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Hong Ye

Publications and source records attributed to Hong Ye.

At least 19 recordsLinked to original sources
PubMed2026

Refining the link between REM sleep behavior disorder and neurodegeneration: Genetic correlation, Mendelian randomization, and colocalization evidence.

Observational studies have proposed a link between isolated rapid eye movement sleep behavior disorder (iRBD) and several neurodegenerative diseases. We employed genome-wide linkage disequilibrium score regression (LDSC), standard two-sample Mendelian randomization (MR), and colocalization analysis to assess the causal links between iRBD and these neurodegenerative conditions. iRBD demonstrated a positive causal association with Alzheimer disease (odds ratio [OR] = 1.02, 95% confidence interval [CI]: 1.00-1.03, P = 1.10E-02), Parkinson disease (OR = 1.10, 95% CI: 1.03-1.16, P = 2.96E-03), and multiple sclerosis (OR = 1.09, 95% CI: 1.02-1.17, P = 1.61E-02). A strong positive genetic correlation with dementia with Lewy bodies was observed (rg = 1.6313, P = .0002), along with a causal association (OR = 1.45, 95% CI: 1.03-2.06, P = 3.53E-02), further supported by colocalization analysis. No significant causal relationship was identified between iRBD and amyotrophic lateral sclerosis (all P > .05). Additionally, reverse Mendelian randomization analyses did not reveal any causal relationships between the neurodegenerative diseases studied and iRBD. Our findings provide robust genetic evidence supporting a causal relationship between iRBD and the risk of multiple neurodegenerative diseases, highlighting the potential for shared pathophysiological mechanisms.

Humans↗
PubMed2026

Overexpression of a subset of long intergenic noncoding RNAs in uterine serous carcinoma predicts poor prognosis.

The evaluation and prediction of uterine serous carcinoma (USC), a type of endometrial cancer that is more severe than endometrioid adenocarcinoma, remain challenging. Long noncoding RNAs (lncRNAs) are frequently dysregulated in human cancers. This study assessed the expression patterns and prognostic values of long intergenic noncoding RNAs (lincRNAs) in USC. RNA sequencing, copy number variation (CNV), and clinical data from The Cancer Genome Atlas were used to investigate various lncRNAs in endometrial cancer. LincRNAs, a major subclass of lncRNAs, exhibit specific expression patterns modulated by CNVs and act as predictors of poor prognosis, survival, and recurrence in USC. Functional analyses were conducted to investigate the roles of lncRNAs in USC. Finally, the expression of these lincRNAs was verified in 32 pairs of USCs collected from the hospital over 3 years. A series of lincRNAs were found to be specifically expressed in USC compared with other lncRNAs and regulated by CNV. Moreover, these specific upregulated lincRNAs, particularly ENSG00000281406, ENSG00000226791, ENSG00000269903, and ENSG00000204277, demonstrated poor prognoses for survival and recurrence in USC. Functionally, our analysis showed that ENSG00000281406 positively correlated with the Wnt signaling pathway, whereas ENSG00000226791, ENSG00000269903, and ENSG00000204277 negatively correlated with the T-cell receptor signaling pathway. Importantly, we confirmed that ENSG00000204277 negatively correlated with CD8+ T-cell immune infiltration in USC. Our results highlight that these lincRNAs can serve as new biomarkers for the prognostic prediction of USC. In particular, ENSG00000204277 may be used as a therapeutic target for USC.

Humans↗
PubMed2026

Cell-type-specific genetic associations in Lewy body dementia identified using single-cell eQTL-based Mendelian randomization.

BACKGROUND: Lewy body dementia (LBD) is a complex neurodegenerative disorder marked by α-synuclein aggregation and dual impairment of cognitive and motor function.While genome-wide association studies have identified risk loci, the cellular mechanisms linking genetic variation to disease susceptibility remain largely unexplored. METHODS: We performed single-cell transcriptome-wide Mendelian randomization using brain cell-type-specific eQTLs across eight major cell types. Genetic associations were evaluated using inverse-variance weighted models, followed by Bayesian colocalization analysis. Replication was performed in independent stratified LBD cohorts based on APOE ε4 carrier status. Phenome-wide association analysis was included as a supplementary, descriptive assessment of cross-trait associations. RESULTS: Expression of ANKRD65 in excitatory neurons was significantly associated with reduced LBD risk (odds ratio = 0.65, 95 % CI: 0.52-0.81, p = 0.00013). This association passed a false discovery rate of 0.1 and showed strong evidence of colocalization (posterior probability = 0.93). Effect direction was consistent across APOE ε4+ and ε4- LBD subgroups in independent cohorts. No genome-wide significant associations were observed with non-neurological traits in the phenome-wide analysis. CONCLUSIONS: Our findings identify a genetically supported, cell-type-resolved association between ANKRD65 expression in excitatory neurons and LBD risk. This study demonstrates the value of integrating cell-resolved transcriptomic regulation with genetic inference to pinpoint functionally relevant targets in neurodegenerative diseases.

Humans↗
PubMed2006

Copper cofactor delivery in plant cells.

Copper (Cu) is a micronutrient that has roles in photosynthesis, respiration, antioxidant activity, cell wall metabolism and hormone perception. Excess Cu is toxic and therefore its delivery has to be tightly regulated. Recent progress in the study of Cu homeostasis has revealed not only components of the Cu delivery machinery but also regulatory systems that control Cu-protein expression and coordinate the activity of Cu-delivery systems. The response of photosynthetic organisms to Cu deficiency indicates the existence of cross-talk between metal cofactor delivery pathways. Next to its well-established roles in plant metabolism, a novel function for Cu, first discovered in plants, is in the biogenesis of molybdenum cofactor. Defects in Cu delivery factors also suggest important roles for Cu in cell expansion.

Coenzymes↗
PubMed2006

Relationship between human sperm-hyaluronan binding assay and fertilization rate in conventional in vitro fertilization.

BACKGROUND: Sperm-hyaluronan-binding assay (HBA) is one of the commercial kits being marketed for routine testing of sperm maturity and fertility. However, there is no report of whether the HBA can provide additional information over standard semen analysis for sperm-fertilizing ability. The objective of this study was to investigate the relationship between HBA and fertilization rate in conventional IVF. METHODS: A total of 175 IVF patients with > or = 3 mature oocytes inseminated were included in the study. Both the standard semen analysis and the HBA were performed on the same ejaculated sperm samples used for IVF treatments. Relationships between the semen analysis and the HBA results and fertilization rate were analysed by both the Spearman test and the multivariate logistic regression analysis. RESULTS: Both total and progressive sperm motility and normal morphology were highly correlated with HBA scores. While both normal sperm morphology and HBA scores were statistically significantly related to fertilization rates, the HBA was less significant than normal sperm morphology. The HBA does not provide additional information for identifying patients with a poor fertilization rate. CONCLUSION: HBA is highly significantly correlated with sperm motility and morphology but is less significant than sperm morphology in relation to the fertilization rate in IVF. Thus, the clinical predictive value of HBA for sperm-fertilizing ability in vitro is limited.

Female↗
PubMed2006

Renal ischemia-reperfusion injury and adenosine 2A receptor-mediated tissue protection: the role of CD4+ T cells and IFN-gamma.

A(2A) adenosine receptor (A(2A)R)-expressing bone marrow (BM)-derived cells contribute to the renal protective effect of A(2A) agonists in renal ischemia-reperfusion injury (IRI). We performed IRI in mice lacking T and B cells to determine whether A(2A)R expressed in CD4+ cells mediate protection from IRI. Rag-1 knockout (KO) mice were protected in comparison to wild-type (WT) mice when subjected to IRI. ATL146e, a selective A(2A) agonist, did not confer additional protection. IFN-gamma is an important early signal in IRI and is thought to contribute to reperfusion injury. Because IFN-gamma is produced by kidney cells and T cells we performed IRI in BM chimeras in which the BM of WT mice was reconstituted with BM from IFN-gamma KO mice (IFN-gamma KO-->WT chimera). We observed marked reduction in IRI in comparison to WT-->WT chimeras providing additional indirect support for the role of T cells. To confirm the role of CD4+ A(2A)R in mediating protection from IRI, Rag-1 KO mice were subjected to ischemia-reperfusion. The protection observed in Rag-1 KO mice was reversed in Rag-1 KO mice that were adoptively transferred WT CD4+ cells (WT CD4+-->Rag-1 KO) or A(2A) KO CD4+ cells (A(2A) KO CD4+-->Rag-1 KO). ATL146e reduced injury in WT CD4+-->Rag-1 KO mice but not in A(2A) KO CD4+-->Rag-1 KO mice. Rag-1 KO mice reconstituted with CD4+ cells derived from IFN-gamma KO mice (IFN-gamma CD4+-->Rag-1 KO) were protected from IRI; ATL146e conferred no additional protection. These studies demonstrate that CD4+ IFN-gamma contributes to IRI and that A(2A) agonists mediate protection from IRI through action on CD4+ cells.

Adenosine A2 Receptor Agonists↗
PubMed2006

CpSufE activates the cysteine desulfurase CpNifS for chloroplastic Fe-S cluster formation.

CpNifS, a cysteine desulfurase required to supply sulfur for ironsulfur cluster biogenesis in Arabidopsis thaliana chloroplasts, belongs to a class of NifS-like enzymes with low endogenous cysteine desulfurase activity. Its bacterial homologue SufS is stimulated by SufE. Here we characterize the Arabidopsis chloroplast protein CpSufE, which has an N-terminal SufE-like domain and a C-terminal BolA-like domain unique to higher plants. CpSufE is targeted to the chloroplast stroma, indicated by green fluorescent protein localization and immunoblot experiments. Like CpNifS, CpSufE is expressed in all major tissues, with higher expression in green parts. Its expression is light-dependent and regulated at the mRNA level. The addition of purified recombinant CpSufE increased the Vmax for the cysteine desulfurase activity of CpNifS over 40-fold and decreased the KM toward cysteine from 0.1 to 0.043 mm. In contrast, CpSufE addition decreased the affinity of CpNifS for selenocysteine, as indicated by an increase in the KM from 2.9 to 4.17 mm, and decreased the Vmax for selenocysteine lyase activity by 30%. CpSufE forms dynamic complexes with CpNifS, indicated by gel filtration, native PAGE, and affinity chromatography experiments. A mutant of CpSufE in which the single cysteine was changed to serine was not active in stimulating CpNifS, although it did compete with WT CpSufE. The iron-sulfur cluster reconstitution activity of the CpNifS-CpSufE complex toward apoferredoxin was 20-fold higher than that of CpNifS alone. We conclude that CpNifS and CpSufE together form a cysteine desulfurase required for iron-sulfur cluster formation in chloroplasts.

Amino Acid Sequence↗
PubMed2006

The N-terminal domain of tumor suppressor p53 is involved in the molecular interaction with the anti-apoptotic protein Bcl-Xl.

Emerging evidences suggest that transcription-independent mechanism of p53 appears to make an important contribution to the overall p53-dependent apoptosis. Recently, it has been postulated that the DNA-binding domain of p53 can interact with Bcl-Xl, and subsequently the proposed molecular interaction has been shown by NMR studies. Interestingly, Chipuk et al. [Cancer Cell 4 (2003) 371] reported that the N-terminal domain of p53 (p53NTD) alone is necessary and sufficient to induce transcription-independent apoptosis. To further define and understand the nature of the molecular recognition between p53 and Bcl-Xl, our current study focuses on p53NTD. We first demonstrated the molecular interaction between p53NTD and Bcl-Xl by co-expressing and purifying the complex. Second, to define the binding interface of the molecular interaction, which is not previously characterized, in the current we employed a NMR-based binding study, showing that the binding site on Bcl-Xl is located in the region including alpha4, the N- and C-termini of alpha3, the N-terminus of alpha5, and the central part of alpha2. To further probe this observation, we then performed fluorescence resonance energy transfer (FRET) assay in cells. The FRET efficiency detected between the donor and acceptor molecules appears to suggest the presence of molecular interaction of p53NTD with Bcl-Xl in cells. Taken together, our data suggest that p53NTD interacts with Bcl-Xl but the characteristic of the molecular interaction appears to be different from that of the DNA-binding domain of p53.

Cell Line, Tumor↗
PubMed2006

Selective sphingosine 1-phosphate 1 receptor activation reduces ischemia-reperfusion injury in mouse kidney.

The mechanisms involved in renal ischemia-reperfusion injury (IRI) are complex and appear to involve the early participation of bone marrow-derived cells. T lymphocytes participate in the pathogenesis of IRI. Sphingosine 1-phosphate (S1P) induces peripheral T cell depletion. Therefore, we hypothesized that S1P1 receptor activation protects kidney from IRI. FTY-720, a non-receptor-selective sphingosine analog, was given intraperitoneally to C57BL/6 mice, and animals were subjected to ischemia for 32 min followed by reperfusion for 24 h. Plasma creatinine, blood count, myeloperoxidase (MPO) activity, and renal histology were determined. IRI led to a marked increase in plasma creatinine, MPO activity, leukocyte infiltration, and vascular permeability. FTY-720 significantly decreased plasma creatinine in a dose-response manner with a maximal reduction of approximately 73 and approximately 69% with doses of 240 and 48 microg/kg, respectively. MPO, leukocyte infiltration, vascular permeability, and peripheral blood lymphocyte counts were markedly decreased with FTY-720 treatment. The protective effect of FTY-720 was reversed with VPC-44116, a selective S1P1 receptor antagonist. Furthermore, SEW-2871, a selective S1P1 agonist, significantly decreased plasma creatinine in a dose-response manner with a maximal reduction of approximately 70% with a dose of 10 mg/kg. Analysis of kidneys by light microscopy revealed minimal histological signs of ischemic injury with FTY-720 or SEW-2871 treatment compared with the vehicle group. Using RT-PCR, we found a time-dependent increase in the S1P1 mRNA expression following IRI that begins after 2 h with the maximum expression at approximately 4 h. We conclude that the protective effect of FTY-720 is due primarily to activation of S1P1 receptors. The mechanism of protection is not known but may be related to peripheral lymphocyte depletion or direct effects on kidney cells expressing S1P1 receptor.

Animals↗
PubMed2006

Biogenesis of iron-sulfur cluster proteins in plastids.

Iron-sulfur (Fe-S) clusters are co-factors of proteins that perform a number of biological roles, including electron transfer, redox and non-redox catalysis, regulation of gene expression, and as sensors within all living organisms, prokaryotes and eukaryotes. These clusters are thought to be among the oldest structures found in biological cells. In chloroplasts, Fe-S clusters play a key role in photosynthetic electron transport as well as nitrogen and sulfur assimilation. The capacity of the Fe atom in Fe-S clusters to take up an electron reversibly provides the required electron carrier capacity in these pathways. Iron and sulfur limitation both affect plant primary production and growth. It has long been known that iron deficiency leads to defects in photosynthesis and bleaching in young leaves, phenomena that are closely linked to a defect in chloroplastic photosystem-I (PSI) accumulation, a major Fe-S containing protein complex in plants. Although the functional importance of Fe-S cluster proteins is evident and isolated chloroplasts have been shown to be able to synthesize their own Fe-S clusters, much is yet to be learned about the biosynthesis of Fe-S proteins in plastids. The recent discovery of a NifS-like protein in plastids has hinted to the existence of an assembly machinery related to bacterial Fe-S assembly systems. This chapter aims to summarize what we presently know about the assembly of Fe-S clusters in plants with an emphasis on green plastids.

Bacterial Proteins↗
PubMed2006

A fuzzy discrete event system approach to determining optimal HIV/AIDS treatment regimens.

Treatment decision-making is complex and involves many factors. A systematic decision-making and optimization technology capable of handling variations and uncertainties of patient characteristics and physician's subjectivity is currently unavailable. We recently developed a novel general-purpose fuzzy discrete event systems theory for optimal decision-making. We now apply it to develop an innovative system for medical treatment, specifically for the first round of highly active antiretroviral therapy of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients involving three historically widely used regimens. The objective is to develop such a system whose regimen choice for any given patient will exactly match expert AIDS physician's selection to produce the (anticipated) optimal treatment outcome. Our regimen selection system consists of a treatment objectives classifier, fuzzy finite state machine models for treatment regimens, and a genetic-algorithm-based optimizer. The optimizer enables the system to either emulate an individual doctor's decision-making or generate a regimen that simultaneously satisfies diverse treatment preferences of multiple physicians to the maximum extent. We used the optimizer to automatically learn the values of 26 parameters of the models. The learning was based on the consensus of AIDS specialists A and B on this project, whose exact agreement was only 35%. The performance of the resulting models was first assessed. We then carried out a retrospective study of the entire system using all the qualifying patients treated in our institution's AIDS Clinical Center in 2001. A total of 35 patients were treated by 13 specialists using the regimens (four and eight patients were treated by specialists A and B, respectively). We compared the actually prescribed regimens with those selected by the system using the same available information. The overall exact agreement was 82.9% (29 out of 35), with the exact agreement with specialists A and B both at 100%. The exact agreement for the remaining 11 physicians not involved in the system training was 73.9% (17 out of 23), an impressive result given the fact that expert opinion can be quite divergent for treatment decisions of such complexity. Our specialists also carefully examined the six mismatched cases and deemed that the system actually chose a more appropriate regimen for four of them. In the other two cases, either would be reasonable choices. Our approach has the capabilities of generalizing, learning, and representing knowledge even in the face of weak consensus, and being readily upgradeable to new medical knowledge. These are practically important features to medical applications in general, and HIV/AIDS treatment in particular, as national HIV/AIDS treatment guidelines are modified several times per year.

Anti-HIV Agents↗
PubMed2006

CpNifS-dependent iron-sulfur cluster biogenesis in chloroplasts.

Iron-sulfur (Fe-S) clusters are important prosthetic groups in all organisms. The biosynthesis of Fe-S clusters has been studied extensively in bacteria and yeast. By contrast, much remains to be discovered about Fe-S cluster biogenesis in higher plants. Plant plastids are known to make their own Fe-S clusters. Plastid Fe-S proteins are involved in essential metabolic pathways, such as photosynthesis, nitrogen and sulfur assimilation, protein import, and chlorophyll transformation. This review aims to summarize the roles of Fe-S proteins in essential metabolic pathways and to give an overview of the latest findings on plastidic Fe-S assembly. The plastidic Fe-S biosynthetic machinery contains many homologues of bacterial mobilization of sulfur (SUF) proteins, but there are additional components and properties that may be plant-specific. These additional features could make the plastidic machinery more suitable for assembling Fe-S clusters in the presence of oxygen, and may enable it to be regulated in response to oxidative stress, iron status and light.

Carbon-Sulfur Lyases↗
PubMed2006

Role of 15-hydroxyeicosatetraenoic acid in phosphorylation of ERK1/2 and caldesmon in pulmonary arterial smooth muscle cells.

We have reported that 15-hydroxyeicosatetraenoic acid (15-HETE) induces pulmonary artery (PA) contraction in rats exposed to hypoxia by activating extracellular signal-regulated kinase 1/2 (ERK1/2). In this study, we investigated the characteristics of 15-HETE mediating phosphorylation of ERK1/2 and caldesmon in rat pulmonary arterial smooth muscle cells (PASMCs). Our data showed that 15-HETE upregulated ERK1/2 phosphorylation in a dose-dependent manner, which could be blocked by ERK pathway inhibitors U0126 and PD98059. ERK1/2 phosphorylation was attenuated by inhibiting endogenous 15-HETE formation with lipoxygenase inhibitor, cinnamyl 3,4-dihydroxy-[alpha]-cyanocinnamate (CDC), in both normoxic and hypoxic PASMCs. ERK1/2 phosphorylation in response to 15-HETE was detected in cytosol as well as in nucleus and phosphorylatd ERK1/2 partly translocated into nucleus, which could be blocked by PD98059. In addition, caldesmon was phosphorylated in 15-HETE-stimulated cells; this could be inhibited by PD98059. These data demonstrated that 15-HETE is associated with ERK1/2 activation and caldesmon phosphorylation in PASMCs and that 15-HETE is at least partly involved in mediating activation of hypoxia-initiated ERK pathway, possibly leading to hypoxic pulmonary vasoconstriction.

Animals↗
PubMed2006

[Effect of exercise stress on cigarette smoking induced downregulation of BKca and Kv1.5 expression in pulmonary arterial smooth muscle cells of rats].

OBJECTIVE: To investigate the effect of exercise stress on chronic cigarette smoking induced downregulation of large conductance calcium-activated potassium channel (BKca) and voltage-dependent delayed rectifier potassium channel (Kv1.5) expression in pulmonary arterial smooth muscle cells of rats. METHODS: Rats were divided into three groups: the normal control group, the smoking control group and the smoking + exercise group. The plasma cortisol level, the potassium channel expression and the pathological changes in lung tissue were determined with HE staining, the immunohistochemistry and the in-situ hybridization. RESULTS: (1) In the smoking + exercise group, the plasma cortisol level was determined immediately after exercise [(1528.7 +/- 469.7) ng/L] and was higher than that determined before exercise [(672.4 +/- 235.7) ng/L] (P < 0.01); (2) The HE staining showed that the chronic pulmonary inflammatory response in the smoking control group was severe while it was mild in the smoking + exercise group; (3) The mRNA and protein expression (OD value) of BKca in the smoking control group (mRNA: 0.2206 +/- 0.0415 for big artery and 0.3935 +/- 0.1378 for small artery; protein: 0.2634 +/- 0.1219 for big artery and 0.0995 +/- 0.0851 for small artery) were less than those in the normal control group. The mRNA expression of BKca in the smoking + exercise group (OD value) (0.5022 +/- 0.1134 for big artery and 0.6408 +/- 0.2135 for small artery) was higher than that in the smoking control group; (4) The mRNA and protein expression of Kv1.5 in the smoking control group (OD value) (mRNA: 0.9354 +/- 0.3290 for big artery and 0.5012 +/- 0.1170 for small artery; protein: 1.1112 +/- 0.3310 for big artery and 0.4736 +/- 0.1250 for small artery) were less than those in the normal control group. The protein expression of Kv1.5 in the smoking + exercise group (0.7445 +/- 0.2690) in small artery was higher than that in the smoking control group. CONCLUSION: Proper exercise stress can decrease inhibition effect of the chronic smoking on the expression of potassium channel BKca and Kv1.5, which perhaps partly results from exercise induced increase of cortisol secretion.

Animals↗
PubMed2005

Adenosine A2A receptor activation attenuates inflammation and injury in diabetic nephropathy.

We previously demonstrated the anti-inflammatory effects and renal tissue protection in response to adenosine A(2A)-receptor (A(2A)R) activation in acute renal injury. We sought to extend these studies and determine the efficacy of A(2A)R agonists in a chronic model of renal injury. We hypothesized that A(2A) agonists mediate renal tissue protection in diabetic nephropathy by reducing glomerular inflammation. Diabetes was induced with single intravenous injection of streptozotocin in Sprague-Dawley rats (50 mg/kg). Increases in urinary albumin excretion (UAE) and plasma creatinine at week 6 in the diabetes group (26- and 6-fold over control, respectively) were markedly reduced by continuous subcutaneous administration of ATL146e (10 ng x kg(-1) x min(-1)), a selective A(2A) agonist. The increase in UAE in the diabetes group was associated with a significant reduction in the expression of slit diaphragm-associated molecules compared with control (nephrin; P < 0.05 and podocin; P < 0.005) that was reversed by ATL146e treatment. Diabetes led to an increase in urinary excretion of monocyte chemoattractant protein-1 (705% of control), TNF-alpha (1,586% of control), IFN-gamma (298% of control), kidney fibronectin mRNA (457% of control), and glomerular infiltration of macrophages (764% of control), effects significantly reduced by ATL146e treatment. Mesangial expansion and basement membrane thickness were reduced with ATL146e. To further confirm the selectivity of ATL146e, we used wild-type (WT) or A(2A)knockout (A(2A)-KO) mice. Four weeks after diabetes, UAE increased significantly in both WT and A(2A)-KO diabetic mice (3.0- and 3.3-fold over control). A(2A) agonist treatment blocked the increase in UAE in WT diabetic mice (P < 0.001), whereas it had no effect on the A(2A)-KO diabetic mice. These results demonstrate that chronic A(2A)R activation in diabetic rats 1) ameliorates histological and functional changes in kidneys induced by diabetes and 2) causes reduced inflammation associated with diabetic nephropathy.

Adenosine A2 Receptor Agonists↗
PubMed2005

ERK1/2 signaling pathway is involved in 15-hydroxyeicosatetraenoic acid-induced hypoxic pulmonary vasoconstriction.

Hypoxia-induced 15-hydroxyeicosatetraenoic acid (15-HETE) is an essential mediator to constrict pulmonary arteries (PA). The signaling pathway involved in 15-HETE-induced PA vasoconstriction remains obscure. The aim of the present study was to test the hypothesis that hypoxic PA constriction induced by 15-HETE was possibly regulated by the extracellular signal-regulated kinase-1/2 (ERK1/2) pathway. PA ring tension measurement, Western blot and immunocytochemistry were used in the study to determine the possible role of ERK1/2 in 15-HETE-induced PA vasoconstriction. The organ bath for PA rings tension study was employed. Adult male Wistar rats were raised in hypoxic environment with fractional inspired oxygen (FIO2, 0.12) for 9 d. PA 1~1.5 mm in diameter were dissected and cut into 3 mm long rings for tension study. ERK1/2 up-stream kinase (MEK) inhibitor PD98059, which blocks the activation of ERK1/2, was used. The results showed that pretreatment of PD98059 significantly blunted 15-HETE-induced PA vasoconstrictions in the rings from hypoxic rat. Moreover, in endothelium-denuded rings, PD98059 also significantly attenuated 15-HETE-induced vasoconstriction. Phosphorylation of ERK1/2 in pulmonary arterial smooth muscle cells (PASMCs) of rat was enhanced evidently when stimulated by 15-HETE. Thus, the data suggest that ERK1/2 signaling pathway is involved in 15-HETE-induced hypoxic pulmonary vasoconstriction.

Animals↗
PubMed2005

15-hydroxyeicosatetraenoic acid depressed endothelial nitric oxide synthase activity in pulmonary artery.

15-hydroxyeicosatetraenoic acid (15-HETE) plays an important role in hypoxia-induced pulmonary vasoconstriction. Release of nitric oxide (NO) is apparently decreased and activity of endothelial nitric oxide synthase (eNOS) is impaired in chronic hypoxia. However, little is known whether 15-HETE contributes to eNOS/NO pathway in the constriction induced by 15-HETE. We examined the response of rat pulmonary artery (PA) rings to 15-HETE, the production of NO, total eNOS expression and the phosphorylation of eNOS in bovine pulmonary artery endothelial cells (BPAECs) stimulated by 15-HETE. Rat PA rings were divided into three groups: endothelium intact group, endothelium denuded group, and nitro-L-arginine methyl ester (L-NAME, 0.1 mmol/L, an inhibitor of eNOS) group. Constrictions to 15-HETE were significantly enhanced in endothelium denuded group and L-NAME group (both P< 0.05 vs endothelium intact group, n= 9); BPAECs were incubated in different conditions to test nitrite production by Greiss method. Nitrite production was significantly reduced by 1 mumol/L 15-HETE (P<0.05), and increased by the lipoxygenase inhibitors, 10 mumol/L cinnamyl 3,4- dihydroxy-[alpha] -cyanocinnamate (CDC, P< 0.05) and 0.1 mmol/L nordihydroguiairetic acid (NDGA, P< 0.01 ); Western blot analysis of extracts from BPAECs incubated with 15-HETE in different time was carried out to test total eNOS expression, and the expression was changed unobviously. Immunoprecipitation (IP) and Western blot analysis of cell extracts from BPAECs treated with 2 mumol/L 15-HETE in different length of time were accomplished, using phospo-eNOS-threonine 495 (Thr495, an inhibitory site) antibody for IP, and eNOS or 15-lipoxygenase (15-LO) antibodies for Western blot. 15-HETE depressed eNOS activity by increasing the levels of phospho-eNOS-Thr 495. The data suggest that eNOS/NO pathway is involved in PA constrictions induced by 15-HETE and that 15-HETE depresses eNOS activity by phosphorylation in Thr495 site. The protein interaction between phospho-eNOS (Thr495) and 15-LO is discovered for the first time.

Animals↗