Hemoglobin A1c and retinal arteriolar narrowing in children with type 1 diabetes: the diagnostics of early atherosclerosis risk in kids study.

BACKGROUND/OBJECTIVE: Microvascular alterations play a key role in the development of diabetes complications. Retinal vessel analysis is a unique method to examine microvascular changes in brain-derived vessels. METHODS: Sixty-seven pediatric and adolescent type 1 diabetes patients and 58 healthy control persons (mean age 12.4 ± 2.9 years) underwent non-mydriatic retinal photography of both eyes. Central retinal arteriolar and central retinal venular (CRVE) diameter equivalents as well as the arteriolar-to-venular ratio were calculated using a semiautomated software. All anthropometric and laboratory parameters were measured according to standardized procedures for children. RESULTS: Retinal vessel diameter did not differ between type 1 diabetic children and healthy controls. However, there was an independent association of higher hemoglobin A1c (HbA1c) levels with arteriolar narrowing. Arteriolar narrowing of 5.4 µm was observed with each percent increase in HbA1c. Longer duration of diabetes was associated with wider retinal arterioles. CRVE was not associated with diabetes duration or HbA1c. CONCLUSIONS: Microvascular arteriolar alterations are already present in childhood and may indicate subclinical atherosclerosis and increased risk of diabetes complications later in life. Future research will have to investigate the potential use of retinal vessel diameters for treatment monitoring and guidance of therapy in children.

Information transmission in HPC-PFC network for spatial working memory in rat.

Spatial working memory is a short-term system for the temporary holding and manipulation of spatial information. Evidence shows that the hippocampus (HPC) and prefrontal cortex (PFC) play important roles in spatial working memory. Though the communication between HPC and PFC is recognized as essential for successful execution of spatial working memory tasks, the directional information transmission in the HPC-PFC network is largely unclear. Therefore, in the present study, neuronal activity was recorded from rat ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC) while the rats performed a spatial working memory task in Y-maze. Then the causality connectivity among the spikes from recorded neurons was estimated using the maximum likelihood estimation and the information flow in the vHPC-mPFC network was calculated to investigate the functional dynamics of the vHPC-mPFC information transmission. Our results showed the increased bidirectional information flow in the vHPC-mPFC network during the spatial working memory task. Both directions of information flow were observed only on trials in which the animal subsequently made the correct response, indicating that the increase in information flow predicted memory accuracy. Furthermore, the information flow from vHPC to mPFC was remarkably higher and preceded that from mPFC to vHPC. These findings suggest that the direct vHPC-mPFC information transmission may be predominant for spatial working memory in rat.

The effect of dietary supplementation of low crude protein on intestinal morphology in pigs.

To explore the effects of reducing the Cp levels on intestinal barrier function, low Cp (LP) and NRC standard Cp (NP) diets were fed to pigs from 45 to 160 days, and in vitro experiments were performed using monolayers of IPEC-J2 cells. The number of goblet cells, expression of proteins related to cell junction, amino acid transport, glucose transport, transepithelial electrical resistance (TEER), dextran permeability, and IL-6 secretion level were detected in pigs. The results demonstrated that a moderate reduction of Cp levels did not affect intestinal morphology, as demonstrated by a normal villi height, crypt depth and normal numbers of goblet cells. The maintenance of the intestinal structure obtained with LP was also confirmed by stable mRNA expression levels of muc2 and E-cadherin in the jejunum. We also found that LP did not affect the protein expression of cationic amino acid transporter 1 (CAT-1) and alanine serine cysteine transporter 1 (ASCT1) from 45 to 160 days. Moreover, the excitatory amino acid transporter 3 (EAAT3), sodium-glucose cotransporter 1 (SGLT1) and glucose transporter (GLUT2) protein expression levels in the jejunum were significantly increased at a certain age during the rearing period. Furthermore, we also demonstrated that a reduction in protein concentration up to 15% in the cultural medium of IPEC-J2 cells did not impact the mucosal barrier function. This study demonstrated that a moderate reduction of the protein level did not affect intestinal mucosal barrier function and morphology in the jejunum.

Cadmium induces inflammatory cytokines through activating Akt signaling in mouse placenta and human trophoblast cells.

INTRODUCTION: Several reports demonstrated that cadmium (Cd) had proinflammatory activities. The present study aimed to investigate whether Cd induces inflammatory cytokines in mouse placenta and human trophoblast cells. METHODS: Human JEG-3 cells were treated with different concentration of CdCl2 (0-50 µM) or CdCl2 (25 µM) for different times. The pregnant mice were administered with CdCl2 (3.0 mg/kg, i.p.) on GD15. RESULTS: TNF-α, IL-8 and IL-6 mRNAs were elevated in CdCl2-treated JEG-3 cells. Several inflammatory cytokines were up-regulated in Cd-treated placenta of mice. Moreover, keratinocyte chemokine (KC), a functional analogue of human IL-8, was increased in maternal serum and amniotic fluid from CdCl2-exposed mice. Additional experiment showed that gestational Cd exposure activated Akt signaling in mouse placenta. Co-culture with CdCl2 elevated pAkt level in JEG-3 cells in concentration- and time-dependent manners. LY294002, a specific inhibitor of PI3K, blocked CdCl2-evoked Akt phosphorylation in JEG-3 cells. Concomitantly, LY294002 inhibited CdCl2-induced IL-8 in JEG-3 cells. N-acetylcysteine (NAC), an antioxidant and a glutathione precursor, blocked CdCl2-evoked Akt phosphorylation in mouse placenta and human trophoblast cells. Additionally, NAC attenuated Cd-induced up-regulation of KC in amniotic fluid. DISCUSSION: Cd induces inflammatory cytokines partially through activating Akt signaling in mouse placenta and human trophoblast cells. NAC may be exploited for prevention of Cd-induced placental inflammation.

N-acetylcysteine alleviates cadmium-induced placental endoplasmic reticulum stress and fetal growth restriction in mice.

Cadmium (Cd) is a developmental toxicant that induces fetal growth restriction (FGR). Placental endoplasmic reticulum (ER) stress is associated with FGR. This study investigated the effects of N-acetylcysteine (NAC) on Cd-induced placental ER stress and FGR. Pregnant mice were intraperitoneally injected with CdCl2 daily from gestational day (GD)13 to GD17. As expected, Cd reduced fetal weight and crown-rump length. Cd decreased the internal space of blood vessels in the placental labyrinth layer and inhibited placental cell proliferation. Several genes of growth factors, such as Vegf-a, placental growth factor, Igf1 and Igf1r, and several genes of nutrient transport pumps, such as Glut1, Fatp1 and Snat2, were down-regulated in placenta of Cd-treated mice. Moreover, Cd evoked placental ER stress. Of interest, NAC alleviated Cd-induced FGR. Additional experiment showed that NAC inhibited Cd-induced impairment of placental development and placental ER stress. Therefore, NAC may be exploited for prevention of Cd-induced placental insufficiency and FGR.

Repetitive Transcranial Magnetic Stimulation Reverses Aß1-42-induced Dysfunction in Gamma Oscillation during Working Memory.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease that gradually induces cognitive deficits in the elderly and working memory impairment is typically observed in AD. Amyloid-ß peptide (Aß) is a causative factor for the cognitive impairments in AD. Gamma oscillations have been recognized to play important roles in various cognitive functions including working memory. Previous study reported that Aß induces gamma oscillation dysfunction in working memory. OBJECTIVE: Although repetitive transcranial magnetic stimulation (rTMS) represents a technique for noninvasive stimulation to induce cortical activity and excitability changes and has been accepted for increasing brain excitability and regulating cognitive behavior, the question whether rTMS can reserve the Aß-induced gamma oscillation dysfunction during working memory remains unclear. The present study aims to investigate the effect of rTMS to the Aß-induced gamma oscillation dysfunction during working memory. METHOD: The present study investigates the rTMS-modulated gamma oscillation in Aß1-42-induced memory deficit. Adult SD rats were divided into four groups: Aß, Con, Aß+rTMS and Con+rTMS. 16-channel local field potentials (LFPs) were recorded from rat medial prefrontal cortex while the rats performed a Y-maze working memory task. Gamma oscillation among LFPs was measured by coherence. RESULTS: The results show that rTMS improved the behavior performance and enhanced gamma oscillation for the Aß-injected subjects. CONCLUSION: These results indicate that rTMS may reserve the Aß-induced dysfunction in gamma oscillation during working memory and thus result in potential benefits for working memory.

Directional hippocampal-prefrontal interactions during working memory.

Working memory refers to a system that is essential for performing complex cognitive tasks such as reasoning, comprehension and learning. Evidence shows that hippocampus (HPC) and prefrontal cortex (PFC) play important roles in working memory. The HPC-PFC interaction via theta-band oscillatory synchronization is critical for successful execution of working memory. However, whether one brain region is leading or lagging relative to another is still unclear. Therefore, in the present study, we simultaneously recorded local field potentials (LFPs) from rat ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC) and while the rats performed a Y-maze working memory task. We then applied instantaneous amplitudes cross-correlation method to calculate the time lag between PFC and vHPC to explore the functional dynamics of the HPC-PFC interaction. Our results showed a strong lead from vHPC to mPFC preceded an animal's correct choice during the working memory task. These findings suggest the vHPC-leading interaction contributes to the successful execution of working memory.

The effect of low protein on colonic mucosal barrier in pigs / El efecto de baja proteína en la barrera mucosa colónica en cerdos

Reducing nitrogen nutrients concentration in dairy food is economic for pig industry. Here, we used finishing pig as model to investigate the effect on colon mucosal barrier and nutrients absorption after reducing crude protein (CP) in dietary from 16 % to 13 %. The results showed that crypt depth, cells, claudin-1 and E-cadherin expression level will not be changed, which implied the integrity of colon mucosal structure. Furthermore, the expressions of ASCT1, EAAT3 and SGLT1 in colon were also maintained at normal levels in 13 % CP dietary. Interestingly, the CAT1 and GLUT2 expression were increased significantly after reducing CP level to 13 %, which might be attributed to the compensatory nutrients absorption. This study implied that 13 % CP was sufficient to maintain normal colon structure and will not change intestinal morphology, which provided a basis for an ideal economic protein feed formula.

La reducción de concentración de nitrógeno en los alimentos lácteos es económicamente favorable para la industria porcina. En este trabajo se utilizó el cerdo de acabado como modelo para investigar el efecto sobre la barrera de la mucosa del colon y la absorción de nutrientes después de reducir la proteína bruta (CP) en la dieta del 16 % al 13 %. Los resultados mostraron que la profundidad de la cripta, las células globulares, el nivel de expresión de Claudin-1 y E-cadherina no cambiaron, lo que implicaría la integridad de la estructura de la mucosa del colon. Además, las expresiones de ASCT1, EAAT3 y SGLT1 en el colon también se mantuvieron en niveles normales en el 13 % de la dieta de CP. Sin embargo, la expresión de CAT1 y GLUT2 incrementó significativamente después de reducir el nivel de CP a 13 %, lo que podría atribuirse a la absorción de nutrientes compensatorios. Este estudio indicó que el CP del 13 % era suficiente para mantener la estructura normal del colon y no cambiaría la morfología intestinal, lo que proporcionó una base para una fórmula económica ideal para la alimentación con proteínas.

Total glucosides of paeony inhibits lipopolysaccharide-induced proliferation, migration and invasion in androgen insensitive prostate cancer cells.

Previous studies demonstrated that inflammatory microenvironment promoted prostate cancer progression. This study investigated whether total glucosides of paeony (TGP), the active constituents extracted from the root of Paeonia Lactiflora Pall, suppressed lipopolysaccharide (LPS)-stimulated proliferation, migration and invasion in androgen insensitive prostate cancer cells. PC-3 cells were incubated with LPS (2.0 µg/mL) in the absence or presence of TGP (312.5 µg /mL). As expected, cells at S phase and nuclear CyclinD1, the markers of cell proliferation, were increased in LPS-stimulated PC-3 cells. Migration activity, as determined by wound-healing assay and transwell migration assay, and invasion activity, as determined by transwell invasion assay, were elevated in LPS-stimulated PC-3 cells. Interestingly, TGP suppressed LPS-stimulated PC-3 cells proliferation. Moreover, TGP inhibited LPS-stimulated migration and invasion of PC-3 cells. Additional experiment showed that TGP inhibited activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK)/p38 in LPS-stimulated PC-3 cells. Correspondingly, TGP attenuated upregulation of interleukin (IL)-6 and IL-8 in LPS-stimulated PC-3 cells. In addition, TGP inhibited nuclear translocation of signal transducer and activator of transcription 3 (STAT3) in LPS-stimulated PC-3 cells. These results suggest that TGP inhibits inflammation-associated STAT3 activation and proliferation, migration and invasion in androgen insensitive prostate cancer cells.

Low vitamin D status is associated with inflammation in patients with prostate cancer.

Vitamin D deficiency has been associated with increased risks of prostate cancer. Nevertheless, the mechanisms remain unclear. The aim of this study was to analyze the association among prostate cancer, vitamin D status and inflammation. Sixty patients with newly diagnosed prostate cancer and 120 age-matched controls were recruited for this study. Vitamin D status was evaluated and serum inflammatory molecules were measured. Serum 25-(OH)D was lower in patients with prostate cancer. Moreover, serum 25(OH)D was lower in patients with severe prostate cancer than patients with mild and moderate prostate cancer. By contrast, serum C-reactive protein (CRP) and interleukin (IL)-8, two inflammatory molecules, were elevated in patients with prostate cancer. Serum 25-(OH)D was negatively correlated with serum CRP and IL-8 in patients with prostate cancer. Additional analysis showed that the percentage of vitamin D receptor positive nucleus in the prostate was reduced in patients with prostate cancer. By contrast, the percentage of nuclear factor kappa B p65-positive nucleus was elevated in patients with prostate cancer. Our results provide evidence that there is an association among prostate cancer, vitamin D deficiency and inflammatory signaling. Inflammation may be an important mediator for prostate cancer progression in patients with low vitamin D status.

Vitamin D3 pretreatment protects against lipopolysaccharide-induced early embryo loss through its anti-inflammatory effects.

PROBLEM: Increasing evidence demonstrates that inflammatory cytokines are involved in LPS-induced adverse pregnant outcomes including early embryo loss. Vitamin D3 (VitD3) has anti-inflammatory activity. We aimed to investigate the effects of vitamin D3 (VitD3) on LPS-induced early embryo loss in mice. METHOD OF STUDY: All pregnant mice except controls were intraperitoneally (ip) injected with LPS on GD7. In VitD3 alone and LPS+VitD3 groups, pregnant mice were pretreated with VitD3 by gavage daily from GD5 to GD7. RESULTS: LPS caused 62.5% pregnant mice with early embryo loss. Interestingly, the rate of abortion dropped to 14.3% when pregnant mice were pretreated with VitD3. Additional experiment showed that VitD3 significantly attenuated LPS-evoked elevation on TNF-α, IFN-γ, MIP-2, and nitrate plus nitrite in maternal serum. In addition, VitD3 alleviated LPS-induced COX-2 expression in the decidua and attenuated the elevation of PGF2α in maternal serum. Although VitD3 had no effect on IL-10 in maternal serum, it induced further elevation of serum IL-10 level in LPS-treated mice. Further analysis showed that VitD3 activated VDR signaling, simultaneously inhibited LPS-induced nuclear translocation of NF-κB p65 subunits in the decidua. CONCLUSIONS: VitD3 protects mice from LPS-induced early embryo loss at least partially through its anti-inflammatory effects.

Transmissible Gastroenteritis Virus Infection Enhances SGLT1 and GLUT2 Expression to Increase Glucose Uptake.

Transmissible gastroenteritis virus (TGEV) is a coronavirus that causes villus atrophy, followed by crypt hyperplasia, reduces the activities of intestinal digestive enzymes, and disrupts the absorption of intestinal nutrients. In vivo, TGEV primarily targets and infects intestinal epithelial cells, which play an important role in glucose absorption via the apical and basolateral transporters Na+-dependent glucose transporter 1 (SGLT1) and facilitative glucose transporter 2 (GLUT2), respectively. In this study, we therefore sought to evaluate the effects of TGEV infection on glucose uptake and SGLT1 and GLUT2 expression. Our data demonstrate that infection with TGEV resulted in increased glucose uptake and augmented expression of EGFR, SGLT1 and GLUT2. Moreover, inhibition studies showed that EGFR modulated glucose uptake in control and TGEV infected cells. Finally, high glucose absorption was subsequently found to promote TGEV replication.

Effects of arginine on intestinal epithelial cell integrity and nutrient uptake.

Arginine is a multifaceted amino acid that is critical to the normal physiology of the gastrointestinal tract. Oral arginine administration has been shown to improve mucosal recovery following intestinal injury. The present study investigated the influence of extracellular arginine concentrations on epithelial cell barrier regulation and nutrition uptake by porcine small intestinal epithelial cell line (IPEC-J2). The results show that reducing arginine concentration from 0·7 to 0·2 mm did not affect the transepithelial electrical resistance value, tight-junction proteins (claudin-1, occludin, E-cadherin), phosphorylated extracellular signal-regulated protein kinases (p-ERK) and mucin-1 expression. Furthermore, reducing arginine concentration stimulated greater expression of cationic amino acid transporter (CAT1), excitatory amino acid transporter (EAAT3) and alanine/serine/cysteine transporter (ASCT1) mRNA by IPEC-J2 cells, which was verified by elevated efficiency of amino acid uptake. Glucose consumption by IPEC-J2 cells treated with 0·2 mm-arginine remained at the same physiological level to guarantee energy supply and to maintain the cell barrier. This experiment implied that reducing arginine concentration is feasible in IPEC-J2 cells guaranteed by nutrient uptake and cell barrier function.

Aß1-42-induced dysfunction in synchronized gamma oscillation during working memory.

Amyloid-ß peptide (Aß) is recognized as a causative factor for the cognitive impairments in Alzheimer's disease (AD). The studies on the effects of Aß to cognitive impairments are beneficial for lifting the veil of the pathophysiology in AD. Neuronal oscillations are proposed to play an important role in cognition and its ensuing behavior. Specially, the synchronized gamma oscillations are essential for the successful execution of working memory. However, whether the Aß will induce the abnormal neuronal oscillations and working memory deficits has remained largely unexplored. In the present study, rats (control and Aß-injected groups) were trained to perform a delay-alternation task on Y-maze while spikes and local field potentials (LFPs) were recorded from multi-electrodes implanted in the medial prefrontal cortex (mPFC), an area that is strongly modulated by working memory. Synchronized neuronal oscillations were assessed by phase locking between spike trains and LFPs. We found the significant working memory impairment in the Aß-injected group. Moreover, in the control group, during the memory retention period, a transient burst of gamma synchronization preceded an animal's correct choice, but not an animal's error choice. In the Aß-injected group, however, gamma synchronization experience no change in neither correct nor error trials. Our results indicate that the Aß1-42-induced dysfunction in gamma synchronization may provide a potential mechanism for working memory deficits.

Vitamin D3 pretreatment alleviates renal oxidative stress in lipopolysaccharide-induced acute kidney injury.

Increasing evidence demonstrates that reactive oxygen species plays important roles in sepsis-induced acute kidney injury. This study investigated the effects of VitD3 pretreatment on renal oxidative stress in sepsis-induced acute kidney injury. Mice were intraperitoneally injected with lipopolysaccharide (LPS, 2.0mg/kg) to establish an animal model of sepsis-induced acute kidney injury. In VitD3+LPS group, mice were orally pretreated with three doses of VitD3 (25 µg/kg) at 1, 24 and 48 h before LPS injection. As expected, oral pretreatment with three daily recommended doses of VitD3 markedly elevated serum 25(OH)D concentration and efficiently activated renal VDR signaling. Interestingly, LPS-induced renal GSH depletion and lipid peroxidation were markedly alleviated in VitD3-pretreated mice. LPS-induced serum and renal nitric oxide (NO) production was obviously suppressed by VitD3 pretreatment. In addition, LPS-induced renal protein nitration, as determined by 3-nitrotyrosine residue, was obviously attenuated by VitD3 pretreatment. Further analysis showed that LPS-induced up-regulation of renal inducible nitric oxide synthase (inos) was repressed in VitD3-pretreated mice. LPS-induced up-regulation of renal p47phox and gp91phox, two NADPH oxidase subunits, were normalized by VitD3 pretreatment. In addition, LPS-induced down-regulation of renal superoxide dismutase (sod) 1 and sod2, two antioxidant enzyme genes, was reversed in VitD3-pretreated mice. Finally, LPS-induced tubular epithelial cell apoptosis, as determined by TUNEL, was alleviated by VitD3 pretreatment. Taken together, these results suggest that VitD3 pretreatment alleviates LPS-induced renal oxidative stress through regulating oxidant and antioxidant enzyme genes.

Vitamin d deficiency attenuates high-fat diet-induced hyperinsulinemia and hepatic lipid accumulation in male mice.

It is increasingly recognized that vitamin D deficiency is associated with increased risks of metabolic disorders among overweight children. A recent study showed that vitamin D deficiency exacerbated inflammation in nonalcoholic fatty liver disease through activating toll-like receptor 4 in a high-fat diet (HFD) rat model. The present study aimed to further investigate the effects of vitamin D deficiency on HFD-induced insulin resistance and hepatic lipid accumulation. Male ICR mice (35 d old) were randomly assigned into 4 groups as follows. In control diet and vitamin D deficiency diet (VDD) groups, mice were fed with purified diets. In HFD and VDD+HFD groups, mice were fed with HFD. In VDD and VDD+HFD groups, vitamin D in feed was depleted. Feeding mice with vitamin D deficiency diet did not induce obesity, insulin resistance, and hepatic lipid accumulation. By contrary, vitamin D deficiency markedly alleviated HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation. Moreover, vitamin D deficiency significantly attenuated HFD-induced up-regulation of hepatic peroxisome proliferator-activated receptor γ, which promoted hepatic lipid uptake and lipid droplet formation, and its target gene cluster of differentiation 36. In addition, vitamin D deficiency up-regulated carnitine palmitoyltrans 2, the key enzyme for fatty acid ß-oxidation, and uncoupling protein 3, which separated oxidative phosphorylation from ATP production, in adipose tissue. These data suggest that vitamin D deficiency is not a direct risk factor for obesity, insulin resistance, and hepatic lipid accumulation. Vitamin D deficiency alleviates HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation through promoting fatty acid ß-oxidation and elevating energy expenditure in adipose tissue.

Supplementation with vitamin D3 during pregnancy protects against lipopolysaccharide-induced neural tube defects through improving placental folate transportation.

Several reports demonstrated that maternal lipopolysaccharide (LPS) exposure at middle gestational stage caused neural tube defects (NTDs). This study investigated the effects of supplementation with vitamin D3 (VitD3) during pregnancy on LPS-induced NTDs. Pregnant mice except controls were ip injected with LPS (25 µg/kg) daily from gestational day (GD)8 to GD12. In LPS+VitD3 group, pregnant mice were orally administered with VitD3 (25 µg/kg) before LPS injection. As expected, a 5-day LPS injection resulted in 62.5% (10/16) of dams and 20.3% of fetuses with NTDs. Additional experiment showed that a 5-day LPS injection downregulated placental proton-coupled folate transporter (pcft) and reduced folate carrier 1 (rfc1), 2 major folate transporters in placentas. Consistent with downregulation of placental folate transporters, folate transport from maternal circulation into embryos was disturbed in LPS-treated mice. Interestingly, VitD3 not only inhibited placental inflammation but also attenuated LPS-induced downregulation of placental folate transporters. Correspondingly, VitD3 markedly improved folate transport from maternal circulation into the embryos. Importantly, supplementation with VitD3 during pregnancy protected mice from LPS-induced NTDs. Taken together, these results suggest that supplementation with VitD3 during pregnancy prevents LPS-induced NTDs through inhibiting placental inflammation and improving folate transport from maternal circulation into the embryos.

Orally administered melatonin prevents lipopolysaccharide-induced neural tube defects in mice.

Lipopolysaccharide (LPS) has been associated with adverse pregnant outcomes, including fetal demise, intra-uterine growth restriction (IUGR), neural tube defects (NTDs) and preterm delivery in rodent animals. Previous studies demonstrated that melatonin protected against LPS-induced fetal demise, IUGR and preterm delivery. The aim of the present study was to investigate the effects of melatonin on LPS-induced NTDs. All pregnant mice except controls were intraperitoneally injected with LPS (25 µg/kg) daily from gestational day (GD)8 to GD12. Some pregnant mice were orally administered with melatonin (MT, 50 mg/kg) before each LPS injection. A five-day LPS injection resulted in 27.5% of fetuses with anencephaly, exencephaly or encephalomeningocele. Additional experiment showed that maternal LPS exposure significantly down-regulated placental proton-coupled folate transporter (pcft) and disturbed folate transport from maternal circulation through the placentas into the fetus. Interestingly, melatonin significantly attenuated LPS-induced down-regulation of placental pcft. Moreover, melatonin markedly improved the transport of folate from maternal circulation through the placentas into the fetus. Correspondingly, orally administered melatonin reduced the incidence of LPS-induced anencephaly, exencephaly or encephalomeningocele. Taken together, these results suggest that orally administered melatonin prevents LPS-induced NTDs through alleviating LPS-induced disturbance of folate transport from maternal circulation through the placenta into the fetus.

Cadmium selectively induces MIP-2 and COX-2 through PTEN-mediated Akt activation in RAW264.7 cells.

Increasing evidence demonstrates that cadmium (Cd) induces inflammation, but its mechanisms remain obscure. The present study showed that treatment with CdCl2 selectively upregulates macrophage inflammatory protein (MIP)-2 and cyclooxygenase (COX)-2 in RAW264.7 cells. Concomitantly, Cd²âº markedly elevated the level of phosphorylated Akt in dose- and time-dependent manners. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), blocked Cd²âº-evoked Akt phosphorylation. Correspondingly, LY294002 significantly repressed Cd²âº-induced upregulation of MIP-2 and COX-2 in RAW264.7 cells. Further experiments showed that treatment with Cd²âº significantly reduced the level of PTEN protein in RAW264.7 cells. MG132, a specific proteasome inhibitor, blocked Cd²âº-induced reduction in PTEN protein as well as Akt phosphorylation, implicating the involvement of proteasome-mediated PTEN degradation. Of interest, Cd²âº-induced degradation of PTEN protein appears to be associated with PTEN ubiquitination. N-acetylcysteine, a glutathione (GSH) precursor, blocked Cd²âº-evoked PTEN degradation as well as Akt phosphorylation. By contrast, L-buthionine-S,R-sulfoximine, an inhibitor of cellular GSH synthesis, exacerbated Cd²âº-induced PTEN degradation and Akt phosphorylation. Alpha-phenyl-N-tert-butylnitrone and vitamin C, two antioxidants, did not prevent from Cd²âº-induced PTEN degradation and Akt phosphorylation. In conclusion, Cd²âº selectively induces MIP-2 and COX-2 through PTEN-mediated PI3K/Akt activation. Cellular GSH depletion mediates Cd²âº-induced PTEN degradation and subsequent PI3K/Akt activation in macrophages.

Folic acid protects against lipopolysaccharide-induced preterm delivery and intrauterine growth restriction through its anti-inflammatory effect in mice.

Increasing evidence demonstrates that maternal folic acid (FA) supplementation during pregnancy reduces the risk of neural tube defects, but whether FA prevents preterm delivery and intrauterine growth restriction (IUGR) remains obscure. Previous studies showed that maternal lipopolysaccharide (LPS) exposure induces preterm delivery, fetal death and IUGR in rodent animals. The aim of this study was to investigate the effects of FA on LPS-induced preterm delivery, fetal death and IUGR in mice. Some pregnant mice were orally administered with FA (0.6, 3 or 15 mg/kg) 1 h before LPS injection. As expected, a high dose of LPS (300 µg/kg, i.p.) on gestational day 15 (GD15) caused 100% of dams to deliver before GD18 and 89.3% of fetuses dead. A low dose of LPS (75 µg/kg, i.p.) daily from GD15 to GD17 resulted in IUGR. Interestingly, pretreatment with FA prevented LPS-induced preterm delivery and fetal death. In addition, FA significantly attenuated LPS-induced IUGR. Further experiments showed that FA inhibited LPS-induced activation of nuclear factor kappa B (NF-κB) in mouse placentas. Moreover, FA suppressed LPS-induced NF-κB activation in human trophoblast cell line JEG-3. Correspondingly, FA significantly attenuated LPS-induced upregulation of cyclooxygenase (COX)-2 in mouse placentas. In addition, FA significantly reduced the levels of interleukin (IL)-6 and keratinocyte-derived cytokine (KC) in amniotic fluid of LPS-treated mice. Collectively, maternal FA supplementation during pregnancy protects against LPS-induced preterm delivery, fetal death and IUGR through its anti-inflammatory effects.