclease analysis (REA) comparisons with past pathogens indicate HAdV-7d has re-emerged in Southern China after an absence of twenty-one years. Recombination analysis reveals this genome differs from the 1950s-era prototype and vaccine strains by a lateral gene transfer, substituting the coding region for the L1 52/55 kDa DNA packaging protein from HAdV-16. DG01_2011 descends from both a strain circulating in Southwestern China (2010) and a strain from Shaanxi causing a fatality and outbreak (Northwestern China; 2009). Due to the higher morbidity and mortality rates associated with HAdV-7, the surveillance, identification, and characterization of these strains in population-dense China by REA and/or whole genome sequencing are strongly indicated. With these accurate identifications of specific HAdV types and an epidemiological database of regional HAdV pathogens, along with the HAdV genome stability noted across time and space, the development, availability, and deployment of appropriate vaccines are needed.
Because of long-term use for chemotherapy and fluid administration in cancer patients, a totally implantable venous access port (TIVAP) has been advised as a feasible catheter. The purpose of this study was to evaluate the effectiveness and safety of ultrasound (US)-guided internal jugular vein (IJV) puncture for TIVAP implantation in patients with breast cancer.
We reviewed the medical records of 492 patients who underwent US-guided IJV puncture for TIVAP implantation at our oncology department between 2010 and 2013. Indications, surgical complications, and early and long-term complications were analyzed.
All TIVAPs were implanted successfully. Indications for TIVAP were chemotherapy alone (88 patients), chemoradiotherapy (387 patients), surgery (12 patients), and parenteral nutrition (5 patients). Complications were observed in 65 (13.21%) patients. The median duration of the TIVAP was 359 days (range, 28 to 712 days) without damage to the port or catheter, or leakage of drugs outside of the port system.
A TIVAP can be employed for chemotherapy and parenteral nutrition on the implantation day. Using a US-guided IJV puncture to completely implant a TIVAP is feasible and safe in patients with breast cancer.
Internal jugular vein; Totally implantable venous access port; Ultrasonography
Patients with type 2 diabetes have increased cancer risk and cancer-related mortality, which can be reduced by metformin treatment. However, it is unclear whether metformin can modulate clinical outcomes in patients with cancer and concurrent type 2 diabetes. We found that there was a relative survival benefit associated with metformin treatment compared with treatment with other glucose-lowering medications in both overall survival and cancer-specific survival. This benefit was also observed in subgroups by cancer type and country.
Describe the influences of different types of glucose-lowering medications on therapeutic outcomes of cancer patients who received standard anticancer treatment.Compare the survival associated with metformin treatment with survival in treatment with other glucose-lowering medications.
Patients with type 2 diabetes have increased cancer risk and cancer-related mortality, which can be reduced by metformin treatment. However, it is unclear whether metformin can also modulate clinical outcomes in patients with cancer and concurrent type 2 diabetes.
Patients and Methods.
A meta-analysis of 20 publications that included 13,008 subjects was performed to investigate the association between metformin and overall survival (OS) as well as cancer-specific survival (CSS) in patients with cancer and concurrent type 2 diabetes.
We found that there was a relative survival benefit associated with metformin treatment compared with treatment with other glucose-lowering medications in both OS and CSS (hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.55–0.79 and HR = 0.62; 95% CI: 0.46–0.84, respectively). These associations were also observed in subgroups by cancer type and country.
These results suggest that metformin is the drug of choice in the treatment of patients with cancer and concurrent type 2 diabetes.
Metformin; Cancer; Diabetes; Survival; Meta-Analysis
Objective: To investigate the association of three polymorphisms in the Interleukin-27 (IL-27) gene with CD risk in Chinese population. Methods: This case-control study involved 312 CD patients and 479 age- and sex-matched healthy controls. Genotyping was performed using PCR-LDR method. Data were analyzed using Haplo. Stats program. Results: There were significant differences between patients and controls in allele distributions of rs153109 (Pallele = 0.036). The risk for CD associated with the rs153109-G mutant allele was increased by 26% (95% CI [confidence interval]: 1.02-1.56; P = 0.03) under the additive model and by 45% (95% CI: 1.07-1.97; P = 0.02) under the dominant model. In haplotype analysis, haplotype T-T-G (in order of rs17855750, rs181206 and rs153109) increased the odds of CD by 37% (95% CI: 1.04-1.81; P = 0.028). Conclusions: In conclusion, genetic defects in IL-27 gene showed remarkable associations with CD in Chinese.
IL-27; polymorphism; Crohn’s diseases; susceptibility; association study
Coupled translocation of mRNA and tRNA through the ribosome, a process catalyzed by elongation factor EF-G, is a crucial step in protein synthesis. The crystal structure of a translocation complex describes the binding states of two tRNAs trapped in mid-translocation. The deacylated P-site tRNA has moved into a partly-translocated pe/E chimeric hybrid state. The anticodon stem-loop of the peptidyl A-site tRNA is captured in transition toward the 30S P site, while its 3′ acceptor end contacts both the A and P loops of the 50S subunit, forming an ap/ap chimeric hybrid state. The structure shows how features of ribosomal RNA rearrange to hand off the A-site tRNA to the P site, revealing an active role for rRNA in the translocation process.
5-Fluorouracil (5-Fu) is one of the most commonly used drugs to treat gastric cancer; however, drug-resistance in cancer cells reduces the efficacy of 5-Fu. Celecoxib may be able to reduce resistance to 5-Fu chemotherapy. The aim of the present study was to investigate the inhibitory effects of a combination of 5-Fu and celecoxib on implanted gastric cancer xenografts in nude mice and to elucidate the underlying mechanism. A tumor-bearing nude mice model was established. The mice were divided into blank control, 5-Fu, celecoxib and combination groups. The weight change and the tumor inhibition rate in each group were calculated. Immunocytochemistry, reverse transcription-polymerase chain reaction and western blotting methods were used to observe hypoxia-inducible factor-2α (HIF-2α), ATP-binding cassette transporter G2 (ABCG2) and octamer-binding transcription factor 4 (Oct-4) expression in the SGC7901 cells. Inhibition of the growth of the implanted gastric cancer was observed in the 5-Fu, celecoxib and combination groups. In the celecoxib and combination treatment groups, the mean tumor mass was significantly less than that in the control group (P<0.05), and the mean tumor mass in the combination treatment group was significantly less than that in the 5-Fu group (P<0.05). The tumor inhibition rates in the 5-Fu, celecoxib and combination groups were 26.36, 59.70 and 88.37%, respectively. The combination group exhibited the highest inhibition rate; the inhibition rates of the combination and celecoxib groups were significantly higher compared with the 5-Fu group (P<0.05). The expression levels of HIF-2, ABCG2 and Oct-4 mRNA and protein were high in the blank control group, and were further increased in the 5-Fu group. However, in the celecoxib and combination groups, the expression levels were lower compared with those in the control group. Significant differences were identified among the 5-Fu, celecoxib and combination groups (P<0.01). Celecoxib has antitumor effects in vivo. The mechanism may be associated with the reduced expression of cancer stem cell markers HIF-2α, Oct-4 and ABCG2. 5-Fu and celecoxib have a synergistic antitumor effect. The mechanism associated with the amelioration of resistance to chemotherapy in gastric cancer and the enhancement of the effect of chemotherapy may be via the reduction of the expression of HIF-2α, ABCG2, Oct-4 and other cancer stem cell markers in the tumor tissues.
5-fluorouracil; celecoxib; hypoxia-inducible factor-2α; ATP-binding cassette transporter G2; octamer-binding transcription factor 4; nude mice; gastric cancer
This study was performed to observe the effects of Zishenpingchan granule on neurobehavioral manifestations and the activity and gene expression of striatal dopamine D1 and D2 receptors of rats with levodopa-induced dyskinesias (LID). We established normal control group, LID model group, and TCM intervention group. Each group received treatment for 4 weeks. Artificial neural network (ANN) was applied to excavate the main factor influencing variation in neurobehavioral manifestations of rats with LID. The results showed that overactivation in direct pathway mediated by dopamine D1 receptor and overinhibition in indirect pathway mediated by dopamine D2 receptor may be the main mechanism of LID. TCM increased the efficacy time of LD to ameliorate LID symptoms effectively mainly by upregulating dopamine D2 receptor gene expression.
Increasing evidence suggests that diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. We performed an updated meta-analysis to examine the association between DM and risk of bladder cancer.
Materials and Methods
We systematically searched the EMBASE and Medline (PubMed) databases (from inception through February 1, 2013) and reviewed the reference lists of relevant publications to search for additional studies. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with random-effects models.
In total, 10 case-control and 14 cohort studies met the inclusion criteria. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer (RR 1.30, 95% CI 1.18–1.43). There was heterogeneity among studies (Pheterogeneity <0.001, I2=81.5%). Cohort studies showed a lower risk (RR 1.23, 95% CI 1.09–1.37) than case-control studies (odds ratio 1.46, 95% CI 1.20–1.78). The positive association was significant only in women (RR 1.23, 95% CI 1.02–1.49), but not in men (RR 1.07, 95% CI 0.97–1.18). The combined RRs remained unchanged before and after the studies on type 1 diabetes were excluded from analysis. The association between DM and bladder cancer risk did not differ significantly by methods of DM ascertainment. The combined RRs were 1.17 (95% CI 1.03–1.34), 1.34 (95% CI 1.19–1.51), and 1.57 (95% CI 0.96–2.55), respectively, when restricting the analysis to the studies accounting for body mass index, cigarette smoking, or glucose-lowering drug use.
This meta-analysis indicates a positive association between DM and risk of bladder cancer. Further studies are warranted to determine whether DM prevention and control can reduce risk of bladder cancer.
AIM: To assess “top-down” treatment for deep remission of early moderate to severe Crohn’s disease (CD) by double balloon enteroscopy.
METHODS: Patients with early active moderate to severe ileocolonic CD received either infusion of infliximab 5 mg/kg at weeks 0, 2, 6, 14, 22 and 30 with azathioprine from week 6 onwards (Group I), or prednisone from week 0 as induction therapy with azathioprine from week 6 onwards (Group II). Endoscopic evaluation was performed at weeks 0, 30, 54 and 102 by double balloon enteroscopy. The primary endpoints were deep remission rates at weeks 30, 54 and 102. Secondary endpoints included the time to achieve clinical remission, clinical remission rates at weeks 2, 6, 14, 22, 30, 54 and 102, and improvement of Crohn’s Disease Endoscopic Index of Severity scores at weeks 30 and 54 relative to baseline. Intention-to-treat analyses of the endpoints were performed.
RESULTS: Seventy-seven patients were enrolled, with 38 in Group I and 39 in Group II. By week 30, deep remission rates were 44.7% and 17.9% in Groups I and II, respectively (P = 0.011). The median time to clinical remission was longer for patients in Group II (14.2 wk) than for patients in Group I (6.8 wk, P = 0.009). More patients in Group I were in clinical remission than in Group II at weeks 2, 6, 22 and 30 (2 wk: 26.3% vs 2.6%; 6 wk: 65.8% vs 28.2%; 22 wk: 71.1% vs 46.2%; 30 wk: 68.4% vs 43.6%, P < 0.05). The rates of clinical remission and deep remission were greater at weeks 54 and 102 in Group I, but the differences were insignificant.
CONCLUSION: Top-down treatment with infliximab and azathioprine, as compared with corticosteroid and azathioprine, results in higher rates of earlier deep remission in early CD.
Crohn’s disease; Top-down treatment; Deep remission; Double balloon enteroscopy; Mucosal healing
Transcription of hepatitis B virus (HBV) from the covalently closed circular DNA (cccDNA) template is essential for its replication. Suppressing the level and transcriptional activity of cccDNA might have anti-HBV effect. Although cellular transcription factors, such as CREB, which mediate HBV transcription, have been well described, transcriptional coactivators that facilitate this process are incompletely understood. In this study we showed that CREB-regulated transcriptional coactivator 1 (CRTC1) is required for HBV transcription and replication. The steady-state levels of CRTC1 protein were elevated in HBV-positive hepatoma cells and liver tissues. Ectopic expression of CRTC1 or its homolog CRTC2 or CRTC3 in hepatoma cells stimulated the activity of the preS2/S promoter of HBV, whereas overexpression of a dominant inactive form of CRTC1 inhibited HBV transcription. CRTC1 interacts with CREB and they are mutually required for the recruitment to the preS2/S promoter on cccDNA and for the activation of HBV transcription. Accumulation of pregenomic RNA (pgRNA) and cccDNA was observed when CRTC1 or its homologs were overexpressed, whereas the levels of pgRNA, cccDNA and secreted HBsAg were diminished when CRTC1 was compromised. In addition, HBV transactivator protein HBx stabilized CRTC1 and promoted its activity on HBV transcription. Our work reveals an essential role of CRTC1 coactivator in facilitating and supporting HBV transcription and replication.
Starch-coated, PEGylated and heparin-functionalized iron oxide magnetic nanoparticles (DNPH) were successfully synthesized and characterized in detail. The PEGylation (20 kDa) process resulted in an average coating of 430 PEG molecules per nanoparticle. After that, heparin conjugation was carried out to attain the final DNPH platform with 35.4 μg of heparin/mg Fe. Commercially acquired heparin-coated magnetic nanoparticles were also PEGylated (HP) and characterized for comparison. Protamine was selected as a model protein to demonstrate the strong binding affinity and high loading content of DNPH for therapeutically relevant cationic proteins. DNPH showed a maximum loading of 22.9 μg protamine/mg Fe. In the pharmacokinetic study, DNPH displayed a long-circulating half-life of 9.37 h, 37.5-fold longer than that (0.15 h) of H P. This improved plasma stability enabled extended exposure of DNPH to the tumor lesions, as was visually confirmed in a flank 9L-glioma mouse model using magnetic resonance imaging (MRI). Quantitative analysis of the Fe content in excised tumor lesions further demonstrated the superior tumor targeting ability of DNPH, with up to 31.36 μg Fe/g tissue (13.07% injected dose (I.D.)/g tissue) and 7.5-fold improvement over that (4.27 μg Fe/g tissue; 1.78% I.D./g tissue) of HP. Overall, DNPH shed light of the potential to be used as a protein drug delivery platform.
Magnetic targeting; Iron oxide nanoparticles; Heparin; 9L-glioma; Magnetic resonance imaging
Directed enzyme/prodrug therapy (DEPT) has promising application for cancer therapy. However, most current DEPT strategies face shortcomings such as the loss of enzyme activity during preparation, low delivery and transduction efficiency in vivo, difficult to be monitored. In current study, a novel magnetic directed enzyme/prodrug therapy (MDEPT) was set up by conjugating β-Glucosidase (β-Glu) to aminated, starch-coated, iron oxide magnetic iron oxide nanoparticles (MNP), abbreviated as β-Glu-MNP, using glutaraldehyde as the crosslinker. This β-Glu-MNP was then characterized in detail by size distribution, zeta potential, FTIR spectra, TEM, SQUID and magnetophoretic mobility analysis. Compared to free enzyme, the conjugated β-Glu on MNP remained 85.54%±6.9% relative activity and showed much better temperature stability. relative activity and showed much better temperature stability. The animal study results showed that β-Glu-MNP display preferable pharmacokinetics characteristic in relation to MNP. With adscititious magnetic field on the surface of tumor, a significant quantity of β-Glu-MNP was selectively delivered into a subcutaneous tumor of glioma-bearing mice. Remarkably, the enzyme activity of the delivered β-Glu in tumor lesions showed as high as 20.123 ± 5.022 mU/g tissue with 2.14 of tumor/non-turmor of β-Glu activity.
β-Glucosidase; magnetic iron oxide nanoparticles; magnetic directed enzyme/prodrug therapy; 9L-glioma
Several research studies in different populations indicate that inflammation may be the link between obesity and insulin resistance (IR). However, this relationship has not been adequately explored among African Americans, an ethnic group with disproportionately high rates of obesity and IR. In this study, we conducted a comparative study of the relationship among adiposity, inflammation, and IR in African Americans and West Africans, the ancestral source population for African Americans. The associations between obesity markers (BMI and waist-to-hip ratio (WHR)), inflammatory markers (high-sensitivity C-reactive protein (hsCRP), haptoglobin, interleukin (IL)-6, and tumor necrosis factor (TNF)-α), and IR (homeostasis model assessment of insulin resistance (HOMAIR)) were evaluated in 247 West Africans and 315 African Americans. In average, African Americans were heavier than the West Africans (by an average of 1.6 BMI units for women and 3 BMI units for men). Plasma hsCRP, haptoglobin, and IL-6 (but not TNF-α level) were higher in African Americans than in West Africans. In both populations, BMI was associated with markers of inflammation and with HOMAIR, and these associations remained significant after adjusting for sex and age. However, the pattern of associations between measured inflammatory markers and IR was different between the two groups. In West Africans, hsCRP was the only inflammatory marker associated with IR. In contrast, hsCRP, haptoglobin, and IL-6 were all associated with IR in African Americans. Interestingly, none of the associations between markers of inflammation and IR remained significant after adjusting for BMI. This finding suggests that in African Americans, the relationship between inflammatory markers and IR is mediated by adiposity.
Trimethylation of lysine 36 of histone H3 (H3K36me3) is found to be associated with various transcription events. In Arabidopsis, the H3K36me3 level peaks in the first half of coding regions, which is in contrast to the 3′-end enrichment in animals. The MRG15 family proteins function as ‘reader’ proteins by binding to H3K36me3 to control alternative splicing or prevent spurious intragenic transcription in animals. Here, we demonstrate that two closely related Arabidopsis homologues (MRG1 and MRG2) are localised to the euchromatin and redundantly ensure the increased transcriptional levels of two flowering time genes with opposing functions, FLOWERING LOCUS C and FLOWERING LOCUS T (FT). MRG2 directly binds to the FT locus and elevates the expression in an H3K36me3-dependent manner. MRG1/2 binds to H3K36me3 with their chromodomain and interact with the histone H4-specific acetyltransferases (HAM1 and HAM2) to achieve a high expression level through active histone acetylation at the promoter and 5′ regions of target loci. Together, this study presents a mechanistic link between H3K36me3 and histone H4 acetylation. Our data also indicate that the biological functions of MRG1/2 have diversified from their animal homologues during evolution, yet they still maintain their conserved H3K36me3-binding molecular function.
In our prior publications we characterized a conserved acetylation motif (K(R)xxKK) of evolutionarily related nuclear receptors. Recent reports showed that peroxisome proliferator activated receptor gamma (PPARγ) deacetylation by SIRT1 is involved in delaying cellular senescence and maintaining the brown remodeling of white adipose tissue. However, it still remains unknown whether lysyl residues 154 and 155 (K154/155) of the conserved acetylation motif (RIHKK) in Pparγ1 are acetylated. Herein, we demonstrate that Pparγ1 is acetylated and regulated by both endogenous TSA-sensitive and NAD-dependent deacetylases. Acetylation of lysine 154 was identified by mass spectrometry (MS) while deacetylation of lysine 155 by SIRT1 was confirmed by in vitro deacetylation assay. An in vivo labeling assay revealed K154/K155 as bona fide acetylation sites. The conserved acetylation sites of Pparγ1 and the catalytic domain of SIRT1 are both required for the interaction between Pparγ1 and SIRT1. Sirt1 and Pparγ1 converge to govern lipid metabolism in vivo. Acetylation-defective mutants of Pparγ1 were associated with reduced lipid synthesis in ErbB2 overexpressing breast cancer cells. Together, these results suggest that the conserved lysyl residues K154/K155 of Pparγ1 are acetylated and play an important role in lipid synthesis in ErbB2-positive breast cancer cells.
acetylation; peroxisome proliferator-activated receptor gamma (Pparγ); nuclear receptors; silent mating type information regulation 2 homolog 1 (SIRT1); lipogenesis
P-glycoprotein (P-gp) mediated drug efflux across the blood–brain barrier (BBB) is an important mechanism underlying poor brain penetration of certain antiepileptic drugs (AEDs). Nanomaterials, as drug carriers, can overcome P-gp activity and improve the targeted delivery of AEDs. However, their applications in the delivery of AEDs have not been adequately investigated. The objective of this study was to develop a nano-scale delivery system to improve the solubility and brain penetration of the antiepileptic drug lamotrigine (LTG).
LTG-loaded Pluronic® P123 (P123) polymeric micelles (P123/LTG) were prepared by thin-film hydration, and brain penetration capability of the nanocarrier was evaluated.
The mean encapsulating efficiency for the optimized formulation was 98.07%; drug-loading was 5.63%, and particle size was 18.73 nm. The solubility of LTG in P123/LTG can increase to 2.17 mg/mL, making it available as a solution. The in vitro release of LTG from P123LTG presented a sustained-release property. Compared with free LTG, the LTG-incorporated micelles accumulated more in the brain at 0.5, 1, and 4 hours after intravenous administration in rats. Pretreatment with systemic verapamil increased the rapid brain penetration of free LTG but not P123/LTG. Incorporating another P-gp substrate (Rhodamine 123) into P123 micelles also showed higher efficiency in penetrating the BBB in vitro and in vivo.
These results indicated that P123 micelles have the potential to overcome the activity of P-gp expressed on the BBB and therefore show potential for the targeted delivery of AEDs. Future studies are necessary to further evaluate the appropriateness of the nanocarrier to enhance the efficacy of AEDs.
antiepileptic drug; lamotrigine; polymeric micelles; P-glycoprotein; pluronic; nanocarrier
Although accumulation of dendritic cell (DC) precursors occurs in bone marrow (BM), the terminal differentiation of these cells takes place outside BM. The signaling, regulating this process, remains poorly understood. We demonstrated that this process could be differentially regulated by Notch ligands: Jagged-1 (Jag1) and Delta-like ligand 1 (Dll1). In contrast to Dll1, Jag1, in vitro and during induced myelopoiesis in vivo, prevented DC differentiation by promoting the accumulation of their precursors. Although both ligands activated Notch in hematopoietic progenitor cells (HPC), they had an opposite effect on Wnt signaling. Dll1 activated Wnt pathways; whereas, Jag1 inhibited it via down-regulation of the expression of the Wnt receptors Frizzled (Fzd). Jag1 suppressed fzd expression by retaining histone deacetylase 1 in the complex with the transcription factor CSL/CBF-1 on the fzd promoter. Our results suggest that DC differentiation, during induced myelopoiesis, can be regulated by the nature of the Notch ligand expressed on adjacent stroma cells.
The utility of combination with CK5/6, IMP3 and TTF1 to differentiate among reactive mesothelial cells (RMs), metastatic adenocarcinoma of lung (LAC) and non-lung (NLAC) origin was investigated by using immunocytochemistry (ICC) and conventional PCR (C-PCR) in pleural effusion. A total of 108 cell blocks (32 RMs, 51 LAC and 25 NLAC were evaluated by ICC for CK5/6, IMP3 and TTF1 protein expression. In addition, we further performed C-PCR for amplification of CK5/6, IMP3 and TTF1 DNA from 28 specimens (9 MAC and 7 RMs, 6 LAC and 6 NLAC) for molecular diagnosis. CK5/6 staining was observed in the majority of reactive specimens (78.1%) and was rare in adenocarcinoma cells (14.5%), whereas the opposite was true for IMP3 and TTF1. We found a high frequency of TTF1 positivity (76.5%) in LAC, but not in NLAC (4.0%); while there was no significant difference of IMP3 expression in LAC (88.2%) and NLAC (88.0%). The 487 bp DNA fragments of IMP3 was expected to be amplified in 6/9 of adenocarcinoma cases showed negative in ICC; and the 394 bp DNA fragments of CK5/6 was also expected to be amplified in 4/7 of RMs cases showed negative in ICC. Consistent with ICC results, there was significant difference of TTF1 expression in the LAC and NLAC compared with IMP3 expression. The combination with CK5/6, IMP3 and TTF1 immunostaining appears to be useful to improve the accuracy of cytological diagnoses between RMs, metastatic adenocarcinoma of lung and non-lung origin in pleural effusion. In addition, C-PCR may act as a useful supplemental approach for ICC, especially negative cases in ICC for differential cytological diagnosis.
CK5/6; IMP3; TTF1; pleural effusion; adenocarcinoma; PCR
Minimally invasive endoscopic biopsy techniques have been widely available as potential alternatives for mediastinal lesions staging in patients with known or suspected lung cancer. Previous efforts have been made to evaluate the diagnostic performance of specific endoscopic modality alone at the level of the mediastinum for staging lung cancer, however, few studies focus on the accuracy of comparisons between different endoscopic modalities, especially at the level of any individual lymph node station. The objective of our study is to determine the diagnostic yields of different endoscopic modalities for staging mediastinal lymphadenopathy in lung cancer, especially concerning the individual lymph node station.
A systematic electronic search of MEDLINE, EMBASE, SinoMed and ISI Web of Science were performed to identify studies evaluating endoscopic modalities accuracy with restriction of English and Chinese languages from inception to an update until May 2014. Data were extracted with the patient as the unit of analysis with regards to the abilities of different endoscopic modalities at the level of mediastinum and particular lymph node station. The methodological quality was assessed independently according to the Quality Assessment of Diagnostic Accuracy Study (QADAS) criteria. An exact binomial rendition of bivariate mixed-effects regression model was used to estimate the pooled sensitivity and specificity. Also, pre–post probability analysis, publication bias analysis and sensitivity analysis were performed for a synthesis of knowledge of this context.
The findings will advance our better available knowledge of optimal clinical decision-making when dealing with staging of mediastinal metastasis in lung cancer.
Trial registration number
PROSPERO—NIHR Prospective Register of Systematic Reviews (CRD42014009792).
The pregnane X receptor (PXR) was isolated as a xenosensor regulating xenobiotic responses. In this study, we show that PXR plays an endobiotic role by impacting lipid homeostasis. Expression of an activated PXR in the livers of transgenic mice resulted in an increased hepatic deposit of triglycerides. This PXR-mediated lipid accumulation was independent of the activation of the lipogenic transcriptional factor SREBP-1c (sterol regulatory element-binding protein 1c) and its primary lipogenic target enzymes, including fatty-acid synthase (FAS) and acetyl-CoA carboxylase 1 (ACC-1). Instead, the lipid accumulation in transgenic mice was associated with an increased expression of the free fatty acid transporter CD36 and several accessory lipogenic enzymes, such as stearoyl-CoA desaturase-1 (SCD-1) and long chain free fatty acid elongase. Studies using transgenic and knock-out mice showed that PXR is both necessary and sufficient for Cd36 activation. Promoter analyses revealed a DR-3-type of PXR-response element in the mouse Cd36 promoter, establishing Cd36 as a direct transcriptional target of PXR. The hepatic lipid accumulation and Cd36 induction were also seen in the hPXR “humanized” mice treated with the hPXR agonist rifampicin. The activation of PXR was also associated with an inhibition of pro-β-oxidative genes, such as peroxisome proliferator-activated receptor α (PPARα) and thiolase, and an up-regulation of PPARγ, a positive regulator of CD36. The cross-regulation of CD36 by PXR and PPARγ suggests that this fatty acid transporter may function as a common target of orphan nuclear receptors in their regulation of lipid homeostasis.