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Abstract: Hypoxia initiated pulmonary vasoconstriction is due to the inhibition of voltage-gated K+ (KV) channels. But the mechanism is unclear. We have evidence that hypoxia activates 15-lipoxygenase (15-LOX) in distal pulmonary arteries and increases the formation of 15-hydroxyeicosatetraenoate (15-HETE). 15-HETE-induced pulmonary artery constriction to be through the inhibition of KV channels (KV1.5, KV2.1 and KV3.4). However, no direct link among hypoxia, 15-HETE and inhibition of KV subtypes is established. Therefore, we investigated whether 15-LOX/15-HETE pathway contributes to the hypoxia-induced down-regulation of KV channels. As KV1.5 channel is O2-sensitive, it was chosen in the initial study. We found that inhibition of 15-LOX suppressed the response of hypoxic pulmonary artery rings to phenylephrine. The expressions of KV1.5 channel mRNA and protein was robustly up-regulated in cultured PASMC and pulmonary artery after blocking of 15-LOX by lipoxygenase inhibitors in hypoxia. The 15-LOX blockade also partly rescued the voltage-gated K+ current (). 15-HETE contributes to the down-regulation of KV1.5 channel, inhibition of and increase of native pulmonary artery tension after hypoxia. Hypoxia inhibits KV1.5 channel through 15-LOX/15-HETE pathway. [Copyright &y& Elsevier]

15-Hydroxyeicosatetraenoic acid (15-HETE) is an important hypoxic product from arachidonic acid (AA) in the wall of pulmonary vessels. Although its effects on pulmonary artery constriction are well known, it remains unclear whether 15-HETE acts on the apoptotic responses in pulmonary artery smooth muscle cells (PASMCs) and whether K+ channels participate in this process. These hypothesises were validated by cell viability assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, mitochondrial potentials assay, caspase activity assay and western blot. We found that 15-HETE enhanced cell survival, suppressed the expression and activity of caspase-3, upregulated bcl-2 and attenuated mitochondrial depolarization, prevented chromatin condensation and partly reversed K+ channel opener-induced apoptosis in PASMCs under serum-deprived conditions. Our data indicated that 15-HETE inhibits the apoptosis in PASMCs through, at least in part, inactivating K+ channels. [ABSTRACT FROM AUTHOR]

Abstract: We have previously reported that subacute hypoxia activates lung 15-lipoxygenase (15-LOX), which catalyzes arachidonic acid to produce 15-HETE, leading to constriction of neonatal rabbit pulmonary arteries. Subacute hypoxia suppresses Kv3.4 channel expression and results in an inhibition of whole-cell K+ currents (I K). Although the Kv channel inhibition is likely to be mediated through 15-HETE, direct evidence is still lacking. To reveal the role of the 15-LOX/15-HETE pathway in the hypoxia-induced down-regulation of Kv3.4 channel expression and inhibition of I K, we performed studies using 15-LOX blockers, whole-cell patch-clamp, semi-quantitative PCR, ELISA and Western blot analysis. We found that Kv3.4 channel expression at the mRNA and protein levels was greatly up-regulated in pulmonary arterial smooth muscle cells after blockade of 15-LOX by CDC or NDGA. The 15-LOX blockade also partially restored I K. In comparison, 15-HETE had a stronger effect than 12-HETE on the expression of Kv3.4 channels. 5-HETE had no noticeable effect on Kv3.4 channel expression. These data indicate that the 15-LOX pathway via its metabolite, 15-HETE, seems to play a role in the down-regulation of Kv3.4 expression and I K inhibition after subacute hypoxia. [Copyright &y& Elsevier]

In the present study, the complete mitochondrial genome of Empoasca sp. was sequenced and assembled. The complete mitogenome of Empoasca sp. was composed of circular DNA molecules, with a total size of 15,152 bp. The base composition of this mitogenome is as follows: A (38.07%), T (40.27%), G (10.51%), and C (11.12%). The mitogenome contains 13 protein-coding genes, 2 ribosomal RNA genes (rRNA), and 22 transfer RNA (tRNA) genes. The taxonomic status of the Empoasca sp. mitogenome exhibits a closest relationship with Empoasca onukii and Empoasca vitis. [ABSTRACT FROM AUTHOR]

Abstract: We have previously reported that 15-hydroxyeicosatetraenoic acid (15-HETE), a metabolite of arachidonic acid by 15-lipoxygenase, causes pulmonary vasoconstriction via increasing the intracellular Ca2+ concentration ([Ca2+]i). However, the multiple sources of Ca2+ that contribute to Ca2+ elevation during and after 15-HETE exposure have not been investigated. In the present study, pulmonary arterial ring technique and confocal laser scanning microscope were used to investigate the origin of Ca2+. 15-HETE (1 μM) elicited an increase in [Ca2+]i in pulmonary artery smooth muscle cells in a time-dependent manner under both normal and hypoxic condition. The increases were composed of an initial rapid rise followed by a slow increase in the present of extracellular Ca2+. The initial rapid phase was attenuated by inositol 1,4,5-triphosphate (IP3) receptor antagonist 2-aminoethoxydiphenyl borate (2-APB) and ryanodine receptor-operated Ca2+ store depletion agent caffeine; the slow increasing phase and the constriction of pulmonary arterial ring were significantly inhibited by voltage-operated Ca2+ channel blocker nifedipine or transient receptor potential canonical (TRPC) channel blocker La3+, and almost completely diminished in Ca2+-free external solution, suggesting that the initial phase depends on intracellular Ca2+ store and the second phase relies on extracellular Ca2+. Interestingly, the effect of caffeine and La3+ but not nifedipine were diminished in the present of 2-APB. Thus, these results suggest that 15-HETE mobilizes Ca2+ signaling through: 1) Ca2+ release immediately from Ca2+ stores via activation of IP3 receptor and, subsequently that of ryanodine receptor, 2) the depletion of Ca2+ through CCE leading to the activation of TRPC, and 3) Ca2+ entry through L-type Ca2+ channels. [Copyright &y& Elsevier]

The aim of the present study was to conduct a meta-analysis for elucidating the effects of antibiotic prophylaxis on infection, rebleeding and mortality in patients who underwent endoscopic therapy for variceal hemorrhage. Articles on antibiotic prophylaxis and on-demand antibiotic administration following endoscopic therapy for acute variceal bleeding were searched on PubMed, Embase and Cochrane Library between January 1959 and February 2024, to elucidate whether the use of prophylactic antibiotics was necessary. The quality of randomized controlled trials (RCTs) was assessed using the Cochrane risk-of-bias assessment tool and RevMan software version 5.4.1 was used for meta-analysis of the data. The current meta-analysis included four RCTs and 322 patients with acute variceal bleeding who underwent endoscopic therapy. All included studies were of high quality according to the Cochrane risk-of-bias assessment tool. According to the results of the meta-analysis, the incidence of infection in the prophylactic antibiotic group was significantly lower than that in the on-demand group [odds ratio (OR), 0.31; 95% confidence interval (CI), 0.13-0.74; P=0.009]. The prophylactic antibiotic group also exhibited a lower incidence of rebleeding compared with that of the on-demand group (OR, 0.37; 95% CI, 0.19-0.72; P=0.003). No significant differences were noted in the incidence of mortality between the two groups (OR, 0.92; 95% CI, 0.45-1.92; P=0.83). In conclusion, the data indicated that antibiotic prophylaxis is recommended to be used in patients who have undergone endoscopic therapy for variceal hemorrhage., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Tao et al.)

Objective: To explore the effectiveness of arthroscopic binding fixation using suture through single bone tunnel for posterior cruciate ligament (PCL) tibial insertion fractures in adults., Methods: Between October 2019 and October 2021, 16 patients with PCL tibial insertion fractures were treated with arthroscopic binding fixation using suture through single bone tunnel. There were 11 males and 5 females with an average age of 41.1 years (range, 26-58 years). The fractures were caused by traffic accident in 12 cases and sports in 4 cases. The time from injury to operation ranged from 2 to 10 days with an average of 6.0 days. The fractures were classified as Meyers-McKeever type Ⅱ in 4 cases and type Ⅲ in 9 cases, and Zaricznyi type Ⅳ in 3 cases. There were 2 cases of grade Ⅰ, 7 cases of grade Ⅱ, and 7 cases of grade Ⅲ in the posterior drawer test. There were 3 cases combined with lateral collateral ligament injury and 2 cases with meniscus injury. The visual analogue scale (VAS) score, Lysholm score, International Knee Documentation Committee (IKDC) score, and knee range of motion were used to evaluate knee joint function. The posterior drawer test and knee stability tester (Kneelax 3) were used to evaluate knee joint stability. The X-ray films were used to evaluate fracture reduction and healing., Results: All incisions healed by first intention after operation. There was no incision infection, popliteal neurovascular injury, or deep venous thrombosis of lower limbs. All patients were followed up 6-12 months, with an average of 10 months. X-ray films at 6 months after operation showed the fractures obtained bone union. There were 11 cases of grade 0, 4 cases of gradeⅠ, and 1 case of grade Ⅱin posterior drawer test, showing significant difference when compared with preoperative results ( Z =23.167, P< 0.001). The VAS score, Lysholm score, IKDC score, knee range of motion, and the results of Kneelax3 examination all significantly improved when compared with preoperative results ( P <0.05)., Conclusion: For adult patients with PCL tibial insertion fractures, the arthroscopic binding fixation using suture through single bone tunnel has the advantages of minimal trauma, good fracture reduction, reliable fixation, and fewer complications. The patient's knee joint function recovers well.

Objective: Inflammation plays a key role in secondary brain damage following intracerebral hemorrhage (ICH). Glycogen synthase kinase-3β (GSK-3β) plays a strong proinflammatory role in many CNS diseases, including stroke. The present study was undertaken to examine the effects of 6-bromoindirubin-3'-oxime (BIO), a specific inhibitor of GSK-3β, on inflammation in ICH rats., Methods: An ICH rat model was induced by autologous whole-blood injection into the striatum. First, 10, 20, 40, 60, 80, or 100 μg/kg BIO was applied to ICH animals to determine an optimal dosage for producing sufficient GSK-3β inhibition in rat ipsilateral hippocampus by Western blotting. Second, 40 μg/kg BIO was applied to ICH rats for 1, 3, 7, or 14 days, respectively, to determine a suitable intervention time course of BIO by Western blotting analysis on GSK-3β. Third, Western blotting and enzyme-linked immunosorbent assay were used for quantification of inflammation-related factors upstream or downstream of GSK-3β in rat ipsilateral hippocampus. Then, immunohistochemical staining was applied to detect activated microglia and apoptotic cells in rat ipsilateral hippocampus. Last, neurobehavioral tests were performed to assess the sensorimotor impairments in the ICH rats., Results: The results show that BIO 1) blocked GSK-3βTyr216 phosphorylation/activation, thus stabilizing β-catenin, increasing upstream brain-derived neurotrophic factor and downstream heat shock protein 70 levels, and decreasing the levels of nuclear factor-κB p65 and cyclooxygenase 2; 2) decreased the levels of the proinflammatory cytokines tumor necrosis factor-α and interleukin (IL)-1β and IL-6 and elevated the level of antiinflammatory cytokine IL-10; 3) inhibited microglia activation and cell apoptosis; and 4) improved the sensorimotor deficits of ICH rats., Conclusions: BIO posttreatment inhibited microglia activation, prevented inflammation and hippocampal cell death, and ameliorated functional and morphological outcomes in a rat ICH model through inactivation of GSK-3β.

Objective: To explore the effectiveness of high strength suture fixation in treatment of patellar transverse fracture., Methods: Between June 2014 and June 2016, 38 patients with the patellar transverse fracture were treated with high strength suture internal fixation. There were 24 males and 14 females with the age of 26 to 64 years (mean, 45 years). There were 6 cases of accident injury and 32 cases of crashing injury. The time interval between injury and surgery was 2-8 days (mean, 5 days). The preoperative visual analogue scale (VAS) score, Lysholm score, and range of motion (ROM) of patients were 84.3±8.4, 44.5±7.2, and (62±12)°, respectively., Results: All patients' incisions healed by first intention after operation. There was no neurovascular injury, deep venous thrombosis of lower limbs, or local foreign matter irritation reaction. The X-ray films showed that the reduction of patella and the location of internal fixator were good at 2 days after operation. All the 38 patients were followed up 12-18 months (mean, 16 months). All fractures healed and the healing time was 2-4 months (mean, 3 months). At last follow-up, according to the Böstman criteria, 36 patients were rated as excellent and 2 as good, with an excellent and good rate of 100%. The VAS score, Lysholm score, and ROM of patients were 10.2±6.6, 93.1±6.4, and (124±14)°, respectively, showing significant differences when compared with preoperative ones ( t =42.759, P =0.000; t =31.099, P =0.000; t =20.727, P =0.000)., Conclusion: Application of high strength suture fixation in the treatment of patellar transverse fracture has advantages of simple to operate, effective fixation, and less complication. It can avoid reoperation of removing the internal fixators. The satisfied ROM and function of the knee joint can be obtained after operation.

Objective: To investigate the short-term effectiveness of joint distraction by Ilizarov combined with arthroscopic debridement in the treatment of knee osteoarthritis (KOA)., Methods: Between January 2014 and January 2015, 15 patients (15 knees) with KOA were treated using arthroscopic debridement assisting with the Ilizarov distraction technology. There were 7 males and 8 females, aged from 45 to 64 years (mean, 55 years). The left knee and the right knee were involved in 6 and 9 cases respectively. The disease duration was 2.0-9.5 years (median, 6 years). They all had received conservative treatment for 6 months and got poor clinical improvement. The preoperative visual analogue scale (VAS) score, the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, the knee injury and osteoarthritis outcome score (KOOS), the range of motion (ROM) for knee, and the radiographic joint space width were 76.2±8.8, 59.3±5.7, 44.3±7.2, (75±21)°, and (2.5±0.4) mm respectively. According to Kellgren-Lawrence grade system, 11 cases were rated as grade III and 4 cases as grade IV., Results: There was no poor incision healing, infection, and deep vein thrombosis. All the 15 patients were followed up 12-18 months (mean, 15.5 months). Patients achieved pain relief. The knee activity was obviously improved. The postoperative VAS score, WOMAC score, KOOS score, and ROM at 12 months were 20.9±7.8, 38.2±5.5, 92.1±6.9, and (118±14)° respectively, showing significant difference when compared with preoperative ones ( t =18.213, P =0.000; t =10.317, P =0.000; t =18.564, P =0.000; t =6.599, P =0.000). Postoperative X-ray film showed that joint space width at 12 months was (3.8±0.3) mm, showing significant difference when compared with preoperative one ( t =10.070, P =0.000)., Conclusion: Joint distraction by Ilizarov combined with arthroscopic debridement can effectively relieve pain, improve the function and quality of life. It was beneficial to cartilaginous tissue repair and delaying the degenerative process of KOA. The short-term effectiveness is satisfactory.

Objective: To investigate the effect of platelet-rich plasma (PRP) gel in total knee arthroplasty., Methods: From January 2011 to January 2013, 30 patients of total knee arthroplasty were received PRP (PRP group) and 30 patients won't received PRP(normal saline group).Routine drainage and functional exercise were applied to the two groups after operation. Postoperative drainage volume, inflammatory reaction, grade of wound healed, Hospital for Special Surgery (HSS) Score for knee, the Feller Score for patella and range of motion (ROM) for knee were evaluated.Independent samples t-test, grade data used rank sum test were used to compared two groups., Results: Postoperative drainage volume was (152 ± 22) ml in PRP group and (432 ± 35) ml in normal saline group. Postoperative drainage volume were statistically significant difference between two groups (t = 37.098, P < 0.05). At 4 days after operation, no inflammatory reaction was observed in 27 cases of PRP group and in 24 cases of normal saline group, mid inflammatory reaction in 2 cases of PRP group and in 4 cases of normal saline group, moderate inflammatory reaction in 1 cases of PRP group and in 2 cases of normal saline group.Wound healed by first intention in 30 patients of PRP group and in 29 patients of normal saline group (29/30), by second intention after 3 days of dressing change in 1 patient of normal saline group using 75% alcohol wet compressed. The adverse reaction rate was 3.3%. The average follow-up period was 16 months, ranging from 10 to 24 months. Three months postoperative HSS score for knee, scores of patellar, scores of anterior knee pain and ROM for knee were statistically significant difference in PRP group and normal saline group (t = 2.288, 2.097, 2.630, 2.104; all P < 0.05). Inflammatory reaction, grade of wound healed, final follow-up HSS score for knee, scores of patellar, scores of anterior knee pain and ROM for knee had no statistically significant difference between PRP group and normal saline group (P > 0.05)., Conclusions: Using PRP gel in total knee arthroplasty can reduce postoperative drainage volume, accelerate the healing of operation incision with no extra complications.It has good short-term clinical effect.

Objective: To investigate the short-term effectiveness of reconstructive locked plate for treating sternoclavicular joint dislocation., Methods: Between February 2008 and February 2012, 11 patients with sternoclavicular joint dislocation were treated with reconstructive locked plate, and the clinical data were retrospectively analyzed. There were 7 males and 4 females, aged 30-55 years (mean, 44 years). The causes of injury included traffic accident in 8 cases and crashing in 3 cases. The disease duration ranged from 2 hours to 11 days (median, 6 days). All patients had anterior dislocation of sternoclavicular joint. According to the Grade system, there were 2 cases of type II and 9 cases of type III., Results: All patients obtained healing of incisions by first intention after operation. There was no neurovascular injury. The X-ray films showed that satisfactory reduction of joint dislocation and stable internal fixation were obtained at 2 days after operation. All patients were followed up 9-24 months (mean, 16 months). According to the Rockwood criteria, the score was 10-15 (mean, 13.2); the results were excellent in 9 cases and good in 2 cases, with an excellent and good rate of 100% at 9 months after operation. No internal fixation failure or re-dislocation occurred. All internal fixators were removed at 9-15 months after operation. Both the stability and the functions of the shoulder joint were good., Conclusion: The reconstructive locked plate in treating sternoclavicular joint dislocation has the advantages of good stability and satisfactory reduction, and the patients can do functional exercises early and obtain good recovery of the shoulder joint function. The short-term effectiveness is satisfactory.

Objective: To explore the effectivness of arthroscopic synovectomy in the treatment of pigmented villonodular synovitis (PVNS) of the knee., Methods: A retrospective analysis was conducted on 13 patients with PVNS of the knee treated with arthroscopic synovectomy between June 2008 and December 2011, including 8 left knees and 5 right knees. There were 9 males and 4 females, aged 25-45 years (mean, 33 years). Of 13 patients, 5 had a history of trauma, and 8 had no history of trauma. The disease duration ranged from 4 months to 80 months (mean, 44 months). The preoperative Lysholm score was 45.3 +/- 4.2, and International Knee Documentation Committee (IKDC) 2000 score was 46.8 +/- 4.9. All patients underwent arthroscopic synovectomy and postoperative radiotherapy., Results: The pathological examination proved PVNS in all cases. All incisions obtained healing by first intention after operation. There was no neurovascular injury or knee infection. The average follow-up period was 21.8 months (range, 12-30 months). The Lysholm score was 90.2 +/- 7.4, and IKDC2000 score was 87.8 +/- 3.8 at last follow-up, showing significant differences when compared with preoperative scores (t = 22.64, P = 0.00; t = 24.32, P = 0.00). No recurrence was observed during follow-up., Conclusion: Arthroscopic synovectomy can be effective in the treatment of PVNS of the knee, and it has the merits of minimal invasion, rapid function recovery of the knee joint, and satisfactory results. So it is a safe, promising, and minimal invasive procedure in treatment of PVNS.

Plant phototropism is an adaptive response to changes in light direction, quantity, and quality that results in optimization of photosynthetic light harvesting, as well as water and nutrient acquisition. Though several components of the phototropic signal response pathway have been identified in recent years, including the blue light (BL) receptors phototropin1 (phot1) and phot2, much remains unknown. Here, we show that the phot1-interacting protein NONPHOTOTROPIC HYPOCOTYL3 (NPH3) functions as a substrate adapter in a CULLIN3-based E3 ubiquitin ligase, CRL3(NPH3). Under low-intensity BL, CRL3(NPH3) mediates the mono/multiubiquitination of phot1, likely marking it for clathrin-dependent internalization from the plasma membrane. In high-intensity BL, phot1 is both mono/multi- and polyubiquitinated by CRL3(NPH3), with the latter event targeting phot1 for 26S proteasome-mediated degradation. Polyubiquitination and subsequent degradation of phot1 under high-intensity BL likely represent means of receptor desensitization, while mono/multiubiquitination-stimulated internalization of phot1 may be coupled to BL-induced relocalization of hormone (auxin) transporters.

The target of rapamycin (TOR) plays a central role in eukaryotic cell growth control. With prevalent hyperactivation of the mammalian TOR (mTOR) pathway in human cancers, strategies to enhance TOR pathway inhibition are needed. We used a yeast-based screen to identify small-molecule enhancers of rapamycin (SMERs) and discovered an inhibitor (SMER3) of the Skp1-Cullin-F-box (SCF)(Met30) ubiquitin ligase, a member of the SCF E3-ligase family, which regulates diverse cellular processes including transcription, cell-cycle control and immune response. We show here that SMER3 inhibits SCF(Met30) in vivo and in vitro, but not the closely related SCF(Cdc4). Furthermore, we demonstrate that SMER3 diminishes binding of the F-box subunit Met30 to the SCF core complex in vivo and show evidence for SMER3 directly binding to Met30. Our results show that there is no fundamental barrier to obtaining specific inhibitors to modulate function of individual SCF complexes.

15-Hydroxyeicosatetraenoic acid (15-HETE) is an important hypoxic product from arachidonic acid (AA) in the wall of pulmonary vessels. Although its effects on pulmonary artery constriction are well known, it remains unclear whether 15-HETE acts on the apoptotic responses in pulmonary artery smooth muscle cells (PASMCs) and whether K(+) channels participate in this process. These hypothesises were validated by cell viability assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, mitochondrial potentials assay, caspase activity assay and western blot. We found that 15-HETE enhanced cell survival, suppressed the expression and activity of caspase-3, upregulated bcl-2 and attenuated mitochondrial depolarization, prevented chromatin condensation and partly reversed K(+) channel opener-induced apoptosis in PASMCs under serum-deprived conditions. Our data indicated that 15-HETE inhibits the apoptosis in PASMCs through, at least in part, inactivating K(+) channels.

20-Hydroxyeicosatetraenoic acid (20-HETE), a omega-hydroxylation product of arachidonic acid catalyzed by cytochrome P450 4A (CYP4A), plays a role in vascular smooth muscle remodeling. Although its effects on angiogenic responses are known, it remains unclear whether 20-HETE acts on apoptosis of pulmonary arterial smooth muscle cells (PASMC), an important step in PASMC remodeling, and what pathways are involved in the process. Here we show evidence for the missing information. The effect of 20-HETE on PASMC apoptosis and the apoptosis-associated signaling pathways were determined with cell viability assay, Annexin V and propidium idodide binding, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), mitochondrial potentials assay, caspase activity assay and Western blots. We found that exogenous 20-HETE suppressed the serum deprivation-induced loss of bovine PASMCs and prevented Annexin V binding, DNA nick end labeling and chromatin condensation. The effect was worsened by 17-octadecynoic acid (17-ODYA), which inhibited the production of endogenous 20-HETE. Furthermore, 20-HETE induced the expression of bcl-2, maintained the stability of mitochondria membrane, and relieved the activation of caspase-9 and caspase-3. Such effects were reversed in the presence of 17-ODYA. Thus, these findings indicate that 20-HETE protects PASMCs against apoptosis by acting on, at least in part, the intrinsic apoptotic pathway.

The aim of the study was to investigate the influence of sodium ozagrel on CYP2D6 (cytochromeP450 2D6) activity. The studies were performed with rat urine and liver microsomes and chemical inhibitors. The metabolism of dextromethorphan (dextrophan/dextromethorphan, dextrophan is a metabolite of dextromethorphan) and phenacetin (paracetamol/phenacetin, paracetamol is a metabolites of phenacetin) was used as probe to measure CYP2D6 and CYP1A2 (cytochromeP450 1A2) activity, respectively, determined by high-performance liquid chromatography (HPLC). The results showed that the metabolism of dextrophan/dextromethorphan in the sodium ozagrel-treated group (37 mg/kg) was higher than that of the control (P<0.05/6) in both in vivo and in vitro studies (r=0.9811). The rate of dextromethorphan metabolism was inhibited by sodium ozagrel and cimetidine in rat liver microsomes prepared from sodium ozagrel-treated rats and control rats group (sodium ozagrel IC(50)=26.5 microM, cimetidine IC(50)=86.3 microM in sodium ozagrel-treated group; sodium ozagrel IC(50)=13.9 microM, cimetidine IC(50)=24.8 microM in control group). The inhibitory effect of sodium ozagrel on CYP2D6 activity was noncompetitive with dextromethorphan with a K(i) of 324.94 microM. Kinetic parameters of the reactions were established by using Lineweaver-Burk with K(m)=0.67 mM and V(max)=2.13 pm/min/mg protein for the sodium ozagrel-treated group and K(m)=0.29 mM, and V(max)=0.91 pm/min/mg protein for the control group, respectively. The expression of CYP2D6 protein in the treated group was higher than that of the control group, as determined by Western blotting. The activity and expression of CYP1A2 did not show obvious differences in the control group and sodium ozagrel treated group. In conclusion, sodium ozagrel metabolism in rats is mediated primarily through CYP2D6, and sodium ozagrel can induce CYP2D6 activity.

The aim of the present study was to investigate the contribution of extracellular signal regulated kinase-1/2 (ERK1/2) to pulmonary artery contraction in response to 4-aminopyridione (4-AP), an inhibitor of a voltage-gated K(+) channels that regulate pulmonary vascular tone. Pulmonary artery rings 1-1.5 mm in diameter from male adult Wistar rat were isolated and cut into 3-mm in length. ERK1/2 up-stream kinase (MEK) inhibitors 2'-amino-3'-methoxyflavone (PD98059) and 1,4-diamino-2,3-dicyano-1,4-bis (2-aminophenylthio)-butadiene (U0126), which block the activation of ERK1/2, were used to test the role of ERK1/2 in 4-AP induced pulmonary arterial vasoconstriction and the influences of 4-AP on expressions of phosphorylated ERK1/2 (p-ERK1/2) in cultured rat pulmonary arterial smooth muscle cells (PASMCs) and whole tissues. Our results show that 4-AP elicited concentration-dependent increases in tension of rat pulmonary artery rings, effects that were reduced by pretreatment of the rings with ERK inhibitors, PD98059 (20 microM) and U0126 (10 microM). Moreover, 4-AP increased the expressions of p-ERK1/2 in cultured PASMCs s and whole tissues, which were prevented by pretreatment of the cells or tissues with U0126. These results indicate that ERK1/2 signaling pathway contributes to pulmonary vasoconstriction induced by 4-AP.

Repression of photomorphogenesis in Arabidopsis thaliana requires activity of the COP9 signalosome (CSN), CDD, and COP1 complexes, but how these three complexes work in concert to accomplish this important developmental switch has remained unknown. Here, we demonstrate that Arabidopsis CULLIN4 (CUL4) associates with the CDD complex and a common catalytic subunit to form an active E3 ubiquitin ligase both in vivo and in vitro. The partial loss of function of CUL4 resulted in a constitutive photomorphogenic phenotype with respect to morphogenesis and light-regulated gene expression. Furthermore, CUL4 exhibits a synergistic genetic interaction with COP10 and DET1. Therefore, this CUL4-based E3 ligase is essential for the repression of photomorphogenesis. This CUL4-based E3 ligase appears to associate physically with COP1 E3 ligase and positively regulates the COP1-dependent degradation of photomorphogenesis-promoting transcription factors, whereas the CSN controls the biochemical modification of CUL4 essential for E3 activity. Thus, this study suggests a biochemical activity connection between CSN and CDD complexes in their cooperation with COP1 in orchestrating the repression of photomorphogenesis.