Analyzing the influence of BDNF heterozygosity on spatial memory response to 17β-estradiol

The recent use of estrogen-based therapies as adjunctive treatments for the cognitive impairments of schizophrenia has produced promising results; however the mechanism behind estrogen-based cognitive enhancement is relatively unknown. Brain-derived neurotrophic factor (BDNF) regulates learning and memory and its expression is highly responsive to estradiol. We recently found that estradiol modulates the expression of hippocampal parvalbumin-positive GABAergic interneurons, known to regulate neuronal synchrony and cognitive function. What is unknown is whether disruptions to the aforementioned estradiol-parvalbumin pathway alter learning and memory, and whether BDNF may mediate these events. Wild-type (WT) and BDNF heterozygous (+/-) mice were ovariectomized (OVX) at 5 weeks of age and simultaneously received empty, estradiol- or progesterone-filled implants for 7 weeks. At young adulthood, mice were tested for spatial and recognition memory in the Y-maze and novel-object recognition test, respectively. Hippocampal protein expression of BDNF and GABAergic interneuron markers, including parvalbumin, were assessed. WT OVX mice show impaired performance on Y-maze and novel-object recognition test. Estradiol replacement in OVX mice prevented the Y-maze impairment, a Behavioral abnormality of dorsal hippocampal origin. BDNF and parvalbumin protein expression in the dorsal hippocampus and parvalbumin-positive cell number in the dorsal CA1 were significantly reduced by OVX in WT mice, while E2 replacement prevented these deficits. In contrast, BDNF(+/-) mice showed either no response or an opposite response to hormone manipulation in both behavioral and molecular indices. Our data suggest that BDNF status is an important biomarker for predicting responsiveness to estrogenic compounds which have emerged as promising adjunctive therapeutics for schizophrenia patients.

Explanation of colon cancer pathophysiology through analyzing the disrupted homeostasis of bile acids

BACKGROUND

The colon plays a key role in regulating the homeostasis of bile acids.

AIM

The present study aims to evaluate the influence of colon cancer towards the homeostasis of bile acids.

METHODS

The free and conjugated bile acids were determined using ultraperformance LC (UPLC) coupled with ABI 4000 QTRAP triple quadrupole instruments.

RESULTS

The results showed that the free bile acids in serum of patients with colon cancers tend to increase, and the conjugated bile acids tended to decrease, especially for taurolithocholate (TLCA) (p<0.001).

CONCLUSION

The alteration of bile acids balance in colon cancers indicated the possibility of complicated diseases due to the disrupted balance of bile acids.

HbA1c levels as predictors of ablation outcome in type 2 diabetes mellitus and paroxysmal atrial fibrillation

AIMS

The aim of this study was to evaluate whether the levels of HbA1c could predict the outcome of ablation in patients with type 2 diabetes mellitus (T2DM) and paroxysmal atrial fibrillation (PAF).

PATIENTS AND METHODS

The study comprised 149 consecutive patients with T2DM and PAF who underwent their first circumferential pulmonary vein isolation. HbA1c levels were measured before ablation. Cox proportional hazards models were constructed to assess the relationship between HbA1c levels and the recurrence of atrial fibrillation (AF).

RESULTS

Of the 149 patients, 60 (40.3 %) developed AF recurrence after a median 12-month follow-up. Multivariate Cox regression analysis revealed that left atrium size and HbA1c were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that an HbA1c cut-off value of ≥ 6.9 % predicted recurrence with 55.0 % sensitivity and 67.4 % specificity (AUC = 0.634). The success rate of ablation was 69.0 % in patients with an HbA1c value of < 6.9 % compared with 46.8 % in those with an HbA1c value of ≥ 6.9 % (log-rank test, p = 0.004).

CONCLUSION

High levels of HbA1c were associated with an increased risk of recurrence of atrial tachyarrhythmia in patients with T2DM and PAF undergoing catheter ablation.

Ischemic postconditioning prevents renal ischemia reperfusion injury through the induction of heat shock proteins in rats

Ischemic postconditioning (IPo) attenuates ischemia-reperfusion injuries (IRI) in various organs, of both animals and humans. This study tested the hypothesis that IPo attenuates renal IRI through the upregulation of heat shock protein (HSP)70, HSP27 and heme oxygenase-1 (HO-1, also known as HSP 32) expression. Adult Sprague Dawley rats were subjected to bilateral renal ischemia for 45 min followed by reperfusion for up to 48 h. One group of rats received IPo prior to restoring full perfusion. Another group was administered 100 mg/kg HSP inhibitor quercetin, injected intraperitoneally 1 h prior to ischemia. Control rats received sham operations. Renal IR resulted in severe morphological and pathological changes, with increased serum creatinine and blood urea nitrogen concentrations. IR resulted in increased inflammation by inducing plasma tumor necrosis factor-α and renal nuclear factor kappa-light-chain-enhancer of activated B cells expression. IR also increased lipid peroxidation, as indicated by elevated malondialdehyde content, reduced superoxide dismutase activity and increased renal apoptosis. Renal HSP70, HSP27 and HO-1 mRNA and protein levels were increased by IR and further elevated by IPo. IPo attenuated these changes observed in pathology, lipid peroxidation, apoptosis and inflammation. Quercetin treatment abolished all the protective effects of IPo. In conclusion, this study showed that IPo can attenuate lipid peroxidation, apoptosis and inflammation as well as renal IRI by upregulating the expression of HSP70, HSP27 and HO-1.

The influence of the HPG axis on stress response and depressive-like behaviour in a transgenic mouse model of Huntington's disease

Huntington's disease (HD) is an autosomal dominant, neurodegenerative disease caused by a CAG tandem repeat mutation encoding a polyglutamine tract expansion in the huntingtin protein. Depression is among the most common affective symptoms in HD but the pathophysiology is unclear. We have previously discovered sexually dimorphic depressive-like behaviours in the R6/1 transgenic mouse model of HD at a pre-motor symptomatic age. Interestingly, only female R6/1 mice display this phenotype. Sexual dimorphism has not been explored in the human HD population despite the well-established knowledge that the clinical depression rate in females is almost twice that of males. Female susceptibility suggests a role of sex hormones, which have been shown to modulate stress response. There is evidence suggesting that the gonads are adversely affected in HD patients, which could alter sex hormone levels. The present study examined the role sex hormones play on stress response in the R6/1 mouse model of HD, in particular, its modulatory effect on the hypothalamic-pituitary-adrenal (HPA) axis and depression-like behaviour. We found that the gonads of female R6/1 mice show atrophy at an early age. Expression levels of gonadotropin-releasing hormone (GnRH) were decreased in the hypothalamus of female HD mice, relative to wild-type female littermates, as were serum testosterone levels. Female serum estradiol levels were not significantly changed. Gonadectomy surgery reduced HPA-axis activity in female mice but had no effect on behavioural phenotypes. Furthermore, expression of the oestrogen receptor (ER) α gene was found to be higher in the adrenal cells of female HD mice. Finally, administration of an ERβ agonist diarylpropionitrile (DPN) rescued depressive-like behaviour in the female HD mice. Our findings provide new insight into the pathogenesis of sexually dimorphic neuroendocrine, physiological and behavioural endophenotypes in HD, and suggest a new avenue for therapeutic intervention.

Extrinsic and intrinsic charge trapping at the graphene/ferroelectric interface

The interface between graphene and the ferroelectric superlattice PbTiO3/SrTiO3 (PTO/STO) is studied. Tuning the transition temperature through the PTO/STO volume fraction minimizes the adorbates at the graphene/ferroelectric interface, allowing robust ferroelectric hysteresis to be demonstrated. "Intrinsic" charge traps from the ferroelectric surface defects can adversely affect the graphene channel hysteresis and can be controlled by careful sample processing, enabling systematic study of the charge trapping mechanism.

Bulk signatures of pressure-induced band inversion and topological phase transitions in Pb(1-x)Sn(x)Se

The characteristics of topological insulators are manifested in both their surface and bulk properties, but the latter remain to be explored. Here we report bulk signatures of pressure-induced band inversion and topological phase transitions in Pb(1-x)Sn(x)Se (x=0.00, 0.15, and 0.23). The results of infrared measurements as a function of pressure indicate the closing and the reopening of the band gap as well as a maximum in the free carrier spectral weight. The enhanced density of states near the band gap in the topological phase gives rise to a steep interband absorption edge. The change of density of states also yields a maximum in the pressure dependence of the Fermi level. Thus, our conclusive results provide a consistent picture of pressure-induced topological phase transitions and highlight the bulk origin of the novel properties in topological insulators.

Loss of Vhl in cartilage accelerated the progression of age-associated and surgically induced murine osteoarthritis

OBJECTIVE

To investigate the role of Vhl in maintaining the integrity of articular cartilage and in the development of experimental osteoarthritis (OA).

METHOD

Histology of articular cartilage and subchondral bone in both Vhl cKO and WT mice were analyzed by histopathology and micro-CT. Articular cartilage destruction and proteoglycan loss were scored in aged (12-month-old) mice as well as in mice with surgically induced OA. Apoptosis of cartilage in age-related and surgically induced OA was detected with TUNEL assay. Expressions of von Hippel-Lindau (VHL), Fas, LC-3, HIF-1α, HIF-2α, p-mTOR and MMP-13 in the knee joints were analyzed by immunostaining.

RESULTS

No gross differences in cartilage were observed between Vhl cKO and WT mice at age 4 months. However, Vhl cKO mice displayed accelerated age-associated spontaneous OA and surgically induced OA. Cartilage destruction and proteoglycan loss were observed in the absence of Vhl. In addition, inactivation of Vhl resulted in up-regulation of HIF-2α and increased chondrocyte apoptosis and decreased expression of autophagy during OA development. Immunohistochemical staining also showed that Vhl deficiency led to increased expression of Fas, p-mTOR and MMP-13, and those genes were associated with cell apoptosis, autophagy and cartilage matrix breakdown, respectively.

CONCLUSION

Loss of Vhl in adult articular cartilage is associated with earlier dysregulation of cartilage homeostasis, characterized by an increased chondrocyte apoptosis, compromised chondrocyte autophagy, and an accelerated age-related and surgery-induced OA development. These results highlight the novel role of Vhl in maintaining joint homeostasis and OA development.

Functional evaluation of the role of C-type lectin domain family 16A at the chromosome 16p13 locus

The type 1 diabetes-associated 16p13 locus contains the CLEC16A gene. Its preferential immune cell expression suggests involvement in autoimmunity. Given its elevated expression in dendritic and B cells - known professional antigen-presenting cells (APCs) - we hypothesize that C-type lectin domain family 16 member A (CLEC16A) may be involved in T cell co-stimulation and consequent activation and proliferation. We also sought to identify CLEC16A's subcellular localization. The effect of the CLEC16A knock-down (KD) on B cell co-stimulation and activation of T cells was tested in human lymphoblastoid cell lines (LCLs) by co-culture with CD4(+) T cells. T cell activation and proliferation were determined by flow-cytometric analysis of CD69 and CD25 expression and carboxyfluorescein succinimidyl ester (CFSE) dilution, respectively. CLEC16A subcellular localization in K562 cells was examined by immunofluorescence. We show that the CLEC16A KD did not affect the tested indices of lymphoblastoid cell line (LCL) APC capacity. Additionally, the percentage of activated T cells following LCL co-culture was not affected significantly by the CLEC16A KD. T cells co-cultured with KD or control LCLs also exhibited similar cell division profiles. CLEC16A co-localized with an endoplasmic reticulum (ER) marker, suggesting that it may be an ER protein. In conclusion, CLEC16A may not be involved in T cell co-stimulation. Additional studies on CLEC16A, accounting for its ER localization, are needed to uncover its biological role.

Barcoded pyrosequencing analysis of the bacterial community of Daqu for light-flavour Chinese liquor

The bacterial community of Daqu affects its characteristics and functions by their metabolic products, such as amylase, protease, esterase. In this study, barcoded pyrosequencing was used to analyse the bacterial communities of three kinds of Daqu for light-flavour Chinese liquor brewing. A total of 13672 sequences were identified as bacterial sequences. The Shannon index of QC, HX and GT for clusters sharing 97% homology was 5·0, 4·2 and 4·2, respectively, indicating that QC had the highest biodiversity. The Good's coverage index of QC, HX and GT was 88·2, 93·4 and 93%, respectively, indicating that the vast majority of phylotypes have been detected. Among the three kinds of Daqu, the majority of annotated reads were assigned to two phyla (Firmicutes and Actinobacteria). The phylum Firmicutes was the most abundant group in QC (74·2%), HX (81·4%) and GT (98·6%), and the phylum Actinobacteria was the second in QC (23·9%), HX (17·9%) and GT (1·1%). There were many lactic acid bacteria in all three kinds of Daqu QC (45·8%), HX (46·3%) and GT (24·7%). In addition, the most abundant family in GT was Bacillus, accounting for 65·0%, while in HX, the families Thermoactinomycetaceae and Streptomycetaceae accounted for 19·5 and 14·1%, respectively, and in QC, 13·1% were Streptomycetaceae, 12·2% were heterofermentative Leuconostocaceae.

SIGNIFICANCE AND IMPACT OF THE STUDY

There are three kinds of Daqu (starter material) used for famous Chinese light-flavour liquor brewing, that is Qingcha, Hongxin and Houhuo. Since Daqu was fermented in an open environment, the microbiology communities were different with different kind of Daqu. Objective bacterial communities determined by barcoded pyrosequencing help to speculate possible metabolic productions, even to guess the function of many kind of Daqu in light-flavour liquor brewing.

Long-term outcome of HLA-haploidentical hematopoietic SCT without in vitro T-cell depletion for adult severe aplastic anemia after modified conditioning and supportive therapy

HLA-haploidentical hematopoietic SCT (HSCT) is an option for severe aplastic anemia (SAA) patients. Here, we evaluated the outcomes of 26 adult-SAA patients who received HLA-haploidentical HSCT in five transplant centers in southwestern China. Most of the patients in this study failed prior therapy and were transfused heavily before the transplantation. The patients received fludarabine+cyclophosphamide+antithymocyte globulin as conditioning regimens and then unmanipulated peripheral blood plus marrow transplantation. Micafungin, i.v. Ig and recombinant human TPO were used for post-grafting infection prevention and supportive care. Of 26 patients, 25 achieved engraftment at a median of 13 days (range, 11-19 days) after HSCT. One of 25 patients experienced graft rejection and did not achieve sustained engraftment after second HSCT. Therefore, the final engraftment rate was 92.3%. Three of 25 (12%) patients developed acute GVHD, 10 of 25 (40%) patients developed chronic GVHD (9 with limited whereas the other with extensive). The OS rate was 84.6% and the average follow-up time was 1313.2 (738-2005) days for surviving patients. This encouraging result suggests that HLA-haploidentical HSCT is an effective therapeutic option for adults with acquired SAA if an HLA-identical donor is not available.

Therapeutic effects of orally administrated antioxidant drugs on acute noise-induced hearing loss

OBJECTIVE

The objective of this study was to investigate the dose-dependent therapeutic effect of the orally administrated antioxidant drugs [4-hydroxy alpha-phenyl-tert-butylnitrone (4-OHPBN) and N-acetyl-L-cysteine (NAC)] on acute noise-induced hearing loss because oral administration is the most commonly used method of drug administration due to its convenience, safety, and economical efficiency.

METHODS

Thirty chinchilla were exposed to a 105 dB octave band noise centered at 4 kHz for 6 h and randomly assigned to a control group (saline only) and three experimental groups [4-OHPBN (10 mg/kg) plus NAC (20 mg/kg), 4-OHPBN (20 mg/kg) plus NAC (50 mg/kg), and 4-OHPBN (50 mg/kg) plus NAC (100 mg/kg)]. The drugs were orally administrated beginning 4 h after noise exposure and then administered twice daily for the next 2 days. Permanent auditory brainstem response threshold shifts, distortion product otoacoustic emission threshold shifts, and the percentage of missing outer hair cell were determined.

RESULTS

The oral administration significantly reduced permanent hearing threshold shift, distortion product otoacoustic emission threshold shift, and the percentage of missing outer hair cell in a dose-dependent manner.

DISCUSSION

This result demonstrates that orally administered drugs can treat acute noise-induced hearing loss in a dose-dependent manner. This suggests that oral administration was effective in treating acute noise-induced hearing loss as in intraperitoneal administration.

An anti-leishmanial thiadiazine agent induces multiple myeloma cell apoptosis by suppressing the nuclear factor kappaB signalling pathway

Background:

Nuclear factor κB (NFκB) has a critical role in the pathophysiology of multiple myeloma. Targeting NFκB is an important strategy for anti-myeloma drug discovery.

Methods:

Luciferase assay was used to evaluate the effects of DETT on NFκB activity. Annexin V–PI double staining and immunoblotting were used to evaluate DETT-induced cell apoptosis and suppression of NFκB signalling. Anti-myeloma activity was studied in nude mice.

Results:

DETT downregulated IKKα, β, p65, and p50 expression and inhibited phosphorylation of p65 (Ser536) and IκBα. Simultaneously, DETT increased IκBα, an inhibitor of the p65/p50 heterodimer, even in the presence of stimulants lipopolysaccharide, tumour necrosis factor-α, or interleukin-6. DETT inhibited NFκB transcription activity and downregulated NFκB-targeted genes, including Bcl-2, Bcl-XL, and XIAP as measured by their protein expression. Deregulation of NFκB signalling by DETT resulted in MM cell apoptosis characterised by cleavage of caspase-3, caspase-8, and PARP. Notably, this apoptosis was partly blocked by the activation of NFκB signalling in the presence of TNFα and IL-6. Moreover, DETT delayed myeloma tumour growth in nude mice without overt toxicity.

Conclusion:

DETT displays a promising potential for MM therapy as an inhibitor of the NFκB signalling pathway.

Membrane microdomain determines the specificity of receptor-mediated modulation of Kv7/M potassium currents

The Kv7/M current is one of the major mechanisms controlling neuronal excitability, which can be modulated by activation of the G protein-coupled receptor (GPCR) via distinct signaling pathways. Membrane microdomains known as lipid rafts have been implicated in the specificity of various cell signaling pathways. The aim of this study was to understand the role of lipid rafts in the specificity of Kv7/M current modulation by activation of GPCR. Methyl-β-cyclodextrin (MβCD), often used to disrupt the integrity of lipid rafts, significantly reduced the bradykinin receptor (B2R)-induced but not muscarinic receptor (M1R)-induced inhibition of the Kv7/M current. B2R and related signaling molecules but not M1R were found in caveolin-containing raft fractions of the rat superior cervical ganglia. Furthermore, activation of B2R resulted in translocation of additional B2R into the lipid rafts, which was not observed for the activation of M1R. The increase of B2R-induced intracellular Ca(2+) was also greatly reduced after MβCD treatment. Finally, B2R but not M1R was found to interact with the IP3 receptor. In conclusion, the present study implicates an important role for lipid rafts in mediating specificity for GPCR-mediated inhibition of the Kv7/M current.