OBJECTIVETo discuss the effect of taurine (Tau) on the proliferation of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs), and study whether the extracellular signal-regulated kinase 1/2 (ERK1/2) signal pathway participated in the Tau-inhibited PASMC proliferation process and the possible molecular mechanism.

METHODThe primary culture was performed for PASMCs in rats. The second to fifth generations were adopted for the experiment. The Tau concentration was 80 mmol x L(-1). The concentration of ERK1/2 blocker (PD98059) was 50 micromol x L(-1). The drug administration time was 24 h. The effect of Tau on the PASMC proliferation was detected by MTT assay, immunofluorescence staining method and western blot under different conditions. The PASMCs were growing were divided into four groups: the normoxia group, the normoxia + Tau group, the hypoxia group and the hypoxia + Tau group. The Western blot was adopted to detect whether the ERK1/2 signal pathway participated in the Tau-inhibited PASMC proliferation process. Subsequently, the PASMCs were divided into five groups: the normoxia group, the hypoxia group, the hypoxia + Tau group, the hypoxia + Tau + PD98059 group and the hypoxia + PD98059 group.

RESULTHypoxia could induce the PASMC proliferation. Under the conditions of normoxia, Tau had no effect on the PASMC proliferation. Under the conditions of normoxia and hypoxia, Tau had no effect on the expression of the tumor necrosis factor-alpha (TNF-alpha) among PASMCs. Tau could reverse the expression up-regulation of hypoxia-induced proliferative cell nuclear antigen (PCNA) (P < 0.01) and Cyclin A (Cyclin A) (P < 0. 05). Under the conditions of normoxia, Tau had no effect on the expression of phosphoryl extracellular signal-regulated kinase 1/2 (p-ERK1/2). Hypoxia could up-regulate the p-ERK1/2 expression (P < 0.01). Tau could reverse the up-regulation of the hypoxia-induced p-ERK1/2 expression(P < 0.01). Both PD98059 and Tau could inhibit the up-regulated expressions of PCNA, Cyclin A and p-ERK1/2. According to the comparison between the single addition of Tau and PD98059 under conditions of hypoxia, the hypoxia + Tau + PD98059 group showed more significant down-regulation in the expressions of PCNA, Cyclin A and p-ERK1/2.

CONCLUSIONTau could inhibit the hypoxia-induced PASMC proliferation, and may regulate it through ERK1/2 pathway.

Animals ; Cell Hypoxia ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; MAP Kinase Signaling System ; drug effects ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Oxygen ; metabolism ; Pulmonary Artery ; cytology ; drug effects ; metabolism ; physiopathology ; Rats ; Rats, Wistar ; Taurine ; pharmacology ; Tumor Necrosis Factor-alpha ; genetics ; metabolism

Objective To determine the effect of iron deficiency on hemoglobin A2(HbA2) expression in patients with β-thalassemia.Methods The participants were recruited from the out-patient clinics of the Pediatrics Department and Obstetrics Department of Affiliated Hospital of Guilin Medical College and from some β-thalassemia major families.Blood samples from the participants were used for blood smear tests and hemoglobin electrophoresis and to analyze serum ferritin (SF),3 alpha-globin gene deletions,and 17 beta-globin point mutations.Results Of the 408 individuals,304 were assigned to group A (normal controls),26 to group B (iron deficiency),56 to group C (β-thalassemia),and 22 to group D (β-thalassemia combined with iron deficiency). The results for the comparison of the mean HbA2 values among pairs of groups were as follows: group A vs group B,q=5.074 7,P<0.05; group A vs group C,q=37.650 8,P<0.05; group A vs group D,q=16.043 0,P<0.05;group C vs group D,q=7.682 9,P<0.05; Group B vs group D,q=15.806 6,P<0.05. There were no significant correlation between SF and HbA2 in all 4 groups.Conclusions Iron deficiency decreased the HbA2 level in both controls and individuals with β-thalassemia. HbA2 levels decreased significantly in individuals with both β-thalassemia and iron deficiency as compared with β-thalassemia group alone. However,they remained significantly higher than both the control and iron-deficient groups. Therefore,the elevation of HbA2 could be used to diagnose β-thalassemia reliably even in the presence of iron deficiency.

We have reported that hypoxia increases the activation of 15-lipoxygenase (15-LO), which converts arachidonic acid (AA) into 15-hydroxyeicosatetraenoic acid (15-HETE) in small pulmonary arteries (PAs). Through inhibition of Kv channels, 15-HETE causes more robust concentration-dependent contraction of PA rings from the hypoxic compared to the normoxic controls. However, the subtypes of Kv channels inhibited by 15-HETE are incompletely understood. The aim of the present study was to identify the contribution of Kv3.4 channel in the process of pulmonary vasoconstriction induced by 15-HETE using the tension studies of PA rings from rat with Kv3.4 channel blocker in tissue bath; to explore the role of vascular endothelium in15-HETE-induced pulmonary vasoconstriction through denuded endothelia of PA rings; and to define the downregulation of 15-HETE on the expression of Kv3.4 channel in cultured pulmonary artery smooth muscle cells (PASMCs) with RT-PCR and Western blot. In the present study, healthy Wistar rats were divided randomly into two groups: Group A with normal oxygen supply and group B with hypoxia. Six days later, the rats were killed. Pulmonary artery rings were prepared for organ bath experiments. Firstly, different concentrations of 15-HETE (10~1 000 nmol/L) were added to the Krebs solution. The isometric tension was recorded using a four-channel force-displacement transducer. Then Kv3.4 channel blocker, 100 nmol/L BDS-I, was added, followed by adding 1 mumol/L 15-HETE, and the isometric tension was recorded. Furthermore, RT-PCR and Western blot were employed to identify the influence of 15-HETE on the expression of Kv3.4 channel in cultured rat PASMCs.The results showed the PA tension was significantly increased both in groups A and B by 15-HETE in a concentration-dependent manner (P<0.05), especially in group B (P<0.05 compared to control); denuded endothelia enhanced 15-HETE concentration-related constrictions in rat PA rings; Kv3.4 channel blocker, BDS-I, significantly decreased the PA ring constriction induced by 15-HETE (P<0.05); the expressions of Kv3.4 mRNA and protein in rat PASMCs were significantly downregulated by 15-HETE (P<0.05). Based on all the information above, we conclude that Kv3.4 channel is involved in vasoconstriction induced by 15-HETE in rat PAs.
Animals ; Cells, Cultured ; Female ; Hydroxyeicosatetraenoic Acids ; pharmacology ; Hypertension, Pulmonary ; physiopathology ; Hypoxia ; physiopathology ; Male ; Muscle, Smooth, Vascular ; cytology ; pathology ; Pulmonary Artery ; cytology ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Shaw Potassium Channels ; antagonists & inhibitors ; genetics ; metabolism ; Vasoconstriction ; drug effects

OBJECTIVETo evaluate the expression of glucose transporter-4 (GLUT4) mRNA in skeletal muscle and subcutaneous adipose tissues and investigate the mechanism of posttraumatic insulin resistance.

METHODSSixteen adult male Wistar rats were randomly divided into 2 group (n equal to 8 in each group), i.e., severe traumatic brain injury (TBI) group due to falls from a height and normal control group. Blood glucose and serum insulin were measured at 0.5 h before trauma and 3 h, 24 h, 72 h, 7 d after trauma, respectively. And insulin sensitivity was calculated by insulin activity index (IAI) formula. Skeletal muscle and subcutaneous adipose tissue samples were collected at the same time when blood was sampled. The changes of expression of GLUT4 mRNA were observed using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSAccompanied by the decrease of insulin sensitivity, the expression of GLUT4 mRNA was significantly decreased in adipose tissues at 24 h and 72 h after trauma (P less than 0.01), however, such phenomena did not appear in skeletal muscle samples.

CONCLUSIONSTo some extent, the development of posttraumatic insulin resistance is related to the abnormality of transcription activity of GLUT4 gene. Adipose tissues show some difference in the transcriptional level of GLUT4 gene after trauma as compared with skeletal muscle tissues.

Adipose Tissue ; metabolism ; Animals ; Brain Injuries ; metabolism ; physiopathology ; Glucose Transporter Type 4 ; metabolism ; Insulin Resistance ; physiology ; Male ; Muscle, Skeletal ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar

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 ; Flavonoids ; pharmacology ; Hydroxyeicosatetraenoic Acids ; antagonists & inhibitors ; pharmacology ; Hypoxia ; physiopathology ; MAP Kinase Signaling System ; physiology ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; Pulmonary Artery ; cytology ; drug effects ; physiopathology ; Rats ; Rats, Wistar ; Vasoconstriction ; drug effects

Objective To clarify the clinical features,therapeutic strategy and prognosis of lipid storage myopathy (LSM).Methods The clinical data and therapeutic effects of 42 LSM patients were summarized retrospectively.All patients were followed up to evaluate their prognosis.Results Data of short-term therapeutic results of all the 42 patients were available.Thirty-three cases were placed in low- doses prednisone and 9 cases in riboflavin.All patients showed marked and quick improvement of symptoms within one month.Among thirty-two patients followed up for more than one year,26 cases had a full recovery and 6 remained to have intolerance to heavy exercise.Thirteen patients had relapses of muscle weakness in various degrees and most of which were induced by exertion,exposure to coldness and upper respiratory tract infection.In 5 patients the symptoms were recurred for more than one time.Among 13 cases with relapses, 7 had family history.Conclusions Our data suggest that LSM is a treatable disease and well responsive to low-doses prednisone.The disease tends to recur,especially in patients with family history.Glutaric aciduria type Ⅱ should be considered in LSM patients who are responsive well to riboflavin,indicating drug therapeutic strategy for LSM should be based on the etiology of the disease.

Objective To investigate the clinical,neuroimaging and myopathological features of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes(MELAS).Methods The clinical manifestations,neuroimaging and myopathological features of 31 patients with MELAS diagnosed in our Neuromuscular Center in the recent 7 years were retrospectively analyzed.A3243G point mutations were analyzed by RFLP method in 10 patients.Results ①Clinical features:There were 18 male patients and 13 female patients.The age of onset ranged from 3 to 43 years,averaging 21.9 years.The averaged duration was 4.9 years.Thirteen patients in this group had family history of maternal inheritance pattern.The main clinical manifestations included short stature(26 patients),recurrent headache and vomiting(24 patients), muscle weakness(22 patients),epileptic seizure(21 patients),cognitive decline(19 patients),visual disturbance(17 patients),sensorineural deafness(16 patients),ataxia(6 patients),psychiatric symptom (8 patients),external ophathalmoplegia(2 patients)and diabetes mellitus(9 patients).The serum CK level was slightly elevated in 6 patients,and the fasting blood lactic acid was increased in 15 of the 18 detected patients.②Neuroimaging features:The stroke-like lesions were mostly confined to cerebral cortex, including temporal lobe(24 patients),occipital lobe(21 patients),parietal lobe(12 patients)and frontal lobe(4 patients).Three patients had deep white matter involvement.Migrating stroke-like lesions were confirmed in 4 patients by repeated cranial CT/MRI examination.In addition,cerebral atrophy(17 patients)and bilateral basilar ganglion calcification(11 patients)were found.③Myopathological features: Scattered ragged red fibers(RRF)in various number were found in all the patients by MGT staining.Other founding included strongly SDH-reactive blood vessel(27 patients),COX enzyme deficiency(19 patients), and mild to moderate lipid storage in RRF(20 patients).④MtDNA analysis showed 9 patients with A3243G point mutation in all the detected 13 patients.Conclusion The clinical and neuroimaging features may offer important clue to the diagnosis of MELAS,but a definite diagnosis of MELAS relies on the myopathology and mtDNA mutation analysis.

Tetramethylpyrazine (TMP), an effective component of traditional Chinese medicine Chuanxiong, is commonly used to resolve embolism. Its possible therapeutic effect against atherosclerosis has received considerable attention recently. Angiotensin II (Ang II) is highly implicated in the proliferation of vascular smooth muscle cells (VSMCs), resulting in atherosclerosis. The mechanisms of TMP in the proliferation of VSMCs induced by Ang II remain to be defined. The present study was aimed to study the effect of TMP on Ang II-induced VSMC proliferation through detection of nuclear factor-kappaB (NF-kappaB) activity and bone morphogenetic protein-2 (BMP-2) expression. Primary cultured rat aortic smooth muscle cells were divided into the control group, Ang II group, Ang II + TMP group and TMP group. Cells in each group were harvested at different time points (15, 30 and 60 min for detection of NF-kappaB activity; 6, 12 and 24 h for measurement of BMP-2 expression). NF-kappaB activation was identified as nuclear staining by immunohistochemistry. BMP-2 expression was observed through Western blot, immunohistochemistry and in situ hybridization. The results showed that: (1) Ang II stimulated the activation of NF-kappaB. Translocation of NF-kappaB p65 subunit from cytoplasm to nucleus appeared as early as 15 min, peaked at 30 min (P<0.01) and declined after 1 h. (2) TMP inhibited Ang II-induced NF-kappaB activation (P<0.01). (3) Ang II increased BMP-2 expression at 6 h but declined it significantly at 12 and 24 h (P<0.01). (4) BMP-2 expression was also kept at high level at 6 h in Ang II + TMP group but maintained at the normal level at 12 and 24 h. (5) There was no significant difference in NF-kappaB activation and BMP-2 expression between the control group and TMP group. These results indicate that TMP inhibits Ang II-induced VSMC proliferation through repression of NF-kappaB activation and BMP-2 reduction, and BMP-2 expression is independent of the NF-kappaB pathway. In conclusion, TMP has therapeutic potential for the treatment of atherosclerosis.
Angiotensin II ; antagonists & inhibitors ; Animals ; Atherosclerosis ; drug therapy ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; analysis ; antagonists & inhibitors ; Immunohistochemistry ; Muscle, Smooth, Vascular ; cytology ; drug effects ; metabolism ; Myocytes, Smooth Muscle ; metabolism ; NF-kappa B ; analysis ; antagonists & inhibitors ; Pyrazines ; pharmacology ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta ; analysis ; antagonists & inhibitors

AIMTo observe the effect of subtypes of Kv channels in rat pulmonary artery smooth muscle cells (PASMCs) on the process of pulmonary vasoconstriction induced by 15-HETE.

METHODSIn the present study, ring of rabbit PA with specific Kv channel blockers were employed to functionally identify certain channel subtypes that took part in the process of 15-HETE induced pulmonary vasoconstriction; RT-PCR and Western blotting analysis were also used to measure the expression of subtypes of Kv in PASMCs exposed to 15-HETE,chronic hypoxia.

RESULTSBlocking of Kv1. 1, Kv1. 2, Kv1. 3 and Kv1. 6 channels did not affect 15-HETE induced vasoconstriction in normoxic rats; 15-HETE did not affect expression of Kv1. 1 and Kv1. 2 channels; 15-HETE significantly downregulated the expression of mRNA and protein of Kv1. 5 and Kv2. 1 in rat PASMCs.

CONCLUSIONThe results suggested that hypoxia may block Kv1. 5 and Kv2. 1 channels via 15-HETE mediated mechanism, leading to decrease numbers of functional Kv1. 5 and Kv2. 1 channels in PASMCs, leading to PA vasoconstriction.

Animals ; Cell Hypoxia ; Cells, Cultured ; Hydroxyeicosatetraenoic Acids ; pharmacology ; Hypoxia ; physiopathology ; Kv1.5 Potassium Channel ; biosynthesis ; genetics ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; metabolism ; Potassium Channels, Voltage-Gated ; antagonists & inhibitors ; Pulmonary Artery ; physiopathology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Shab Potassium Channels ; biosynthesis ; genetics ; Vasoconstriction ; drug effects

Objective To observes the change of early effective biomarkers of endothelial injury with lowarsenic exposure in drinking water. MethodsNinety rurad residents, who had lived in Yanhe village, Xuyi county and Jiangsu province for at least 10 years, were recruited by simple random sampling in this study. The level of arsenic in their household shallow well were divided into three groups, which were ＜ 10 (32 people), 10 - 50(28 people) and ＞ 50 μg/L(30 people). Blood samples from individuals were collected. Malondialdehyde(MDA) in human plasma, which is considered as the most important marker for monitoring lipid peroxidation, was determined as conjugate with tetrabutylammonium hydrogen sulphate(TBA). The level of anti-superoxide anion radical(O-·2),C-reactive protein(CRP) and NO in human plasma was measured with colorimetry, turbidimetry and nitric acid reductase, respectively. The number of circulating endothelial progenitor cells(CEPCs) in peripheral blood was analyzed by CD133+/KDR+ antibodies and flow cytometry. Results Ninety cases underwent questionnaires. Between the groups, the difference of the levels of MDA (61.1, 65.5, 67.5 μmol/kg), O-·2 (4774.6, 5143.3, 4736.0 U/kg) ,CRP[(5.92 ± 2.44), (5.11 ± 2.40), (5.55 ± 2.96)mg/L], and NO[(659.8 ± 387.5), (667.4 ± 486.6), (762.1 ±763.2)μmol/kg], was not statistically significant (F =0.00, 0.46, 0.80, 0.47, all P ＞ 0.05). The difference of the number of CEPCs in different groups of arsenic in drinking water was statistically significant(0.96 x 10-5, 0.77 x 10-5,1.59 x 10-5, F=5.08, P＜ 0.05), where ＜ 10, 10 - 50 μg/L groups were significantly lower than ＞ 50 μg/L group (q =4.58, 6.65, all P ＜ 0.05). ConclusionsThe number of CEPCs in peripheral blood changes significantly with lower-arsenic exposure, whereas there are no obvious changes with the markers of oxidized damage and inflammation. This is the first human demonstration showing that lower-arsenic exposure may cause endothelial injury.