O-GlcNAc transferase in astrocytes modulates depression-related stress susceptibility through glutamatergic synaptic transmission

Major depressive disorder is a common and devastating psychiatric disease, the prevalence and burden are substantially increasing worldwide. Multiple studies of depression patients have implicated glucose metabolic dysfunction in the pathophysiology of depression. However, the molecular mechanisms by which glucose and related metabolic pathways modulate depressive-like behaviors are largely uncharacterized. UDP-GlcNAc is a glucose metabolite with pivotal functions as a donor molecule for O-GlcNAcylation. O-GlcNAc transferase (OGT), a key enzyme in protein O-GlcNAcylation, catalyzes protein posttranslational modification by O-GlcNAc and acts as a stress sensor. Here, we show that Ogt mRNA was increased in depression patients and that astroglial OGT expression was specifically upregulated in the medial prefrontal cortex of susceptible mice after chronic social defeat stress. The selective deletion of astrocytic OGT resulted in antidepressant-like behaviors, moreover, astrocytic OGT in the mPFC bidirectionally regulated vulnerability to social stress. Furthermore, OGT modulated glutamatergic synaptic transmission through O-GlcNAcylation of glutamate transporter-1 (GLT-1) in astrocytes. OGT astrocyte-specific knockout preserved the neuronal morphology atrophy and Ca2+ activity deficits caused by chronic stress and resulted in antidepressant effects. Altogether, our study reveals that astrocytic OGT in the mPFC regulates depressive-like behaviors through the O-GlcNAcylation of GLT-1 and could be a potential target for antidepressants.

Polydatin enhances glomerular podocyte autophagy homeostasis by improving Nrf2-dependent antioxidant capacity in fructose-fed rats

High fructose is considered a causative factor for oxidative stress and autophagy imbalance that cause kidney pathogenesis. Antioxidant polydatin isolated from Polygonum cuspidatum has been reported to protect against kidney injury. In this study, polydatin was found to ameliorate fructose-induced podocyte injury. It activated mammalian target of rapamycin complex 1 (mTORC1) and suppressed autophagy in glomeruli of fructose-fed rats and in fructose-exposed conditionally immortalized human podocytes (HPCs). Polydatin also enhanced nuclear factor-E2-related factor 2 (Nrf2)-dependent antioxidant capacity to suppress fructose-induced autophagy activation in vivo and in vitro, with the attenuation of fructose-induced up-regulation of cellular light chain 3 (LC3) II/I protein levels. This effect was abolished by Raptor siRNA in fructose-exposed HPCs. These results demonstrated that polydatin ameliorated fructose-induced autophagy imbalance in an mTORC1-dependent manner via improving Nrf2-dependent antioxidant capacity during podocyte injury. In conclusion, polydatin with anti-oxidation activity suppressed autophagy to protect against fructose-induced podocyte injury.

Pterostilbene Improves Hepatic Lipid Accumulation via the MiR-34a/Sirt1/SREBP-1 Pathway in Fructose-Fed Rats

High fructose intake promotes hepatic lipid accumulation. Pterostilbene, a natural analogue of resveratrol found in diet berries, exhibits a hepatoprotective property. Here, we studied the protection by pterostilbene against fructose-induced hepatic lipid accumulation and explored its possible mechanism. We observed a high expression of microRNA-34a (miR-34a, P < 0.05) and a low expression of its target, sirtuin1 (Sirt1, mRNA: P < 0.01; protein: P < 0.001), with the overactivation of downstream sterol regulatory element-binding protein-1 (SREBP-1) lipogenic pathway (nuclear SREBP-1 protein: P < 0.05; FAS and SCD1 mRNA: P < 0.01), in rat livers, as well as BRL-3A and HepG2 cells, stimulated by fructose. More interestingly, pterostilbene recovered the fructose-disturbed miR-34a expression (0.3-0.5-fold vs fructose control, P < 0.05), Sirt1 protein level (1.2- to 1.5-fold vs fructose control, P < 0.05), and SREBP-1 lipogenic pathway, resulting in significant amelioration of hepatocyte lipid accumulation in animal [hepatic triglyceride and total cholesterol (TG&TC) mg/g·wet tissue: 4.90 ± 0.19, 5.23 ± 0.16, 5.20 ± 0.29 vs fructose control 9.73 ± 1.06, P < 0.001; 3.18 ± 0.30, 3.31 ± 0.39, 3.37 ± 0.47 vs 5.67 ± 0.28, P < 0.001] and cell models (BRL-3A TG&TC mmol/g·protein: 0.123 ± 0.011 vs 0.177 ± 0.004, P < 0.001; 0.169 ± 0.011 vs 0.202 ± 0.008, P < 0.05; HepG2: 0.257 ± 0.005 vs 0.303 ± 0.016, P < 0.05; 0.143 ± 0.004 vs 0.201 ± 0.008, P < 0.001). These results provide the experimental evidence supporting the anti-lipogenic effect of pterostilbene against fructose-induced hepatic lipid accumulation via modulating the miR-34a/Sirt1/SREBP-1 pathway.

Comparison of the broody behavior characteristics of different breeds of geese

A low laying performance in goose is one of the key factors preventing the industrial development, and the laying performance is related to broody behavior. However, the characteristics of broody behavior in geese remain unclear. In this study, the total 144 geese (300 day old), including Zhedong geese (Anser cygnoides), Sichuan geese (Anser cygnoides), and Carlos geese (Anser anser) were selected and assigned to 1 of 3 groups/breed (including 4♂+12♀). Laying and broody behaviors were recorded using the infrared video cameras from 2016 November 11 to 2017 June 15. The broody behavior was detected in 19.4% of Carlos geese, 33.3% of Sichuan geese, and 100% of Zhedong geese. Different goose breeds showed similar behavior characteristics. The low frequency of feeding, drinking, and low body weight were observed in the middle of broodiness. As the brooding progressed, the body temperature showed a downward trend and then recovered, whereas no difference was observed in Carlos goose. In addition, the plasma hormone concentration from different breeds and stages of broodiness were compared. The contents of FSH (follicle-stimulating hormone) and LH (luteinizing hormone) in geese were greater in the laying stage than that in the broody stage. Fewer FSH and LH were detected in Zhedong geese and Carlos geese, more in Sichuan geese. In broody goose, the PRL (prolactin) concentrations of the 3 goose breeds peaked in the middle of broodiness, and greater PRL was detected in Sichuan geese than those in Carlos geese and Zhedong geese. Finally, we compared egg production between the broody and non-broody geese in the observation period. The egg production of broody Carlos geese was 27, which was significantly higher than non-broody geese (14 eggs), while in Sichuan geese there was no significant difference between broody (24 eggs) and non-broody geese (26 eggs). Finally, the higher egg production was found with the more broody times in Zhedong geese. Taken together, although the different goose breeds showed similar broody behavior characteristics, the broody rate and hormone secretion were dissimilar, and the Zhedong geese exhibited strong broody feature.

IL-17A exacerbates neuroinflammation and neurodegeneration by activating microglia in rodent models of Parkinson's disease

Neuroinflammation has been involved in pathogenesis of Parkinson's disease (PD), a chronic neurodegenerative disease characterized neuropathologically by progressive dopaminergic neuronal loss in the substantia nigra (SN). We recently have shown that helper T (Th)17 cells facilitate dopaminergic neuronal loss in vitro. Herein, we demonstrated that interleukin (IL)-17A, a proinflammatory cytokine produced mainly by Th17 cells, contributed to PD pathogenesis depending on microglia. Mouse and rat models for PD were prepared by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or striatal injection of 1-methyl-4-phenylpyridinium (MPP⁺), respectively. Both in MPTP-treated mice and MPP⁺-treated rats, blood-brain barrier (BBB) was disrupted and IL-17A level increased in the SN but not in cortex. Effector T (Teff) cells that were adoptively transferred via tail veins infiltrated into the brain of PD mice but not into that of normal mice. The Teff cell transfer aggravated nigrostriatal dopaminergic neurodegeneration, microglial activation and motor impairment. Contrarily, IL-17A deficiency alleviated BBB disruption, dopaminergic neurodegeneration, microglial activation and motor impairment. Anti-IL-17A-neutralizing antibody that was injected into lateral cerebral ventricle in PD rats ameliorated the manifestations mentioned above. IL-17A activated microglia but did not directly affect dopaminergic neuronal survival in vitro. IL-17A exacerbated dopaminergic neuronal loss only in the presence of microglia, and silencing IL-17A receptor gene in microglia abolished the IL-17A effect. IL-17A-treated microglial medium that contained higher concentration of tumor necrosis factor (TNF)-α facilitated dopaminergic neuronal death. Further, TNF-α-neutralizing antibody attenuated MPP⁺-induced neurotoxicity. The findings suggest that IL-17A accelerates neurodegeneration in PD depending on microglial activation and at least partly TNF-α release.

Endoplasmic reticulum stress-induced iRhom2 up-regulation promotes macrophage-regulated cardiac inflammation and lipid deposition in high fat diet (HFD)-challenged mice: Intervention of fisetin and metformin

Endoplasmic reticulum stress (ERS) has been implicated in obesity-associated cardiac remodeling and dysfunction. Inactive rhomboid protein 2 (iRhom2), also known as Rhbdf2, is an inactive member of the rhomboid intramembrane proteinase family, playing an essential role in regulating inflammation. Nevertheless, the role of ERS-meditated iRhom2 pathway in metabolic stress-induced cardiomyopathy remains unknown. In the study, we showed that 4-PBA, as an essential ERS inhibitor, significantly alleviated high fat diet (HFD)-induced metabolic disorder and cardiac dysfunction in mice. Additionally, lipid deposition in heart tissues was prevented by 4-PBA in HFD-challenged mice. Moreover, 4-PBA blunted the expression of iRhom2, TACE, TNFR2 and phosphorylated NF-κB to prevent HFD-induced expression of inflammatory factors. Further, 4-PBA restrained HFD-triggered oxidative stress by promoting Nrf-2 signaling. Importantly, 4-PBA markedly suppressed cardiac ERS in HFD mice. The anti-inflammation, anti-ERS and anti-oxidant effects of 4-PBA were verified in palmitate (PAL)-incubated macrophages and cardiomyocytes. In addition, promoting ERS could obviously enhance iRhom2 signaling in vitro. Intriguingly, our data demonstrated that PAL-induced iRhom2 up-regulation apparently promoted macrophage to generate inflammatory factors that could promote cardiomyocyte inflammation and lipid accumulation. Finally, interventions by adding fisetin or metformin significantly abrogated metabolic stress-induced cardiomyopathy through the mechanisms mentioned above. In conclusion, this study provided a novel mechanism for metabolic stress-induced cardiomyopathy pathogenesis. Therapeutic strategy to restrain ROS/ERS/iRhom2 signaling pathway could be developed to prevent myocardial inflammation and lipid deposition, consequently alleviating obesity-induced cardiomyopathy.

MicroRNA-381 suppresses proliferation and invasion of prostate cancer cells through downregulation of the androgen receptor

Prostate cancer (PCa) is the most frequently diagnosed malignancy in men and its incidence has increased rapidly worldwide. Notably, the molecular mechanisms underlying prostate tumorigenesis have not been fully identified. The levels of microRNA (miR)-381 have been explored in numerous types of malignancy; however, the expression levels and biological function of miR-381 in PCa remain largely unknown. In the present study, reverse-transcription polymerase chain reaction was used to detect the expression levels of miR-381 in PCa cells and normal prostate epithelial cells. Subsequently, miR-381 antisense oligonucleotides and mimics were transfected into LNCaP PCa cells. Bioinformatics analysis was performed to identify the potential target genes of miR-381. Protein expression analysis, dual-luciferase reporter assay and a rescue assay were used to confirm the target of miR-381. The data suggested that the expression levels of miR-381 were significantly decreased in PCa cells compared with in normal prostatic epithelial cells. Furthermore, transfection of LNCaP cells with miR-381 mimics suppressed their proliferation, migration and invasion. In addition, bioinformatics analysis suggested that the androgen receptor (AR) was a target gene of miR-381. miR-381 suppressed the expression levels of AR by directly binding to its 3'-untranslated region. Furthermore, transfection with an AR plasmid partially attenuated miR-381-induced inhibition of cell proliferation, migration and invasion. The results of the present study suggested that miR-381 may act as a tumor suppressor in PCa by directly targeting the AR.

Comparisons in geese of the courtship, mating behaviors and fertility of the Carlos and Sichuan breeds and the breed crosses

The Chinese goose originated from the swan goose (Anser cygnoides) and the European goose originated from the greylag goose (Anser anser). The Chinese and European geese have the potential to crossbreed. Whether interspecific differences in mating behaviors affect successful hybridization is unknown. In this study, 10-month-old Carlos geese (n = 120; Anser anser) and Sichuan geese (Anser cygnoides) were selected, and 12 multi-male parent families (3♂+12♀) were established. The courtship and mating behaviors of pure and cross-bred combinations of the Carlos and Sichuan geese were recorded using video cameras. Initiative courtship by males was the main type of courtship. Fixed mating, mating interference, and uncooperative mating were common in the flocks. The frequencies of some courtship and mating behaviors were less in the cross-bred groups (Carlos ganders × Sichuan geese, Sichuan ganders × Carlos geese) compared with the Sichuan pure-bred groups (P < 0.05). The Carlos male geese had some unique mating behaviors (i.e., one-to-one mating, formation of distinct hierarchies, and competition interference). The fertility rate had a significant correlation with the frequency of successful mating (r_p = 0.992, P < 0.05), rather than with the courtship behavior. These results indicate there were lesser frequencies of courtship and successful matings in the cross-breeding than purebreeding groups. Furthermore, the fertility rate depended largely on the successful mating behavior and was independent of the courtship behavior.

Prolonged PM2.5 exposure elevates risk of oxidative stress-driven nonalcoholic fatty liver disease by triggering increase of dyslipidemia

An increasing number of studies have shown that air pollution containing particulate matter (PM) ≤ 2.5 µm (PM2.5) plays a significant role in the development of metabolic disorder and other chronic diseases. Inflammation and oxidative stress caused by metabolic syndrome are widely determined to be critical factors in the development of nonalcoholic fatty liver disease (NAFLD) pathogenesis. However, there is no direct evidence of this, and the underlying molecular mechanism is still not fully understood. In this study, we investigated the role of inflammation and oxidative stress caused by prolonged PM2.5 exposure in dyslipidemia-associated chronic hepatic injury, and further determined whether an increase in hepatic inflammation and oxidative stress promoted lipid accumulation in the liver, ultimately increasing the risk of NAFLD. Therefore, we studied changes in indicators of metabolic disorder and in symbolic indices of NAFLD. We confirmed increases in insulin resistance, glucose tolerance, peripheral inflammation and dysarteriotony in PM2.5-induced mice. Oxidative stress and inflammatory response in the liver caused by PM2.5 inhalation contributed to abnormal hepatic function, further promoting lipid accumulation in the liver. Moreover, we observed inhibition of oxidative stress and inflammatory response by pyrrolidine dithiocarbamate (PDTC) and N-acetyl-L-cysteine (NAC) in vitro, suggesting that oxidative stress and inflammatory in liver cells aggravated by PM2.5 contributed to hepatic injury by altering normal lipid metabolism. These results indicate a new goal for preventing and treating air pollution-induced diseases: suppression of oxidative stress and inflammatory response.

Multicombination Approach Suppresses Listeria monocytogenes-Induced Septicemia-Associated Acute Hepatic Failure: The Role of iRhom2 Signaling

The mortality rate of acute liver failure significantly increases due to fatal septicemia. Inactive rhomboid protein 2 (iRhom2) is an essential regulator of shedding TNF-α by trafficking with TNF-α converting enzyme (TACE). Fisetin, a flavonoid present in various fruits and plants, possesses anti-oxidative stress and anti-inflammatory activities. Here, multi-combination nanoparticles Fe@Au conjugated with fisetin, iRhom2 small interfering RNA (siRNA), and TNF-α inhibitor (FN) are prepared to examine their effects on fatal septicemia-associated hepatic failure induced by Listeria monocytogenes (LM) in mice and to reveal the underlying mechanisms. After LM infection, upregulation of glutamic-oxalacetic transaminease, glutamic-pyruvic transaminase, alkaline phosphatase, TNF-α, malondialdehyde, H₂ O₂ , and O₂^- is observedcompared to FN-treated mice. The iRhom2/TACE/TNF-α signals are enhanced in vivo and in vitro, resulting in oxidative stress, which is especially associated with the activation of kupffer cells and other macrophages. Decrease in Nrf2 activation and increase of inflammation-associated regulators are also noted in vivo and in vitro. Furthermore, overexpression of TNF-α derived from macrophages aggravates hepatic failure. Inversely, the processes above are restored by FN nanoparticles through the regulation of the iRhom2/TACE/TNF-α axis and Nrf2 activation. These findings suggest that FN may be a potential approach to protect against bacterial septicemia-related diseases by targeting iRhom2.

Pterostilbene and allopurinol reduce fructose-induced podocyte oxidative stress and inflammation via microRNA-377

High dietary fructose is an important causative factor in the development of metabolic syndrome-associated glomerular podocyte oxidative stress and injury. Here, we identified microRNA-377 (miR-377) as a biomarker of oxidative stress in renal cortex of fructose-fed rats, which correlated with podocyte injury and albuminuria in metabolic syndrome. Fructose feeding increased miR-377 expression, decreased superoxide dismutase (SOD) expression and activity, and caused O2(-) and H2O2 overproduction in kidney cortex or glomeruli of rats. This reactive oxygen species induction increased p38 MAPK phosphorylation and thioredoxin-interacting protein (TXNIP) expression and activated the NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome to produce interleukin-1β in kidney glomeruli of fructose-fed rats. These pathological processes were further evaluated in cultured differentiated podocytes exposed to 5mM fructose, or transfected with miR-377 mimic/inhibitor and TXNIP siRNA, or co-incubated with p38 MAPK inhibitor, demonstrating that miR-377 overexpression activates the O2(-)/p38 MAPK/TXNIP/NLRP3 inflammasome pathway to promote oxidative stress and inflammation in fructose-induced podocyte injury. Antioxidants pterostilbene and allopurinol were found to ameliorate fructose-induced hyperuricemia, podocyte injury, and albuminuria in rats. More importantly, pterostilbene and allopurinol inhibited podocyte miR-377 overexpression to increase SOD1 and SOD2 levels and suppress the O2(-)/p38 MAPK/TXNIP/NLRP3 inflammasome pathway activation in vivo and in vitro, consistent with the reduction of oxidative stress and inflammation. These findings suggest that miR-377 plays an important role in glomerular podocyte oxidative stress, inflammation, and injury driven by high fructose. Inhibition of miR-377 by antioxidants may be a promising therapeutic strategy for the prevention of metabolic syndrome-associated glomerular podocyte injury.

Quercetin and allopurinol reduce liver thioredoxin-interacting protein to alleviate inflammation and lipid accumulation in diabetic rats

BACKGROUND AND PURPOSE

Thioredoxin-interacting protein (TXNIP), a regulator of cellular oxidative stress, has been associated with activation of NOD-like receptor 3 (NLRP3) inflammasome, inflammation and lipid metabolism, suggesting it has a role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) in diabetes. In this study we investigated whether TXNIP is involved in type 1 diabetes-associated NAFLD and whether antioxidants, quercetin and allopurinol, alleviate NAFLD by targeting TXNIP.

EXPERIMENTAL APPROACH

Diabetes was induced in male Sprague-Dawley rats by a single i.p. injection of 55 mg · kg⁻¹ streptozotocin. Quercetin and allopurinol were given p.o. to diabetic rats for 7 weeks. Hepatic function, oxidative stress, inflammation and lipid levels were determined. Rat BRL-3A and human HepG2 cells were exposed to high glucose (30 mM) in the presence and absence of antioxidants, TXNIP siRNA transfection or caspase-1 inhibitor, Ac-YVAD-CMK.

KEY RESULTS

Quercetin and allopurinol significantly inhibited the TXNIP overexpression, activation of NLRP3 inflammasome, down-regulation of PPARα and up-regulation of sterol regulatory element binding protein-1c (SREBP-1c), SREBP-2, fatty acid synthase and liver X receptor α, as well as elevation of ROS and IL-1β in diabetic rat liver. These effects were confirmed in hepatocytes in vitro and it was further shown that TXNIP down-regulation contributed to the suppression of NLRP3 inflammasome activation, inflammation and changes in PPARα and SREBPs.

CONCLUSIONS AND IMPLICATIONS

Inhibition of hepatic TXNIP by quercetin and allopurinol contributes to the reduction in liver inflammation and lipid accumulation under hyperglycaemic conditions. The targeting of hepatic TXNIP by quercetin and allopurinol may have therapeutic implications for prevention of type 1 diabetes-associated NAFLD.

Enhanced novelty-induced corticosterone spike and upregulated serotonin 5-HT1A and cannabinoid CB1 receptors in adolescent BTBR mice

Hypothalamic pituitary adrenal (HPA) axis responses to change and social challenges during adolescence can influence mental health and behavior into adulthood. To examine how HPA tone in adolescence may contribute to psychopathology, we challenged male adolescent (5 weeks) and adult (16 weeks) BTBR T(+)tf/J (BTBR) and 129S1/SvImJ (129S) mice with novelty in sociability tests. In prior studies these strains had exaggerated or altered HPA stress responses and low sociability relative to C57BL/6J mice in adulthood. In adolescence these strains already exhibited similar or worse sociability deficits than adults or age-matched C57 mice. Yet BTBR adolescents were less hyperactive and buried fewer marbles than adults. Novelty-induced corticosterone (CORT) spikes in adolescent BTBR were double adult levels, and higher than 129S or C57 mice at either age. Due to their established role in HPA feedback, we hypothesized that hippocampal Gαi/o-coupled serotonin 5-HT1A and cannabinoid CB1 receptor function might be upregulated in BTBR mice. Adolescent BTBR mice had higher hippocampal 5-HT1A density as measured by [(3)H] 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) binding than C57 mice, and adult BTBR 8-OH-DPAT-stimulated GTPγS binding was higher than in either C57 or 129S mice in this region. Further, BTBR hippocampal CB1 density measured by [(3)H]CP55,940 binding was 15-20% higher than in C57. CP55,940-stimulated GTPγS binding in adult BTBR dentate gyrus was 30% higher then 129S (p<0.05), but was not a product of greater neuronal or cell density defined by NeuN and DAPI staining. Hence hyperactive HPA responsiveness during adolescence may underlie 5-HT1A and CB1 receptor up-regulation and behavioral phenotype of BTBR mice.

[Efficacy observation on traumatic nerve injury treated with different acupuncture therapies]

OBJECTIVE

To observe the difference in the efficacy on traumatic nerve injury among electroacupuncture, warm needling therapy and electroacupuncture plus warm needling therapy and explore the better therapeutic method.

METHODS

The electromyography (EMG) and electroneurography (ENG) of 93 cases showed traumatic nerve injury of moderate damage. According to the single blind randomization principle, they were divided into an electroacupuncture (EA) group, a warm needling therapy (WN) group and an EA plus WN group, 31 cases in each one. The main acupoints were selected from Yangming Meridian and Shaoyang Meridian corresponding to the distribution of damaged nerves. EA, WN and EA plus WN were applied separately. The treatment was given once every day, 15 treatments made one session. After 3 sessions of treatment (45 treatments in total), EMG and ENG were re-checked and the results were analyzed statistically.

RESULTS

Regarding the total effective rate and effective rate, it was 96. 8% (30/31) in the EA plus WN group, which was better than 74.2% (23/31) in the EA group and 77. 4% (24/31) in the WN group (P<0. 05). Concerning to the improvements of EMG, the result in the EA plus WN group was 96.8% (30/31), which was better than the other two groups [74. 2%(23/31),74. 2%(23/31)] (P<0. 05). In terms of the recovery of nerve conduction and amplitude, the results in EA plus WN group [(50.9+/-4. 6)m/s,(8. 8+/-2. 9),microVx1 000] were better than the other two groups [(43.7+/-3.1)m/s,(4. 2+/-1. 9)microV X 1 000,(43. 8+/-3. 3)m/s,(4. 5+/-2. 2)microV X 1 000] (P<0. 05).

CONCLUSION

EA combined with WN is a better therapy of acupuncture and moxibustion in the treatment of traumatic nerve injury.

Morin reduces hepatic inflammation-associated lipid accumulation in high fructose-fed rats via inhibiting sphingosine kinase 1/sphingosine 1-phosphate signaling pathway

SphK1/S1P signaling pathway is involved in the development of hepatic inflammation and injury. But its role in high fructose-induced NAFLD has not yet been reported. The aim of this study was to elucidate the crucial role of SphK1/S1P signaling pathway in high fructose-induced hepatic inflammation and lipid accumulation in rats. Moreover, the hepatoprotective effects of morin, a flavonoid with anti-inflammatory and anti-hyperlipedimic activities, on these hepatic changes in rats were investigated. High fructose-fed rats were orally treated with morin (30 and 60mg/kg) and pioglitazone (4mg/kg) for 8 weeks, respectively. Fructose feeding induced hyperlipidemia, and activated SphK1/S1P signaling pathway characterized by the elevation of SphK1 activity, S1P production as well as SphK1, S1PR1 and S1PR3 protein levels, which in turn caused NF-κB signaling activation to produce IL-1β, IL-6 and TNF-α and inflammation in the liver of rats. Subsequently, hepatic insulin and leptin signaling impairment and lipid metabolic disorder were observed in this animal model, resulting in liver lipid accumulation. Morin restored high fructose-induced the activation of hepatic SphK1/S1P signaling pathway in rats. Subsequently, the reduced NF-κB signaling activation by morin decreased inflammatory cytokine production, recovered insulin and leptin signaling impairment to reduce lipid accumulation and injury in the rat liver. These effects of morin were confirmed in Buffalo rat liver (BRL3A) cell model stimulated with 5mM fructose. Thus, the inhibition of hepatic SphK1/S1P signaling pathway may be a novel mechanism by which morin exerts hepatoprotection in high fructose-fed rats, possibly involving liver inflammation inhibition and lipid accumulation recovery.

Building and analyzing protein interactome networks by cross-species comparisons

Background

A genomic catalogue of protein-protein interactions is a rich source of information, particularly for exploring the relationships between proteins. Numerous systems-wide and small-scale experiments have been conducted to identify interactions; however, our knowledge of all interactions for any one species is incomplete, and alternative means to expand these network maps is needed. We therefore took a comparative biology approach to predict protein-protein interactions across five species (human, mouse, fly, worm, and yeast) and developed InterologFinder for research biologists to easily navigate this data. We also developed a confidence score for interactions based on available experimental evidence and conservation across species.

Results

The connectivity of the resultant networks was determined to have scale-free distribution, small-world properties, and increased local modularity, indicating that the added interactions do not disrupt our current understanding of protein network structures. We show examples of how these improved interactomes can be used to analyze a genome-scale dataset (RNAi screen) and to assign new function to proteins. Predicted interactions within this dataset were tested by co-immunoprecipitation, resulting in a high rate of validation, suggesting the high quality of networks produced.

Conclusions

Protein-protein interactions were predicted in five species, based on orthology. An InteroScore, a score accounting for homology, number of orthologues with evidence of interactions, and number of unique observations of interactions, is given to each known and predicted interaction. Our website http://www.interologfinder.org provides research biologists intuitive access to this data.

[Relationship between ureaplasma urealyticum infection and ectopic pregnancy]

OBJECTIVES

To explore the relationship between different subtypes of Ureaplasma Urealyticum infection and ectopic pregnancy.

METHODS

Ectopic pregnancy group included 33 patients and another 40 patients undergoing salpingo-ovariectomy with ovarian cyst or uterine myoma were investigated as control group. Polymerase chain reaction technique was used to detect Uu DNA in the two groups samples from endosalpinx and secretion of cervix. At the same time, these samples were set to electron microscope for examination.

RESULTS

(1) Uu was detected in 27 fallopian tubal epithelium tissues among 33 ectopic pregnancy samples (81.8%), in which biovar1 was positive in 17 samples (52%, 17/33), biovar 2 was positive in 15 (46%, 15/33) and both biovar 1 and 2 positive was 5 (15.2%). While in the control group, Uu was detected in 24 fallopian tubal epithelium tissues among 40 samples (60%), in which biovar1 was positive in 21 samples (52%, 21/40), biovar 2 was positive in 5 (12%, 5/40) and both biovar 1 and 2 positive was 2 (5%). There was no significant difference between the two groups in Uu of biovar 1 (P > 0.05). The positive rate of Uu in biovar 2 show a significant difference (P < 0.05). (2) Co-expression samples in both fallopian tubal epithelium and cervical mucus samples from ectopic pregnancy patients in biovar1 was 13 (72.2%), and in biovar 2 was 11 (71.4%). While in control group, co-expression samples in both fallopian tubal epithelium and cervical mucus samples in biovar 1 was 18 (81.8%), and in biovar 2 was 5 (71.4%). There was no significant difference between the two groups in co-expression in both fallopian tubal epithelium and cervical mucus samples (P > 0.05). (2) The fallopian tubes infected by biovar 2 have a high rate (90%) of ciliary adhesion and exuviation. While there is a low rate (10%) for biovar1 with ciliary adhesion and exuviation. There was significant difference between the two groups of Uu (P < 0.05).

CONCLUSION

The infection of ureaplasma urealyticum may increase the occurrence of fallopian pregnancy. The infection of ureaplasma urealyticum may be concerned with the morphological changes and functional damage of uterine fallopian epithelium.

DLX3 mutation associated with autosomal dominant amelogenesis imperfecta with taurodontism

Amelogenesis imperfecta hypoplastic-hypomaturation with taurodontism (AIHHT) is an autosomal dominant (AD) trait associated with enamel defects and enlarged pulp chambers. In this study, we mapped an AIHHT family to human chromosome 17 q21-q22 (lod score 3.3) and identify a two basepair deletion (CT) at nucleotide 560 in DLX3 associated with the disease. This mutation causes a frameshift altering the last two amino acids of the DNA-binding homeodomain introducing a premature stop codon truncating the protein by 88 amino acids. This is the first report of a mutation within the homeodomain of DLX3. Previous studies have shown a DLX3 mutation outside the homeodomain associated with tricho-dento-osseous syndrome (TDO) suggesting TDO and some forms of AIHHT are allelic.

Dentin phosphoprotein compound mutation in dentin sialophosphoprotein causes dentinogenesis imperfecta type III

A rare compound mutation involving a 36 bp deletion and 18 bp insertion within exon 5 of the dentin sialophosphoprotein (DSPP) gene has been identified in a family with dentinogenesis imperfecta type III (DGI-III). The DSPP gene encodes two major tooth matrix proteins dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). DSPP mutations associated with DGI-III results in an in frame truncation of the serine aspartic acid triplet repeat found in DPP near the highly conserved carboxyl terminal region shortening the protein by six amino acids. Clinically this family presents with discolored amber opalescent teeth and severe attrition of the tooth structure. This study is the first report of a mutation within DPP associated with a genetic dentin disease. Our study indicates that DGI-III is allelic with some forms of DGI-II with and without progressive hearing loss and dentin dysplasia type II that have been shown to be caused by mutations within the DSP coding or signal peptide regions.

Cloning, characterization, and tissue expression pattern of mouse Nma/BAMBI during odontogenesis

Degenerate oligonucleotides to consensus serine kinase functional domains previously identified a novel, partial rabbit tooth cDNA (Zeichner-David et al., 1992) that was used in this study to identify a full-length mouse clone. A 1390-base-pair cDNA clone was isolated encoding a putative 260-amino-acid open reading frame containing a hydrophobic 25-amino-acid potential transmembrane domain. This clone shares some homology with the TGF-beta type I receptor family, but lacks the intracellular kinase domain. DNA database analysis revealed that this clone has 86% identity to a newly isolated human gene termed non-metastatic gene A and 80% identity to a Xenopus cDNA clone termed BMP and activin membrane bound inhibitor. Here we report the mouse Nma/BAMBI cDNA sequence, the tissue expression pattern, and confirmed expression in dental cell lines. This study demonstrates that Nma/BAMBI is a highly conserved protein across species and is expressed at high levels during odontogenesis.

Developmental regulation of dentin sialophosphoprotein during ameloblast differentiation: a potential enamel matrix nucleator

The two major dentin matrix proteins, dentin sialoprotein and dentin phosphoprotein have been shown to be expressed as a single large transcript termed dentin sialophosphoprotein (DSPP). These non-collagenous matrix proteins, identified biochemically by their unique physical-chemical properties, are specific cleavage products of a large parent acidic phosphorylated protein (pI 4.0). Previous studies have shown expression of dentin sialoprotein at the protein level by ameloblasts. The purpose of this study was to determine the temporal-spatial pattern of DSPP expression during amelogenesis. In situ hybridization and immunohistochemistry were performed on sections of developing mouse molars. These data were correlated with RT-PCR analysis of in vitro enamel organ epithelium monolayer cell cultures enriched for ameloblasts. Our data indicates initial expression of the DSPP transcripts and protein during early ameloblast differentiation prior to the secretory phase when the majority of the enamel matrix is formed. Ameloblasts appear to tightly down-regulate DSPP transcription as enamel matrix formation is up-regulated. These data demonstrate DSPP expression during amelogenesis is under highly controlled developmental regulation. Therefore, DSPP may have a primary role in the initial mineralization events of both enamel and dentin, acting as a potential nucleator of hydroxyapatite crystal formation.

Identification and characterization of a cDNA for mouse ameloblastin

Ameloblastin was first identified as one of the most abundant novel transcripts from a random screening of a rat incisor cDNA library. In situ hybridization experiments have shown ameloblastin expression to be specific to ameloblasts, with highest levels in secretory and maturation stage ameloblasts and cells of the epithelial root sheath. Ameloblastin has been identified as a candidate gene for the local hypoplastic form of autosomal dominant amelogenesis imperfecta, by virtue of it's location within the critical disease locus. The purpose of this study was to isolate a full length mouse ameloblastin cDNA and determine its temporal expression pattern during odontogenesis. A newborn mouse molar cDNA library was screened using a rat ameloblastin cDNA probe. Positive clones were confirmed by PCR analysis with ameloblastin-specific primers, and their size determined with vector-specific primers. Phage clones were rescued to phagemid using Exassist helper phage and the nucleotide sequence determined. We report here the identification of two clones, exhibiting alternative splicing of the putative open reading frame, and use of multiple polyadenylation signals. Nucleotide sequence analysis indicated a high degree of similarity to rat ameloblastin, rat amelin 1 and 2 and porcine sheathlin. Reverse transcriptase-PCR analysis using mouse first and second mandibular molar mRNA indicated initial expression at E-14. This is one day after the initial expression of tuftelin (E-13) and one day prior to that of amelogenin (E-15).

Human ameloblastin gene: genomic organization and mutation analysis in amelogenesis imperfecta patients

A gene encoding the enamel protein ameloblastin (AMBN) was recently localized to a region on chromosome 4q21 containing a gene for the inherited enamel defect local hypoplastic amelogenesis imperfecta (AIH2). Ameloblastin protein is located at the Tomes processes of secretory ameloblasts and in the sheath space between rod-interrod enamel, and the AMBN gene therefore represents a viable candidate gene for local hypoplastic amelogenesis imperfecta (AI). In this study, the genomic organization of human AMBN was characterized. The gene was shown to consist of 13 exons and 12 introns. An alternatively spliced 45 bp sequence was shown not to represent a separate exon and is most likely spliced by the use of a cryptic splice site. The finding that there were no recombinations between an intragenic microsatellite and AIH2 encouraged us to evaluate this gene's potential role as a candidate gene for local hypoplastic AI. Mutation screening was performed on all 13 exons in 20 families and 8 sporadic cases with 6 different forms of AI. DNA variants were found but none that was associated exclusively with local hypoplastic AI or any of the other variants of AI in the identified Swedish families. This study excludes the coding regions and the splice sites of AMBN from a causative role in the pathogenesis of AIH2.

Enamelin maps to human chromosome 4q21 within the autosomal dominant amelogenesis imperfecta locus

Amelogenesis imperfecta is a group of hereditary enamel defects. Of the autosomal dominant forms, only the local hypoplastic type has been mapped to human chromosome 4q 13-4q21. Enamelin is a large enamel matrix protein secreted by ameloblasts. The purpose of this study was to determine the human chromosomal localization of enamelin to establish an association with various forms of amelogenesis imperfecta. Chromosomal mapping was performed by polymerase chain reaction (PCR) amplification using somatic hybrid and deletion/derivation cell line panels with an enamelin primer set based on 100% conserved regions between pig and mouse cDNAs. Sequence-tagged site content mapping using eight markers within the critical local hypoplastic amelogenesis imperfecta region was then performed using an isolated human enamelin genomic BAC clone. The human enamelin amplicon was confirmed by DNA sequence analysis, revealing 81% and 73% identity to pig and mouse cDNAs, respectively. PCR amplification using a somatic cell hybrid panel placed enamelin on chromosome 4 with analysis of a regional chromosome 4 mapping panel refining the localization to 4q 13.1-q21.23. An identified human enamelin BAC genomic clone was shown to contain markers D4S2604 and D4S2670, as well as the first exon of the human ameloblastin gene, placing enamelin in the critical amelogenesis imperfecta locus between markers HIS1 and D4S2604 at 4q21. Our results suggest that enamelin is a strong candidate gene for this disease. Furthermore, human 4q21 may contain a second cluster of enamel matrix genes located proximally to the identified cluster of dentin and bone genes.

Cloning, characterization and immunolocalization of human ameloblastin

Amelogenesis imperfecta is a broad classification of hereditary enamel defects, exhibiting both genetic and clinical diversity. Most amelogenesis imperfecta cases are autosomal dominant disorders, yet only the local hypoplastic form has been mapped to human chromosome 4q between D4S242 1 and the albumin gene. An enamel protein cDNA, termed ameloblastin (also known as amelin and sheathlin), has been isolated from rat, mouse and pig. Its human homolog has been mapped to chromosome 4q21 between markers D4S409 and D4S400, flanking the local hypoplastic amelogenesis imperfecta critical region. Therefore, ameloblastin is a strong candidate gene for this form of amelogenesis imperfecta. To facilitate genetic studies related to this dental disease, we isolated and characterized a human ameloblastin cDNA. A human third molar cDNA library was screened and two ameloblastin clones identified. Nucleotide sequencing of these cDNAs indicated alternative splicing of the putative open reading frame, use of different polyadenylation signals, and a high degree of similarity to reported rat, mouse and porcine cDNAs. Immunohistochemistry studies on embryonic human teeth using an antibody to recombinant ameloblastin indicated ameloblastin expression by ameloblasts with localization in the enamel matrix associated with the sheath structures.

Comparative study of MSX-2, DLX-5, and DLX-7 gene expression during early human tooth development

Msx and Dlx family transcription factors are key elements of craniofacial development and act in specific combinations with growth factors to control the position and shape of various skeletal structures in mice. In humans, the mutations of MSX and DLX genes are associated with specific syndromes, such as tooth agenesis, craniosynostosis, and tricho-dento-osseous syndrome. To establish some relationships between those reported human syndromes, previous experimental data in mice, and the expression patterns of MSX and DLX homeogenes in the human dentition, we investigated MSX-2, DLX-5, and DLX-7 expression patterns and compared them in orofacial tissues of 7.5- to 9-wk-old human embryos by using in situ hybridization. Our data showed that MSX-2 was strongly expressed in the progenitor cells of human orofacial skeletal structures, including mandible and maxilla bones, Meckel's cartilage, and tooth germs, as shown for DLX-5. DLX-7 expression was restricted to the vestibular lamina and, later on, to the vestibular part of dental epithelium. The comparison of MSX-2, DLX-5, and DLX-7 expression patterns during the early stages of development of different human tooth types showed the existence of spatially ordered sequences of homeogene expression along the vestibular/lingual axis of dental epithelium. The expression of MSX-2 in enamel knot, as well as the coincident expression of MSX-2, DLX-5, and DLX-7 in a restricted vestibular area of dental epithelium, suggests the existence of various organizing centers involved in the control of human tooth morphogenesis.

Genetic linkage of the dentinogenesis imperfecta type III locus to chromosome 4q

Dentinogenesis imperfecta type III (DGI-III) is an autosomal-dominant disorder of dentin formation which appears in a tri-racial southern Maryland population known as the "Brandywine isolate". This disease has suggestive evidence of linkage to the long arm of human chromosome 4 (LOD score of 2.0) in a family presenting with both juvenile periodontitis and DGI-III. The purpose of this study was to screen a family presenting with only DGI-III to determine if this locus was indeed on chromosome 4q. Furthermore, we wanted to determine if DGI-III co-localized with dentinogenesis imperfecta type II (DGI-II), which has been localized to 4q21-q23. Therefore, a large kindred from the Brandywine isolate was identified, oral examination performed, and blood samples collected from 21 family members. DNA from this family was genotyped with 6 highly polymorphic markers that span the DGI-II critical region of chromosome 4q. Analysis of the data yielded a maximum two-point LOD score of 4.87 with a marker for the dentin matrix protein 1 (DMP1) locus, a gene contained in the critical region for DGI-II. Our results demonstrated that the DGI-III locus is on human chromosome 4q21 within a 6.6 cM region that overlaps the DGI-II critical region. These results are consistent with the hypothesis that DGI-II is either an allelic variant of DGI-III or the result of mutations in two tightly linked genes.

Expression of DLX5 during human embryonic craniofacial development

Dlx (distal-less gene) homeogenes encode transcription factors that are involved in the patterning of orofacial skeleton derived from cephalic neural crest cells. In order to study the role of DLX genes during embryonic development in human, DLX5 expression pattern was investigated in 6- to 11-week-old human embryos. A DLX5 PCR fragment was amplified from a human dental cDNA library subcloned and used for in situ hybridization investigations. DLX5 gene expression was primarily detected in the mandible at 6 weeks and then, after in the maxilla. DLX5 gene expression became restricted to progenitor cells of developing tooth germs, bones and cartilages of mandible and maxilla. During odontogenesis from bud to late cap stages, DLX5 transcripts were present in both dental epithelium and mesenchyme tissues. DLX5 expression was restricted to few cells in the vestibular aspect of the dental epithelium, while DLX5 mRNA signal was more widely distributed in dental mesenchyme. The observed expression pattern of DLX5 homeogene extends the proposed site-specific combination of homeogene expression in neural crest derived cells to human specific dentition. Furthermore, during the bud and cap stages of tooth morphogenesis, the asymmetric expression of DLX5 in the dental epithelium and dental mesenchyme may contribute to the complex patterning of human tooth shape.

Identification of a novel isoform of mouse dentin matrix protein 1: spatial expression in mineralized tissues

Dentin matrix protein 1 (Dmp1) is an acidic phosphoprotein first identified by cDNA cloning from a rat tooth library. Northern blot hybridization of a variety of tissues detected Dmp1 mRNAs only in odontoblasts, suggesting that this protein was odontoblast specific. In situ hybridization studies showed expression of Dmp1 in odontoblasts with transient expression in secretory ameloblasts. The purpose of this study was to isolate and characterize a mouse Dmp1 cDNA and determine its spatial expression pattern related to other mineralizing tissues. A mouse molar cDNA library was screened with a 32P-labeled Dmp1 polymerase chain reaction amplification product in order to isolate a full-length clone. DNA sequence analysis of the largest mouse Dmp1 cDNA (2802 base pairs [bp]) revealed an open reading frame of 1509 nucleotides encoding a 503 amino acid protein with a single polyadenylation signal. Comparison with rat and bovine Dmp1 sequence showed high homology and the identification of a 45 bp (15 amino acid) insert, representing an alternative spliced mRNA. This 45 bp segment was shown to represent a small exon by DNA analysis of a mouse genomic Dmp1 clone. In situ hybridization studies revealed a much broader Dmp1 tissue expression pattern than previously reported. Dmp1 transcripts were detected in the odontoblast and ameloblasts, osteoblasts, and cementoblasts. Our data indicate that Dmp1 is alternatively spliced, and the primary full-length transcript contains a 45 bp insert which is encoded by a small exon. Therefore, Dmp1 is not a tooth-specific protein but rather is expressed in a number of mineralizing tissues including enamel, bone, and cementum.

Dentin phosphoprotein and dentin sialoprotein are cleavage products expressed from a single transcript coded by a gene on human chromosome 4. Dentin phosphoprotein DNA sequence determination

Dentin is the major mineralized extracellular matrix of the tooth. The organic components of dentin consist of type I collagen (90%) with 10% noncollagenous proteins, which are also components of bone. Two dentin proteins, dentin sialoprotein and dentin phosphoprotein, have been shown to be tooth-specific being expressed mostly by odontoblast cells. In this study, we screened a mouse molar tooth library for dentin sialoprotein and dentin phosphoprotein cDNA clones. Analysis of the clones resulted in characterization of a 4420-nucleotide cDNA that contained a 940-amino acid open reading frame. The signal peptide and NH2-terminal sequence was 75% homologous to the cDNA sequence of rat dentin sialoprotein. The continued open reading frame, however, contained a RGD sequence followed by a region of repeated aspartic acid and serine residues. This portion of the protein codes for amino acid sequence consistent with that of dentin phosphoprotein. The noncoding region contains three potential polyadenylation signals, two of which were shown to be utilized. Northern blot analysis indicated the presence of two major transcripts of 4.4 and 2.2 kilobases in odontoblasts. Chromosomal mapping localized the gene to human chromosome 4. These data suggest that the previously identified dentin extracellular matrix proteins, dentin sialoprotein and dentin phosphoprotein, are expressed as a single cDNA transcript coding for a protein that is specifically cleaved into two smaller polypeptides with unique physical-chemical characteristics. Therefore, we propose that the gene be named dentin sialophosphoprotein. The location of the human dentin sialophosphoprotein gene on chromosome 4 suggests that this gene may be a strong candidate gene for the genetic disease dentinogenesis imperfecta type II.

Dentin matrix protein-1, a candidate gene for dentinogenesis imperfecta

Dentinogenesis imperfecta (DGI) is an autosomal dominant inherited dental disease which affects dentin production and mineralization. Genetic linkage studies have determined linkage between DGI type II and group-specific component (Gc, vitamin D binding protein), interferon (gamma)-induced cytokine protein 10 (INP10) and secreted phosphoprotein 1 (SSP1, osteopontin, bone sialoprotein 1, early T-lymphocyte activation 1). Therefore, the gene locus has been localized to the long arm of human chromosome 4 in the region 4q13-q21. Dentin matrix protein-1 (DMP-1, AG-1) is a new acidic, phosphorylated dentin extracellular matrix protein which has recently been identified by cDNA cloning. The purpose of this study was to establish the possible association of DMP-1 with DGI type II by determining the human chromosomal localization of this protein. A DMP-1 DNA probe was generated1using PCR amplification of the mouse full-length DMP-1 and labeled with [32P] d-CTP. A panel of rodent somatic cell hybrid clones, previously cytogenetically characterized, was used for the assignment. High stringently DNA hybridization studies and analysis of the chromosomal cell panel indicated that the DMP-1 gene locus is located on human chromosome 4. This data supports the hypothesis that DMP-1 is a candidate gene for the genetic disease DGI type II. This is based on chromosomal localization to human chromosome 4, the expression of DMP-1 mostly by odontoblasts, and its purported physical-chemical properties.