Search

The intrauterine environment is a major contributor to increased rates of metabolic disease in adults. Intrahepatic cholestasis of pregnancy (ICP) is a liver disease of pregnancy that affects 0.5%-2% of pregnant women and is characterized by increased bile acid levels in the maternal serum. The influence of ICP on the metabolic health of offspring is unknown. We analyzed the Northern Finland birth cohort 1985-1986 database and found that 16-year-old children of mothers with ICP had altered lipid profiles. Males had increased BMI, and females exhibited increased waist and hip girth compared with the offspring of uncomplicated pregnancies. We further investigated the effect of maternal cholestasis on the metabolism of adult offspring in the mouse. Females from cholestatic mothers developed a severe obese, diabetic phenotype with hepatosteatosis following a Western diet, whereas matched mice not exposed to cholestasis in utero did not. Female littermates were susceptible to metabolic disease before dietary challenge. Human and mouse studies showed an accumulation of lipids in the fetoplacental unit and increased transplacental cholesterol transport in cholestatic pregnancy. We believe this is the first report showing that cholestatic pregnancy in the absence of altered maternal BMI or diabetes can program metabolic disease in the offspring.

Tumor suppressors are so named because cancers occur in their absence, but these genes also have important functions in development, metabolism and tissue homeostasis. Here, we discuss known and potential functions of tumor suppressor genes during tissue regeneration, focusing on the evolutionarily conserved tumor suppressors pRb1, p53, Pten and Hippo. We propose that their activity is essential for tissue regeneration. This is in contrast to suggestions that tumor suppression is a trade-off for regenerative capacity. We also hypothesize that certain aspects of tumor suppressor pathways inhibit regenerative processes in mammals, and that transient targeted modification of these pathways could be fruitfully exploited to enhance processes that are important to regenerative medicine.

Objective: Preterm infants often show intolerance to the first enteral feeds, and the structural and functional basis of this intolerance remains unclear. We hypothesized that preterm and term neonates show similar gut trophic responses to feeding but different expression of intestinal functional proteins, thus helping to explain why preterm neonates are more susceptible to feeding-induced disorders such as necrotizing enterocolitis (NEC)., Methods: Incidence of feeding-induced NEC, intestinal mass, and brush border enzyme activities, and the intestinal proteome in preterm cesarean-delivered pigs were compared with the corresponding values in pigs delivered spontaneously at term., Results: For both preterm and term pigs, mucosal mass and maltase activity increased (50%-100%), whereas lactase decreased (-50%), relative to values at birth. Only preterm pigs were highly NEC sensitive (30% vs 0% in term pigs, P < 0.05). By gel-based proteomics, 36 identified proteins differed in expression, with most proteins showing downregulation in preterm pigs, including proteins related to intestinal structure and actin filaments, stress response, protein processing, and nutrient metabolism., Conclusions: Despite that enteral feeding induces rapid gut tropic response in both term and preterm neonates, the expression level of cellular proteins related to mucosal integrity, metabolism, and stress response differed markedly (including complement 3, prohibitin, ornithine carbamoyltransferase, and arginosuccinate synthetase). These proteins may play a role in the development of functional gut disorders and NEC in preterm neonates.

Rationale: The Ca(2+) sensitivity of the myofilaments is increased in hypertrophic cardiomyopathy and other heart diseases and may contribute to a higher risk for sudden cardiac death. Ca(2+) sensitization increases susceptibility to reentrant ventricular tachycardia in animal models, but the underlying mechanism is unknown., Objective: To investigate how myofilament Ca(2+) sensitization creates reentrant arrhythmia susceptibility., Methods and Results: Using hypertrophic cardiomyopathy mouse models (troponinT-I79N) and a Ca(2+) sensitizing drug (EMD57033), here we identify focal energy deprivation as a direct consequence of myofilament Ca(2+) sensitization. To detect ATP depletion and thus energy deprivation, we measured accumulation of dephosphorylated Connexin 43 (Cx43) isoform P0 and AMP kinase activation by Western blotting and immunostaining. No differences were detected between groups at baseline, but regional accumulation of Connexin 43 isoform P0 occurred within minutes in all Ca(2+)-sensitized hearts, in vivo after isoproterenol challenge and in isolated hearts after rapid pacing. Lucifer yellow dye spread demonstrated reduced gap junctional coupling in areas with Connexin 43 isoform P0 accumulation. Optical mapping revealed that selectively the transverse conduction velocity was slowed and anisotropy increased. Myofilament Ca(2+) desensitization with blebbistatin prevented focal energy deprivation, transverse conduction velocity slowing, and the reentrant ventricular arrhythmias., Conclusions: Myofilament Ca(2+) sensitization rapidly leads to focal energy deprivation and reduced intercellular coupling during conditions that raise arrhythmia susceptibility. This is a novel proarrhythmic mechanism that can increase arrhythmia susceptibility in structurally normal hearts within minutes and may, therefore, contribute to sudden cardiac death in diseases with increased myofilament Ca(2+) sensitivity.

Mitochondrial oxidative metabolism plays a key role in meeting energetic demands of cells by oxidative phosphorylation (OxPhos). Here, we have briefly discussed (a) the dynamic relationship that exists among glycolysis, the tricarboxylic acid (TCA) cycle, and OxPhos; (b) the evidence of impaired OxPhos (i.e. mitochondrial dysfunction) in breast cancer; (c) the mechanisms by which mitochondrial dysfunction can predispose to cancer; and (d) the effects of host and environmental factors that can negatively affect mitochondrial function. We propose that impaired OxPhos could increase susceptibility to breast cancer via suppression of the p53 pathway, which plays a critical role in preventing tumorigenesis. OxPhos is sensitive to a large number of factors intrinsic to the host (e.g. inflammation) as well as environmental exposures (e.g. pesticides, herbicides and other compounds). Polymorphisms in over 143 genes can also influence the OxPhos system. Therefore, declining mitochondrial oxidative metabolism with age due to host and environmental exposures could be a common mechanism predisposing to cancer.

Accumulating evidence suggests that both an adverse prenatal and early postnatal environment increase susceptibility to renal and metabolic dysfunction later in life; however, whether exposure to adverse conditions during both prenatal and postnatal development act synergistically to potentiate the severity of renal and metabolic injury remains unknown. Sprague-Dawley rats were fed either a standard diet or a diet high in fat/fructose throughout pregnancy and lactation. After being weaned, female offspring were randomized to either standard diet or the high-fat/high-fructose diet, resulting in the following treatment groups: NF-NF, offspring of mothers fed a standard diet and fed a standard diet postnatally; NF-HF, offspring of mothers fed a standard diet and fed a high-fat/fructose diet postnatally; HF-NF, offspring of mothers fed a high-fat/fructose diet and fed a standard diet postnatally; HF-HF, offspring of mothers fed a high-fat/fructose diet and fed a high-fat/fructose diet postnatally. At the time of euthanasia (17 wk of age), HF-HF offspring weighed 30% more and had 110% more visceral fat than NF-NF offspring. The HF-HF offspring also had elevated blood glucose levels, glucose intolerance, 286% increase in urine albumin excretion, and 60% increase in glomerulosclerosis compared with NF-NF. In addition, HF-HF offspring exhibited a 100% increase in transforming growth factor-β protein expression and 116% increase in the abundance of infiltrated macrophages compared with the NF-NF offspring. These observations suggest that high-fat/fructose feeding during prenatal and throughout postnatal life increases the susceptibility to renal and metabolic injury later in life.

The construct of frailty is germane to that of aging, but a clinical definition of frailty is still wanted. In the geriatric literature, frailty has been conceived in two different ways. The first one is a threshold beyond which the functional reserve of a person is critically reduced and the tolerance of stress negligible. The second is as a progressive reduction of functional reserve due to a progressive accumulation of deficit. In this construct it may be hard to distinguish frailty from aging. Neither concept has at present a clear application in the management of older cancer patients. Studies are needed to establish whether the construct of frailty proposed by Fried et al. may be predictive of decreased cancer-independent survival and of decreased treatment tolerance in older cancer patients., (Copyright © 2013 S. Karger AG, Basel.)

Voltage-gated sodium channels (VGSCs) are essential for the generation and propagation of action potentials in electrically excitable cells. Dominant mutations in SCN1A, which encodes the Nav1.1 VGSC α-subunit, underlie several forms of epilepsy, including Dravet syndrome (DS) and genetic epilepsy with febrile seizures plus (GEFS+). Electrophysiological analyses of DS and GEFS+ mouse models have led to the hypothesis that SCN1A mutations reduce the excitability of inhibitory cortical and hippocampal interneurons. To more directly examine the relative contribution of inhibitory interneurons and excitatory pyramidal cells to SCN1A-derived epilepsy, we first compared the expression of Nav1.1 in inhibitory parvalbumin (PV) interneurons and excitatory neurons from P22 mice using fluorescent immunohistochemistry. In the hippocampus and neocortex, 69% of Nav1.1 immunoreactive neurons were also positive for PV. In contrast, 13% and 5% of Nav1.1 positive cells in the hippocampus and neocortex, respectively, were found to co-localize with excitatory cells identified by CaMK2α immunoreactivity. Next, we reduced the expression of Scn1a in either a subset of interneurons (mainly PV interneurons) or excitatory cells by crossing mice heterozygous for a floxed Scn1a allele to either the Ppp1r2-Cre or EMX1-Cre transgenic lines, respectively. The inactivation of one Scn1a allele in interneurons of the neocortex and hippocampus was sufficient to reduce thresholds to flurothyl- and hyperthermia-induced seizures, whereas thresholds were unaltered following inactivation in excitatory cells. Reduced interneuron Scn1a expression also resulted in the generation of spontaneous seizures. These findings provide direct evidence for an important role of PV interneurons in the pathogenesis of Scn1a-derived epilepsies., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Citrobacter rodentium is a natural mouse pathogen widely used as a model for enteropathogenic and enterohemorrhagic Escherichia coli infections in humans. While C. rodentium causes self-limiting colitis in most inbred mouse strains, it induces fatal diarrhoea in susceptible strains. The physiological pathways as well as the genetic determinants leading to susceptibility have remained largely uncharacterized. Here we use a forward genetic approach to identify the R-spondin2 gene as a major determinant of susceptibility to C. rodentium infection. Robust induction of R-spondin2 expression during infection in susceptible mouse strains causes a potent Wnt-mediated proliferative response of colonic crypt cells, leading to the generation of an immature and poorly differentiated colonic epithelium with deficiencies in ion-transport components. Our data demonstrate a previously unknown role of R-spondins and Wnt signalling in susceptibility to infectious diarrhoea and identify R-spondin2 as a key molecular link between infection and intestinal homoeostasis.

The molecular mechanism underlying the development of Barrett's esophagus (BE), the precursor to esophageal adenocarcinoma, remains unknown. Our previous work implicated sonic hedgehog (Shh) signaling as a possible driver of BE and suggested that bone morphogenetic protein 4 (Bmp4) and Sox9 were downstream mediators. We have utilized a novel in vivo tissue reconstitution model to investigate the relative roles of Bmp4 and Sox9 in driving metaplasia. Epithelia reconstituted from squamous epithelial cells or empty vector-transduced cells had a stratified squamous phenotype, reminiscent of normal esophagus. Expression of Bmp4 in the stromal compartment activated signaling in the epithelium but did not alter the squamous phenotype. In contrast, expression of Sox9 in squamous epithelial cells induced formation of columnar-like epithelium with expression of the columnar differentiation marker cytokeratin 8 and the intestinal-specific glycoprotein A33. In patient tissue, A33 protein was expressed specifically in BE, but not in normal esophagus. Expression of Cdx2, another putative driver of BE, alone had no effect on reconstitution of a squamous epithelium. Furthermore, epithelium coexpressing Cdx2 and Sox9 had a phenotype similar to epithelium expressing Sox9 alone. Our results demonstrate that Sox9 is sufficient to drive columnar differentiation of squamous epithelium and expression of an intestinal differentiation marker, reminiscent of BE. These data suggest that Shh-mediated expression of Sox9 may be an important early event in the development of BE and that the potential for inhibitors of the hedgehog pathway to be used in the treatment of BE and/or esophageal adenocarcinoma could be tested in the near future.

Neonatal seizures can lead to later life epilepsy and neurobehavioral deficits, and there are no treatments to prevent these sequelae. We showed previously that hypoxia-induced seizures in a neonatal rat model induce rapid phosphorylation of serine-831 (S831) and Serine 845 (S845) sites of the AMPA receptor GluR1 subunit and later neuronal hyperexcitability and epilepsy, suggesting that seizure-induced posttranslational modifications may represent a novel therapeutic target. To unambiguously assess the contribution of these sites, we examined seizure susceptibility in wild-type mice versus transgenic knock-in mice with deficits in GluR1 S831 and S845 phosphorylation [GluR1 double-phosphomutant (GluR1 DPM) mice]. Phosphorylation of the GluR1 S831 and S845 sites was significantly increased in the hippocampus and cortex after a single episode of pentyleneterazol-induced seizures in postnatal day 7 (P7) wild-type mouse pups and that transgenic knock-in mice have a higher threshold and longer latencies to seizures. Like the rat, hypoxic seizures in P9 C57BL/6N wild-type mice resulted in transient increases in GluR1 S831 and GluR1 S845 phosphorylation in cortex and were associated with enhanced seizure susceptibility to later-life kainic-acid-induced seizures. In contrast, later-life seizure susceptibility after hypoxia-induced seizures was attenuated in GluR1 DPM mice, supporting a role for posttranslational modifications in seizure-induced network excitability. Finally, human hippocampal samples from neonatal seizure autopsy cases also showed an increase in GluR1 S831 and S845, supporting the validation of this potential therapeutic target in human tissue.

Background: Marijuana use by teenagers often predates the use of harder drugs, but the neurobiological underpinnings of such vulnerability are unknown. Animal studies suggest enhanced heroin self-administration (SA) and dysregulation of the endogenous opioid system in the nucleus accumbens shell (NAcsh) of adults following adolescent Δ(9)-tetrahydrocannabinol (THC) exposure. However, a causal link between proenkephalin (Penk) expression and vulnerability to heroin has yet to be established., Methods: To investigate the functional significance of NAcsh Penk tone, selective viral-mediated knockdown and overexpression of Penk was performed, followed by analysis of subsequent heroin SA behavior. To determine whether adolescent THC exposure was associated with chromatin alteration, we analyzed levels of histone H3 methylation in the NAcsh via chromatin immunoprecipitation at five sites flanking the Penk gene transcription start site., Results: Here we show that regulation of the Penk opioid neuropeptide gene in NAcsh directly regulates heroin SA behavior. Selective viral-mediated knockdown of Penk in striatopallidal neurons attenuates heroin SA in adolescent THC-exposed rats, whereas Penk overexpression potentiates heroin SA in THC-naïve rats. Furthermore, we report that adolescent THC exposure mediates Penk upregulation through reduction of histone H3 lysine 9 (H3K9) methylation in the NAcsh, thereby disrupting the normal developmental pattern of H3K9 methylation., Conclusions: These data establish a direct association between THC-induced NAcsh Penk upregulation and heroin SA and indicate that epigenetic dysregulation of Penk underlies the long-term effects of THC., (Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

A substantial body of epidemiological, clinical, cellular, and molecular evidence converges to suggest that conditions during the intrauterine period of life play a critical role in developmental programming to influence subsequent health and susceptibility for common, complex disorders. Elucidation of the biological mechanisms underlying these effects is an area of considerable interest and investigation, and it is important to determine whether these mechanisms are distinct for different health outcomes or whether there are some common underlying pathways that may account for the effects of disparate prenatal and early postnatal conditions on various health and disease risk phenotypes. We propose that telomere biology may represent a common underlying mechanism connecting fetal programming and subsequent health outcomes. It appears that the initial establishment of telomere length and regulation of telomere homeostasis may be plastic and receptive to the influence of intrauterine and other early life conditions. Moreover, telomere homeostasis in various cell types may serve as a fundamental integrator and regulator of processes underlying cell genomic integrity and function, aging, and senescence over the life span. We advance the hypothesis that context- and time-inappropriate exposures to various forms of physiological stress (maternal-placental-fetal endocrine aberrations and immune, inflammatory, and oxidative stresses) during the intrauterine period of development may alter or program the telomere biology system in a manner that accelerates cellular dysfunction, aging, and disease susceptibility over the life span.

Background: The exceptional physical-chemical properties of carbon nanotubes have lead to their use in diverse commercial and biomedical applications. However, their utilization has raised concerns about human exposure that may predispose individuals to adverse health risks. The present study investigated the susceptibility to cardiac ischemic injury following a single exposure to various forms of multi-walled carbon nanotubes (MWCNTs). It was hypothesized that oropharyngeal aspiration of MWCNTs exacerbates myocardial ischemia and reperfusion injury (I/R injury)., Methods: Oropharyngeal aspiration was performed on male C57BL/6J mice with a single amount of MWCNT (0.01 - 100 μg) suspended in 100 μL of a surfactant saline (SS) solution. Three forms of MWCNTs were used in this study: unmodified, commercial grade (C-grade), and functionalized forms that were modified either by acid treatment (carboxylated, COOH) or nitrogenation (N-doped) and a SS vehicle. The pulmonary inflammation, serum cytokine profile and cardiac ischemic/reperfusion (I/R) injury were assessed at 1, 7 and 28 days post-aspiration., Results: Pulmonary response to MWCNT oropharyngeal aspiration assessed by bronchoalveolar lavage fluid (BALF) revealed modest increases in protein and inflammatory cell recruitment. Lung histology showed modest tissue inflammation as compared to the SS group. Serum levels of eotaxin were significantly elevated in the carboxylated MWCNT aspirated mice 1 day post exposure. Oropharyngeal aspiration of all three forms of MWCNTs resulted in a time and/or dose-dependent exacerbation of myocardial infarction. The severity of myocardial injury varied with the form of MWCNTs used. The N-doped MWCNT produced the greatest expansion of the infarct at any time point and required a log concentration lower to establish a no effect level. The expansion of the I/R injury remained significantly elevated at 28 days following aspiration of the COOH and N-doped forms, but not the C-grade as compared to SS., Conclusion: Our results suggest that oropharyngeal aspiration of MWCNT promotes increased susceptibility of cardiac tissue to ischemia/reperfusion injury without a significant pulmonary inflammatory response. The cardiac injury effects were observed at low concentrations of MWCNTs and presence of MWCNTs may pose a significant risk to the cardiovascular system.

Human memory and naive CD4 T cells can mainly be identified by the reciprocal expression of the CD45RO or CD45RA isoforms. In HIV-1 infection, blood CD45RO memory CD4 T cells are preferentially infected and serve as a major viral reservoir. The molecular mechanism dictating this differential susceptibility to HIV-1 remains largely obscure. Here, we report that the different susceptibility of memory and naive T cells to HIV is not determined by restriction factors such as Apobec3G or BST2. However, we observed a phenotypic distinction between human CD45RO and CD45RA resting CD4 T cells in their cortical actin density and actin dynamics. CD45RO CD4 T cells possess a higher cortical actin density and can be distinguished as CD45RO(+)Actin(high). In contrast, CD45RA T cells are phenotypically CD45RA(+)Actin(low). In addition, the cortical actin in CD45RO memory CD4 T cells is more dynamic and can respond to low dosages of chemotactic induction by SDF-1, whereas that of naive cells cannot, despite a similar level of the chemokine receptor CXCR4 present on both cells. We further demonstrate that this difference in the cortical actin contributes to their differential susceptibility to HIV-1; resting memory but not naive T cells are highly responsive to HIV-mediated actin dynamics that promote higher levels of viral entry and early DNA synthesis in resting memory CD4 T cells. Furthermore, transient induction of actin dynamics in resting naive T cells rescues HIV latent infection following CD3/CD28 stimulation. These results suggest a key role of chemotactic actin activity in facilitating HIV-1 latent infection of these T cell subsets.

Intrauterine growth retardation predisposes toward long-term morbidity from type 2 diabetes and cardiovascular disease. To explain this association, the concept of programming was introduced to indicate a process whereby a stimulus or insult at a critical period of development has lasting or lifelong consequences on key endocrine and metabolic pathways. Subtle changes in cell composition of tissues, induced by suboptimal conditions in utero, can influence postnatal physiological functions. There is increasing evidence, suggesting that liver may represent one of the candidate organs targeted by programming, undergoing structural, functional and epigenetic changes following exposure to an unfavorable intrauterine environment. The aim of this review is to provide insights into the molecular mechanisms underlying liver programming that contribute to increase the cardiometabolic risk in subjects with intrauterine growth restriction.

Objectives: The aim of this study was to evaluate the links between connexin43 (Cx43) expression, myocardial conduction velocity, and ventricular tachycardia in a model of healed myocardial infarction., Background: Post-infarction ventricular arrhythmias frequently cause sudden death. Impaired myocardial conduction has previously been linked to ventricular arrhythmias. Altered connexin expression is a potential source of conduction slowing identified in healed scar border tissues. The functional effect of increasing border-zone Cx43 has not been previously evaluated., Methods: Twenty-five Yorkshire pigs underwent anterior infarction by transient left anterior descending coronary artery occlusion, followed by weekly testing for arrhythmia inducibility. Twenty animals with reproducibly inducible sustained monomorphic ventricular tachycardia were randomized 2:1:1 to receive AdCx43, Adβgal, or no gene transfer. One week later, animals underwent follow-up electrophysiologic study and tissue assessment for several functional and molecular measures., Results: Animals receiving AdCx43 had less electrogram fractionation and faster conduction velocity in the anterior-septal border zone. Only 40% of AdCx43 animals remained inducible for ventricular tachycardia, while 100% of controls were inducible after gene transfer. AdCx43 animals had 2-fold higher Cx43 protein levels in the anterior-septal infarct border, with similar percents of phosphorylated and intercalated disk-localized Cx43 compared with controls., Conclusions: These data mechanistically link Cx43 expression to slow conduction and arrhythmia susceptibility in the healed scar border zone. Targeted manipulation of Cx43 levels improved conduction velocity and reduced ventricular tachycardia susceptibility. Cx43 gene transfer represents a novel treatment strategy for post-infarction arrhythmias., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Seizure susceptibility to neurological insults, including chemical convulsants, is age-dependent and most likely reflective of overall differences in brain excitability. The molecular and cellular mechanisms underlying development-dependent seizure susceptibility remain to be fully understood. Because the mammalian target of rapamycin (mTOR) pathway regulates neurite outgrowth, synaptic plasticity and cell survival, thereby influencing brain development, we tested if exposure of the immature brain to the mTOR inhibitor rapamycin changes seizure susceptibility to neurological insults. We found that inhibition of mTOR by rapamycin in immature rats (3-4 weeks old) increases the severity of seizures induced by pilocarpine, including lengthening the total seizure duration and reducing the latency to the onset of seizures. Rapamycin also reduces the minimal dose of pentylenetetrazol (PTZ) necessary to induce clonic seizures. However, in mature rats, rapamycin does not significantly change the seizure sensitivity to pilocarpine and PTZ. Likewise, kainate sensitivity was not significantly affected by rapamycin treatment in either mature or immature rats. Additionally, rapamycin treatment down-regulates the expression of potassium-chloride cotransporter 2 (KCC2) in the thalamus and to a lesser degree in the hippocampus. Pharmacological inhibition of thalamic mTOR or KCC2 increases susceptibility to pilocarpine-induced seizure in immature rats. Thus, our study suggests a role for the mTOR pathway in age-dependent seizure susceptibility., (Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.)

Background: The receptor for formylated peptides, formyl peptide receptor 1 (FPR1), potently activates and serves as a chemoattractant receptor for neutrophils., Aim: Given the abundance of neutrophils in the inflamed colon, our aim was to determine if the FPR1 mediates colonic neutrophil migration, using the dextran sodium sulfate (DDS)-induced model of colitis., Methods: Formyl peptide receptor 1 gene-deficient mice were administered DDS in drinking water for a single 5-day period (acute) or in two 5-day periods separated by 16 days (chronic). At the end of the treatment their colons were excised, measured, and prepared for histological evaluation., Results: FPR1(-/-) mice experienced less severe acute colonic pathology than C57BL/6 (wildtype) mice. The opposite was observed following the second colitis cycle, with FPR1(-/-) mice developing worse pathology than wildtype mice. Both strains had similar numbers of infiltrating neutrophils in ulcerated areas of the colon after a single DSS cycle, but FPR1(-/-) mice had significantly more neutrophils in the ulcerated mucosa after two cycles. There was no difference in the capacity of neutrophils from each strain to migrate to chemoattractants. Since the FPR1(-/-) mice had larger ulcers compared to the wildtype mice, we propose that the FPR1(-/-) mice failed to recover at the same rate as wildtype mice. This apparent difference in restitution could not be attributed to observable differences in annexin A1., Conclusions: We conclude that neutrophil migration into the inflamed mouse colon does not depend on FPR1 but that FPR1 contributes in other pathological mechanisms that are harmful during acute inflammation but protective during chronic inflammation.

Connexin 32 (Cx32) is a major gap junction protein in the liver. The authors previously demonstrated that transgenic rats carrying a dominant negative mutant of Cx32 (Cx32ΔTg) have much decreased capacity for gap junctional intercellular communication (GJIC) and increased susceptibility to diethylnitrosamine (DEN)-induced hepatocarcinogenesis as compared to littermate wild-type (wt) rats. To evaluate the age-dependent susceptibility to DEN-induced hepatocarcinogenesis and alteration of GJIC function, male Cx32ΔTg and wt rats at 10, 30, or 85 weeks old were given a single intraperitoneal administration of DEN (40 mg/rat) and sacrificed 12 weeks later. The number and area of glutathione S-transferase placental form (GST-P)-positive preneoplastic foci were significantly increased in the liver of 10- and 30-wk-old Cx32ΔTg rats compared with age-matched wt. However, in the 85-wk-old rats, both Cx32ΔTg and wt rats had similarly large number and area of GST-P-positive foci, and the difference was not significant. Interestingly, function of hepatic GJIC was reduced and protein and mRNA expression of Cx32 were decreased with aging in wt rats. These results suggest that a decline of hepatic intercellular communication through gap junction results in increased susceptibility to DEN-induced hepatocarcinogenesis in aged rats.

Background: APOBEC3 proteins are host factors that restrict infection by retroviruses like HIV, MMTV, and MLV and are variably expressed in hematopoietic and non-hematopoietic cells, such as macrophages, lymphocytes, dendritic, and epithelia cells. Previously, we showed that APOBEC3 expressed in mammary epithelia cells function to limit milk-borne transmission of the beta-retrovirus, mouse mammary tumor virus. In this present study, we used APOBEC3 knockout mice and their wild type counterpart to query the role of APOBEC3 in sexual transmission of LP-BM5 MLV - the etiological agent of murine AIDs (mAIDs)., Results: We show that mouse APOBEC3 is expressed in murine genital tract tissues and gametes and that genital tract tissue of APOBEC3-deficient mice are more susceptible to infection by LP-BM5 virus. APOBEC3 expressed in genital tract tissues most likely plays a role in decreasing virus transmission via the sexual route, since mice deficient in APOBEC3 gene have higher genitalia and seminal plasma virus load and sexually transmit the virus more efficiently to their partners compared to APOBEC3+ mice. Moreover, we show that female mice sexually infected with LP-BM5 virus transmit the virus to their off-spring in APOBEC3-dependent manner., Conclusion: Our data indicate that genital tissue intrinsic APOBEC3 restricts genital tract infection and limits sexual transmission of LP-BM5 virus.

Individuals with type 2 diabetes are at increased risk of acquiring melioidosis, a disease caused by Burkholderia pseudomallei infection. Although up to half of melioidosis patients have underlying diabetes, the mechanisms involved in this increased susceptibility are unknown. We found that B. pseudomallei-infected PBMCs from diabetic patients were impaired in IL-12p70 production, which resulted in decreased IFN-γ induction and poor bacterial killing. The defect was specific to the IL-12-IFN-γ axis. Defective IL-12 production was also observed during Mycobacterium tuberculosis infection, in which diabetes is likewise known to be a strong risk factor. In contrast, IL-12 production in diabetic cells was not affected upon Salmonella enterica infection or in response to TLR2, -3, -4, and -5 ligands. Poor IL-12 production correlated with a deficiency in intracellular reduced glutathione (GSH) concentrations in diabetic patients. Addition of GSH or N-acetylcysteine to PBMCs selectively restored IL-12 and IFN-γ production and improved bacterial killing. Furthermore, the depletion of GSH in mice led to increased susceptibility to melioidosis, reduced production of IL-12p70, and poorer disease outcome. Our data thus establish a link between GSH deficiency in diabetes and increased susceptibility to melioidosis that may open up new therapeutic avenues to protect diabetic patients against some intracellular bacterial pathogens.

The heritability of schizophrenia is well established, and has motivated the search for genetic variation that contributes to susceptibility. Recent progress from both genome-wide association and copy number variant studies have identified risk loci, however, these are at very different ends of the susceptibility spectrum with respect to allele frequency and effect size. It is likely that investigations of common variants have surrendered their full yield, but rare variant exploration is at the very beginning., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The central histaminergic neuron system is an important regulator of activity stages such as arousal and sleep. In several epilepsy models, histamine has been shown to modulate epileptic activity and histamine 1 (H1) receptors seem to play a key role in this process. However, little is known about the H1 receptor-mediated seizure regulation during the early postnatal development, and therefore we examined differences in severity of kainic acid (KA)-induced status epilepticus (SE) and consequent neuronal damage in H1 receptor knock out (KO) and wild type (WT) mice at postnatal days 14, 21, and 60 (P14, P21, and P60). Our results show that in P14 H1 receptor KO mice, SE severity and neuronal damage were comparable to those of WT mice, whereas P21 KO mice had significantly decreased survival, more severe seizures, and enhanced neuronal damage in various brain regions, which were observed only in males. In P60 mice, SE severity did not differ between the genotypes, but in KO group, neuronal damage was significantly increased. Our results suggest that H1 receptors could contribute to regulation of seizures and neuronal damage age-dependently thus making the histaminergic system as a challenging target for novel drug design in epilepsy., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The mechanisms underlying immune deficiency in diabetes are largely unknown. In the present study, we demonstrate that diabetic mice are highly susceptible to polymicrobial sepsis due to reduction in rolling, adhesion, and migration of leukocytes to the focus of infection. In addition, after sepsis induction, CXCR2 was strongly downregulated in neutrophils from diabetic mice compared with nondiabetic mice. Furthermore, CXCR2 downregulation was associated with increased G-protein-coupled receptor kinase 2 (GRK2) expression in these cells. Different from nondiabetic mice, diabetic animals submitted to mild sepsis displayed a significant augment in α1-acid glycoprotein (AGP) hepatic mRNA expression and serum protein levels. Administration of AGP in nondiabetic mice subjected to mild sepsis inhibited the neutrophil migration to the focus of infection, as well as induced l-selectin shedding and rise in CD11b of blood neutrophils. Insulin treatment of diabetic mice reduced mortality rate, prevented the failure of neutrophil migration, impaired GRK2-mediated CXCR2 downregulation, and decreased the generation of AGP. Finally, administration of AGP abolished the effect of insulin treatment in diabetic mice. Together, these data suggest that AGP may be involved in reduction of neutrophil migration and increased susceptibility to sepsis in diabetic mice.

While stressful life events confer increased risk for the development of psychopathology, most individuals experiencing adversity maintain normal psychological functioning, suggesting that individual differences may influence the susceptibility to develop stress-related psychiatric disorders. However, little is known about what determines this difference between individuals at the molecular level. In the present study, we identify that protein tyrosine phosphatase nonreceptor type 5 (PTPN5) (also known as STEP) is a critical determinant of differences in individual susceptibility to develop stress-related cognitive and morphological changes in rats. Our data demonstrate that ablation of PTPN5 expression delays physiological recovery from stress and augments the development of stress-related cognitive and morphological changes, whereas overexpression of a constitutively active variant of PTPN5 enhances the individual's resilience to stress. Our data also reveal that reduced PTPN5 expression prolongs the duration of extracellular signal-regulated kinase activation, leading to an elevation of Ca(V)1.2 channel expression and a recovery delay of K(V)4.2 channels from inactivation, which in turn heightens neuronal vulnerability to glutamate toxicity. Moreover, intraperitoneal injections of L-type Ca(2+) channel blocker nifedipine after stress resulted in a significantly lower rate for developing stress-related cognitive and morphological changes seen in PTPN5 knockdown rats. Together, these results identify a novel role for PTPN5 in mediating the development of stress-related cognitive and morphological changes and suggest that people with PTPN5 deficiency may have a greater susceptibility to capture the deleterious effects of stress.

Stromal cell-derived factor-1 (SDF-1/CXCL12) induces intracellular signaling pathways crucial for mobilization, migration, proliferation and survival of many cell types via CXCR4, a chemokine CXC-motif receptor, member of the G protein-coupled receptor family. Despite playing a key role in such major processes as embryogenesis, cell differentiation and organ regeneration, molecular mechanisms underlying CXCR4 signaling remain elusive, even more so, as CXCR4 seems to activate both G-protein-dependent and G-protein-independent pathways. CXCR4 is expressed on multiple cell types including lymphocytes, hematopoietic stem cells, endothelial and epithelial cells, and cancer cells. In fact, overexpression of this receptor has been detected in many different types of cancer. The SDF-1/CXCR4 axis is also involved in tumor progression, angiogenesis, metastasis, and survival. This pathway is therefore a target for therapeutics that can block the SDF-1/CXCR4 interaction or inhibit downstream intracellular signaling. Clinical mobilization of hematopoietic stem cells (HSC), a nowadays popular method of collecting material for hematopoietic progenitor stem cell transplantation, is also dependent on the SDF-1/CXCR4 axis. Granulocyte colony-stimulating factor (G-CSF), administered to a transplant donor during clinical treatment, violates interactions between CXCR4 and its ligand, which results in degradation of HSC anchorage in bone marrow and the release of these cells into peripheral blood. In this paper we describe the clinical significance of CXCR4 and its ligand, as well as the role of CXCR4 and its gene polymorphisms in disease susceptibility.

We propose a model wherein chronic stress results in glucocorticoid receptor resistance (GCR) that, in turn, results in failure to down-regulate inflammatory response. Here we test the model in two viral-challenge studies. In study 1, we assessed stressful life events, GCR, and control variables including baseline antibody to the challenge virus, age, body mass index (BMI), season, race, sex, education, and virus type in 276 healthy adult volunteers. The volunteers were subsequently quarantined, exposed to one of two rhinoviruses, and followed for 5 d with nasal washes for viral isolation and assessment of signs/symptoms of a common cold. In study 2, we assessed the same control variables and GCR in 79 subjects who were subsequently exposed to a rhinovirus and monitored at baseline and for 5 d after viral challenge for the production of local (in nasal secretions) proinflammatory cytokines (IL-1β, TNF-α, and IL-6). Study 1: After covarying the control variables, those with recent exposure to a long-term threatening stressful experience demonstrated GCR; and those with GCR were at higher risk of subsequently developing a cold. Study 2: With the same controls used in study 1, greater GCR predicted the production of more local proinflammatory cytokines among infected subjects. These data provide support for a model suggesting that prolonged stressors result in GCR, which, in turn, interferes with appropriate regulation of inflammation. Because inflammation plays an important role in the onset and progression of a wide range of diseases, this model may have broad implications for understanding the role of stress in health.

The high susceptibility of dopaminergic (DA) neurons to cellular stress is regarded as a primary cause of Parkinson's disease. Here we investigate the role of the serum response factor (SRF), an important regulator of anti-apoptotic responses, for the survival of DA neurons in mice. We show that loss of SRF in DA neurons does not affect their viability and does not influence dopamine-dependent behaviors. However, ablation of SRF causes exacerbated sensitivity to 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine (MPTP), leading to significantly greater loss of DA neurons in the substantia nigra, compared with DA neurons located in the ventral tegmental area. In addition, loss of SRF decreases levels of the anti-apoptotic proteins brain-derived neurotrophic factor (BDNF) and Bcl-2, a plausible underlying cause of increased sensitivity to oxidative stress. These observations support the notion that dysfunction of the SRF-activating mitogen-associated kinase pathway may be part of Parkinson's disease etiology., (© 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.)

Signal abnormalities of cortical gray matter, compared with the deep nuclear structures, have received less attention in Wilson's disease (WD). They nearly always accompanied white matter signal change, and commonly are associated with epilepsy and psychiatric features. We report herein two cases diagnosed as WD who, in addition to characteristic deep nuclear lesions on MR imaging, had widespread cerebral cortical paramagnetic signals dramatically detected by susceptibility-weighted imaging. T2-weighted MR images did not show any cortico-subcortical hyperintense lesions. To our knowledge, these findings have not been described before and may help to further characterize the disease., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Introduction: The in vivo role of peroxisome proliferator-activated receptor (PPAR)-γ, an essential transcriptional mediator of lipid and glucose metabolism, in atrial fibrillation (AF) remains to be fully elucidated. We investigated the effects of pioglitazone, a PPAR-γ activator, in an in vivo AF rat model., Methods and Results: We studied 3 groups of Wistar rats: young group, 3-month-old rats treated with vehicle; aged group, 9-month-old rats treated with vehicle; and aged+Pio group, 9-month-old rats treated with pioglitazone. After 4-week treatment, AF duration induced by 30-second burst pacing, gene and protein expressions, and atrial structural changes were compared between the 3 groups. Atrial oxidant reducing activity was measured by electron spin resonance method. AF duration was markedly prolonged in the aged group but significantly shortened in the aged+Pio group. Age-induced decrease in free radical reducing activity was reversed by pioglitazone. Gene and protein expression levels of antioxidant molecules Sod2 (MnSOD) and Hspa1a (heat shock 70 protein) were significantly enhanced, and p22(phox) and gp91(phox), two NADPH oxidase subunits, were significantly decreased in aged+Pio rats. Pioglitazone treatment significantly increased phosphorylated (p-) Akt but significantly reduced p-ERK1/2 and p-JNK. Pioglitazone significantly restored p-Bad and reduced cleaved caspase-3 and -9, indicating that pioglitazone prevented age-related enhancement of apoptotic signaling. Microscopic analysis revealed suppression of age-related histological changes (interstitial fibrosis and apoptosis) by pioglitazone., Conclusions: Pioglitazone inhibited age-related arrhythmogenic atrial remodeling and AF perpetuation by improving antioxidant capacity and inhibiting the mitochondrial apoptotic signaling pathway. PPAR-γ activators could become a novel upstream therapy for age-related AF., (© 2011 Wiley Periodicals, Inc.)

RAD51C, a RAD51 paralog, has been implicated in homologous recombination (HR), and germ line mutations in RAD51C are known to cause Fanconi anemia (FA)-like disorder and breast and ovarian cancers. The role of RAD51C in the FA pathway of DNA interstrand cross-link (ICL) repair and as a tumor suppressor is obscure. Here, we report that RAD51C deficiency leads to ICL sensitivity, chromatid-type errors, and G(2)/M accumulation, which are hallmarks of the FA phenotype. We find that RAD51C is dispensable for ICL unhooking and FANCD2 monoubiquitination but is essential for HR, confirming the downstream role of RAD51C in ICL repair. Furthermore, we demonstrate that RAD51C plays a vital role in the HR-mediated repair of DNA lesions associated with replication. Finally, we show that RAD51C participates in ICL and double strand break-induced DNA damage signaling and controls intra-S-phase checkpoint through CHK2 activation. Our analyses with pathological mutants of RAD51C that were identified in FA and breast and ovarian cancers reveal that RAD51C regulates HR and DNA damage signaling distinctly. Together, these results unravel the critical role of RAD51C in the FA pathway of ICL repair and as a tumor suppressor.

Nitric oxide is a gaseous signaling molecule that participates in a large variety of physiological functions and may have a role in the pathology of altitude illnesses, such as acute mountain sickness (AMS). The effect of normobaric hypoxia on the fraction of exhaled NO ( [Formula: see text] ) is a controversial area of high altitude physiology, with the effect varying widely across studies. We exposed 19 male subjects to normobaric hypoxia for 6h and measured [Formula: see text] and AMS (via Lake Louise Score) each hour. For data analysis, subjects were divided into AMS-positive and AMS-negative groups based on their Lake Louise Scores during exposure. Eighteen subjects completed the study, and the incidence of AMS was 50%. Mean [Formula: see text] was unchanged at hour 1 but was significantly elevated above baseline for the remainder of the normobaric hypoxia exposure (p<0.001). Subjects who developed AMS had a significantly lower mean [Formula: see text] at baseline compared to resistant subjects (p=0.013). Further investigations are warranted to confirm our results and to understand the physiological basis of this association., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Brain injury from carbon monoxide (CO) poisoning occurs due to tissue hypoxia and direct CO-mediated histotoxicity. Recently developed susceptibility-weighted imaging (SWI) is sensitive for the detection of accumulated hemosiderin and iron secondary to cerebral hemorrhage. Therefore, we hypothesized that SWI may be helpful for identifying petechial hemorrhagic transformation secondary to acute hypoxic damage during subacute CO intoxication. Our case series with subacute CO intoxication revealed that the SWIs of all patients showed low signal intensities in the globus pallidus, representing the accumulation of iron or calcium secondary to hypoxic damage from acute CO intoxication. These results suggest that SWI may be a useful MR technique for illustrating brain damage in subacute delayed CO intoxication., (Copyright © 2011. Published by Elsevier B.V.)

Purpose: Obesity is a major public health problem worldwide, and of late, epidemiological studies indicate a preponderance of cataracts under obesity conditions. Although cataract is a multifactorial disorder and various biochemical mechanisms have been proposed, the influence of obesity on cataractogenesis has yet to be investigated. In such a scenario, a suitable animal model that develops cataract following the onset of obesity will be a welcome tool for biomedical research. Therefore, we investigated the molecular and biochemical basis for predisposition to cataract in the obese mutant rat models established in our institute because 15%-20% of these rats develop cataracts spontaneously as they reach 12-15 months of age., Methods: We analyzed the major biochemical pathways in the normal lenses of different age groups of our obese mutant rat strains, Wistar/Obese (WNIN/Ob) and WNIN/GR-Ob, the former with euglycemia and the latter with an additional impaired glucose tolerance trait. In addition, sorbitol levels were estimated in the cataractous lenses of the obese rats., Results: Except for the polyol pathway, all the principal pathways of the lens remained unaltered. Therefore, sorbitol levels were found to be high in the normal eye lenses of obese rats (WNIN/Ob and WNIN/GR-Ob) compared to their lean controls from three months of age onwards. Between WNIN/Ob and WNIN/GR-Ob, the levels of sorbitol were higher in the latter, suggesting a synergistic effect of impaired glucose tolerance along with obesity in the activation of the sorbitol pathway. Either way, an elevated sorbitol pathway seemed to be the predisposing factor responsible for cataract formation in these mutant rats., Conclusions: Activation of the sorbitol pathway indeed enhances the risk of cataract development in conditions such as metabolic syndrome. These rat models thus may be valuable tools for investigating obesity-associated cataract and for developing intervention strategies, based on these findings.

This review focuses on how environmental factors through epigenetics modify disease risk and health outcomes. Major epigenetic events, such as histone modifications, DNA methylation, and microRNA expression, are described. The function of dose, duration, composition, and window of exposure in remodeling the individual's epigenetic terrain and disease susceptibility are addressed. The ideas of lifelong editing of early-life epigenetic memories, transgenerational effects through germline transmission, and the potential role of hydroxylmethylation of cytosine in developmental reprogramming are discussed. Finally, the epigenetic effects of several major classes of environmental factors are reviewed in the context of pathogenesis of disease. These include endocrine disruptors, tobacco smoke, polycyclic aromatic hydrocarbons, infectious pathogens, particulate matter, diesel exhaust particles, dust mites, fungi, heavy metals, and other indoor and outdoor pollutants. We conclude that the summation of epigenetic modifications induced by multiple environmental exposures, accumulated over time, represented as broad or narrow, acute or chronic, developmental or lifelong, may provide a more precise assessment of risk and consequences. Future investigations may focus on their use as readouts or biomarkers of the totality of past exposure for the prediction of future disease risk and the prescription of effective countermeasures.

Fas ligand is a well-known inducer of apoptosis in cells expressing its receptor Fas; it also prevents autoimmunity by inducing apoptosis of activated T cells. However, Fas ligand also mediates non-apoptotic functions involving inflammatory cell migration and cytokine responses. We sought here to study the role of Fas ligand in nephrotoxic nephritis, a model of crescentic glomerulonephritis, using generalized lymphoproliferative disorder (GLD) mice on a C57BL/6 background, which have defective Fas ligand and display only mild autoimmunity. These mice were significantly protected from glomerular crescent formation, glomerular thrombosis, renal impairment, and albuminuria 15 days after the induction of glomerulonephritis in comparison with wild-type mice. There were a reduced number of apoptotic cells in the glomeruli of nephritic GLD mice but no defect in their antibody responses or splenocyte proliferation at 15 days following the induction of glomerulonephritis. Bone marrow transplantation from wild-type mice restored disease susceptibility to GLD mice; however, wild-type mice were not protected when transplanted with bone marrow from GLD mice. Mesangial cells express Fas ligand in vitro, and these cells isolated from GLD mice produced lower amounts of monocyte chemoattractive protein-1 following interleukin-1 stimulation compared with cells from wild-type mice. Thus, Fas ligand-defective mice are protected from nephrotoxic nephritis, a disease in which both circulating and intrinsic renal cells appear to have a role.

Crohn's disease (CD) is associated with intestinal dysbiosis evidenced by an altered microbiome forming thick biofilms on the epithelium. Additionally, adherent-invasive E. coli (AIEC) strains are frequently isolated from ileal lesions of CD patients indicating a potential role for these strains in disease pathogenesis. The composition and characteristics of the host microbiome are influenced by environmental factors, particularly diet. Polysaccharides added to food as emulsifiers, stabilizers or bulking agents have been linked to bacteria-associated intestinal disorders. The escalating consumption of polysaccharides in Western diets parallels an increased incidence of CD during the latter 20(th) century. In this study, the effect of a polysaccharide panel on adhesiveness of the CD-associated AIEC strain LF82 was analyzed to determine if these food additives promote disease-associated bacterial phenotypes. Maltodextrin (MDX), a polysaccharide derived from starch hydrolysis, markedly enhanced LF82 specific biofilm formation. Biofilm formation of multiple other E. coli strains was also promoted by MDX. MDX-induced E. coli biofilm formation was independent of polysaccharide chain length indicating a requirement for MDX metabolism. MDX exposure induced type I pili expression, which was required for MDX-enhanced biofilm formation. MDX also increased bacterial adhesion to human intestinal epithelial cell monolayers in a mechanism dependent on type 1 pili and independent of the cellular receptor CEACAM6, suggesting a novel mechanism of epithelial cell adhesion. Analysis of mucosa-associated bacteria from individuals with and without CD showed increased prevalence of malX, a gene essential for MDX metabolism, uniquely in the ileum of CD patients. These findings demonstrate that the ubiquitous dietary component MDX enhances E. coli adhesion and suggests a mechanism by which Western diets rich in specific polysaccharides may promote dysbiosis of gut microbes and contribute to disease susceptibility.

Methylation of cytosines at CpG sites is a common epigenetic DNA modification that can be measured by a large number of methods, now even in a genome-wide manner for hundreds of thousands of sites. The application of DNA methylation analysis is becoming widely popular in complex disorders, for example, to understand part of the "missing heritability". The DNA samples most readily available for methylation studies are derived from whole blood. However, blood consists of many functionally and developmentally distinct cell populations in varying proportions. We studied whether such variation might affect the interpretation of methylation studies based on whole blood DNA. We found in healthy male blood donors there is important variation in the methylation profiles of whole blood, mononuclear cells, granulocytes, and cells from seven selected purified lineages. CpG methylation between mononuclear cells and granulocytes differed for 22% of the 8252 probes covering the selected 343 genes implicated in immune-related disorders by genome-wide association studies, and at least one probe was differentially methylated for 85% of the genes, indicating that whole blood methylation results might be unintelligible. For individual genes, even if the overall methylation patterns might appear similar, a few CpG sites in the regulatory regions may have opposite methylation patterns (i.e., hypo/hyper) in the main blood cell types. We conclude that interpretation of whole blood methylation profiles should be performed with great caution and for any differences implicated in a disorder, the differences resulting from varying proportions of white blood cell types should be considered.

Disturbances in the prenatal period are linked to metabolic disorders in adulthood, implying the hypothalamic systems of appetite and energy balance regulation. In order to analyze the central effects of a high-fat-sucrose (HFS) diet in prenatally stressed (PNS) female adult rats, Wistar dams were exposed to chronic-mild-stress during the third week of gestation and were then compared with unstressed controls. Adult female offspring were fed a chow or HFS diet for 10 weeks. Changes in body weight, adiposity as well as expression and methylation levels of selected hypothalamic genes were analyzed. PNS induced lower birthweight and body length with no changes in body fat mass. After the HFS diet, the expected overweight model was observed accompanied by higher adiposity and insulin resistance, which was worsened by PNS. The stress model induced higher energy intake in adulthood. Hypothalamic gene expression analysis revealed that the HFS diet decreased Slc6a3 (dopamine active transporter), NPY (neuropeptide Y) and IR (insulin receptor) and increased POMC (pro-opiomelanocortin). Hypothalamic DNA methylation levels in the promoter region of Slc6a3 revealed that Slc6a3 was hypermethylated by the HFS diet in CpG site -53 bp to the transcription start site. HFS diet also hypermethylated CpG site -167 bp of the POMC promoter only in nonstressed animals. No correlations were found between gene expression and DNA methylation levels. These results imply that early-life stress in females increased predisposition to diet-induced obesity in adulthood., (Copyright © 2012 S. Karger AG, Basel.)

There is evidence that pulmonary arterial hypertension plays a major role in the occurrence of high altitude pulmonary edema (HAPE). We tested the hypothesis that the pulmonary arterial systolic pressure response to a challenge associated with hypoxia and mild exercise may be considered a predictive factor of HAPE. Pulmonary arterial systolic pressure was measured by Doppler echocardiography in 8 HAPE susceptible (HAPE-S) subjects and 8 HAPE resistant mountaineers (HAPE-R) during a hypoxic exercise challenge established by the French Association for Sport Medicine (Richalet's test). Pulmonary arterial systolic pressure during hypoxic exercise allowed a significant discrimination between the groups, although an overlap of values was observed. When expressed as individual variations from baseline to hypoxic exercise level however, we found a highly significant difference. No overlap was observed between HAPE-R (range: 6.7-18.5 mmHg) and HAPE-S (range: 19.2-30.4 mmHg) groups, with a cut-off value at 19 mmHg. Plasma Vascular Endothelial growth factor (VEGF) and malondialdehyde (MDA) increased in response to hypoxic exercise only in HAPE-S group. Individual increases in pulmonary arterial systolic pressure during hypoxic exercise from basal resting normoxic values seem relevant to estimate HAPE susceptibility when measured during the Richalet's test., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The aim of this case-control study is to explore the role of aberrations in xenobiotic metabolism in inducing oxidative DNA damage and altering the susceptibility to breast cancer. Cytochrome P4501A1 (CYP1A1) m1 (OR: 1.41, 95% CI 1.08-1.84), CYP1A1 m4 (OR: 5.13, 95% CI 2.68-9.81), Catecholamine-O-methyl transferase (COMT) H108L (OR: 1.49, 95% CI 1.16-1.92), and glutathione S-transferase (GST) T1 null (OR: 1.68, 95% CI 1.09-2.59) variants showed association with breast cancer risk. Reduced folate carrier 1 (RFC1) 80A/CYP1A1 m1/CYP1A1 m4 and RFC1 80A/thymidylate synthase (TYMS) 5'-UTR 2R/methionine synthase (MTR) 2756G/COMT 108L genetic combinations were found to inflate breast cancer risk under the conditions of low dietary folate (345 ± 110 vs. 379 ± 139 μg/day) and low plasma folate (6.81 ± 1.25 vs. 7.09 ± 1.26 ng/ml) by increasing plasma 8-oxo-2'-deoxyguanosine (8-oxodG). This increase in 8-oxodG is attributed to low methionine (49.38 ± 23.74 vs. 53.90 ± 23.85 μmol/l); low glutathione (378 ± 242 vs. 501 ± 126 μmol/l) and GSTT1 null variant; and hypermethylation of CpG island of extracellular-superoxide dismutase (EC-SOD) (92.78 ± 11.49 vs. 80.45 ± 9.86%), which impair O-methylation of catechol estrogens to methoxy estrogens, conjugation of glutathione to semiquinones/quinones and free radical scavenging respectively. Our results suggest cross-talk between one-carbon metabolism and xenobiotic metabolism influencing oxidative DNA damage and susceptibility to breast cancer.

Tick resistance in cattle is mainly found in zebu (Bos indicus) animals, although it is also present in some taurine (B. taurus) breeds. In order to characterize functional genes involved in tick resistance/susceptibility in cattle, two cDNA libraries were generated using skin tissues of selected Holstein x Gyr animals. A total of 2700 high-quality reads from both resistant and susceptible cDNA were assembled into 458 sequences (contigs) and 834 singletons, with a mean size of 447.7 nucleotides. Assignment of homologous proteins by BLASTX revealed 790 (61.1%) and 300 (23.2%) hits in resistant and susceptible cDNA, respectively; 121 of these hits matched bovine proteins. A total of 502 (38.9%) unique sequences were found to have no significant homology with known sequences and were classified as novel sequences. In general, the most abundant sequences consisted of those coding for hypothetical proteins whose function had not yet been determined, in addition to ribosomal proteins, binding proteins and structural proteins, such as keratin and collagen. The most abundant protein found was collagen type III alpha, although ribosomal proteins accounted for half of the 40 most frequent hits. In addition, five matches within the top 40 best hits corresponded to immune response proteins. These sequences could be used for future studies on functional genomics of cattle tick resistance as well as for genomic sequencing projects.

Arsenic shares many physicochemical properties with phosphorus, so that arsenic can be taken up inadvertently by cells through the pathways for phosphorus. As a phosphate analog, arsenate competes with phosphate and enters cells via phosphate transporters. In the cell, arsenate can be recognized as a substrate by enzymes that usually use phosphate as a substrate. The phosphate for arsenate swap results in wasteful 'futile cycles' in metabolic pathways, uncoupled oxidative phosphorylation and extreme DNA instability. The disrupting metabolic effects of arsenic have an evolutionary meaning, so that all living organisms-from chemoautotrophic organisms that grow by reducing or oxidizing arsenic to metazoan--carry highly conserved arsenic resistance genes. Arsenic resistance can result from different strategies including selective transport to maximize phosphate uptake and minimize entry of arsenate, active transport to export arsenate, arsenic storage in specialized compartments, enzyme selectivity toward phosphate, and increased efficiency of DNA repair systems. None of these strategies is infallible, though, and susceptibility to arsenic toxicity varies between taxa in many orders of magnitude. Even arsenic-hypertolerant organisms will stop to grow and will eventually die when exposed to arsenic over species-specific resistance limits. The arsenic for phosphorus swap is an accidental one, it does not warrant a conclusion in favor of the essentiality of arsenic to life as we know it., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Endothelial phenotype heterogeneity plays an important role in the susceptibility of arteries to atherosclerosis. Regions of blood flow disturbance correlate with the development of disease. Here, we briefly outline the association of endoplasmic reticulum stress with endothelium in regions of athero-susceptibility in vivo. It is an important example of susceptible cell phenotype that is likely linked to proinflammatory and oxidative stress pathways. The endothelium in such regions is chronically exposed to complex hemodynamic shear stresses that may be considered as a risk factor for atherosclerosis via these mechanisms.

The present study was focused to characterize the effects of intrahippocampal application of R-verapamil, a P-glycoprotein blocker, and High Frequency Electrical Stimulation (HFS) at 130 Hz, on seizure susceptibility and extracellular concentrations of glutamate and γ-aminobutyric acid (GABA) in hippocampus of kindled rats with drug-resistant seizures. Fully kindled rats classified in responsive and non-responsive to phenytoin were used for this purpose. In contrast with responsive animals, non-responsive rats showed lower afterdischarge threshold (ADT) values in pre-kindling conditions and required less number of kindling trials to achieve the kindled state. Once the animals attained the kindled state, both epileptic groups presented high glutamate and low GABA interictal release, effect more evident in non-responsive rats. In hippocampus of responsive animals, GABA levels demonstrated two increases at 120 and 240 min after the ictal event, a situation no detected for non-responsive rats. Kindled animals receiving hippocampal HFS showed augmented ADT, an effect associated with enhanced GABA release in responsive rats. Intrahippocampal perfusion of R-verapamil (5 mM) decreased the seizure susceptibility (high ADT values), enhanced the interictal GABA release and the postictal levels of glutamate and GABA in responsive and non-responsive rats. It is conclude that alterations of glutamate and GABA release in the epileptic hippocampus of non-responsive animals resemble those found in hippocampus of patients with refractory TLE. In addition, intrahippocampal application of HFS and R-verapamil modifies the amino acid release and reduces the seizure susceptibility of both, responsive and non-responsive rats., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the differences of oxidative stress level between obesity-prone rats and obesity-resistant rats., Methods: Male Wistar rats were divided into control group (10 rats) fed with basal diet and high fat group (30 rats) fed with high-fat diet for 6 weeks. Ten rats in obesity-prone (OP) group and obesity-resistant (OR) group were selected from the high-fat diet group according to the gain of body weight. All rats were killed by the end of 13th week. Serum SOD, MDA, GSH-Px, blood lipids and fatty acids were detected by standard methods., Results: SOD was lower in OP rats than that in OR rats and control rats. GSH-Px was lower in OP rats than that in OR rats. MDA was higher in OP rats than that in control rats. The energy intake, body fat content, FBG, serum lipids, serum insulin, ISI and free fatty acids in OP rats were significantly different from those in OR rats, but there were no differences between OR and control rats., Conclusion: Compared with OR rats, the oxidative stress responses were increased and the antioxidant capacities were decreased in OP rats after 13 weeks of experiment.

Polycyclic aromatic hydrocarbons (PAHs) are believed to be among the causative agents for lung cancer in smokers. PAHs require metabolic activation for carcinogenicity. One pathway produces diol epoxides that react with DNA, causing mutations. Because diol epoxides are converted to tetraols, quantitation of tetraols can potentially be used to identify smokers who may be at higher risk for lung cancer. Our approach uses [D(10)]phenanthrene, a labeled version of phenanthrene, a noncarcinogenic PAH structurally analogous to carcinogenic PAH. Although smokers are exposed to PAH by inhalation, oral dosing would be more practical for phenotyping studies. Therefore, we investigated [D(10)]phenanthrene metabolism in smokers after administration by inhalation in cigarette smoke or orally. Sixteen smokers received 10 μg of [D(10)]phenanthrene in a cigarette or orally. Plasma and urine samples were analyzed for [D(10)]r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene ([D(10)]PheT), the major end product of the diol epoxide pathway, by gas chromatography-negative ion chemical ionization-tandem mass spectrometry. The ratios of [D(10)]PheT (oral dosing/inhalation) in 15 smokers were 1.03 ± 0.32 and 1.02 ± 0.35, based on plasma area under the concentration-time curve (0-∞) and total 48-h urinary excretion, respectively. Overall, there was no significant difference in the extent of [D(10)]PheT formation after the two different routes of exposure in smokers. A large interindividual variation in [D(10)]PheT formation was observed. These results demonstrate that the level of [D(10)]PheT in urine after oral dosing of [D(10)]phenanthrene can be used to assess individual capacity of PAH metabolism by the diol epoxide pathway.

Developmental epigenetic changes, such as DNA methylation, have been recognized as potential pathogenic factors in inflammatory bowel diseases, the hallmark of which is an exaggerated immune response against luminal microbes. A methyl-donor (MD) diet can modify DNA methylation at select murine genomic loci during early development. The components of the MDs are routinely incorporated into prenatal human supplements. Therefore, we studied the effects of maternal MD supplementation on offspring colitis susceptibility and colonic mucosal DNA methylation and gene expression changes in mice as a model. Additionally, we investigated the offspring mucosal microbiomic response to the maternal dietary supplementation. Colitis was induced by dextran sulfate sodium. Colonic mucosa from offspring of MD-supplemented mothers following reversal to control diet at weaning was interrogated by methylation-specific microarrays and pyrosequencing at postnatal days 30 (P30) and P90. Transcriptomic changes were analyzed by microarray profiling and real-time reverse transcription polymerase chain reaction. The mucosal microbiome was studied by high throughput pyrosequencing of 16S rRNA. Maternal MD supplementation induced a striking susceptibility to colitis in offspring. This phenotype was associated with colonic mucosal DNA methylation and expression changes. Metagenomic analyses did not reveal consistent bacteriomic differences between P30 and P90, but showed a prolonged effect of the diet on the offspring mucosal microbiome. In conclusion, maternal MD supplementation increases offspring colitis susceptibility that associates with persistent epigenetic and prolonged microbiomic changes. These findings underscore that epigenomic reprogramming relevant to mammalian colitis can occur during early development in response to maternal dietary modifications.