Exposure to perfluorooctane sulfonate in utero reduces testosterone production in rat fetal Leydig cells

BACKGROUND

Perfluorooctane sulfonate (PFOS) is a synthetic material that has been widely used in industrial applications for decades. Exposure to PFOS has been associated with decreased adult testosterone level, and Leydig cell impairment during the time of adulthood. However, little is known about PFOS effects in utero on fetal Leydig cells (FLC).

METHODS AND RESULTS

The present study investigated effects of PFOS on FLC function. Pregnant Sprague Dawley female rats received vehicle (0.05% Tween20) or PFOS (5, 20 mg/kg) by oral gavage from gestational day (GD) 11-19. At GD20, testosterone (T) production, FLC numbers and ultrastructure, testicular gene and protein expression levels were examined. The results indicate that exposures to PFOS have affected FLC function as evidenced by decreased T production, impaired FLC, reduced FLC number, and decreased steroidogenic capacity and cholesterol level in utero.

CONCLUSION

The present study shows that PFOS is an endocrine disruptor of male reproductive system as it causes reduction of T production and impairment of rat fetal Leydig cells.

Exposure to perfluorooctane sulfonate in utero reduces testosterone production in rat fetal Leydig cells

BACKGROUND

Perfluorooctane sulfonate (PFOS) is a synthetic material that has been widely used in industrial applications for decades. Exposure to PFOS has been associated with decreased adult testosterone level, and Leydig cell impairment during the time of adulthood. However, little is known about PFOS effects in utero on fetal Leydig cells (FLC).

METHODS AND RESULTS

The present study investigated effects of PFOS on FLC function. Pregnant Sprague Dawley female rats received vehicle (0.05% Tween20) or PFOS (5, 20 mg/kg) by oral gavage from gestational day (GD) 11-19. At GD20, testosterone (T) production, FLC numbers and ultrastructure, testicular gene and protein expression levels were examined. The results indicate that exposures to PFOS have affected FLC function as evidenced by decreased T production, impaired FLC, reduced FLC number, and decreased steroidogenic capacity and cholesterol level in utero.

CONCLUSION

The present study shows that PFOS is an endocrine disruptor of male reproductive system as it causes reduction of T production and impairment of rat fetal Leydig cells.

Decreases in electrocardiographic R-wave amplitude and QT interval predict myocardial ischemic infarction in Rhesus monkeys with left anterior descending artery ligation

Clinical studies have demonstrated the predictive values of changes in electrocardiographic (ECG) parameters for the preexisting myocardial ischemic infarction. However, a simple and early predictor for the subsequent development of myocardial infarction during the ischemic phase is of significant value for the identification of ischemic patients at high risk. The present study was undertaken by using non-human primate model of myocardial ischemic infarction to fulfill this gap. Twenty male Rhesus monkeys at age of 2–3 years old were subjected to left anterior descending artery ligation. This ligation was performed at varying position along the artery so that it produced varying sizes of myocardial infarction at the late stage. The ECG recording was undertaken before the surgical procedure, at 2 h after the ligation, and 8 weeks after the surgery for each animal. The correlation of the changes in the ECG waves in the early or the late stage with the myocardial infarction size was analyzed. The R wave depression and the QT shortening in the early ischemic stage were found to have an inverse correlation with the myocardial infarction size. At the late stage, the R wave depression, the QT prolongation, the QRS score, and the ST segment elevation were all closely correlated with the developed infarction size. The poor R wave progression was identified at both the early ischemic and the late infarction stages. Therefore, the present study using non-human primate model of myocardial ischemic infarction identified the decreases in the R wave and the QT interval as early predictors of myocardial infarction. Validation of these parameters in clinical studies would greatly help identifying patients with myocardial ischemia at high risk for the subsequent development of myocardial infarction.

Proteomic and properties analysis of botanical insecticide rhodojaponin III-induced response of the diamondback moth, Plutella xyllostella (L.)

BACKGROUND

Rhodojaponin III, as a botanical insecticide, affects a wide variety of biological processes in insects, including reduction of feeding, suspension of development, and oviposition deterring of adults in a dose-dependent manner. However, the mode of these actions remains obscure.

PRINCIPAL FINDINGS

In this study, a comparative proteomic approach was adopted to examine the effect of rhodojaponin III on the Plutella xyllostella (L.). Following treating 48 hours, newly emergence moths were collected and protein samples were prepared. The proteins were separated by 2-DE, and total 31 proteins were significantly affected by rhodojaponin III compared to the control identified by MALDI-TOF/TOF-MS/MS. These differentially expressed proteins act in the nervous transduction, odorant degradation and metabolic change pathways. Further, gene expression patterns in treated and untreated moths were confirmed by qRT-PCR and western blot analysis. RNAi of the chemosensory protein (PxCSP) gene resulted in oviposition significantly increased on cabbage plants treated with rhodojaponin III.

CONCLUSIONS

These rhodojaponin III-induced proteins and gene properties analysis would be essential for a better understanding of the potential molecular mechanism of the response to rhodojaponin III from moths of P. xylostella.

Transcript and protein profiling analysis of the Destruxin A-induced response in larvae of Plutella xylostella

BACKGROUND

Destruxins (dtxs) are the mycotoxin produced by certain entomopathogenic fungi, such as Metarhizium anisopliae, Aschersonia sp, Alternaria brassicae and Ophiosphaerella herpotrichae. It can affect a wide variety of biological processes in insects, including innate immune, Ca(2+) channel in cells, and apoptosis in a dose-dependent manner. Dtxs have been used as biological control agent for a long time, however, their molecular mechanism of action is still unknown.

PRINCIPAL FINDINGS

In this study, both digital gene expression (DGE) and two-dimensional electrophoresis (2-DE) approaches were adopted to examine the effects of dtx A on Plutella xyllostella (L.) larvae. By using DGE and 2-DE analyses, 1584 genes and 42 protein points were identified as being up- or down regulated at least 2-fold in response to dtx A. Firstly, injection of dtx A to larvae accelerated the increase of peptidoglycan recognition protein (PGRP), which could activate the Toll signal pathway inducing production of antibacterial substances such as cecropin and gloverin. Dtx A also stimulated prophenoloxidase (proPO) system which plays an important role in innate immunity and leads to melanization of external organisms. Secondly, dtx A suppressed the expression of genes related to the Toll pathway, and induced expression of serine proteinase inhibitors (serpins), especially the serpin 2 that blocked process of the proPO system. Finally, other physiological process like xenobiotics detoxification, apoptosis, calcium signaling pathway and insect hormone biosynthesis, were also mediated in response to dtx A toxicity.

CONCLUSIONS

Transcript and protein profiling analyses will provide an insight into the potential molecular mechanism of action in P. xylostella larvae in response to dtx A.

Interleukin-33 mediates formalin-induced inflammatory pain in mice

Interleukin-33 (IL-33), a member of the IL-1 family, has attracted growing interest since its discovery in 2003. IL-33 has been implicated in many diseases, including arthritis, asthma, allergies, and cardiovascular and infectious diseases. However, few studies have investigated its role in the transmission and modulation of pain. The present study was designed to explore the possible roles of IL-33 and its receptor, ST2, in formalin-induced inflammatory pain in mice. We found that both subcutaneous (s.c., 300 ng) and intrathecal injection (i.t., 3 ng) of recombinant IL-33 (rIL-33) increased paw lifting and licking time not only in normal mice but also in formalin models. Administration of ST2 antibody, which blocked the IL-33/ST2 signaling, alleviated the formalin-induced spontaneous pain behavior. Moreover, the ST2(-/-) mice showed significantly decreased pain behavior, as well as reduced ultrasonic vocalization induced by formalin, compared with the wild-type group. Additionally, ST2 antibody alleviated the potentiating effects of rIL-33 on pain behavior in the formalin mice, indicating that IL-33 plays a role in pain modulation through its ST2 receptor. These data suggest IL-33 and its ST2 receptor mediate formalin-induced inflammatory pain, and as a result this cytokine and its receptor may be new targets for the development of analgesics.

Reduction of nutrient contaminants into shallow eutrophic waters through vegetated treatment beds

One of the most effective mitigative approaches to eutrophication is the reduction of nutrient loading into water bodies. Bioremediation presents an economically viable and ecologically sustainable technology to nutrient pollution control taking advantage of the remarkable ability of plants and their associated microbial community to assimilate and remove nutrients from the environment. In this study, four emergent macrophytes (Cyperus haspan, Pandanus amaryllifolius, Pontederia cordata and Thalia geniculata) and two floating plants (Hygroryza aristata and Pistia stratiotes) were deployed in bank-side treatment beds and comparatively assessed for their remediative capabilities for nutrient control. P. stratiotes exhibited the highest removal efficiency for both nitrate and phosphate among the six plant species studied. Emergent macrophytes, P. amaryllifolius, C. haspan and P. cordata, were also found to be highly effective in nutrient uptake exhibiting removal efficiencies up to 100%. With the exception of T. geniculata, depletion of nutrients as a result of plant uptake significantly impeded the natural colonization of algae invariably leading to improvements in water quality in terms of turbidity and pH. Suppression of algae proliferation by T. geniculata was not preceded by a reduction in nutrient concentrations suggesting that T. geniculata may be directly inhibiting algal growth through allelopathy.

Susceptibility towards enterotoxigenic Escherichia coli F4ac diarrhea is governed by the MUC13 gene in pigs

Enterotoxigenic Escherichia coli (ETEC) F4ac is a major determinant of diarrhea and mortality in neonatal and young pigs. Susceptibility to ETEC F4ac is governed by the intestinal receptor specific for the bacterium and is inherited as a monogenic dominant trait. To identify the receptor gene (F4acR), we first mapped the locus to a 7.8-cM region on pig chromosome 13 using a genome scan with 194 microsatellite markers. A further scan with high density markers on chromosome 13 refined the locus to a 5.7-cM interval. Recombination breakpoint analysis defined the locus within a 2.3-Mb region. Further genome-wide mapping using 39,720 informative SNPs revealed that the most significant markers were proximal to the MUC13 gene in the 2.3-Mb region. Association studies in a collection of diverse outbred populations strongly supported that MUC13 is the most likely responsible gene. We characterized the porcine MUC13 gene that encodes two transcripts: MUC13A and MUC13B. Both transcripts have the characteristic PTS regions of mucins that are enriched in distinct tandem repeats. MUC13B is predicated to be heavily O-glycosylated, forming the binding site of the bacterium; while MUC13A does not have the O-glycosylation binding site. Concordantly, 127 independent pigs homozygous for MUC13A across diverse breeds are all resistant to ETEC F4ac, and all 718 susceptible animals from the broad breed panel carry at least one MUC13B allele. Altogether, we conclude that susceptibility towards ETEC F4ac is governed by the MUC13 gene in pigs. The finding has an immediate translation into breeding practice, as it allows us to establish an efficient and accurate diagnostic test for selecting against susceptible animals. Moreover, the finding improves our understanding of mucins that play crucial roles in defense against enteric pathogens. It revealed, for the first time, the direct interaction between MUC13 and enteric bacteria, which is poorly understood in mammals.

Efficacy and tolerability of vildagliptin as add-on therapy to metformin in Chinese patients with type 2 diabetes mellitus

AIM

To investigate the efficacy and tolerability of vildagliptin as add-on therapy to metformin in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin.

METHODS

This was a 24-week, randomized, double-blind, placebo-controlled study. Patients with T2DM (N = 438) with haemoglobin A1c (HbA1c) of 7.0-10.0% and fasting plasma glucose (FPG) <15 mmol/l (<270 mg/dl) were randomized (1 : 1 : 1) to vildagliptin 50 mg bid, vildagliptin 50 mg qd or placebo in addition to metformin.

RESULTS

The treatment groups were well balanced at baseline [mean HbA1c, 8.0%, FPG, 8.8 mmol/l (158 mg/dl); body mass index, 25.5 kg/m(2) ]. The adjusted mean change (AMΔ) in HbA1c at endpoint was -1.05 ± 0.08%, -0.92 ± 0.08% and -0.54 ± 0.08% in patients receiving vildagliptin 50 mg bid, 50 mg qd and placebo, respectively. The between-treatment difference (vildagliptin 50 mg bid-placebo) was -0.51 ± 0.11%, p < 0.001. A greater proportion of vildagliptin-treated patients met at least one responder criterion (82.1 and 70.7%) compared to placebo-treated patients (60.4%). The AMΔ at endpoint for FPG with vildagliptin 50 mg bid, -0.95 mmol/l (-17.1 mg/dl); 50 mg qd, -0.84 mmol/l (-15.1 mg/dl) was significantly different compared with the placebo -0.26 mmol/l (-4.68 mg/dl) (p ≤ 0.001). Adverse events (AEs) were reported as 34.2, 36.5 and 37.5% for patients receiving vildagliptin 50 mg bid, 50 mg qd or placebo, respectively. Two patients in the vildagliptin 50 mg qd and one in the placebo group reported serious AEs, which were not considered to be related to the study drug; one incidence of hypoglycaemic event was reported in the vildagliptin 50 mg bid group.

CONCLUSION

Vildagliptin as add-on therapy to metformin improved glycaemic control and was well tolerated in Chinese patients who were inadequately controlled by metformin only.

Immunohistochemical detection of differentially localized up-regulation of lysyl oxidase and down-regulation of matrix metalloproteinase-1 in rhesus monkey model of chronic myocardial infarction

Myocardial remodeling after ischemic infarction is characterized by collagen accumulation leading to replacement and interstitial fibrosis. Type I and III collagens are predominant components in cardiac fibrosis. Lysyl oxidase (LOX) facilitates the cross-linking of type I and III fibrils, resulting in the formation of stiff fibers and their subsequent tissue deposition. However, the matrix metalloproteinases (MMPs), a family of zinc-dependent enzymes, function in the degradation of the collagen components of extracellular matrix. Tissue inhibitors for MMPs (TIMPs) manipulate the action of MMPs. To understand the contribution of these molecules to cardiac fibrosis, we developed a rhesus monkey model to determine the changes in LOX, MMP1 and TIMP1 in relation to collagen deposition after myocardial ischemic infarction. Male rhesus monkeys were subjected to left anterior descending artery ligation along with sham-operated controls. Histological examination and immunochemistry were performed eight weeks after the ischemic injury. The results showed that both type I and III collagens were increased in the scar area and in the interstitium, and the ratio of type I/III collagens also increased in the scar area but not in the interstitium. The expression of LOX was up-regulated, but the expression of MMP1 was down-regulated in residual myocytes of the scar area and the border zone. The expression of TIMP1 was not changed. The data thus demonstrated that the collagen deposition in infarcted myocardium is correlated with an enhanced cross-linking capacity and a decreased degradation process.

Exome sequencing identifies compound heterozygous mutations in CYP4V2 in a pedigree with retinitis pigmentosa

Retinitis pigmentosa (RP) is a heterogeneous group of progressive retinal degenerations characterized by pigmentation and atrophy in the mid-periphery of the retina. Twenty two subjects from a four-generation Chinese family with RP and thin cornea, congenital cataract and high myopia is reported in this study. All family members underwent complete ophthalmologic examinations. Patients of the family presented with bone spicule-shaped pigment deposits in retina, retinal vascular attenuation, retinal and choroidal dystrophy, as well as punctate opacity of the lens, reduced cornea thickness and high myopia. Peripheral venous blood was obtained from all patients and their family members for genetic analysis. After mutation analysis in a few known RP candidate genes, exome sequencing was used to analyze the exomes of 3 patients III2, III4, III6 and the unaffected mother II2. A total of 34,693 variations shared by 3 patients were subjected to several filtering steps against existing variation databases. Identified variations were verified in the rest family members by PCR and Sanger sequencing. Compound heterozygous c.802-8_810del17insGC and c.1091-2A>G mutations of the CYP4V2 gene, known as genetic defects for Bietti crystalline corneoretinal dystrophy, were identified as causative mutations for RP of this family.

Assessment of correlation between CT angiographic clot load score, pulmonary perfusion defect score and global right ventricular function with dual-source CT for acute pulmonary embolism

OBJECTIVE

The purpose of this study was to prospectively investigate the correlation between CT angiographic clot load (CTACL) score, pulmonary perfusion defect (PPD) score and the global right ventricular function in the assessment of pulmonary embolism (PE) severity.

METHODS

49 patients with acute PE, who underwent dual-source CT scan, were included in the study. CT angiography and perfusion imaging were performed. Data from electrocardiogram-gated coronary angiography scanning protocol were used for right ventricular function analysis. Two readers evaluated the CTACL and PPD scores using the Qanadli and Chae methods, respectively.

RESULTS

The PPD score had a strong positive correlation with the CTACL score (r=0.72, p<0.001) and both scores in turn had a strong positive correlation with the right ventricular/left ventricular (RV/LV) diameter ratio (r=0.60, r=0.62, p<0.001). However, the PPD score had a strong negative correlation with ejection fraction (EF) (r=-0.63, p<0.001) while the CTACL score had a low negative correlation with EF (r=-0.33, p=0.02). Between the RV/LV<1 group (n=35) and the RV/LV >1 group (n=14), the PPD score, CTACL score, pulmonary artery trunk diameter, EF and reflux of inferior vena cava were significantly different, all with p<0.001. The end-systolic volume (p=0.01) was significantly different but the end-diastolic volume (p=0.11) and stroke volume (p=0.08) showed no statistically significant difference between the two groups.

CONCLUSION

Therefore, considering PPD scores, CTACL scores and cardiovascular manifestations together may be helpful in the evaluation of PE severity.

Association of B3GNT5 polymorphisms with susceptibility to ETEC F4ab/ac in the white Duroc × Erhualian intercross and 15 outbred pig breeds

The B3GNT5 gene is a candidate for the F4ab/ac receptor conferring susceptibility to enterotoxigenic Escherichia coli (ETEC) F4ab/ac in pigs. In this study, we screened mutations in the complete coding region of the porcine B3GNT5 gene and identified four SNPs in the 3' untranslated regions. We genotyped the four SNPs across a large-scale White Duroc × Chinese Erhualian F2 resource population (total F2 = 755) and 292 purebred piglets representing 15 Chinese and Western breeds. We found that the g.1476G→A locus and haplotypes [A;T;G;T] and [A;G;G;T] had significant association with susceptibility to ETEC F4ac in the resource population. None of the B3GNT5 polymorphisms and haplotypes was associated with susceptibility to ETEC F4ab/ac in outbred piglets. This result, together with other reports, supports the conclusion that B3GNT5 is not the responsible gene encoding the ETEC F4ab/ac receptors.

Cardiac arrhythmias induced by chloral hydrate in rhesus monkeys

Chloral hydrate has been long used as a safe sedative and hypnotic drug in humans. However, reports on its cardiovascular adverse effects have been published from time to time. The present study was undertaken to use Rhesus monkeys as a model to define the dose regiment of chloral hydrate at which cardiac arrhythmias can be induced and the consequences of the cardiac events. Male Rhesus monkeys of 2-3 years old were intravenously infused with chloral hydrate starting at 50 mg/kg with an increasing increment of 25 mg/kg until the occurrence of cardiac arrhythmias. In addition, a traditional up-and-down dosing procedure was applied to define a single dose level at which cardiac arrhythmias can be induced. The data obtained showed that when the sequentially escaladed dose reached 125 mg/kg, cardiac arrhythmias occurred in all monkeys tested. The single effective dose to cause cardiac arrhythmias calculated from the crossover analysis was 143 ± 4 mg/kg. This value would be equivalent to 68.6 ± 1.9 mg/kg for children and 46.4 ± 1.3 mg/kg for adults in humans. Under either multiple or single dose condition, cardiac arrhythmias did not occur before 40 min after the onset of anesthesia induced by chloral hydrate. Cardiac arrhythmias were recovered without help at the end of the anesthesia in most cases, but also continued after the regain of consciousness in some cases. The cardiac arrhythmias were accompanied with compromised cardiac function including suppressed fractional shortening and ejection fraction. This study thus suggests that cautions need to be taken when chloral hydrate is used above certain levels and beyond a certain period of anesthesia, and cardiac arrhythmias induced by chloral hydrate need to be closely monitored because compromised cardiac function may occur simultaneously. In addition, patients with cardiac arrhythmias induced by chloral hydrate should be monitored even after they are recovered from the anesthesia.