Dual-Functional Nanoparticles for In Situ Sequential Detection and Imaging of ATP and H2 O2

Within a complex biological sample, the in situ sequential detection of multiple molecules without any interference is greatly desirable. Dual-functional nanoparticles are constructed, with the enzyme-based core-shell structures, for the in situ sequential detection of ATP and H2 O2 within the same biological system.

Zoledronic Acid Improves Bone Quality in the Streptozotocin-Induced Diabetes Rat through Affecting the Expression of the Osteoblast-Regulating Transcription Factors

AIMS

To evaluate the short term effect of zoledronic acid on bone remodeling in the streptozotocin induced diabetes rats.

MATERIALS AND METHODS

Diabetes was induced by an injection of streptozotocin (60 mg/kg). The rats were treated with zoledronic acid (0.1 mg/kg) at the onset of diabetes (Z-I group) and 2 weeks later (Z-II group). Rats were sacrificed at the 1, 2, 3, 4 and 5 weeks after the onset of diabetes. Real-time PCR and western blot were performed to detect the expression of the following osteogenic gene mRNAs and their proteins: bone morphogenetic proteins 2 (BMP2), Runx2, Osterix and Noggin. The bone mineral density (BMD) and the mechanical resistance test was measured.

RESULTS

BMP2, Runx2 and Osterix mRNA and protein expression in group D had regulated down, while Noggin expression increased. Z-I treatment could reverse the results. However group Z-II showed only a transient reversing effect. On the 5^th week in group D, the BMD decreased, the bone trabecular distance increased, while the trabecular thickness and bone trabecular volume were reduced, the biomechanics index decreased significantly. Zoledronic acid treatment restored these alterations.

CONCLUSIONS

Zoledronic acid administered in the early stage of the diabetes could prevent the osteopenia. The underlying mechanisms might be that zoledronic acid treatment reversed the effect of diabetes on the expression of osteoblast-regulating transcription factors: BMP2, Runx2 and Osterix.

Association of K121Q Polymorphism in Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 with Clinical Characteristics of Metabolic Syndrom

PURPOSE

This study aimed to investigate the relationships between K121Q polymorphism of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and clinical characteristics of metabolic syndrome (MS) in northern Han Chinese.

MATERIALS AND METHODS

A total of 209 MS patients and 248 healthy controls of Han ethnic group in northern China were enrolled in this study. Various clinical parameters of these participants were firstly collected and compared, including age, sex, body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressures (SBP/DBP), fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model assessment of insulin resistance index (HOMA-IR), total cholesterol (TC), triglycerides (TG), high-density and low-density lipoprotein cholesterol (LDL-C/HDL-C). Then K121Q polymorphism of ENPP1 was determined by PCR and restriction enzyme digestion, and its relations with related clinical parameters were finally analyzed.

RESULTS

When compared with healthy controls, the age, BMI, WC, SBP, DBP, FPG, FINS, HOMA-IR, TC, TG and LDL-C were all significantly increased in MS patients (P<0.001). The allele frequencies of K and Q alleles in ENPP1 were 90.19% and 9.81% in MS patients, and 91.73% and 8.27% in healthy controls, respectively. Besides, only BMI and WC were significantly increased in MS patients carrying Q alleles (P<0.001), while no significant relations were found between K121Q polymorphism and other clinical parameters in either MS patients or healthy controls.

CONCLUSION

The K121Q polymorphism of ENPP1 showed no direct correlation with MS, although it showed some correlation with BMI and WC in MS patients.

Analysis of uridine diphosphate glucuronosyl transferase 1A1 gene mutations in neonates with unconjugated hyperbilirubinemia

This study was carried out to analyze uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1) gene mutations in neonates with unconjugated hyperbilirubinemia, from two different ethnic groups. Polymerase chain reaction and gene sequencing were used to analyze the differences in genotypes and allele frequencies of different gene mutations among the ethnic groups; this was followed by checking their correlation with the serum bilirubin level and the occurrence of unconjugated hyperbilirubinemia in neonates. Our results reveal that the UGT1A1 mutant genotype, 211G>A, is distributed differently in the case vs control groups, as well as in the Zhuang vs Han ethnic groups. Moreover, this difference is statistically significant (P < 0.05); the total serum bilirubin (TSB) and unconjugated bilirubin (UCB) levels in patients carrying the single homozygous mutation, 211G>A, were markedly higher than that in patients without the mutation (P < 0.05). Furthermore, the TSB and UCB levels were significantly different between patients carrying single or compound 211G>A heterozygous mutation, (TA)6/7, and 1941C>G/2042C>G heterozygous mutation, and patients without mutation (P > 0.05). Our findings suggest that the 211G>A mutation in the first exon may be a risk factor for unconjugated hyperbilirubinemia in Zhuang and Han neonates. The serum bilirubin levels seem to be affected by the homozygosity or heterozygosity of the UGT1A1 gene mutation; 211G>A homozygous mutation is an important factor that causes a rise in bilirubin in neonates with unconjugated hyperbilirubinemia.

Radiolabeled pyridinyl analogues of dibenzylideneacetone as β-amyloid imaging probes

In continuation of our investigation of the dibenzylideneacetone scaffold as Aβ imaging probes, a series of derivatives containing pyridine rings with lower lipophilicity was synthesized and evaluated.

In vivo near-infrared and Cerenkov luminescence imaging of amyloid-β deposits in the brain: a fluorinated small molecule used for dual-modality imaging

Three fluorinated (¹⁹F or ¹⁸F) small molecules were evaluated as fluorescent or radiolabeled probes for Aβ deposits in the brain.

Dietary Influence on Calcitropic Hormones and Adiposity in Caucasian and African American Postmenopausal Women Assessed by Structural Equation Modeling (SEM)

OBJECTIVES

To examine differences in hydroxycholecalciferol (25(OH)D) and parathyroid hormone (PTH) concentrations between Caucasian and African American (AA) postmenopausal women, as well as the effects of dietary calcium, protein and vitamin D intakes on 25(OH)D, PTH, and body adiposity using structural equation modeling (SEM).

DESIGN

Population-based prospective cohort study.

SETTING

Academic research using the baseline data from two longitudinal studies. Participants Included n=113 Caucasian and n=40 African American, postmenopausal women who completed the baseline data collection and met inclusion criteria (dietary calcium intake <900 mg/day and being generally healthy) between 2006 and 2010.

MAIN OUTCOME

Dietary intake of calcium and vitamin D, assessed by dietary records, were examined in relation to calcitropic hormones concentrations and adiposity markers. Independent t-tests, confirmatory factor analysis, SEM and multi-group analyses were conducted to examine the aforementioned relationships as well as group differences among hormones, dietary intake, anthropometrics, age and other factors.

RESULTS

Dietary calcium and protein intakes were significantly lower in AA women. Years since menopause were significantly higher in AA compared to Caucasian women. PTH and 25(OH)D levels were significantly lower in AA compared to Caucasian women. Dietary calcium and protein intakes did not influence body adiposity in either group of women. Dietary vitamin D had minimal indirect (via 25(OH)D levels) influence on adiposity.

CONCLUSION

The study confirmed the positive relationship of 25(OH)D with adiposity markers and both AA and Caucasian women. The study provides a unique example of the use of SEM in nutrition research within a clinical context. This model should be further tested in other populations.

99mTc(CO)3-Labeled Benzothiazole Derivatives Preferentially Bind Cerebrovascular Amyloid: Potential Use as Imaging Agents for Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is a disorder affecting the elderly that is characterized by amyloid-β (Aβ) deposition in blood vessel walls of the brain. A series of 99mTc(CO)3-labeled benzothiazole derivatives as potential SPECT imaging probes for cerebrovascular Aβ deposition is reported. Rhenium surrogate displayed high affinities to Aβ aggregates with Ki values ranging from 106 to 42 nM, and they strongly stained Aβ deposits in transgenic mice (Tg) and Alzheimer's disease (AD) patients. In vitro autoradiography on brain sections of Tg and AD patients confirmed that [99mTc]24 possessed sufficient affinity for Aβ plaques, and [99mTc]24 could only label Aβ deposition in blood vessels but not Aβ plaques in the parenchyma of the brain of AD patients. Moreover, [99mTc]24 possessed favorable initial uptake (1.21% ID/g) and fast blood washout (blood2 min/blood60 min=23) in normal mice. These preliminary results suggest that [99mTc]24 may be used as an Aβ imaging probe for the detection of CAA.

A role of 1,25(OH)2D3 supplementation in rats with nonalcoholic steatohepatitis induced by choline-deficient diet

BACKGROUND AND AIMS

It has been reported that 1,25(OH)2D3 (1,25-VD3) ameliorates the progression of nonalcoholic steatohepatitis (NASH). However, it is unclear whether 1,25-VD3 plays a role in NASH induced by a choline-deficient (CD) diet. In this study, we investigated the roles of 1,25-VD3 in the development and progression of NASH in rats induced by a CD diet.

METHODS AND RESULTS

Wistar rats with NASH induced by a CD diet were subjected to intraperitoneal injections of 1, 5, or 10 μg/kg of 1,25-VD3 twice weekly for 12 weeks. The administration of 1,25-VD3 decreased free fatty acids (FFAs), triglycerides (TGs), thiobarbituric acid-reactive substances (TBARS), the number of apoptotic cells, and the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the liver, and it improved liver histology, but it did not change the total antioxidant capacity (TAOC) in the liver. Interestingly, the level of CK18-M30 was decreased in the liver of model animals. Treatment with 1,25-VD3 may restrain the downregulation of CK18-M30 in the liver and its release into the bloodstream, thus decreasing the level of serum CK18-M30. 1,25-VD3 supplementation elevated the serum level of 25(OH)D3 and the expression of VDR in the liver. The dose-effect relationship of 1,25-VD3 indicated that 1,25-VD3 slows down the development and progression of NASH induced by a CD diet, but higher doses of 1,25-VD3 may lead to adverse effects.

CONCLUSION

The results suggest the presence of both antagonistic and adverse dose-dependent effects of the long-term supplementation of 1,25-VD3 on NASH induced by a CD diet.

Association of TUSC3 gene polymorphisms with non-syndromic mental retardation based on nuclear families in the Qinba mountain area of China

TUSC3 interacts with the protein phosphatase 1 and magnesium ion transport system, which plays an important role in learning and memory. Abnormal conditions of learning and memory are common clinical characteristics of mental retardation (MR). However, the association of TUSC3 genetic polymorphisms with MR remains unknown. A total of 456 DNA samples including 174 nuclear families containing MR were collected in the Qinba mountain area of China. The genotypes of eight tag single nucleotide polymorphisms of TUSC3 were evaluated with traditional genetic methods. Family-based association tests, transmission disequilibrium tests (TDTs), and haplotype relative risk (HRR) analyses were performed to investigate the association between genetic variants of the TUSC3 gene and MR. The genetic polymorphisms rs10093881, rs6530893, and rs6994908 were associated with MR (all P values <0.05) based upon the results of single-site TDT and HRR analyses. The haplotype block consisting of rs6530893 and rs6994908, harboring the sixth exon of TUSC3, was also associated with MR (all P values <0.05). This study demonstrated an association between genetic polymorphisms of the TUSC3 gene and MR in the Qinba mountain area, the sixth exon of which might contribute to the risk of MR. However, further studies are needed on the causal mechanisms in this association.

Compounds for imaging amyloid-β deposits in an Alzheimer's brain: a patent review

INTRODUCTION

β-amyloid (Aβ) plaques in the brain are regarded as a hallmark of Alzheimer's disease (AD), and the imaging of Aβ is a critical step for early diagnosis. Extensive research has been done to develop probes for targeting Aβ with available imaging modalities.

AREAS COVERED

In this review, the authors give an overview of published patents and papers about the discovery and development of compounds possessing potential utilization in imaging Aβ for the diagnosis of AD. SciFinder is the main electronic database for patent study in this review.

EXPERT OPINION

Despite achievements in Aβ imaging, there is still a need to develop innovative compounds with selectivity and high affinity to Aβ. Positron emission tomography imaging agents will still be the trend in the field in the short term. Due to the low costs for single-photon emission computed tomography (SPECT) and the excellent nuclear properties of (99m)Tc, substantial research should be conducted on the development of the probes for SPECT. Refining the current imaging techniques and in the meantime developing new efficient imaging multimodality and compounds would be a promising approach to imaging Aβ.

2-Phenylbenzothiazole conjugated with cyclopentadienyl tricarbonyl [CpM(CO)3] (M = Re,99mTc) complexes as potential imaging probes for β-amyloid plaques

[CpM(CO)₃] (M = Re,^99mTc)-labeled 2-phenylbenzothiazoles designed by a conjugate approach were evaluated as SPECT tracers for Aβ plaques.

The synthesis and evaluation of near-infrared probes with barbituric acid acceptors for in vivo detection of amyloid plaques

A new array of near-infrared probes containing barbituric acid acceptors has been developed as Aβ imaging agents.

[Relationship between serum histamine levels and ST-segment resolution in patients with acute myocardial infarction treated with primary percutaneous coronary intervention]

OBJECTIVE

To investigate the dynamic changes in serum histamine levels and their association with ST-segment resolution in patients with acute ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

A total of 84 consecutive STEMI patients who received primary PCI were enrolled in this study. The dynamic changes in serum histamine levels were observed from before PCI to 1 week after PCI. Factors associated with ST-segment resolution were identified by multivariate regression analysis.

RESULTS

The serum histamine levels of STEMI patients decreased during the first week after PCI. Multivariate regression analysis showed that the factors associated with ST-segment resolution 2 h after PCI were: the histamine level 2 h after PCI (r=-0.361, P=0.001), pain to balloon time, infarct related artery, and thrombolysis in myocardial infarction (TIMI) flow grade after PCI.

CONCLUSION

The higher histamine level 2 h after PCI was independently associated with poor myocardial reperfusion in STEMI patients.

(99m)Tc-labeled-2-arylbenzoxazole derivatives as potential Aβ imaging probes for single-photon emission computed tomography

Four neutral (99m)Tc/Re-labeled 2-arylbenzoxazole derivatives conjugated to bis (aminoethanethiol) (BAT) chelating ligand via a short propoxy spacer were synthesized and evaluated. In vitro binding assay showed that they displayed binding affinities to Aβ1-42 aggregates (Ki = 15.86-393.18 nM). In vitro autoradiography studies further confirmed the high and specific binding of [(99m)Tc]20 to β-amyloid plaques on brain sections of transgenic mice. Biodistribution study of [(99m)Tc]17-20 in normal mice displayed moderate initial brain uptake (0.96-1.55%ID/g at 2 min), and fast washed out from the brain (0.14-0.40%ID/g at 60 min), especially for [(99m)Tc]20 with a brain2min/brain60min ratio of 8.86. Taken together, these preliminary data suggested that [(99m)Tc]20 may be a potential imaging probe for detecting amyloid plaques in the brain.

Novel cyclopentadienyl tricarbonyl (99m)tc complexes containing 1-piperonylpiperazine moiety: potential imaging probes for sigma-1 receptors

We report the design, synthesis, and evaluation of a series of novel cyclopentadienyl tricarbonyl (99m)Tc complexes as potent σ1 receptor radioligands. Rhenium compounds 3-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)propylcarbonylcyclopentadienyl tricarbonyl rhenium (10a) and 4-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)butylcarbonylcyclopentadienyl tricarbonyl rhenium (10b) possessed high in vitro affinity for σ1 receptors and moderate to high selectivity for σ2 receptors and the vesicular acetylcholine transporter. Biodistribution studies in mice demonstrated high initial brain uptake for corresponding (99m)Tc derivatives [(99m)Tc]23 and [(99m)Tc]24 of 2.94 and 2.13% injected dose (ID)/g, respectively, at 2 min postinjection. Pretreatment of haloperidol significantly reduced the radiotracer accumulation of [(99m)Tc]23 or [(99m)Tc]24 in the brain. Studies of the cellular uptake of [(99m)Tc]23 in C6 and DU145 tumor cells demonstrated a reduction of accumulation by incubation with haloperidol, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine (SA4503), or 1,3-di-o-tolyl-guanidine (DTG). Furthermore, blocking studies in C6 glioma-bearing mice confirmed the specific binding of [(99m)Tc]23 to σ1 receptors in the tumor.

Radioiodinated benzyloxybenzene derivatives: a class of flexible ligands target to β-amyloid plaques in Alzheimer's brains

Benzyloxybenzene, as a novel flexible scaffold without rigid planarity, was synthesized and evaluated as ligand toward Aβ plaques. The binding site calculated for these flexible ligands was the hydrophobic Val18_Phe20 channel on the flat surface of Aβ fiber. Structure-activity relationship analysis generated a common trend that binding affinities declined significantly from para-substituted ligands to ortho-substituted ones, which was also quantitatively illustrated by 3D-QSAR modeling. Autoradiography in vitro further confirmed the high affinities of radioiodinated ligands [125I]4, [125I]24, and [125I]22 (Ki=24.3, 49.4, and 17.6 nM, respectively). In biodistribution, [125I]4 exhibited high initial uptake and rapid washout property in the brain with brain2 min/brain60 min ratio of 16.3. The excellent in vitro and in vivo biostability of [125I]4 enhanced its potential for clinical application in SPECT imaging of Aβ plaques. This approach could also allow the design of a new generation of Aβ targeting ligands without rigid and planar framework.

Effect of codon optimization on expression levels of human cystatin C in Pichia pastoris

Human cystatin C (CysC) is a cysteine proteinase inhibitor with many potential applications. To facilitate further studies of the functions and applications of CysC, we improved the heterologous expression of CysC using a basic codon optimization method. In this study, we cloned the high-GC content wild-type sequence of the CysC gene and also designed a slightly AT-biased sequence, with codons optimized for expression in the Pichia pastoris GS115 strain. Our results showed that the optimized coding sequence of human CysC increased the expression and secretion of the CysC protein by approximately 3- to 5-fold (90-96 mg CysC/L) in yeast, compared with the expression levels of the native CysC gene (17.9-18.4 mg CysC/L). We designed, constructed, and applied an optimized version of the CysC gene for the Pichia expression system. Our results demonstrate that the optimized coding sequence provides a higher yield of secreted CysC than that produced using the wild-type gene. Our data also serve as a practical example demonstrating a rational design strategy for the heterologous expression of secreted proteins.