Structural requirements of flavonoids to induce heme oxygenase-1 expression

Population studies suggest cardiovascular health benefits of consuming fruits and vegetables rich in polyphenolic compounds such as flavonoids. We reported previously that the flavonoid quercetin protects arteries from oxidant-induced endothelial dysfunction and attenuates atherosclerosis in apolipoprotein E gene knockout mice, with induction of heme oxygenase-1 (Hmox1) playing a critical role. The present study investigated the structural requirements of flavonoids to induce Hmox1 in human aortic endothelial cells (HAEC). We identified ortho-dihydroxyl groups and an α,β-unsaturated system attached to a catechol as the key structural requirements for Hmox1 induction. Active but not inactive flavonoids had a low oxidation potential and prevented ascorbate autoxidation, suggesting that Hmox1 inducers readily undergo oxidation and that oxidized, rather than reduced, flavonoids may be the biological inducer of Hmox1. To test this hypothesis, we synthesized stable derivatives of caffeic acid (3-(3,4-dihyroxyphenyl)-2-propenoic acid) containing either ortho-dihydroxy or ortho-dioxo groups. Compared with the dihydroxy compound, the quinone analog induced Hmox1 more potently in HAEC and also provided enhanced protection to arteries of wild type animals against oxidant-induced endothelial dysfunction. In contrast, the quinone analog failed to provide protection against oxidant-induced endothelial dysfunction in arteries of Hmox1^-/- mice, establishing a key role for Hmox1 in vascular protection. These results suggest that oxidized forms of dietary polyphenols are the likely inducers of Hmox1 and may explain in part the protective cardiovascular effects of diets rich in these compounds.

[Clinical analysis of Behçet disease associated with pulmonary vascular disease]

Objective: To investigate the clinical features, therapy and prognosis of Behcet's disease(BD) complicated with pulmonary vascular diseases (PVD). Methods: The clinical manifestation, hemodynamics, pulmonary artery angiographic findings, therapy and prognosis of PVD in BD in Shanghai Pulmonary Hospital from January 2009 to August 2016 were analyzed retrospectively. Results: Seven patients with average of (37±20) years were included. The ratio of male vs. female was 6∶1. Vascular involvement included pulmonary hypertension (PH) (4/7), pulmonary embolism (PE) (3/7) and pulmonary artery aneurysms (PAA) (3/7). All patients received immunosuppressive agents and all PH patients had therapy of PH target drugs. Three out of 4 PE patients underwent anticoagulant therapy. Conclusion: PVD is a rare complication of BD. The common clinical manifestations are PH, PE and PAA. Management of immunosuppressive agents may improve the prognosis and should be recommended.

Molecular and Cellular Mechanisms of Palate Development

Development of the mammalian secondary palate involves highly dynamic morphogenetic processes, including outgrowth of palatal shelves from the oral side of the embryonic maxillary prominences, elevation of the initially vertically oriented palatal shelves to the horizontal position above the embryonic tongue, and subsequently adhesion and fusion of the paired palatal shelves at the midline to separate the oral cavity from the nasal cavity. Perturbation of any of these processes could cause cleft palate, a common birth defect that significantly affects patients' quality of life even after surgical treatment. In addition to identifying a large number of genes required for palate development, recent studies have begun to unravel the extensive cross-regulation of multiple signaling pathways, including Sonic hedgehog, bone morphogenetic protein, fibroblast growth factor, transforming growth factor β, and Wnt signaling, and multiple transcription factors during palatal shelf growth and patterning. Multiple studies also provide new insights into the gene regulatory networks and/or dynamic cellular processes underlying palatal shelf elevation, adhesion, and fusion. Here we summarize major recent advances and integrate the genes and molecular pathways with the cellular and morphogenetic processes of palatal shelf growth, patterning, elevation, adhesion, and fusion.

Identification of Osr2 Transcriptional Target Genes in Palate Development

Previous studies have identified the odd-skipped related 2 (Osr2) transcription factor as a key intrinsic regulator of palatal shelf growth and morphogenesis. However, little is known about the molecular program acting downstream of Osr2 in the regulation of palatogenesis. In this study, we isolated palatal mesenchyme cells from embryonic day 12.5 (E12.5) and E13.5 Osr2^RFP/+ and Osr2^RFP/- mutant mouse embryos and performed whole transcriptome RNA sequencing analyses. Differential expression analysis of the RNA sequencing datasets revealed that expression of 70 genes was upregulated and expression of 61 genes was downregulated by >1.5-fold at both E12.5 and E13.5 in the Osr2^RFP/- palatal mesenchyme cells, in comparison with Osr2^RFP/+ littermates. Gene ontology analysis revealed enrichment of signaling molecules and transcription factors crucial for skeletal development and osteoblast differentiation among those significantly upregulated in the Osr2 mutant palatal mesenchyme. Using quantitative real-time polymerase chain reaction (RT-PCR)and in situ hybridization assays, we validated that the Osr2^-/- embryos exhibit significantly increased and expanded expression of many osteogenic pathway genes, including Bmp3, Bmp5, Bmp7, Mef2c, Sox6, and Sp7 in the developing palatal mesenchyme. Furthermore, we demonstrate that expression of Sema3a, Sema3d, and Sema3e, is ectopically activated in the developing palatal mesenchyme in Osr2^-/- embryos. Through chromatin immunoprecipitation, followed by RT-PCR analysis, we demonstrate that endogenous Osr2 protein binds to the promoter regions of the Sema3a and Sema3d genes in the embryonic palatal mesenchyme. Moreover, Osr2 expression repressed the transcription from the Sema3a and Sema3d promoters in cotransfected cells. Since the Sema3 subfamily of signaling molecules plays diverse roles in the regulation of cell proliferation, migration, and differentiation, these data reveal a novel role for Osr2 in regulation of palatal morphogenesis through preventing aberrant activation of Sema3 signaling. Together, these data indicate that Osr2 controls multiple molecular pathways, including BMP and Sema3 signaling, in palate development.

MTA1 modulated by miR-30e contributes to epithelial-to-mesenchymal transition in hepatocellular carcinoma through an ErbB2-dependent pathway

MTA1 is a metastasis-associated protein, which is essential to epithelial-to-mesenchymal transition (EMT). However, information concerning its up- and downstream regulation is rare. We investigated its upstream regulation and downstream effector in human hepatocellular carcinoma (HCC). In total, 94 paired HCC and adjacent tissue samples were involved in the study, and the results indicated that decreased miR-30e levels were associated with increased MTA1 levels in human HCC. miR-30e exerted its regulation of MTA1 transcription by binding to its 3'-untranslated region, and was negatively associated with EMT. Furthermore, significantly higher expression of MTA1 was associated with overexpression of v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (ErbB2) in human HCC, and MTA1 can promote transcription of ErbB2 by binding with histone deacetylase 2 (HDAC2) and acting as a promoter. The EMT promotion effect caused by MTA1 largely depended on ErbB2, and reducing the activity of ErbB2 can significantly attenuate EMT promotion by causing overexpression of MTA1 both in vitro and in vivo. In general, downregulation of miR-30e can increase levels of MTA1 in human HCC, and furthermore promote cell invasion and metastasis by promoting ErbB2.

Modulating Wnt Signaling Rescues Palate Morphogenesis in Pax9 Mutant Mice

Cleft palate is a common birth defect caused by disruption of palatogenesis during embryonic development. Although mutations disrupting components of the Wnt signaling pathway have been associated with cleft lip and palate in humans and mice, the mechanisms involving canonical Wnt signaling and its regulation in secondary palate development are not well understood. Here, we report that canonical Wnt signaling plays an important role in Pax9-mediated regulation of secondary palate development. We found that cleft palate pathogenesis in Pax9-deficient embryos is accompanied by significantly reduced expression of Axin2, an endogenous target of canonical Wnt signaling, in the developing palatal mesenchyme, particularly in the posterior regions of the palatal shelves. We found that expression of Dkk2, encoding a secreted Wnt antagonist, is significantly increased whereas the levels of active β-catenin protein, the essential transcriptional coactivator of canonical Wnt signaling, is significantly decreased in the posterior regions of the palatal shelves in embryonic day 13.5 Pax9-deficent embryos in comparison with control littermates. We show that small molecule-mediated inhibition of Dickkopf (DKK) activity in utero during palatal shelf morphogenesis partly rescued secondary palate development in Pax9-deficient embryos. Moreover, we found that genetic inactivation of Wise, which is expressed in the developing palatal shelves and encodes another secreted antagonist of canonical Wnt signaling, also rescued palate morphogenesis in Pax9-deficient mice. Furthermore, whereas Pax9^del/del embryos exhibit defects in palatal shelf elevation/reorientation and significant reduction in accumulation of hyaluronic acid-a high molecular extracellular matrix glycosaminoglycan implicated in playing an important role in palatal shelf elevation-80% of Pax9^del/del;Wise^-/- double-mutant mouse embryos exhibit rescued palatal shelf elevation/reorientation, accompanied by restored hyaluronic acid accumulation in the palatal mesenchyme. Together, these data identify a crucial role for canonical Wnt signaling in acting downstream of Pax9 to regulate palate morphogenesis.

Activin and Bmp4 Signaling Converge on Wnt Activation during Odontogenesis

Previous studies show that both activin and Bmp4 act as crucial mesenchymal odontogenic signals during early tooth development. Remarkably, mice lacking activin-βA ( Inhba^-/-) and mice with neural crest-specific inactivation of Bmp4 ( Bmp4^ncko/ncko) both exhibit bud-stage developmental arrest of the mandibular molar tooth germs while their maxillary molar tooth germs completed morphogenesis. In this study, we found that, whereas expression of Inhba and Bmp4 in the developing tooth mesenchyme is independent of each other, Bmp4^ncko/nckoInhba^-/- compound mutant mice exhibit early developmental arrest of all tooth germs. Moreover, genetic inactivation of Osr2, a negative regulator of the odontogenic function of the Bmp4-Msx1 signaling pathway, rescues mandibular molar morphogenesis in Inhba^-/- embryos. We recently reported that Osr2 and the Bmp4-Msx1 pathway control the bud-to-cap transition of tooth morphogenesis through antagonistic regulation of expression of secreted Wnt antagonists, including Dkk2 and Sfrp2, in the developing tooth mesenchyme. We show here that expression of Dkk2 messenger RNAs was significantly upregulated and expanded into the tooth bud mesenchyme in Inhba^-/- embryos in comparison with wild-type littermates. Furthermore, in utero treatment with either lithium chloride, an agonist of canonical Wnt signaling, or the DKK inhibitor IIIC3a rescued mandibular molar tooth morphogenesis in Inhba^-/- embryos. Together with our finding that the developing mandibular molar tooth bud mesenchyme expresses significantly higher levels of Dkk2 than the developing maxillary molar tooth mesenchyme, these data indicate that Bmp4 and activin signaling pathways converge on activation of the Wnt signaling pathway to promote tooth morphogenesis through the bud-to-cap transition and that the differential effects of loss of activin or Bmp4 signaling on maxillary and mandibular molar tooth morphogenesis are mainly due to the differential expression of Wnt antagonists, particularly Dkk2, in the maxillary and mandibular tooth mesenchyme.

Conformation transitions of a single polyelectrolyte chain in a poor solvent: a replica-exchange lattice Monte-Carlo study

The thermodynamic behaviors of a strongly charged polyelectrolyte chain in a poor solvent are studied using replica-exchange Monte-Carlo simulations on a lattice model, focusing on the effects of finite chain length and the solvent quality on the chain conformation and conformation transitions. The neutralizing counterions and solvent molecules are considered explicitly. The thermodynamic quantities that vary continuously with temperature over a wide range are computed using the multiple histogram reweighting method. Our results suggest that the strength of the short-range hydrophobic interaction, the chain length, and the temperature of the system, characterized by ε, N, and T, respectively, are important parameters that control the conformations of a charged chain. When ε is moderate, the competition between the electrostatic energy and the short-range hydrophobic interaction leads to rich conformations and conformation transitions for a longer chain with a fixed length. Our results have unambiguously demonstrated the stability of the n-pearl-necklace structures, where n has a maximum value and decreases with decreasing temperature. The maximum n value increases with increasing chain length. Our results have also demonstrated the first-order nature of the conformation transitions between the m-pearl and the (m-1)-pearl necklaces. With the increase of ε, the transition temperature increases and the first-order feature becomes more pronounced. It is deduced that at the thermodynamic limit of infinitely long chain length, the conformational transitions between the m-pearl and the (m-1)-pearl necklaces may remain first order when ε > 0 and m = 2 or 3. Pearl-necklace conformations cannot be observed when either ε is too large or N is too small. To observe a pearl-necklace conformation, the T value needs to be carefully chosen for simulations performed at only a single temperature.

[End tidal PCO(2) for evaluation of severity of disease in idiopathic pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension]

Objective: To explore the difference in end tidal PCO(2) (P(ET)CO(2)) between idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH), and to analyze the correlation between P(ET)CO(2) and the indexes of disease severity in IPAH and CTEPH patients. Methods: Data were retrieved from 68 IPAH patients and 52 CTEPH patients who all had received right-heart catheterization, pulmonary function test and cardiopulmonary exercise testing at Shanghai Pulmonary Hospital from October 2011 to October 2014. In addition, other clinical parameters were also collected. Results: The IPAH group had a significantly higher mPAP, PVR [(60±16) mmHg (1 mmHg=0.133 kPa), (13±6) Wood U ] than the CTEPH group [(46±12) mmHg, (9±4) Wood U, t=4.90, 4.83, all P<0.01]. Meanwhile, the IPAH group had a lower percentage of predicted peakVO(2), oxygen pulse [(45±15)%, (60±22)%] compared with the CTEPH group [(53±16)%, (68±21)%, t=-2.42, -1.96, all P<0.05]. The value of P(ET)CO(2) at rest, AT, peak in the IPAH patients [(27±5), (28±7), (25±7) mmHg] were higher than those in the CTEPH patients [(24±4) mmHg, (23±6) mmHg, (21±6) mmHg, t=3.22-4.54, all P<0.01]. There was a significantly difference in P(ET)CO(2) at AT and peak between WHO-FC Ⅰ-Ⅱ and Ⅲ-Ⅳ subgroups in IPAH (t=2.55, 2.60, all P<0.05) and CTEPH (t=2.39, P<0.05), except for P(ET)CO(2) at peak in the CTEPH patients (t=1.71, P>0.05). A moderately inverse correlation was found between P(ET)CO(2) at AT and NT-proBNP in the IPAH group (r=-0.58, P<0.01), meanwhile P(ET)CO(2) at AT in the CTEPH group was weakly correlated with NT-proBNP (r=-0.34, P<0.05). Conclusions: Compared with the CTEPH patients, the IPAH patients had significantly decreased exercise capacity and increased P(ET)CO(2). P(ET)CO(2) could reflect the disease severity in both IPAH and CTEPH patients, being superior in IPAH than in CTEPH. Furthermore, P(ET)CO(2) at AT might be better than P(ET)CO(2) at peak in reflecting the ventilatory efficiency.

Surgical treatment of Denis type B thoracolumbar burst fracture with neurological deficiency by paraspinal approach

We aimed to describe the surgical technique and clinical outcomes of paraspinal-approach reduction and fixation (PARF) in a group of patients with Denis type B thoracolumbar burst fracture (TLBF) with neurological deficiencies. A total of 62 patients with Denis B TLBF with neurological deficiencies were included in this study between January 2009 and December 2011. Clinical evaluations including the Frankel scale, pain visual analog scale (VAS) and radiological assessment (CT scans for fragment reduction and X-ray for the Cobb angle, adjacent superior and inferior intervertebral disc height, and vertebral canal diameter) were performed preoperatively and at 3 days, 6 months, and 1 and 2 years postoperatively. All patients underwent successful PARF, and were followed-up for at least 2 years. Average surgical time, blood loss and incision length were recorded. The sagittal vertebral canal diameter was significantly enlarged. The canal stenosis index was also improved. Kyphosis was corrected and remained at 8.6±1.4^o (P>0.05) 1 year postoperatively. Adjacent disc heights remained constant. Average Frankel grades were significantly improved at the end of follow-up. All 62 patients were neurologically assessed. Pain scores decreased at 6 months postoperatively, compared to before surgery (P<0.05). PARF provided excellent reduction for traumatic segmental kyphosis, and resulted in significant spinal canal clearance, which restored and maintained the vertebral body height of patients with Denis B TLBF with neurological deficits.

[Effect of zinc ion on the expression of osteoblastic proteins in MC3T3-E1 cells in inflammatory environment]

OBJECTIVE

To investigate the effect of zinc ion on the expression of osteoblastic proteins.

METHODS

Mice osteoblasts MC3T3-E1 cells were subcultured. Inflammatory environment model was established by tumor necrosis factor α(TNF-α)at a concentration of 10 mg/L. According to different concentration of Zn(2+), the cells were divided into TNF-α group, control group, group A(TNF-α+10(-4) mol/L Zn(2+)), group B(TNF-α+10(-5) mol/L Zn(2+)), group C(TNF-α+10(-6) mol/L Zn(2+)). After 24, 48, and 72 h of culture, cell counting kit-8(CCK-8)assay was used to analyze the proliferation of the cells. ALP activity was examined. Bone morphogenetic protein-2(BMP-2), Runt-related transcription factor 2(RUNX2), Osterix and receptor activator of NF-κB ligand(RANKL)protein levels were determined by Western blotting after 72 h of culture.

RESULTS

The cells grew by adherence after 24 h. After 72 h, the cells grew dense, and the cells showed long spindle shape or irregular shape. The proliferation of osteoblasts in TNF-α group, group B and group C became lower than that in the control group(P<0.05), and was not significantly different between group A and the control group(P >0.05). ALP activity examination demonstrated that the groups cultured for 72 h revealed the highest ALP activity and the most prominent differentation compared with 24 h and 48 h groups. ALP activity was significantly decreased in TNF-α group, group B and group C compared with control group(P<0.05), but was not significantly different between group A and control group(P>0.05). The protein levels of BMP-2, RUNX2 and Osterix were significantly decreased in TNF-α group, group B and group C compared with control group(P<0.05), while showed no significant difference between group A and the control group. Protein level of RANKL was significantly increased in TNF-α group, grope B and group C compared with control group(P<0.05), while showed no significant difference between group A and control group.

CONCLUSIONS

The concentration of 10(-4) mol/L Zn(2+) can significantly increase the expression of osteoblastic proteins such as ALP, BMP-2, RUNX2, Osterix and decrease the expression of RANKL in mice osteoblasts in TNF-α inflammatory environment.

Influence of Grafting Point Distribution on the Surface Structures of Y-Shaped Polymer Brushes in Solution

We report a simulated annealing study of surface structures of the Y-shaped copolymers grafted onto a planar substrate in nonselective solvents. The influences of the lateral size of the grafting surface and the distribution manner of the grafting point on the order degree of the ripple structures are investigated. Under uniformly distribution conditions, it is found that the well-defined ripple structures can be formed when the lateral size less than a threshold which depends on the solvent quality and grafting density. However, introducing a density fluctuation into the uniformly distribution grafting points in different ways, the defects with different degrees are observed in the ripple structures. The influence of the density fluctuations on the ripple phase are studied quantitatively. Furthermore, the possibility of the formation of surface structures with long-range order induced by directed self-assembly is investigated. The findings provide guidelines for fabricating patterned surfaces with highly ordered structures.

Phase behavior of ABC-type triple-hydrophilic block copolymers in aqueous solutions

The phase behavior of symmetric ABC triple-hydrophilic triblock copolymers in concentrated aqueous solutions is investigated using a simulated annealing technique. Two typical cases, in which the hydrophilicity of the middle B-block is either stronger or weaker than that of the end A- and C-blocks, are studied. In these two cases, a variety of phase diagrams are constructed as a function of the volume fraction of the B-block and the copolymer concentration ([Formula: see text] for both non-frustrated and frustrated copolymers. Structures, such as two-color alternatingly packed cylinders or gyroid, and lamellae-in-lamellae etc. that do not occur in the melt system, are obtained in solutions. Rich phase transition sequences, especially re-entrant phase transitions involving complex continuous networks of alternating gyroid and alternating diamond are observed for a given copolymer with decreasing [Formula: see text] . The difference in hydrophilicity among different blocks can result in inhomogeneous distribution of solvent molecules in the morphology, and with the decrease of [Formula: see text] , the distribution of solvent molecules presents a non-monotonic variation. This results in a non-monotonic variation of the effective volume fraction of each domain with the decrease of [Formula: see text] , which induces the re-entrant phase transitions. The presence of a good solvent for all the blocks can cause changes in the effective segregation strengths between different blocks and also in chain conformations, hence can alter the bulk phases and results in the occurrence of new structures and phase transitions. Especially, structures having A-C interfaces or A-C mixed domains can be obtained even in the non-frustrated copolymer systems, and structures obtained in the frustrated systems may be similar to those obtained in the non-frustrated systems. The window of the alternating gyroid structures may occupy a large part of the phase diagram for non-frustrated copolymers with stronger B-hydrophilicity. This behavior can be used to tune the self-assembled structures of block copolymers.