Unified one-electron Hamiltonian formalism of spin-orbit Jahn-Teller and pseudo-Jahn-Teller problems in tetrahedral and octahedral symmetries.

Heavy element compounds with high symmetries often feature both spin-orbit coupling and vibronic coupling. This is especially true for systems with tetrahedral and octahedral symmetries, whose electronic states may be threefold degenerate and experience complicated Jahn-Teller and pseudo-Jahn-Teller interactions. To accurately describe these interactions, high quality spin-orbit vibronic Hamiltonian operators are needed. In this study, we present a unified one-electron Hamiltonian formalism for spin-orbit vibronic interactions for systems in all tetrahedral and octahedral symmetries. The formalism covers all spin-orbit Jahn-Teller and pseudo-Jahn-Teller problems in the symmetries with arbitrary types and arbitrary numbers of vibrational modes and generates Hamiltonian expansion formulas of arbitrarily high order.

0D/2D mixed-dimensional perovskite constructed by thiol- and disulfide-containing ligands.

Reduced-dimensional (RD) perovskites have shown attractive chemical and physical properties for optoelectronic applications. Incorporating large organic ligands enables infinite tunability in the components and structures. Theoretically, it is feasible to apply multiple types of organic ligands in a single RD crystal to achieve multiple-dimensional perovskites. However, the coexistence of different organic ligands commonly introduces competing crystal growths that inhibit the formation of a more complex crystal structure. Herein, we report a case of mixed-dimensional (MD) perovskite single crystal containing two types of sulfide-containing ligands. We show that the application of ketones can partially oxidize organothiol ligands in the precursor solution. The resultant disulfide-based ligands can be co-incorporated with the thiol-based ligand in a single MD perovskite crystal. X-ray diffraction confirmed that the structure contains both layered and isolated inorganic components constructed by face-sharing lead halide octahedra. Unlike conventional RD structures, the MD perovskite shows an enlarged bandgap with valence band maximum and conduction band minimum being spatially separated, and isotropic optical features, as revealed by x-ray diffraction, spectroscopies, and density functional theory computation.

Rapid BMI Increases and Persistent Obesity in Small-for-Gestational-Age Infants.

Purpose: In order to compensate for the early intrauterine growth restriction, small-for-gestational age (SGA) infants have "catch-up growth" after birth. Increased caloric intake has been suggested for SGA infants conventionally. It is important to determine if the early growth rate of body mass index (BMI) is associated with risk of persistent obesity later in life. In this longitudinal cohort study, we assessed the BMI of a large cohort of children who were SGA at birth to determine their risk of persistent obesity at school age (6-7 years) due to excessive weight gain in the first 3 years of life. Methods: We collected the height and weight data of 23,871 SGA babies. A polynomial function was used to fit the BMI-for-age z-score (BAZ) values of 0-6 years old SGA children and interpolate their growth trajectory. In addition, we screened out 6,959 children from 23,871 children to further evaluate the dynamic changes of early childhood BMI. We divided the school-age children into groups as non-obese (BAZ < 2) and obese (BAZ > 2), and determined the association between changes in BMI and school-age obesity. Results: From the perspective of BMI distribution, the interpolated growth trajectory indicated that SGA children reaching overweight status or developing obesity by 3 years of age, continued to have obesity until school age (R2, 0.65; R2, 0.21). The retrospective analysis showed that children who were overweight and had obesity during school age had a high BMI from early age. By analyzing the changes in early BMI, we found that the fastest growth of SGA children occurred in the early infancy before 6 months and they continued to grow rapidly for a period of time. Interestingly, former SGA children who maintained a near overweight (1 < BAZ < 2) status before the age of 2 maintained an appropriate growth rate and usually did not develop obesity. Conclusions: A rapid increase in BMI during early infancy in former SGA newborns leads to a persistent risk of obesity. The energy intake of SGA infants should appropriately meet the infants' growth needs and early BMI changes should be closely monitored for an optimal integrated management.

Spontaneous Polarization Effect and Photocatalytic Activity of Layered Compound of BiOIO3.

Internal polarized electric field is found to be an effective and available strategy to separate photogenerated electron-hole pairs. By this method, the efficiency of photocatalytic reactions can be obviously enhanced. Here, the layered compound of BiOIO3 with spontaneous polarization was synthesized by a simple hydrothermal method. Taking another bismuth compound BiOI as a counterpart, which has a similar layered structure, the spontaneous polarization effects of BiOIO3 were analyzed and confirmed. The photocatalytic activity of BiOIO3 and BiOI were evaluated by the degradation of methyl orange. Methyl orange was almost completely photocatalytically decomposed by BiOIO3 and BiOI in 40 and 90 min, respectively. The separation and transfer behaviors of photogenerated electron-hole pairs were investigated by a series of photoelectrochemical characterizations. It is further proved the separation and transmission efficiency of BiOIO3 are higher than those of BiOI. According to the results of density of theory calculations, the internal polarized electric field in BiOIO3 is ascribed to the spatial asymmetry of the IO3 group, which is estimated to ∼1.5 × 1010 V/m. Under the action of this internal polarized electric field, the photogenerated electrons and holes would transfer along opposite directions, i.e., photogenerated electrons and holes respectively gather at the Bi/I side and O side. Additionally, superoxide radicals (•O2-) and holes (h+) are produced during the degradation process, which are responsible for the high visible-light photocatalytic activity. Finally, the cyclic degradation test proves that its photocatalytic performance has long-term stability. Therefore, BiOIO3 polar material can be used as one of the alternative materials for efficient photocatalytic reaction.

[Studies of the norm and psychometrical properties of the ages and stages questionnaires, third edition, with a Chinese national sample].

OBJECTIVE: To introduce the Ages and Stages Questionnaires, Third Edition (ASQ-3), to China, created ASQ-Chinese (ASQ-C) and carried out studies of its national norm and the psychometrical properties in the children aged 1-66 months in the mainland of China in collaboration with the author of the ASQ System and under the authorizations from its publisher on translation, researches, publication and distribution of the ASQ-3. METHOD: The ASQ-3 questionnaires were translated and adapted into a Simplified Chinese version, the ASQ-C, with six steps such as translation, back-translation and adaptation and so on to ensure consistency with the core of the original document and to have the cultural relevance in China.A stratified cluster sampling method was utilized to recruit children aged 1-66 months with respect to demographic characteristics such as the proportion of population in each administrative region and in urban and rural areas and so on that are representative of 2010 China census data.A sample size of over 200 was collected for each ASQ-C age interval.Children were excluded from the normative sample who (1) are from communities or villages at an elevation of 2 000 m or above and(or) where simplified Chinese is not the official language, or (2) had been diagnosed as having a developmental delay by any authoritative organizations.The national normative sample for the ASQ-C had a total sample size of 4 452, sample size within each age interval ranged from 218 to 227, including 2 230 male cases and 2 222 female cases, 2 236 urban cases and 2 216 rural cases.A convenience sample was recruited from the normative sample to examine inter-rater reliability and test-retest reliability in all six administrative regions.Researchers completed the ASQ-C on the same child with their parents for 162 children for inter-rater reliability(the size of each ASQ-C age interval was 5-9); parents of 168 children completed another age-appropriate ASQ-C for test-retest reliability during 10-15 days after they completed the normative ASQ-C(The size of each ASQ-C age interval is 6-10). Another convenience sample was recruited from the follow-up of low birth weight infants for the concurrent validity of the ASQ-C in comparison with the Beijing Gesell.Parents of 198 children completed age-appropriate ASQ-C and professional administered to the children with the Beijing Gesell.In the ASQ-C norm and test-retest reliability, parents completed the age-appropriate ASQ-C, independently or with needed assistance. In inter-rater reliability, researchers completed the same ASQ-C after parents. In validity test, after parents completing age-appropriate ASQ-C, professional tested children with the Beijing Gesell.Data were analyzed using SPSS version 13.0 software.The mean and standard deviation of the national normative sample were calculated, reliability and validity of the ASQ-C was examined. RESULT: The demographic characteristics of this Chinese sample match the 2010 China census data on gender, urban or rural location, and family income.All 20 intervals of the ASQ-C were standardized on 21 national normative samples.Cronbach's alpha coefficient for the whole measure was 0.8.The Pearson correlation coefficient between the ASQ-C total scores of the two raters was 0.8.The Pearson correlation coefficient between the ASQ-C total scores of the two times was 0.8 (all P<0.000 1). The sensitivity of ASQ-C was 87.50% and the specificity of ASQ-C was 84.48%.The percentage of the agreement between the ASQ-C and the Beijing Gesell was 84.74%. CONCLUSION: These findings indicate that the ASQ-C is a reliable and valid measure with a representative national sample aged 1-66 months.It can be used to screen and monitor the development of children in the mainland of China.

Effect of synthetic link N peptide on the expression of type I and type II collagens in human intervertebral disc cells.

Intervertebral disc (IVD) degeneration is associated with proteolytic degradation of proteoglycan aggregates present within the extracellular matrix of the disc. Link N peptide (DHLSDNYTLDHDRAIH) is the N-terminal peptide of link protein, which stabilizes the proteoglycan aggregates. It is generated in vivo by proteolytic degradation during tissue turnover. It has been previously shown that this peptide can stimulate the synthesis of collagens by articular cartilage and bovine IVD cells in vitro. Being a synthetic peptide, Link N has considerable financial benefits for clinical use over recombinant growth factors because it is extremely cheap to produce. The purpose of the present study was to determine the effect of Link N on the expression of types I and II collagen and investigate the cellular mechanisms of Link N signal transduction in human IVD cells. The present results suggest that Link N stimulates the expression of types I and II collagen in human IVD cells. More specifically, Link N stimulated the expression of type I in nucleus pulposus (NP) cells, but not in annulus fibrosus cells. As Link N also decreased the phosphorylation of p38 in NP cells only, results suggest that p38 is a mediator of the effect of Link N on type I collagen expression. p38 is a member of the mitogen-activated protein kinase family highlighted by three major cascades: p38, c-Jun amino-terminal kinase, and extracellular signal-regulated kinase pathways. Link N showed no effect on the latter two pathways, suggesting a specific effect of Link N on the p38 cascade. On the other hand, Link N stimulated the expression of type II collagen in both NP and annulus fibrosus, suggesting that other mechanisms are implicated in the control of type II collagen expression in disc cells, without excluding p38 for the NP. In conclusion, the present study showed that Link N can modulate the expression of collagen in human IVD cells.

[Studies of the norm and psychometric properties of Ages and Stages Questionnaires in Shanghai children].

OBJECTIVE: To introduce the Ages and Stages Questionnaire (ASQ) to China, we created ASQ-Chinese (ASQ-C) and carried out studies of its norm and the psychometrical properties in Shanghai children aged 3-66 months in collaboration with the author of the ASQ with the permissions from the publisher. METHOD: The 19 ASQ intervals were translated into Chinese, to make the ASQ-C culturally relevant, and back translated into English. The project used a stratified cluster sampling method and recruited children aged 3 - 66 months with respect to demographic characteristics that were representative of Shanghai census data, and excluded the children whose mother tongue was not Chinese and/or diagnosed with disabilities by the authoritative hospitals in Shanghai. Parents/caregivers of the 8472 children either independently completed the age-appropriate ASQ-Cs or completed with help from the researchers for the normative samples. Among them, professionals completed the age-appropriate ASQ-C again for 519 children within six days after the parents/caregivers completed the ASQ-C for inter-rater reliability. In terms of test-retest reliability, 651 parents completed another age-appropriate questionnaires within a 10- to 23-day interval. For concurrent validity, BSIDII were administered with 255 children from 6, 12, 18, 24, and 30-month ASQ-C age intervals. The cutoffs of the ASQ-C and the BSIDII were all set at the two standard deviations below the means. The statistical analysis was carried out using SPSS 13.0. RESULT: The ASQ-Cs were independently completed by 85.25% of the parents/caregivers; the percentage of gender, family income and region of residence were similar to the Shanghai population census conducted in the recent years. Two standard deviations below the means were used as the cutoff scores of the ASQ-Cs across the age intervals. In terms of internal consistency of the ASQ-C, Cronbach standardized alpha was 0.77. The Pearson correlation coefficient between the ASQ-C total scores of the two testers was 0.84 (P < 0.0001). The Pearson correlation coefficient between the ASQ-C total scores of the two tests was 0.82 (P < 0.0001). The percentage of the agreement between the ASQ-C and the BSID II was 84.31%, the sensitivity of ASQ-C was 85.00%, and the specificity of ASQ-C was 84.26%. CONCLUSION: It is practicable that the ASQ-C can be completed by the parents/caregivers of Shanghai children. ASQ-C has solid psychometric properties and is worthy of further research and introduction to China.

[Thyroid disruption induced by pentachlorophenol].

OBJECTIVE: To assess thyroid disruption induced by sodium pentachlorophenol (PCP) using Organization for Economic Co-operation and Development (OECD) recommended TG 407 method. METHODS: A total of 30 specific pathogen free (SPF) SD adult male and female rats were randomly divided into 3 groups, and treated with water, 0.33 and 30 mg x kg(-1)x d(-1) of PCP-Na by oral gavage for consecutive 28 days, respectively. After final treatment, histological changes of thyroid were observed by hematoxylin-eosin stain, and the levels of thyroid hormones (total thyroxine (TT(4)), free thyroxine (FT(4)), total triiodothyronine (TT(3)), and free triiodothyronine (FT(3))) were determined by radioimmunoassay. The expression levels of thyroid receptors (TRalpha and TRbeta) mRNA and deiodinases (DioI, DioII and DioIII) mRNA in liver were analyzed by RT-PCR. RESULTS: In high dose group, liver weight coefficient of male and female rats were (4.82 +/- 0.42)% and (4.99 +/- 0.17)%, increased by 36.2% (t = 7.338, P < 0.01) and 41.8% (t = 8.955, P < 0.01), compared to control group ((3.54 +/- 0.14)%, (3.52 +/- 0.19)%), respectively, while the significant changes of kidney or thyroid weight were not observed. In high dose group, the levels of TT(4) and FT(4) in serum of male rats were (64.95 +/- 7.16) nmol/L and (8.16 +/- 2.29) pmol/L, and decreased by 26.6% (t = -3.999, P < 0.01) and 42.3% (t = -4.112, P < 0.01) compared to control group ((88.48 +/- 6.99) nmol/L, (14.13 +/- 1.68) pmol/L). In the same group, FT(4) in serum of female rats was (4.94 +/- 0.89) pmol/L, decreased by 55.5% (t = -3.380, P = 0.012) compared to control group ((11.10 +/- 3.40) pmol/L) and TT(3) and FT(3) in serum of female rats were (1.92 +/- 0.24) nmol/L and (3.05 +/- 0.79) pmol/L, increased by 74.5% (t = 5.263, P < 0.01) and 55.6% (t = 3.495, P < 0.01) compared to control group ((1.10 +/- 0.23) nmol/L, (1.96 +/- 0.32) pmol/L), respectively. PCP-Na didn't affect the expression levels of TRalpha, TRbeta, DioIII mRNA in high dose group, while DioII expression of male rats (0.209 +/- 0.017) down-regulated by 79.2% (t = -5.426, P < 0.01) compared to control group (1.006 +/- 0.137), and DioI expression of female rats (1.844 +/- 0.189) up-regulated by 66.6% (t = 4.359, P < 0.01) compared to control group (1.005 +/- 0.083), indicating DioI and DioII poss different sensitivity to adverse effects induced by PCP-Na between male and female rats. The histopathological results showed that PCP-Na could give rise to hyperplasia of the follicular epithelium cells, and the depletion of colloid. There were no significant changes in serum THs levels and expression of TRalpha, TRbeta, DioI-IIImRNA in low dose group. However, sporadic lymphocytic infiltration, follicles amplification in part and slightly increased in thickness of follicular cells were observed in this group. CONCLUSION: PCP is a kind of thyroid disrupting chemical.

Effect of parathyroid hormone on type X and type II collagen expression in mesenchymal stem cells from osteoarthritic patients.

A major drawback of current cartilage and intervertebral disc tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients express type X collagen (COL10), a marker of late-stage chondrocyte hypertrophy (associated with endochondral ossification). Parathyroid hormone (PTH) regulates endochondral ossification by inhibiting chondrocyte differentiation toward hypertrophy. In this study, we investigated the effect of PTH on expression of COL10 in MSCs from OA patients and analyzed the potential mechanisms related to its effect. MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Expanded cells were then incubated for 0-48 h without (control) or with 100 nM PTH (1-34). Protein expression and phosphorylation were measured by Western blot. Results showed that PTH (1-34) inhibited expression of COL10 in MSCs from OA patients in a time-dependent manner. In parallel, PTH (1-34) stimulated expression of COL2, a marker of chondrogenic differentiation. Results also showed that PTH (1-34) inhibited in a sustained manner the phosphorylation of p38 and AKT protein kinase signaling pathways. Interestingly, the modulation of COL2 and COL10 gene expression was significant as rapidly as after 1 h in the presence of PTH (1-34); changes in the phosphorylation of p38 and AKT were significant only after 6 h. This suggests that while p38 and AKT protein kinase signaling pathways may not be required to initiate the regulation of expression of COL2 and COL10 by PTH (1-34), these pathways may modulate later events necessary for preventing precocious MSC hypertrophy.

[Effects of lycopene on cerebral ischemia-reperfusion injury in rats].

OBJECTIVE: To study the protective effects of lycopene (LP) on cerebral ischemia-reperfusion injury and oxidative stress in SD rats and the mechanism of them. METHODS: The rats were divided into five groups: normal control group, model control group, sham group and two LP groups (fed with 5 mg/kg bw or 20 mg/kg bw of lycopene daily for 15 days). The model for cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO). The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion. The rats were put to death 24 h after reperfusion. The size of cerebral infarction was measured. The activities of iNOS, SOD, CAT and the contents of NO and MDA in brain and serum uric acid were measured. The expressions of Bcl-2 mRNA and HIF-1alphamRNA in cortex were examined by using reverse transcription polymerase chain reaction (RT-PCR) technique. RESULTS: In comparison with the model group, the neurological deficits were milder, the volumes of cerebral infarction were smaller, the activities of SOD, CAT in brain tissue were higher, the activities of iNOS as well as the contents of NO, MDA in brain tissue and serum uric acid were lower in Lycopene groups. Compared with the model group and control group, the expression of HIF-1 alpha mRNA of cortex in the high dose lycopene (20 mg/kg bw) group was up-regulated; while the expression of Bcl-2 mRNA of cortex was up-regulated only in the low dose lycopene (5 mg/kg bw) group. CONCLUSION: There were some protective effects of oral administration of lycopene against cerebral ischemia-reperfusion injuries induced by focal cerebral ischemia and oxidative stress. The possible mechanism may be related with increasing activities of antioxidant enzymes, inhibiting lipid peroxidation, decreasing activities of iNOS,and up-regulating the expression of HIF-1alpha mRNA as well as Bcl-2 mRNA.

[Cutoff scores of the Ages and Stages Questionnaire-Chinese for screening infants and toddlers].

OBJECTIVE: To study the validity and accuracy of differing cutoff scores of the Ages and Stages Questionnaires-Chinese (ASQ-C) for screening infants and toddlers in comparison with the gold standard, Bayley Scale of Infant Development, Second Edition (BSID II). METHOD: The 269 samples were enrolled from the normative children, aged 3 - 31 months, of the ASQ-C in Shanghai. The age-appropriate ASQ-Cs were completed by parents/caregivers and the BSIDIIwas administered by professionals. The cutoff scores of -2 standard deviation (s), -1.5 s, and -s for the ASQ-C were examined against BSID II with the cutoff scores set at -2 s as the standard of developmental delay, -s as the standard of suspected developmental delay and developmental delay respectively. Agreement between the classifications of the ASQ-C (i.e., typical, suspected, delay) was compared with the classification of the BSID II (typical, suspected, delay), sensitivity, specificity, Youden Index and area under ROC curve of ASQ-C were examined. The statistical analysis was carried out using SPSS 13.0. RESULT: When the cutoff score for BSID II was -2 s, the -2 s cutoff score for ASQ-C exhibited the following properties: the highest agreement of 83.64%, the sensitivity and specificity both above 80% being respectively 88.46% and 83.13%, the highest Youden Index of 0.72 and the largest area of 0.86 under ROC curve. The -1.5 s cutoff score for ASQ-C showed the following properties: 71.75% agreement, 100% sensitivity, 68.72% specificity, Youden Index = 0.69, the area under ROC curve = 0.84. The -s cutoff score for ASQ-C showed the following properties: the lowest agreement of 55.02%, 100% sensitivity, the lowest specificity of 50.21%, the lowest Youden Index of 0.50, and the smallest area of 0.75 under ROC curve. When the cutoff score for BSID II was set at -s, the -2 s for ASQ-C showed the following properties: the highest agreement of 85.87%, the lowest sensitivity of 68.57%, the highest specificity of 91.96%, Youden Index = 0.61, the smallest area = 0.77 under ROC curve. The -1.5 s for ASQ-C showed the following properties: the agreement of 80.67%, the sensitivity and specificity both above 70% being respectively 85.71% and 78.89%, the highest Youden Index of 0.65, the largest area of 0.82 under ROC. The -s cutoff score for ASQ-C showed the following properties: the lowest agreement of 68.40%, the highest sensitivity of 94.29%, the lowest specificity of 59.30%, the lowest Youden Index of 0.54, and the area under ROC curve = 0.80. When the cutoff score for BSID II was -1 to 2 s, the identifying percentages of the -2 s, -1.5 s and -s for the ASQ-C were 56.82%, 77.27% and 90.91%, respectively. CONCLUSION: For developmental delay identification, the -2 s cutoff score for ASQ-C produces the most robust validity and highest accuracy; for the identification of suspected developmental delay and developmental delay, the -1.5 s cutoff score for ASQ-C has the highest screening accuracy with appropriate sensitivity and specificity; for identifying the suspected developmental delay, the -s cutoff score for ASQ-C has the highest percentage of the identification. It is necessary to add 1 - 2 s to the ASQ-C's cutoff scores as the standard for screening suspected developmental delays.

Regulation of the novel Mg2+ transporter transient receptor potential melastatin 7 (TRPM7) cation channel by bradykinin in vascular smooth muscle cells.

BACKGROUND: Transient receptor potential melastatin 7 (TRPM7) channels have been identified in the vasculature. However, their regulation and function remain unclear. METHODS: Here, we tested the hypothesis that bradykinin and its second messenger cAMP upregulate TRPM7, which stimulates activation of annexin-1 (TRPM7 substrate) and increases transmembrane Mg2+ transport and vascular smooth muscle cell (VSMC) migration. Human and rat VSMCs were studied. TRPM7 phosphorylation was assessed by immunoprecipitation:immunoblotting using antiphospho-serine/threonine and anti-TRPM7 antibodies. [Mg2+]i was measured by mag-fura-2. TRPM7 was downregulated by small interfering RNA and 2-aminoethoxydiphenyl borate. Annexin-1 activity was assessed by cytosol-to-membrane translocation. Cell migration and invasion, functional responses to bradykinin, were assessed in transwell chambers. RESULTS: Bradykinin increased expression of TRPM7 and annexin-1. TRPM7 was rapidly (5 min) phosphorylated on serine/threonine but not on tyrosine residues by bradykinin. [Mg2+]i was increased in bradykinin-stimulated cells (0.53 versus 0.68 mmol/l, basal versus bradykinin, P < 0.01). Annexin-1 activation was increased by bradykinin and inhibited by 2-aminoethoxydiphenyl borate. Although Hoe 140 (B2 receptor antagonist), U-73122 (phospholipase C inhibitor), 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (c-Src inhibitor) and chelerythrine (protein kinase C inhibitor) blocked bradykinin actions, dibutyryl-c-AMP was without effect. In small interfering RNA-transfected and in 2-aminoethoxydiphenyl borate-treated cells, bradykinin-induced Mg2+ influx and VSMC migration were reduced. CONCLUSION: Our results demonstrate that bradykinin regulates TRPM7 and its downstream target annexin-1 through phospholipase C-dependent, protein kinase C-dependent and c-Src-dependent and cAMP-independent pathways; effects are mediated through bradykinin type 2 receptor; and bradykinin regulates VSMC [Mg2+]i and migration through TRPM7. These data identify TRPM7/annexin-1/Mg2+ as a novel pathway in bradykinin signaling.

Redox-sensitive signaling by angiotensin II involves oxidative inactivation and blunted phosphorylation of protein tyrosine phosphatase SHP-2 in vascular smooth muscle cells from SHR.

Angiotensin II (Ang II) signaling in vascular smooth muscle cells (VSMCs) involves reactive oxygen species (ROS) through unknown mechanisms. We propose that Ang II induces phosphorylation of growth signaling kinases by redox-sensitive regulation of protein tyrosine phosphatases (PTP) in VSMCs and that augmented Ang II signaling in spontaneously hypertensive rats (SHRs) involves oxidation/inactivation and blunted phosphorylation of the PTP, SHP-2. PTP oxidation was assessed by the in-gel PTP method. SHP-2 expression and activity were evaluated by immunoblotting and by a PTP activity assay, respectively. SHP-2 and Nox1 were downregulated by siRNA. Ang II induced oxidation of multiple PTPs, including SHP-2. Basal SHP-2 content was lower in SHRs versus WKY. Ang II increased SHP-2 phosphorylation and activity with blunted responses in SHRs. Ang II-induced SHP-2 effects were inhibited by valsartan (AT(1)R blocker), apocynin (NAD(P)H oxidase inhibitor), and Nox1 siRNA. Ang II stimulation increased activation of ERK1/2, p38MAPK, and AKT, with enhanced effects in SHR. SHP-2 knockdown resulted in increased AKT phosphorylation, without effect on ERK1/2 or p38MAPK. Nox1 downregulation attenuated Ang II-mediated AKT activation in SHRs. Hence, Ang II regulates PTP/SHP-2 in VSMCs through AT(1)R and Nox1-based NAD(P)H oxidase via two mechanisms, oxidation and phosphorylation. In SHR Ang II-stimulated PTP oxidation/inactivation is enhanced, basal SHP-2 expression is reduced, and Ang II-induced PTP/SHP-2 phosphorylation is blunted. These SHP-2 actions are associated with augmented AKT signaling. We identify a novel redox-sensitive SHP-2-dependent pathway for Ang II in VSMCs. SHP-2 dysregulation by increased Nox1-derived ROS in SHR is associated with altered Ang II-AKT signaling.

[Mechanism of protective effects of procyanidins on liver injury induced by alcohol in mice].

OBJECTIVE: To study the mechanism of protective effects of procyanidins on liver injury model induced by alcohol in mice. METHODS: Mice were divided into 3 groups to set up the model of liver injury induced by alcohol in mice: the group of liver injury induced by alcohol, the group of procyanidins with low doses (100mg/kg), the group of procyanidins with high doses(300mg/kg). Then established normal group of control. The model of liver injury induced by alcohol in mice was used to investigate the protective effects at low and high doses procyanidins in serum indicated by alanine aminotransferase (ALT), asparate aminotransferase (AST) and in liver homogenate indicated by malonaldehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS). The levels of Cu,Zn-SOD mRNA in hepatic tissue and toll like receptor 4 (TLR4) mRNA were determined by using reverse transcription polymerase chain reaction (RT-PCR) technique. RESULTS: The procyanidins with low and high doses could reduce ALT, MDA, ROS content and increase SOD level, up-regulate the expression of Cu, Zn-SOD mRNA and down-regulate the expression of TLR4 mRNA. CONCLUSION: Mechanism of the protective effects on liver injuries of mice induced by alcoholmay be associated with promoting the expression of Cu, Zn-SOD and suppressing the expression of TLR4 mRNA.

Increased systemic inflammation and oxidative stress in patients with worsening congestive heart failure: improvement after short-term inotropic support.

In the present study, we evaluated circulating pro-inflammatory mediators and markers of oxidative stress in patients with decompensated CHF (congestive heart failure) and assessed whether clinical recompensation by short-term inotropic therapy influences these parameters. Patients with worsening CHF (n=29, aged 61.9+/-2.7 years), NYHA (New York Heart Association) class III-IV, and left ventricular ejection fraction of 23.7+/-1.8% were studied. Controls comprised age-matched healthy volunteers (n=15; 54.1+/-3.2 years). Plasma levels of cytokines [IL (interleukin)-6 and IL-18], chemokines [MCP-1 (monocyte chemotactic protein-1)], adhesion molecules [sICAM (soluble intercellular adhesion molecule), sE-selectin (soluble E-selectin)], systemic markers of oxidation [TBARS (thiobarbituric acid-reactive substances), 8-isoprostaglandin F(2alpha) and nitrotyrosine] and hs-CRP (high-sensitivity C-reactive protein) were measured by ELISA and colorimetric assays at admission and 30 days following 72-h milrinone (n=15) or dobutamine (n=14) infusion. Plasma IL-6, IL-18, sICAM, E-selectin, hs-CRP and oxidative markers were significantly higher in patients on admission before inotropic treatment compared with controls (P<0.05). Short-term inotropic support improved clinical status as assessed by NYHA classification and by the 6-min walk test and significantly decreased plasma levels of IL-6, IL-18, sICAM, hs-CRP and markers of oxidation (P<0.05) at 30 days. The effects of milrinone and dobutamine were similar. In conclusion, our results demonstrate that patients with decompensated CHF have marked systemic inflammation and increased production of oxygen free radicals. Short-term inotropic support improves functional status and reduces indices of inflammation and oxidative stress in patients with decompensated CHF.

Differential regulation of transient receptor potential melastatin 6 and 7 cation channels by ANG II in vascular smooth muscle cells from spontaneously hypertensive rats.

Intracellular Mg2+ depletion has been implicated in vascular dysfunction in hypertension. We demonstrated that transient receptor potential melastatin 7 (TRPM7) cation channels mediate Mg2+ influx in VSMCs. Whether this plays a role in [Mg2+]i deficiency in hypertension is unclear. Here, we tested the hypothesis that downregulation of TRPM7 and its homologue TRPM6 is associated with reduced [Mg2+]i and that ANG II negatively regulates TRPM6/7 in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR). Cultured VSMCs from Wistar Kyoto (WKY) and SHR were studied. mRNA and protein expression of TRPM6 and TRPM7 were assessed by RT-PCR and immunoblotting, respectively. Translocation of annexin-1, specific TRPM7 substrate, was measured as an index of TRPM7 activation. [Mg2+]i was determined using mag fura-2. VSMCs from WKY and SHR express TRPM6 and TRPM7. Basal TRPM6 expression was similar in WKY and SHR, but basal TRPM7 content was lower in VSMCs from SHR vs. WKY. This was associated with significantly reduced [Mg2+]i in SHR cells (P < 0.01). ANG II time-dependently increased TRPM6 expression, with similar responses in WKY and SHR. ANG II significantly increased TRPM7 expression in WKY (P < 0.05), but not in SHR. Annexin-1 translocation was reduced 1.5-2-fold in SHR vs. WKY. Our findings demonstrate that TRPM6 and TRPM7 are differentially regulated in VSMCs from SHR and WKY. Whereas TRPM6 is unaltered in SHR, expression of TRPM7 is blunted. This was associated with attenuated annexin-1 translocation and decreased VSMC [Mg2+]i in SHR. Downregulation of TRPM7, but not TRPM6, may play a role in altered Mg2+ homeostasis in VSMCs from SHR.

[Effects of grape seed proanthocyanidins extracts on experimental diabetic nephropathy in rats].

OBJECTIVE: To study the effects of grape seed proanthocyanidins extracts(GSPE) and its mechanism on early renal lesions of diabetic rats. METHODS: Diabetic rats induced by alloxan were given GSPE intragastrically for 6 weeks, then the antioxidative indexes and NO content, NOS activity in kidney and serum were measured, and the renal function indexes were tested as well. RESULTS: Compared with the diabetic group, the urinary protein/24h, levels of blood urea nitrogen(BUN)and serum creatinine(SCr), creatinine clearance rate(CCr) and the ratio of kidney weight/body weight were decreased, the SOD activity in kidney was raised while MDA content was fall in the GSPE group(high dose), and the differences were all significant. The NO content in the kidney and NOS activity in kidney and serum decreased in the GSPE (low dose)group, and there was significant difference when compared with diabetic group( P <0.05) . CONCLUSION: GSPE has the effect in protecting kidney of diabetic rats, the mechanism might be related with its action in increasing the renal antioxidative ability,decreasing the content of NO and the activity of NOS in kidney and serum.

Negative regulation of RhoA/Rho kinase by angiotensin II type 2 receptor in vascular smooth muscle cells: role in angiotensin II-induced vasodilation in stroke-prone spontaneously hypertensive rats.

OBJECTIVE: To test whether angiotensin II (Ang II) through the Ang II type 2 receptor (AT2R), downregulates RhoA/Rho kinase, which plays a role in AT1 receptor (AT1R)-mediated function. METHODS: In vitro studies were performed in A10 vascular smooth muscle cells (VSMC) and in vivo studies in mesenteric arteries from Wistar-Kyoto (WKY) and stroke-prone spontaneously hypertensive (SHRSP) rats. VSMC were stimulated with Ang II (10 mol/l), CGP42112A (10 mol/l, a selective AT2R agonist) +/- valsartan (10 mol/l, an AT1R antagonist), or the Rho kinase inhibitor fasudil (10 mol/l). AT1R and AT2R expression and myosin light chain (MLC) phosphorylation were determined by immunoblotting. RhoA activity was assessed by measuring membrane translocation. Functional significance between AT2R, RhoA/Rho kinase and vasodilation was assessed in arteries from valsartan-treated (30 mg/kg per day, 14 days) WKY and SHRSP rats. Vasodilatory responses to Ang II (10-10 mol/l) were performed in norepinephrine pre-contracted vessels +/- valsartan(10 mol/l), PD123319 (10 mol/l, an AT2R antagonist) or fasudil (10 mol/l). RESULTS: A10 VSMC expressed AT1R and AT2R. In valsartan-treated cells, Ang II-induced RhoA translocation was reduced versus controls (42 +/- 6%, P < 0.05). Similar responses were obtained with CGP42112A (45 +/- 6%, P < 0.05). This was associated with decreased MLC activation. Fasudil abrogated Ang II- and CGP42112A-mediated effects. Ang II evoked a significant vasodilatory response only in valsartan-treated SHRSP (max dilation 40 +/- 7%). PD123319 blocked these effects. Fasudil increased AngII-induced relaxation in SHRSP vessels. AT2R expression was increased by valsartan (two- to three-fold) in SHRSP arteries. RhoA translocation was increased two-fold in untreated SHRSP (P < 0.05) and was reduced by valsartan (P < 0.05). These changes were associated with decreased MLC phosphorylation. CONCLUSIONS: Ang II/AT2R negatively regulates vascular RhoA/Rho kinase/MLC phosphorylation. These processes may play a role in Ang II-mediated vasodilation in conditions associated with vascular AT2R upregulation, such as in SHRSP chronically treated with AT1R blockers, which may contribute to blood pressure lowering by these antihypertensive agents.

Role of the actin cytoskeleton in angiotensin II signaling in human vascular smooth muscle cells.

Angiotensin II (Ang II) regulates vascular smooth muscle cell (VSMC) function by activating signaling cascades that promote vasoconstriction, growth, and inflammation. Subcellular mechanisms coordinating these processes are unclear. In the present study, we questioned the role of the actin cytoskeleton in Ang II mediated signaling through mitogen-activated protein (MAP) kinases and reactive oxygen species (ROS) in VSMCs. Human VSMCs were studied. Cells were exposed to Ang II (10-7 mol/L) in the absence and presence of cytochalasin B (10-6 mol/L, 60 min), which disrupts the actin cytoskeleton. Phosphorylation of p38MAP kinase, JNK, and ERK1/2 was assessed by immuno blotting. ROS generation was measured using the fluoroprobe chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (4 micromol/L). Interaction between the cytoskeleton and NADPH oxidase was determined by evaluating the presence of p47phox in the Triton X-100 insoluble membrane fraction. Ang II significantly increased phosphorylation of p38MAP kinase, JNK, and ERK1/2 (two- to threefold above control, p < 0.05). Cytochalasin B pretreatment attenuated p38MAP kinase and JNK effects (p < 0.05) without altering ERK1/2 phosphorylation. ROS formation, which was increased in Ang II stimulated cells, was significantly reduced by cytochalasin B (p < 0.01). p47phox, critically involved in NADPH oxidase activation, colocalized with the actin cytoskeleton in Ang II stimulated cells. Our data demonstrate that Ang II mediated ROS formation and activation of p38MAP kinase and JNK, but not ERK1/2, involves the actin cytoskeleton in VSMCs. In addition, Ang II promotes interaction between actin and p47phox. These data indicate that the cytoskeleton is involved in differential MAP kinase signaling and ROS generation by Ang II in VSMCs. Together, these studies suggest that the cytoskeleton may be a central point of crosstalk in growth- and redox-signaling pathways by Ang II, which may be important in the regulation of VSMC function.

Angiotensin II-dependent chronic hypertension and cardiac hypertrophy are unaffected by gp91phox-containing NADPH oxidase.

The gp91phox-containing NADPH oxidase is the major source of reactive oxygen species (ROS) in the cardiovascular system and inactivation of gp91phox has been reported to blunt hypertension and cardiac hypertrophy seen in angiotensin (Ang) II-infused animals. In the current study, we sought to determine the role of gp91phox-derived ROS on cardiovascular outcomes of chronic exposure to Ang II. The gp91phox-deficient mice were crossed with transgenic mice expressing active human renin in the liver (TTRhRen). TTRhRen mice exhibit chronic Ang II-dependent hypertension and frank cardiac hypertrophy by age 10 to 12 weeks. Four genotypes of mice were generated: control, TTRhRen trangenics (TTRhRen), gp91phox-deficient (gp91-), and TTRhRen transgenic gp91phox-deficient (TTRhRen/gp91-). Eight to 10 mice/group were studied. ROS levels were significantly reduced (P<0.05) in the heart and aorta of TTRhRen/gp91- and gp91-mice compared with control counterparts, and this was associated with reduced cardiac, aortic, and renal NADPH oxidase activity (P<0.05). Systolic blood pressure (SBP), cardiac mass, and cardiac fibrosis were increased in TTRhRen versus controls. In contrast to its action on ROS generation, gp91phox inactivation had no effect on development of hypertension or cardiac hypertrophy in TTRhRen mice, although interstitial fibrosis was reduced. Cardiac and renal expression of gp91phox homologues, Nox1 and Nox4, was not different between groups. Thus, although eliminating gp91phox-associated ROS production may be important in cardiovascular consequences in acute insult models, it does not prevent the development of hypertension and cardiac hypertrophy in a model in which the endogenous renin-angiotensin system is chronically upregulated.