The main objective of this study is to explore the impact of cyclic RGD peptides and 99mTc chelates on biological properties of 99mTc radiotracers. Cyclic RGD peptide conjugates, HYNIC-K(NIC)-RGD2 (HYNIC = 6-hydrazinonicotinyl; RGD2 = E[c(RGDfK)]2 and NIC = nicotinyl) HYNIC-K(NIC)-3G-RGD2 (3G-RGD2 = Gly-Gly-Gly-E[Gly-Gly-Gly-c(RGDfK)]2), and HYNIC-K(NIC)-3P-RGD2 (3P-RGD2 = PEG4-E[PEG4-c(RGDfK)]2), were prepared. Macrocyclic 99mTc complexes [99mTc(HYNIC-K(NIC)-RGD2)(tricine)] (1), [99mTc(HYNIC-K(NIC)-3G-RGD2)(tricine)] (2) and [99mTc(HYNIC-K(NIC)-3P-RGD2)(tricine)] (3) were evaluated for their biodistribution and tumor-targeting capability in athymic nude mice bearing MDA-MB-435 human breast tumor xenografts. It was found that 1, 2 and 3 could be prepared with high specific activity (~111GBq/3mol). All three 99mTc radiotracers have two major isomers, which show almost identical uptake in tumors and normal organs. Replacing the bulky and highly charged [99mTc(HYNIC)(tricine)(TPPTS)] (TPPTS = trisodium triphenylphosphine-3,3′,3″-trisulfonate) with a smaller [99mTc(HYNIC-K(NIC))(tricine)] resulted in less uptake in the kidneys and lungs for 3. Surprisingly, all three 99mTc radiotracers shared a similar tumor uptake (1: 5.73 ± 0.40 %ID/g; 2: 5.24 ± 1.09 %ID/g; and 3: 4.94 ± 1.71 %ID/g) at 60 min p.i. The metabolic stability of 99mTc radiotracers depends on cyclic RGD peptides (3P-RGD2 > 3G-RGD2 ~ RGD2) and 99mTc chelates ([99mTc(HYNIC)(tricine)(TPPTS)] > [99mTc(HYNIC-K(NIC))(tricine)]). Immunohistochemical studies revealed a linear relationship between the αvβ3 expression levels and tumor uptake or tumor/muscle ratios of 3, suggesting that 3 is useful for monitoring the tumor αvβ3 expression. Complex 3 is a very attractive radiotracer for detection of integrin αvβ3 –positive tumors.
integrin αvβ3; 99mTc -labeled cyclic RGD peptides; breast tumor imaging
Stem cell transplantation has been investigated for repairing damaged tissues in various injury models. Monitoring the safety and fate of transplanted cells using noninvasive methods is important to advance this technique into clinical applications.
In this study, lower-limb ischemia models were generated in nude mice by femoral artery ligation. As negative-contrast agents, positively charged magnetic iron oxide nanoparticles (aminopropyltriethoxysilane-coated Fe2O3) were investigated in terms of in vitro labeling efficiency, effects on human mesenchymal stromal cell (hMSC) proliferation, and in vivo magnetic resonance imaging (MRI) visualization. Ultimately, the mice were sacrificed for histological analysis three weeks after transplantation.
With efficient labeling, aminopropyltriethoxysilane-modified magnetic iron oxide nanoparticles (APTS-MNPs) did not significantly affect hMSC proliferation. In vivo, APTS-MNP-labeled hMSCs could be monitored by clinical 3 Tesla MRI for at least three weeks. Histological examination detected numerous migrated Prussian blue-positive cells, which was consistent with the magnetic resonance images. Some migrated Prussian blue-positive cells were positive for mature endothelial cell markers of von Willebrand factor and anti-human proliferating cell nuclear antigen. In the test groups, Prussian blue-positive nanoparticles, which could not be found in other organs, were detected in the spleen.
APTS-MNPs could efficiently label hMSCs, and clinical 3 Tesla MRI could monitor the labeled stem cells in vivo, which may provide a new approach for the in vivo monitoring of implanted cells.
hind-limb ischemia; magnetic resonance imaging; iron oxide particles; stem cell implant
P2X purinoceptor 7 (P2X7R), an ATP-gated ion channel, plays an important role during the innate immune response in mammals. However, relatively little is known about the role of P2X7R in the fish immune system. Here, we cloned a cDNA sequence encoding ayu (Plecoglossus altivelis) P2X7R (aP2X7R). The predicted protein was composed of 574 amino acid residues with a P2X family signature, two transmembrane domains, and a long C-terminal. aP2X7R transcripts were mainly distributed in ayu immune tissues and significantly increased in all tested tissues and in macrophages after Listonella anguillarum infection. The aP2X7R protein was upregulated significantly in macrophages upon bacterial challenge. An antibody against the ectodomain of aP2X7R (aEPAb) and an antagonist (oATP) were used to block aP2X7R. aP2X7R siRNA was also used to knockdown the receptor expression in ayu macrophages. Cell death induced by ATP was significantly inhibited in ayu macrophages after aEPAb, oATP, or siRNA treatment. Moreover, aP2X7R ablation also resulted in suppression of phagocytic activity and ATP-induced bacterial killing in ayu macrophages. Our results indicated that aP2X7R was upregulated after infection and mediated cell death, phagocytosis, and bacterial killing of ayu macrophages.
We used Medicare administrative data to examine trends in primary and revision THA utilization and hospital volume. Between 1991 and 2005 primary and revision THA utilization increased by 40.9% and 16.8% respectively. The percentage of primary THA procedures performed in high volume hospitals (those in the highest quintile of volume) increased slightly from 58.0% of all procedures in 1991 to 58.7% in 2005 (P-value < 0.01). The percentage of revisions performed in high volume hospitals increased from 60.9% to 62.4% (P-value < 0.01). The percentage of primary THA procedures performed by low volume hospitals remained relatively stable (P-value = 0.36) while the percentage of revision THA performed by low volume hospitals declined (P-value < 0.001). In aggregate these results suggest minimal evidence that regionalization of THA is occurring.
Stress and glucocorticoid stress hormones inhibit neurogenesis, whereas antidepressants increase neurogenesis and block stress-induced decrease of neurogenesis. Our previous studies have shown leptin, an adipocyte-derived hormone with antidepressant-like properties 1, promotes baseline neurogenesis in the adult hippocampus 2. The present study aimed to determine whether leptin is able to restore stress-induced suppression of neurogenesis in a rat chronic unpredictable stress (CUS) model of depression. Chronic treatment with leptin reversed the CUS-induced reduction of hippocampal neurogenesis and depression-like behaviors. Leptin treatment elicited delayed long-lasting antidepressant-like effects in the behavioral despair test, and this effect was blocked by ablation of neurogenesis with X-irradiation. The functional isoform of the leptin receptor, LepRb, and the glucocorticoid receptor (GR) were colocalized in hippocampal neural stem/progenitor cells in vivo and in vitro. Leptin treatment reversed the GR agonist dexamethasone (DEX)-induced reduction of proliferation of cultured neural stem/progenitor cells from adult hippocampus. Further mechanistic analysis revealed that leptin and DEX converged on GSK3β and β-catenin. DEX decreased Ser9 phosphorylation and increased Tyr216 phosphorylation of GSK3β, while leptin increased Ser9 phosphorylation and attenuated the effects of DEX at both Ser9 and Tyr216 phosphorylation sites of GSK3β. Moreover, leptin increased total level and nuclear translocation of β-catenin, a primary substrate of GSK3 β and a key regulator in controlling neural progenitor proliferation, and reversed the inhibitory effects of DEX on β-catenin. Together, our results suggest that adult neurogenesis is involved in the delayed long-lasting antidepressant-like behavioral effects of leptin, and leptin treatment counteracts chronic stress and glucocorticoid-induced suppression of hippocampal neurogenesis via activating the GSK3β/β-catenin signaling pathway.
leptin; chronic unpredictable stress; glucocorticoids; neurogenesis; depression; glycogen synthase kinase 3β; β-catenin
Breast cancer patients often develop locoregional or distant recurrence years after mastectomy. Understanding the mechanism of metastatic recurrence after dormancy is crucial for improving the cure rate for breast cancer. Here, we characterized a bone metastasis dormancy model to show that aberrant expression of vascular cell adhesion molecule 1 (VCAM-1), in part dependent on the activity of the NFκB pathway, promotes the transition from indolent micrometastasis to overt metastasis. By interacting with the cognate receptor integrin α4β1, VCAM-1 recruits monocytic osteoclast progenitors and elevates local osteoclast activity. Antibodies against VCAM-1 and integrin α4 effectively inhibit bone metastasis progression and preserve bone structure. These findings establish VCAM-1 as a promising target for the prevention and inhibition of metastatic recurrence in bone.
AIM: To analyze the correlation of treatment method with the outcome of all the hepatic metastatic melanoma (HMM) patients from our hospital.
METHODS: There were altogether nine cases of HMM that had been treated in the PUMCH hospital during the past 25 years, from December 1984 to February 2010. All of the cases developed hepatic metastasis from primary cutaneous melanoma. A retrospective review was performed on all the cases in order to draw informative conclusion on diagnosis and treatment in correlation with the prognosis. Clinical features including symptoms, signs, blood test results, B-ultrasound and computed tomography (CT) imaging characteristics, and pathological data were analyzed in each case individually. A simple comparison was made on case by case basis instead of performing statistical analysis since the case numbers are low and patients were much diversified in each item that has been analyzed. Literatures on this subject were reviewed in order to draw a safe conclusion and found to be supportive to our finding in a much broad scope.
RESULTS: There are six males and three females whose ages ranged 39-74 years old with an average of 58.8. Patients were either with or without symptoms at the time of diagnosis. The liver function and tumor marker exam were normal in all but one patient. The incidence of HMM does not affect liver function and was not related to virus infection status in the liver. Most of these HMM patients were also accompanied by the metastases of other locations, including lung, abdominal cavity, and cervical lymph nodes. Ultrasound examinations showed lesions ranging 2-12 cm in diameter, with no- or low-echo peripheral areola. Doppler showed blood flow appeared inside some tumors as well as in the surrounding area. CT image demonstrated low density without uniformed lesions, characterized with calcification in periphery, and enhanced in the arterial phase. Contrast phase showed heterogeneous enhancement, with a density higher than normal liver tissue, which was especially apparent at the edge. Patients were treated differently with following procedures: patients #1, #6 and #8 were operated with hepatectomy with or without removal of primary lesion, and followed by comprehensive biotherapy/chemotherapy; patient #9 received hepatectomy only; patient #2 received bacille calmette-guerin treatment only; patient #7 had Mile’s surgery but no hepatectomy; and patients #3, #4 and #5 had supportive treatment without specific measurement. The patients who had resections of metastatic lesions followed by post-operative comprehensive therapy have an average survival time of 30.7 mo, which is much longer than those did not receive surgery treatment (4.6 mo). Even for the patient receiving a resection of HMM only, the post-operative survival time was 18 mo at the time we reviewed the data. This patient and the patient #6 are still alive currently and subjected to continue following up.
CONCLUSION: Surgical operation should be first choice for HMM treatment, and together with biotherapy/chemotherapy, hepatectomy is likely to bring better prognosis.
Malignant melanoma; Hepatic metastatic tumor; Hepatectomy; Hepatic metastatic melanoma; Prognosis; Biotherapy; Chemotherapy
Lack of representative data about hidden groups, like men who have sex with men (MSM), hinders an evidence-based response to the HIV epidemics. Respondent-driven sampling (RDS) was developed to overcome sampling challenges in studies of populations like MSM for which sampling frames are absent. Internet-based RDS (webRDS) can potentially circumvent limitations of the original RDS method. We aimed to implement and evaluate webRDS among a hidden population.
Methods and Design
This cross-sectional study took place 18 February to 12 April, 2011 among MSM in Vietnam. Inclusion criteria were men, aged 18 and above, who had ever had sex with another man and were living in Vietnam. Participants were invited by an MSM friend, logged in, and answered a survey. Participants could recruit up to four MSM friends. We evaluated the system by its success in generating sustained recruitment and the degree to which the sample compositions stabilized with increasing sample size.
Twenty starting participants generated 676 participants over 24 recruitment waves. Analyses did not show evidence of bias due to ineligible participation. Estimated mean age was 22 years and 82% came from the two large metropolitan areas. 32 out of 63 provinces were represented. The median number of sexual partners during the last six months was two. The sample composition stabilized well for 16 out of 17 variables.
Results indicate that webRDS could be implemented at a low cost among Internet-using MSM in Vietnam. WebRDS may be a promising method for sampling of Internet-using MSM and other hidden groups.
There is overwhelming evidence that dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs), mainly EPA (C20:5n-3) and DHA (C22:6n-3), has cardiovascular protective effects on patients with type 2 diabetes mellitus (T2DM) but not on healthy people. Because the T2DM heart increases fatty acid oxidation (FAO) to compensate for the diminished utilization of glucose, we hypothesize that T2DM hearts consume more n-3 PUFAs and, therefore, need more n-3 PUFAs. In the present study, we investigated the changes in cardiac n-3 PUFAs and peroxisomal beta-oxidation, which are responsible for the degradation of PUFAs in a high-fat diet (HFD) and low-dose streptozotocin- (STZ) induced type 2 diabetic rat model.
Methods and results
The capillary gas chromatography results showed that all the n-3 (or omega-3) PUFAs, especially DHA (~50%) and EPA (~100%), were significantly decreased, and the n-6/n-3 ratio (~115%) was significantly increased in the hearts of diabetic rats. The activity of peroxisomal beta-oxidation, which is crucial to very-long-chain and unsaturated FA metabolism (including DHA), was significantly elevated in DM hearts. Additionally, the real-time PCR results showed that the mRNA expression of most peroxisomal beta-oxidation key enzymes were up-regulated in T2DM rat hearts, which might contribute to the reduction of n-3 (or omega-3) PUFAs.
In conclusion, our results indicate that T2DM hearts consume more n-3 PUFAs, especially DHA and EPA, due to exaggerated peroxisomal beta-oxidation.
n-3 PUFA; EPA; DHA; T2DM; FAO; Peroxisomal β-oxidation
Stem cell therapy has shown great promise for regenerative repair of injured or diseased tissues. Adipose-derived stem cells (ADSCs) have become increasingly attractive candidates for cellular therapy. Magnetic resonance imaging has been proven to be effective in tracking magnetic-labeled cells and evaluating their clinical relevance after cell transplantation. This study investigated the feasibility of imaging green fluorescent protein-expressing ADSCs (GFP-ADSCs) labeled with superparamagnetic iron oxide particles, and tracked them in vivo with noninvasive magnetic resonance imaging after cell transplantation in a model of mouse carotid artery injury.
GFP-ADSCs were isolated from the adipose tissues of GFP mice and labeled with superparamagnetic iron oxide particles. Intracellular stability, proliferation, and viability of the labeled cells were evaluated in vitro. Next, the cells were transplanted into a mouse carotid artery injury model. Clinical 3 T magnetic resonance imaging was performed immediately before and 1, 3, 7, 14, 21, and 30 days after cell transplantation. Prussian blue staining and histological analysis were performed 7 and 30 days after transplantation.
GFP-ADSCs were found to be efficiently labeled with superparamagnetic iron oxide particles, with no effect on viability and proliferation. Homing of the labeled cells into the injured carotid artery tissue could be monitored by magnetic resonance imaging.
Magnetically labeled ADSCs with expression of GFP can home into sites of vascular injury, and may provide new insights into understanding of cell-based therapy for cardiovascular lesions.
adipose-derived stem cells; carotid artery injury; magnetic resonance imaging; iron oxide particles; cell therapy
Intrauterine inflammation is known to be a risk factor for the development of periventricular leukomalacia (PVL) and cerebral palsy. In recent years, activated microglial cells have been implicated in the pathogenesis of PVL and in the development of white matter injury. Clinical studies have shown the increased presence of activated microglial cells diffusely throughout the white matter in brains of patients with PVL. In vitro studies have reported that activated microglial cells induce oligodendrocyte damage and white matter injury by release of inflammatory cytokines, reactive nitrogen and oxygen species and the production of excitotoxic metabolites. PK11195 [1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide] is a ligand that is selective for the 18-kDa translocator protein expressed on the outer mitochondrial membrane of activated microglia and macrophages. When labeled with carbon-11, [11C]PK11195 can effectively be used as a ligand in positron emission tomography (PET) studies for the detection of activated microglial cells in various neuroinflammatory and neurodegenerative conditions. In this study, we hypothesized that the magnitude of [11C]-(R)-PK11195 uptake in the newborn rabbit brain, as measured using a small-animal PET scanner, would match the severity of motor deficits resulting from intrauterine inflammation-induced perinatal brain injury. Pregnant New Zealand white rabbits were intrauterinely injected with endotoxin or saline at 28 days of gestation. Kits were born spontaneously at 31 days and underwent neurobehavioral testing and PET imaging following intravenous injection of the tracer [11C]-(R)-PK11195 on the day of birth. The neurobehavioral scores were compared with the change in [11C]PK11195 uptake over the time of scanning, for each of the kits. Upon analysis using receiver operating characteristic curves, an optimal combined sensitivity and specificity for detecting abnormal neurobehavioral scores suggestive of cerebral palsy in the neonatal rabbit was noted for a positive change in [11C]PK11195 uptake in the brain over time on PET imaging (sensitivity of 100% and area under the curve of >0.82 for all parameters tested). The strongest agreements were noted between a positive uptake slope – indicating increased [11C]PK11195 uptake over time – and worsening scores for measures of locomotion (indicated by hindlimb movement, forelimb movement, circular motion and straight- line motion; Cohen's κ >0.75 for each) and feeding (indicated by ability to suck and swallow and turn the head during feeding; Cohen's κ >0.85 for each). This was also associated with increased numbers of activated microglia (mean ratio ± SD of activated to total microglia: 0.96 ± 0.16 in the endotoxin group vs. 0.13 ± 0.08 in controls; p < 0.001) in the internal capsule and corona radiata. Our findings indicate that the magnitude of [11C]PK11195 binding measured in vivo by PET imaging matches the severity of motor deficits in the neonatal rabbit. Molecular imaging of ongoing neuroinflammation in the neonatal period may be helpful as a screening biomarker for detecting patients at risk of developing cerebral palsy due to a perinatal insult.
Microglia; Positron emission tomography; Neuroinflammation; Cerebral palsy; Maternal inflammation
To examine outcomes of Medicare enrollees who underwent primary total knee arthroplasty (TKA) in top-ranked orthopedic hospitals identified through the U.S. News & World Report hospital rankings and 2 comparison groups of hospitals.
Patients and Methods
We used Medicare Part A data to identify patients who underwent primary TKA between January 1, 2006, and December 31, 2006, in 3 groups of hospitals: (1) top-ranked according to U.S. News & World Report rankings; (2) not top-ranked, but eligible for ranking; and (3) not eligible for ranking by U.S. News & World Report. We compared the demographics and comorbidity of patients treated in the 3 hospital groups. We examined rates of postoperative adverse outcomes—a composite consisting of hemorrhage, pulmonary embolism, deep vein thrombosis, wound infection, myocardial infarction, or mortality within 30 days of surgery. We also compared 30-day all-cause readmission rates and hospital length of stay (LOS) across groups.
Our cohort consisted of 48 top-ranked hospitals (performing 10,477 primary TKAs), 288 eligible non–top-ranked hospitals (28,938 TKAs), and 481 hospitals not eligible for ranking (25,297 TKAs). Unadjusted rates of the composite outcome were modestly higher for top-ranked hospitals (4.3%, 455 patients) as compared with non–top-ranked hospitals (4.1%, 1191 patients) and hospitals ineligible for ranking (3.3%, 843 patients) (P<.001), but these differences were no longer significant after accounting for differences in patient complexity. Likewise, there were no significant differences in readmission rates or LOS across groups.
Rates of postoperative complications and readmission and hospital LOS were similar for Medicare patients who underwent primary TKA in top-ranked and non–top-ranked hospitals.
AHA, American Hospital Association; CMS, Centers for Medicare and Medicaid Services; DVT, deep vein thrombosis; HRR, hospital referral region; ICD-9-MC, International Classification of Diseases, Ninth Revision, Clinical Modification; LOS, length of stay; MED-PAR, Medicare Provider Analysis and Review; PE, pulmonary embolism; TKA, total knee arthroplasty
Synchronous primary endometrial and ovarian cancers are uncommon. The purpose of this study was to evaluate the clinicopathological characteristics, treatment and prognosis of synchronous primary endometrial and ovarian cancers. The clinicopathological characteristics of 43 patients with synchronous primary endometrial and ovarian cancers in the Obstetrics and Gynecology Hospital of Fudan University between 1999 and 2009 were retrospectively reviewed. Our results revealed that the median age at the time of diagnosis was 51 years (range, 29–71). The common presenting symptoms were abnormal uterine bleeding (AUB, 65.12%), abdominal mass (25.58%), abdominal pain and abdominal fullness (39.53%). An elevated CA125 level was observed in the majority of patients (n=20, 76.9%). Endometrioid type accounted for 60.47% of uterine carcinomas and different pathological types, including serous adenocarcinoma, clear cell carcinoma, adenosquamous and acanthoadenocarcinoma, were also identified in synchronous primary endometrial and ovarian cancers. All patients underwent surgical intervention (hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy or debulking surgery). The 5-year survival rate was 86.05% and nine patients had recurrence (20.93%). The early stage group (FIGO stages I and II) had more favorable prognosis than the advanced stage group (FIGO stages III and IV; P<0.05). In conclusion, synchronous primary endometrial and ovarian cancers are different from either primary endometrial carcinoma or ovarian cancer and are usually identified at early stages with a good prognosis.
synchronous primary cancers; endometrial cancer; ovarian cancer; prognosis
Oxytocin neurons represent one of the major subsets of neurons in the paraventricular hypothalamus (PVH), a critical brain region for energy homeostasis. Despite substantial evidence supporting a role of oxytocin in body weight regulation, it remains controversial whether oxytocin neurons directly regulate body weight homeostasis, feeding or energy expenditure. Pharmacologic doses of oxytocin suppress feeding through a proposed melanocortin responsive projection from the PVH to the hindbrain. In contrast, deficiency in oxytocin or its receptor leads to reduced energy expenditure without feeding abnormalities. To test the physiological function of oxytocin neurons, we specifically ablated oxytocin neurons in adult mice. Our results show that oxytocin neuron ablation in adult animals has no effect on body weight, food intake or energy expenditure on a regular diet. Interestingly, male mice lacking oxytocin neurons are more sensitive to high fat diet-induced obesity due solely to reduced energy expenditure. In addition, despite a normal food intake, these mice exhibit a blunted food intake response to leptin administration. Thus, our study suggests that oxytocin neurons are required to resist the obesity associated with a high fat diet; but their role in feeding is permissive and can be compensated for by redundant pathways.
Lymphocytes act as a major component of the adaptive immune system, taking very crucial responsibility for immunity. Differences in proportions of T-cell subpopulations in peripheral blood among individuals under same conditions provide evidence of genetic control on these traits, but little is known about the genetic mechanism of them, especially in swine. Identification of the genetic control on these variants may help the genetic improvement of immune capacity through selection.
To identify genomic regions responsible for these immune traits in swine, a genome-wide association study was conducted. A total of 675 pigs of three breeds were involved in the study. At 21 days of age, all individuals were vaccinated with modified live classical swine fever vaccine. Blood samples were collected when the piglets were 20 and 35 days of age, respectively. Seven traits, including the proportions of CD4+, CD8+, CD4+CD8+, CD4+CD8−, CD4−CD8+, CD4−CD8− and the ratio of CD4+ to CD8+ T cells were measured at the two ages. All the samples were genotyped for 62,163 single nucleotide polymorphisms (SNP) using the Illumina porcineSNP60k BeadChip. 40833 SNPs were selected after quality control for association tests between SNPs and each immune trait considered based on a single-locus regression model. To tackle the issue of multiple testing in GWAS, 10,000 permutations were performed to determine the chromosome-wise and genome-wise significance levels of association tests. In total, 61 SNPs with chromosome-wise significance level and 3 SNPs with genome-wise significance level were identified. 27 significant SNPs were located within the immune-related QTL regions reported in previous studies. Furthermore, several significant SNPs fell into the regions harboring known immunity-related genes, 14 of them fell into the regions which harbor some known T cell-related genes.
Our study demonstrated that genome-wide association studies would be a feasible way for revealing the potential genetics variants affecting T-cell subpopulations. Results herein lay a preliminary foundation for further identifying the causal mutations underlying swine immune capacity in follow-up studies.
T lymphocyte subpopulations; Genome-wide association study; Swine
Human depression is associated with cognitive deficits. It is critical to have valid animal models in order to investigate mechanisms and treatment strategies for these associated conditions. The goal of this study was to determine the association of cognitive dysfunction with depression-like behaviour in an animal model of depression and investigate the neural circuits underlying the behaviour. Mice that were exposed to social defeat for 14 d developed depression-like behaviour, i.e. anhedonia and social avoidance as indicated by reduced sucrose preference and decreased social interaction. The assessment of cognitive performance of defeated mice demonstrated impaired working memory in the T-maze continuous alternation task and enhanced fear memory in the contextual and cued fear-conditioning tests. In contrast, reference learning and memory in the Morris water maze test were intact in defeated mice. Neuronal activation following chronic social defeat was investigated by c-fos in-situ hybridization. Defeated mice exhibited preferential neural activity in the prefrontal cortex, cingulate cortex, hippocampal formation, septum, amygdala, and hypothalamic nuclei. Taken together, our results suggest that the chronic social defeat mouse model could serve as a valid animal model to study depression with cognitive impairments. The patterns of neuronal activation provide a neural basis for social defeat-induced changes in behaviour.
c-fos mRNA expression; chronic social defeat; cognition; depression; fear memory; working memory
Leptin receptors (Lepr) are expressed on midbrain dopamine neurons. However, the specific role of Lepr signaling in dopamine neurons remains to be clarified. In the present study, we generated a line of conditional knockout mice lacking functional leptin receptors selectively on dopamine neurons (LeprDAT-Cre). These mice exhibit normal body weight and feeding. Behaviorally, LeprDAT-Cre mice display an anxiogenic-like phenotype in the elevated plus-maze, light-dark box, social interaction and novelty-suppressed feeding tests. Depression-related behaviors in the chronic stress-induced anhedonia, forced swim and tail-suspension tests were not affected by deletion of Lepr in dopamine neurons. In vivo electrophysiological recordings of dopamine neurons in the ventral tegmental area (VTA) revealed an increase in burst firing in LeprDAT-Cre mice. Moreover, blockade of D1-dependent dopamine transmission in the central amygdala by local microinjection of the D1 antagonist SCH23390 attenuated the anxiogenic phenotype of LeprDAT-Cre mice. These findings suggest that leptin receptor signaling in midbrain dopamine neurons has a crucial role for the expression of anxiety and for the dopamine modulation of amygdala function.
Leptin receptor; dopamine neurons; feeding; anxiety; ventral tegmental area; central amygdala
Surveys were carried out to better understand the tick vector ecology and genetic diversity of Huaiyangshan virus (HYSV) in both regions of endemicity and regions of nonendemicity. Haemaphysalis longicornis ticks were dominant in regions of endemicity, while Rhipicephalus microplus is more abundant in regions of nonendemicity. HYSV RNA was found in human and both tick species, with greater prevalence in H. longicornis and lesser prevalence in R. microplus. Phylogenetic analyses indicate that HYSV is a novel species of the genus Phlebovirus.
Taurine is a sulfur-containing amino acid present in high concentrations in mammalian tissues. It has been implicated in several processes involving brain development and neurotransmission. However, the role of taurine in hippocampal neurogenesis during brain development is still unknown. Here we show that taurine regulates neural progenitor cell (NPC) proliferation in the dentate gyrus of the developing brain as well as in cultured early postnatal (P5) hippocampal progenitor cells and hippocampal slices derived from P5 mice brains. Taurine increased cell proliferation without having a significant effect on neural differentiation both in cultured P5 NPCs as well as cultured hippocampal slices and in vivo. Expression level analysis of synaptic proteins revealed that taurine increases the expression of Synapsin 1 and PSD 95. We also found that taurine stimulates the phosphorylation of ERK1/2 indicating a possible role of the ERK pathway in mediating the changes that we observed, especially in proliferation. Taken together, our results demonstrate a role for taurine in neural stem/progenitor cell proliferation in developing brain and suggest the involvement of the ERK1/2 pathways in mediating these actions. Our study also shows that taurine influences the levels of proteins associated with synapse development. This is the first evidence showing the effect of taurine on early postnatal neuronal development using a combination of in vitro, ex-vivo and in vivo systems.
Research has shown that bradykinin β2 receptor (BDKRB2) −58T/C gene polymorphism is correlated with the risk of essential hypertension (EH), but the results remain inconclusive.
Objective and Methods
The objective of this study was to explore the association between BDKRB2−58T/C gene polymorphism and EH. A meta-analysis of 11 studies with 3882 subjects was conducted. Pooled odds ratios (ORs) for the association between BDKRB2−58T/C gene polymorphism and EH and their corresponding 95% confidence intervals (CIs) were estimated using the random effects model.
The BDKRB2−58T/C gene polymorphism was significantly correlated with EH under an allelic genetic model (OR = 1.24, 95% CI = 1.05–1.46; P = 0.01), a dominant genetic model (OR = 0.65, 95% CI = 0.47–0.90; P = 0.01), a recessive genetic model (OR = 1.146, 95% CI = 1.035–1.269; P = 0.009), a homozygote genetic model (OR = 1.134, 95% CI = 1.048–1.228; P = 0.002), and a heterozygote genetic model (OR = 1.060, 95% CI = 1.009–1.112; P = 0.019).
The BDKRB2−58T/C gene polymorphism is associated with increased EH risk. The results of this study suggest that carriers of the −58C allele are susceptible to EH.
Aptamer-based tumor targeted drug delivery system is a promising approach that may increase the efficacy of chemotherapy and reduce the related toxicity. HER2 protein is an attractive target for tumor-specific drug delivery because of its overexpression in multiple malignancies, including breast, gastric, ovarian, and lung cancers.
In this paper, we developed a new HER2 aptamer (HB5) by using systematic evolution of ligands by exponential enrichment technology (SELEX) and exploited its role as a targeting ligand for delivering doxorubicin (Dox) to breast cancer cells in vitro.
The selected aptamer was an 86-nucleotide DNA molecule that bound to an epitope peptide of HER2 with a Kd of 18.9 nM. The aptamer also bound to the extracellular domain (ECD) of HER2 protein with a Kdof 316 nM, and had minimal cross reactivity to albumin or trypsin. In addition, the aptamer was found to preferentially bind to HER2-positive but not HER2-negative breast cancer cells. An aptamer-doxorubicin complex (Apt-Dox) was formulated by intercalating Dox into the DNA structure of HB5. The Apt-Dox complex could selectively deliver Dox to HER2-positive breast cancer cells while reducing the drug intake by HER2-negative cells in vitro. Moreover, Apt-Dox retained the cytotoxicity of Dox against HER2-positive breast cancer cells, but reduced the cytotoxicity to HER2-negative cells.
The results suggest that the selected HER2 aptamer may have application potentials in targeted therapy against HER2-positive breast cancer cells.
Aptamer; HER2; Breast cancer; Tumor targeted therapy
Barrett's esophagus is an intestine-like metaplasia and precursor of esophageal adenocarcinoma. Triggered by gastroesophageal reflux disease, the origin of this metaplasia remains unknown. p63-deficient mice, which lack squamous epithelia, may model acid-reflux damage. We show here that p63 null embryos rapidly develop intestine-like metaplasia with gene expression profiles similar to Barrett's metaplasia. We track its source to a unique embryonic epithelium that is normally undermined and replaced by p63-expressing cells. Significantly, we show that a discrete population of these embryonic cells persists in adult mice and humans at the squamocolumnar junction, the source of Barrett's metaplasia. Upon programmed damage to the squamous epithelium, we show that these embryonic cells migrate towards adjacent, specialized squamous cells in a process that may recapitulate early Barrett's. Our findings suggest that certain precancerous lesions, such as Barrett's, initiate not from genetic alterations but from competitive interactions between cell lineages driven by opportunity.
The unit cell of the title compound, C36H36N2, contains two independent molecules which are located about inversion centers. In each molecule the quinoline rings are almost planar, with mean deviations of 0.0302 (1) and 0.0173 (1) Å. In the crystal, molecules are linked by C—H⋯π interactions into a three-dimensional network.
It is now well established that the glutamatergic system contributes to the pathophysiology of depression. Exposure to stress, a major precipitating factor for depression, enhances glutamate release that can contribute to structural abnormalities observed in the brain of depressed subjects. On the other hand, it has been demonstrated that NMDA antagonists, like ketamine, exert an antidepressant effect at preclinical and clinical levels. On these bases, the purpose of our study was to investigate whether chronic mild stress is associated with specific alterations of the NMDA receptor complex, in adult rats, and to establish whether concomitant antidepressant treatment could normalize such deficits. We found that chronic stress increases the expression of the obligatory GluN1 subunit, as well as of the accessory subunits GluN2A and GluN2B at transcriptional and translational levels, particularly in the ventral hippocampus. Concomitant treatment with the antidepressant duloxetine was able to normalize the increase of glutamatergic receptor subunit expression, and correct the changes in receptor phosphorylation produced by stress exposure. Our data suggest that prolonged stress, a condition that has etiologic relevance for depression, may enhance glutamate activity through post-synaptic mechanisms, by regulating NMDA receptors, and that antidepressants may in part normalize such changes. Our results provide support to the notion that antidepressants may exert their activity in the long-term also via modulation of the glutamatergic synapse.
Hypoglycemia and neuroglucopenia stimulate AMP-activated protein kinase (AMPK) activity in the hypothalamus and this plays an important role in the counterregulatory responses, i.e. increased food intake and secretion of glucagon, corticosterone and catecholamines. Several upstream kinases that activate AMPK have been identified including Ca2+/Calmodulin-dependent protein kinase kinase (CaMKK), which is highly expressed in neurons. However, the involvement of CaMKK in neuroglucopenia-induced activation of AMPK in the hypothalamus has not been tested. To determine whether neuroglucopenia-induced AMPK activation is mediated by CaMKK, we tested whether STO-609 (STO), a CaMKK inhibitor, would block the effects of 2-deoxy-D-glucose (2DG)-induced neuroglucopenia both ex vivo on brain sections and in vivo. Preincubation of rat brain sections with STO blocked KCl-induced α1 and α2-AMPK activation but did not affect AMPK activation by 2DG in the medio-basal hypothalamus. To confirm these findings in vivo, STO was pre-administrated intracerebroventricularly (ICV) in rats 30 min before 2DG ICV injection (40 µmol) to induce neuroglucopenia. 2DG-induced neuroglucopenia lead to a significant increase in glycemia and food intake compared to saline-injected control rats. ICV pre-administration of STO (5, 20 or 50 nmol) did not affect 2DG-induced hyperglycemia and food intake. Importantly, activation of hypothalamic α1 and α2-AMPK by 2DG was not affected by ICV pre-administration of STO. In conclusion, activation of hypothalamic AMPK by 2DG-induced neuroglucopenia is not mediated by CaMKK.