Research progress on the effect of mitochondrial and endoplasmic reticulum stress caused by hypoxia during pregnancy on preeclampsia and intrauterine growth restriction / 生理学报

Preeclampsia and intrauterine growth restriction (IUGR) of the fetus are the two most common pregnancy complications worldwide, affecting 5%-10% of pregnant women. Preeclampsia is associated with significantly increased maternal and fetal morbidity and mortality. Hypoxia-induced uteroplacental dysfunction is now recognized as a key pathological factor in preeclampsia and IUGR. Reduced oxygen supply (hypoxia) disrupts mitochondrial and endoplasmic reticulum (ER) function. Hypoxia has been shown to alter mitochondrial reactive oxygen species (ROS) homeostasis and induce ER stress. Hypoxia during pregnancy is associated with excessive production of ROS in the placenta, leading to oxidative stress. Oxidative stress occurs in a number of human diseases, including high blood pressure during pregnancy. Studies have shown that uterine placental tissue/cells in preeclampsia and IUGR show high levels of oxidative stress, which plays an important role in the pathogenesis of both the complications. This review summarizes the role of hypoxia-induced mitochondrial oxidative stress and ER stress in the pathogenesis of preeclampsia/IUGR and discusses the potential therapeutic strategies targeting oxidative stress to treat both the pregnancy complications.

Factors affecting pulmonary arterial pressure in response to high-altitude hypoxic stress / 生理学报

The alteration of pulmonary artery pressure is an important physiological indicator to reflect the organism's adaptation to acclimatization or the pathological injury in response to high-altitude hypoxic environment. The effects of hypoxic stress at different altitudes for different time on pulmonary artery pressure are different. There are many factors involved in the changes of pulmonary artery pressure, such as the contraction of pulmonary arterial smooth muscle, hemodynamic changes, abnormal regulation of vascular activity and abnormal changes of cardiopulmonary function. Understanding of the regulatory factors of pulmonary artery pressure in hypoxic environment is crucial in clarifying the relevant mechanisms of hypoxic adaptation, acclimatization, prevention, diagnosis, treatment and prognosis of acute and chronic high-altitude diseases. In recent years, great progress has been made in the study regarding the factors affecting pulmonary artery pressure in response to high-altitude hypoxic stress. In this review, we discuss the regulatory factors and intervention measures of pulmonary arterial hypertension induced by hypoxia from the aspects of hemodynamics of circulatory system, vasoactive state and changes of cardiopulmonary function.

A Case of Human Hepatic Alveolar Echinococcosis Accompanied by Lung and Brain Metastases

Alveolar echinococcosis (AE) is considered as a fatal zoonosis caused by the larvae of Echinococcus multilocularis. The lungs and brain are the most common metastatic organs. We report a human case of hepatic alveolar echinococcosis accompanied by lung and brain metastasis. In particular, the patient had a history of tuberculosis and the lung lesions were easily misdiagnosed as lung abscesses. The lesions of liver and lung underwent radical resection and confirmed as alveolar echinococcosis by pathological examination. The patient had no surgical complications after operation and was discharged after symptomatic treatment. Unfortunately, the patient later developed multiple intracerebral AE metastases. We required the patient to take albendazole orally for life and follow up.

A Case of Human Hepatic Alveolar Echinococcosis Accompanied by Lung and Brain Metastases

Alveolar echinococcosis (AE) is considered as a fatal zoonosis caused by the larvae of Echinococcus multilocularis. The lungs and brain are the most common metastatic organs. We report a human case of hepatic alveolar echinococcosis accompanied by lung and brain metastasis. In particular, the patient had a history of tuberculosis and the lung lesions were easily misdiagnosed as lung abscesses. The lesions of liver and lung underwent radical resection and confirmed as alveolar echinococcosis by pathological examination. The patient had no surgical complications after operation and was discharged after symptomatic treatment. Unfortunately, the patient later developed multiple intracerebral AE metastases. We required the patient to take albendazole orally for life and follow up.

Hypoxia inducing factor related genetic adaptation in high-altitude and pharmacological modulation / 药学学报

Adaptation to hypoxia of the plateau environment has been a focus of scientific research in decades. The geographical distributions of such living environment include the Qinghai-Tibet Plateau, Andean Plateau in South America and Ethiopian Plateau. Over the past century, the unique features of physiological adaptation to high-altitude chronic hypoxia have been documented scientifically. The genetic studies of hypoxic adaptation in the past decade have revealed genetic bases of human high-altitude adaptation, with a close relationship to the hypoxia inducible factor (HIF) pathway and hypoxia response elements (HREs). Interestingly, the genetic pattern of adaptation to hypoxia is not the same among the three plateau populations. Tibetan has developed the best high-altitude adaptation, with modification of the HIF pathway as the key genetic element. Due to the wide range of HIF pathways, HIFs could regulate hundreds of downstream genes and are closely related to various diseases such as cancer, inflammation, ischemia, acute organ damage and infection, etc. The treatment researches of these diseases through HIFs-related regulations have led to the development of stabilizers and inhibitors of HIF pathway. We review here the adaptive responses of the three plateau populations to the hypoxic environment, and the genetic mechanism of HIF and HREs in the different ethnic high-altitude populations. Classes of HIF inhibitors, such as PI3K and/or mammalian target of rapamycin (mTOR) inhibitors, DNA-binding inhibitors, histone deacetylase inhibitors, heat-shock protein 90 inhibitors, cardiac glycosides, transcription inhibitors, topoisomerase inhibitors, and HIF activators including 2-OG mimics, Fe2+ chelators, prolyl hydroxylase (PHD) active-site blockers and CUL2 deneddylators have been presented with the drug examples. In addition, the top 3 chemical-disease and chemical-gene (protein) co-occurrences have been presented from the Pubmed literature search. The review could serve as references for research of hypoxia adaptation and HIF-related diseases.

Roles of SPK in Regulation of Hypoxia Induced Proliferation and Glucose Consume of Leukemia Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To clarify the roles of SPK pathway in the regulation of proliferation, survival and glucose consume of human erythroleukemia TF-1 cells.</p><p><b>METHODS</b>The interfering in SPK expression of TF-1 cells was performed using leutivirus vector-mediated shRNA, the interference efficacy of SPK in TF-1 cells was detected by RT-qPCR and Western blot, the viability of TF-1 cell proliferation was detected by using CCK-8 method, the apoptosis of TF-1 cells was determined by flow cytmetry with Annexin V staining.</p><p><b>RESULTS</b>Hypoxia up-regulated the expression of HIF-1α, HIF-2α, and SPK in TF-1 cells. SPK treatment resulted in reduced proliferation and induced apoptosis in TF-1 cells. Furthermore, knockdown of the SPK significantly reduced utilization and consumption of glucose.</p><p><b>CONCLUSION</b>The SPK is key signalling molecule involved in regulation of hypoxia-induced proliferation and glucose metabolism in TF-1 cells, and plays an important rote in proliferation and energy metabolism of leukemia cells.</p>

Research Advance on Promoting Angiogenesis of Mesenchymal Stem Cells-Review / 中国实验血液学杂志

Mesenchymal stem cells (MSC) possess important biological characteristics of tissue repair and regeneration. MSC exert the properties promoting endogenous angiogenesis and have been widely applied in treatment of ischemia diseases. The therapeutic potency of MSC for ischemia diseases is owing to their secretion of angiogenic growth factors and release of exosomes. MSC promote angiogenesis stronger in hypoxia environment, and their miRNA played an important role in mediating regulation. This review summarizes recent advances in treatment of angiogenesis using MSC and their mechanisms. The angiogenic activities of MSC under hypoxia condition and their regulation by a miRNA network were discussed.

MiR-486 Regulates the Glycometabolism of Hematopoietic Cells by Targeting Sirt1 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanism of miR-486 on glycometabolism of hematopoietic cells.</p><p><b>METHODS</b>qRT-PCR was applied to detect the expression of miR-486 or Sirt1 on TF-1 cells under hypoxia. Lentivirus was used to mediate the overexpression or inhibition of miR-486 on TF-1 cells and qRT-PCR was used to detect the expressions of Sirt1, glucose transporter 1(Glut1) and glucose transporter 4(Glut4). Lentivirus-mediated Sirt1-shRNA transduction was used to knockdown Sirt1 expression which was detected by qRT-PCR and Western blot. The expressions of Glut1 and Glut4 were determined by qRT-PCR.</p><p><b>RESULTS</b>Hypoxia promoted the expression of miR-486 and inhibited the expression of Sirt1. MiR-486 overexpression could inhibit the expression of Sirt1 and promote the expressions of Glut1 and Glut4, whereas miR-486 silencing upregulated the sirt1 expression and inhibited the expressions of Glut1 and Glut4. And inhibition of Sirt1 expression increased the expressions of Glut1 and Glut4.</p><p><b>CONCLUSION</b>MiR-486 can regulate the glycometabolism of hematopoietic cells by targeting Sirt1.</p>

Contraction responses of isolated aortic rings of pika (Ochotona curzoniae) and Sprague-Dawley rat to hypoxia / 生理学报

The aim of the present study was to observe the effects of hypoxia on tensions of aortic rings of pika (Ochotona curzoniae) and Sprague-Dawley (SD) rat. The aortic rings were prepared, and in vitro vascular ring perfusion was used to assay the effects of hypoxia or different drugs on contraction responses of the rings with or without endothelium. The results showed that, there was no difference of the contractions to KCl (80 mmol/L) between the aortic rings of the pikas and SD rats. After pre-contraction with NE (1 μmol/L), the aortic rings with endothelium of the SD rats showed obvious relaxation to ACh (1 μmol/L), whereas the aortic rings of the pikas, no matter with or without endothelium, showed significant and unusual contraction to ACh. The aortic rings of pikas, no matter with or without endothelium, exhibited greater contraction when treated by 1 h of hypoxia, compared with those in SD rats; The similar result was showed under hypoxia in combination with Ca(2+) removal. These results suggest that the contraction response to hypoxia in pika is more sensitive compared to that in SD rat, which is dependent on the release of calcium from intracellular calcium store.

No relation between ACE-I/D polymorphism and high altitude pulmonary edema in the Han Chinese / 中国应用生理学杂志

<p><b>OBJECTIVES</b>To explore whether the angiotensin I -converting enzyme (ACE) I/D (insertion/ deletion) polymorphism is associated with the susceptibility to high altitude pulmonary edema (HAPE) in the Han Chinese.</p><p><b>METHODS</b>One hundred and forty-seven HAPE-p (HAPE patients) and 193 HAPE-r (HAPE resistants) were enrolled from the Yushu earthquake reconstruction workers in Qinghai province where the altitude is over 3 500 m above sea level. Blood samples were collected from each of the HAPE-p and HAPE-r groups. Information about physiological phenotypes was obtained via fieldwork investigation. The ACE-I/D polymorphism in HAPE-p and HAPE-r was detected by polymerase chain reaction (PCR).</p><p><b>RESULTS</b>The SaO2 was significantly lower while HR was significantly higher in HAPE-p group than those in HAPE-r group. The genotype frequencies of ACE-I/D for II, ID, DD in HAPE-r and HAPE-p groups were 0.430, 0.446, 0.124 and 0.435, 0.469, 0.095, respectively, the allelic frequencies of I and D were 0.650, 0.350 and 0.670, 0.330, respectively. The OR of ID, DD and D alleles relative to II for HAPE was 0.961 (0.610-1.514), 1.322 (0.634-2.758) and 1.080 (0.783-1.489). There was no significant difference of the genotypic and the allelic frequencies in ACE-I/D polymorphism between HAPE-p and HAPE-r groups.</p><p><b>CONCLUSIONS</b>There is no relation between ACE-I/D polymorphism and HAPE in the Han Chinese.</p>

Effect of different altitudes on telomere length of rat peripheral blood leukocyte / 生理学报

The present study was aimed to investigate the effect of different altitudes on telomere length of rat peripheral blood leukocyte and possible mechanism. Sixty male rats were randomly divided into three groups, lower altitude control group (10 m), moderate altitude group (2 260 m) and very high altitude group (simulated 5 000 m). The moderate altitude group and very high altitude group rats were transported to Xining and hypobaric chamber in Qinghai University, respectively. The peripheral blood specimens were extracted 30 d after the transportation. By means of real-time PCR, automatic blood cell analyzer, ELISA, TBA and WST-1 methods, the telomere lengths of blood leukocyte, the hemoglobin (Hb) contents, the plasma levels of telomerase reverse transcriptase (TERT) and hypoxia-inducible factor 1α (HIF-1α), the plasma content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured, respectively. The results showed that the telomere lengths of peripheral blood leukocyte in moderate altitude group were longer than those in control group and very high altitude group. The changes of TERT were compatible with the telomere length of peripheral blood leukocyte under different altitudes. The levels of HIF-1α in moderate altitude group and very high altitude group were higher than that of control group. The very high altitude group showed decreased SOD activities and increased level of MDA, compared with the other two groups. These results suggest that the telomere lengths of rat peripheral blood leukocyte in moderate altitude are elongated, and that the telomere-elongating effect is lost under very high altitude. The changes of HIF-1α, TERT and oxidative stress damage are the main mechanisms of telomere length changes. Moderate altitude living might be beneficial to increasing the life span in mammals.

Energy power in mountains: difference in metabolism pattern results in different adaption traits in Tibetans / 中国应用生理学杂志

Energy metabolism plays an important role in life survival for species living in high altitude hypoxia condition. Air-breathing organisms require oxygen to create energy. Tibetans are the well-adapted highlanders in Qinghai-Tibetan Plateau. It was thought that different metabolic approaches could lead to different adaptation traits to high altitude hypoxia. Recently identified hypoxia inducible factors pathway regulators, endothelial PAS domain protein1 (EPAS1)/HIF-2a and PPARA, were involved in decreasing hemoglobin concentrations in Tibetans. Because EPAS1 and PPARA also modulated the energy metabolism during hypoxia, we hypothesized that positive selected EPAS1 and PPARA genes were also involved in unique energy metabolisms in Tibetans. In this brief review, we take a look into genetic determinations to energy metabolisms for hypoxia adaptations traits in Tibetans and mal-adaptive conditions such as high altitude diseases.

Neurological adaptations to hypoxia in Tibetan antelope (Pantholops hodgsonii) with a view of molecular biology of respiratory globin-neuroglobin / 中国应用生理学杂志

Neuroglobin (Ngb) is a respiratory protein that is preferentially expressed in brain of mouse and man. In this article, Tibetan antelope, living at altitude of 3 000-5 000 m for millions of years, was selected as the model of hypoxia-tolerant adaptation species. Using reverse transcription polymerase chain reaction (RT-PCR) and Western blot techniques, expression of Ngb gene was amplified and analyzed in antelope brain tissue. Our results showed that Ngb homology protein in Tibetan antelope was identified with more sequence similarity with cattle (96%), sheep (95%), and human (95%). We detected that there were some mutations occurred in the Open Reading Frame of Ngb in Tibetan antelope compared with sheep. Phylogenetic analysis of Ngb chain showed that it was closer to cattle than the others. This study suggests possible roles of central nervous system enriched Ngb in adaptation of Tibetan antelope to extremely high altitude.

Study on the content of myoglobin and the activity of lactate dehydrogenase and malate dehydrogenase in skeletal muscle of tibetan antelope / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the adaptive mechanism to hypoxia in skeletal muscle of tibetan antelope.</p><p><b>METHODS</b>Tibetan sheep which living at the same altitude (4 300 m) with tibetan antelope and low altitude (1 800 m) sheep as control, the content of myoglobin (Mb) and lactic acid (LA), the activity of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in skeletal muscles among three animals were analyzed by spectrophotometer.</p><p><b>RESULTS</b>The content of myoglobin in skeletal muscle of tibetan antelope significantly higher than that of tibetan sheep and low altitude sheep (P < 0.05). And the content of LA in skeletal muscle of tibetan antelope significantly lower than that of tibetan sheep and low altitude sheep (P < 0.05), activity of LDH and MDH in skeletal muscle was significantly lower and higher respectively than that of tibetan sheep and low altitude sheep (P < 0.05). There was no significant difference between tibetan sheep and low altitude sheep.</p><p><b>CONCLUSION</b>Tibetan antelope may improve their ability to get oxygen under hypoxia by increasing the content of myoglobin in skeletal muscle, and the proportion of aerobic metabolism is high in skeletal muscle, it may be relate that with high myoglobin content in skeletal muscle, we suppose that high myoglobin content in skeletal muscle of tibetan antelope might be one of the molecular basis to adapt hypoxia.</p>

Comparisons of endocrine hormones levels between Tibetan antelope and Tibetan sheep / 生理学报

The Tibetan antelope, a prototype mammal, has developed a unique adaptation to extreme high altitude-associated hypoxia. To investigate the role of the endocrine system in adaptation to high altitude in the Tibetan antelope, comparisons of endocrine hormones levels between Tibetan antelope (n = 9) and Tibetan sheep (n = 10) were performed. Both two kinds of animals were captured at an altitude of 4 300 m and then transported to experimental base at 2 800 m altitude. The blood samples were drawn from right external jugular vein in the next morning, and the 20 hormones in hypothalamus-adenohypophysis-peripheral hormonal axis were measured with radioimmunoassay or enzyme-linked immunosorbent assay. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean pulmonary arterial pressure (mPAP) were recorded using catheterization. Moreover, hemoglobin (Hb) content was measured by blood analyser. The results showed that, the levels of FT(3), FT(4) and Ang II in Tibetan antelope were significantly lower than those in Tibetan sheep, whereas TRH, CRH, GHRH, F, E(2), Ald, ACTH and CGRP levels were significantly greater in Tibetan antelope than those in the Tibetan sheep. Compared with Tibetan sheep, Tibetan antelope showed lower HR, mPAP, SBP, DBP and Hb content. In Tibetan antelope and Tibetan sheep, both Hb and Ang II were correlated positively with respective mPAP. In Tibetan antelope, FT(3) level was correlated positively with GH and negatively with ACTH. These results suggest that the endocrine system of Tibetan antelope is characterized by low energy expenditure and high stress, which may be one of the mechanisms underlying the Tibetan antelope adaptation to chronic hypoxia.

Genetic cloning and expression of hypoxia inducible factor 1 alpha in high altitude hypoxic adaptation species Tibetan antelope (Pantholops hodgsonii) / 生理学报

In order to investigate the role of the hypoxia inducible factor 1 alpha (HIF-1α) in the adaptation mechanism to high altitude hypoxia, the cloning of the HIF-1α gene cDNA of Tibetan antelope (Pantholops hodgsonii), using RT-PCR and RACE, was applied, and the comparative analysis of the tissue-specific expressions of HIF-1α among Tibetan antelope, Tibetan sheep and plain sheep was performed using real-time PCR and Western blot. The sequence analysis indicated that the cDNA sequences acquired by cloning from the HIF-1α gene of Tibetan antelope comprised a 2 471-bp open reading frame (ORF) and a 1 911-bp 3'UTR. The similarity between its coding sequence, predicted amino acid sequence and HIF-1α of other mammals exceeded 87%, in which the similarity with cow was up to more than 98%, which showed that this sequence was the cDNA of HIF-1α of Tibetan antelope. The results of real-time PCR and Western blot showed that expressions of HIF-1α mRNA and protein appeared in Tibetan antelope's lung, cardiac muscle and skeletal muscle, with the highest expression in lung. HIF-1α mRNA and protein had obvious differential expression in these tissues. Further research showed that Tibetan antelope and Tibetan sheep possessed higher expressions of HIF-1α protein in the three tissues above-mentioned compared with plain sheep, and the expressions of HIF-1α mRNA and protein in Tibetan antelope's lung, cardiac muscle and skeletal muscle were higher than those of Tibetan sheep. It illustrates that the hypoxic HIF-1α-specific expression is one of the molecular bases of high altitude hypoxia adaptation in Tibetan antelope.

The body weight loss during acute exposure to high-altitude hypoxia in sea level residents / 生理学报

Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at sea level (sea level group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were measured in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline measurements). Measurements were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was measured in 20 subjects from the sea level group (sea level subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the sea level group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the sea level group (r=0.677, P<0.01), while the correlation was absent in the moderate altitude group (r=0.296, P>0.05). In the sea level subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the sea level group (4.69±2.48) than that in the moderate altitude group (2.97±1.38), and was significantly correlated with baseline body weight. These results indicate that (1) the person with higher body weight during stay at high altitude loses more weight, and this is more pronounced in sea level natives when compared with that in moderate altitude natives; (2) heavier individuals are more likely to develop AMS than leaner individuals during exposure to high-altitude hypoxia.

Changes of serum angiogenesis in patients with chronic mountain sickness / 中国应用生理学杂志

<p><b>AIM</b>The clinical manifestation of chronic mountain sickness (CMS) is polycythemia, pulmonary hypertension and mionectic blood. However, the pathogenesis of it is not identified now. So it is necessary to investigate the effects of the angiogenic growth factors on the pathophysiologic development of CMS.</p><p><b>METHODS</b>The serum levels of basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) in 13 healthy Tibetan natives (Native), 17 healthy people in Xining (control group) and 35 CMS patients were determined by quantitative sandwich enzyme immunoassay. Meanwhile, the levels of Hb, Hct and SaO2 were determined.</p><p><b>RESULTS</b>The serum levels of bFGF (107.26 +/- 7.86) ng/L, PDGF (630.18 +/- 9.89) ng/L and VEGF (543.74 +/- 6.76) ng/L in CMS were significantly higher than those in Natives (37.01 +/- 9.16; 292.16 +/- 6.88; 125.51 +/- 7.26) ng/L, and in control group (40.58 +/- 5.34; 287.68 +/- 8.33; 76.26 +/- 4.60) ng/L, respectively (P < 0.01). There was no difference between the natives and the control group in bFGF and PDGF (P > 0.05), while there was predominant difference between the Natives and the control group in VEGF (P < 0.01). There was a predominant positive correlation between the serum levels of bFGF, PDGF or VEGF and hemoglobin concentrations in CMS respectively (P < 0.01). And there were positive relations between angiogenic growth factors each other.</p><p><b>CONCLUSION</b>The serum levels of bFGF, PDGF and VEGF in patients with CMS significantly increase, these angiogenic growth factors may play important role on the pathophysiologic development of CMS; the VEGF level likely contributes to the adaptation to plateau hypoxia in healthy Tibetan natives; the elevated bFGF, PDGF and VEGF levels are likely associated with excessive erythropoiesis in CMS.</p>

The dynamic changing profiles of peripheral white blood cell telomere length in populations of different ages living at different altitude areas / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the length of telomere DNA and age at different altitude areas.</p><p><b>METHODS</b>All 172 peripheral blood samples were randomly selected from healthy individuals of different ages from 25 to 65 years old. High altitude group (47 males, 48 females) living at an altitude of 4380 m (HA group), sea level group (39 males, 38 females) living at an altitude of 43 m (SL group). The terminal restriction fragment (TRF) length of telomere DNA was measured by Southern blotting analysis. The plasma levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were assayed.</p><p><b>RESULTS</b>Average TRF lengths of males and females in HA groups were 10.45 +/- 1.35 and 10.50 +/- 1.45. Average TRF lengths of males and females in SL groups were 11.29 +/- 1.10 and 11.31 +/- 1.13. A negative correlation was shown between the average TRF length and age of males in two groups (P < 0.01). This was also the case for females. ANOVA test was used to analyze the difference between TRF length and gender at different ages (P < 0.001). It was shown that there was significant difference in TRF length between the male (25 years old and 55 years old) and female (25 years old and 55 years old) in two groups at different ages (P < 0.05). The plasma levels of SOD and MDA were significant different between HA groups and SL groups (25-44 years old groups/45-65 years old groups) (P < 0.05).</p><p><b>CONCLUSION</b>Obviously shortening of telomere was observed by increasing of ages in high altitude groups. There was a negative correlation between the length of telomere DNA and ages. Telomere shortening became more obviously in high altitude group than in sea level group in keeping with the age increases.</p>

Effects of RNAi on hypoxia inducible factor-1alpha activity and proliferation of hypoxic pulmonary artery smooth muscle cells in rat / 生理学报

Pulmonary vascular remodeling is one of the major characteristics of hypoxia-induced pulmonary hypertension, mainly represented by over-proliferation of pulmonary artery smooth muscle cells (PASMCs). Hypoxia inducible factor-1alpha (HIF-1alpha) is a transcription factor which is produced by the cells exposed to hypoxia. HIF-1alpha up-regulates the expression of many hypoxia response genes (HRGs) for the body to adapt to hypoxia and maintain homeostasis. The expression of HIF-1alpha in the PASMCs is remarkably elevated under hypoxic condition and it stimulates the proliferation of PASMCs. In this experiment, we used gene clone technology to design and synthesize two siRNAs based on the sequence of HIF-1alpha mRNA. They were separately subcloned into the plasmid of pGenesil-1 containing U6 promoter. The pGenesil-1 vector of the RNA interference eukaryotic expression vector specific to HIF-1alpha gene was constructed. DNA sequencing of the plasmid verified the successful construction of the HIF-1alpha RNAi. We isolated and cultured the PASMCs of rat. The pGenesil-1 vector was transferred into the PASMCs with METAFECTENE in vitro. The positive cell clones transfected with pGenesil-1 were obtained after being screened with 400 mug/ml G418. These PASMCs were cultured in normoxia and hypoxia. After 48 h, the effects of RNAi on the expression of HIF-1alpha mRNA were detected by RT-PCR. The cellular growth activities were assayed by MTT colorimetry and flow cytometry in vitro. The results showed that for the PASMCs cultured in hypoxia for 48 h, the cell proliferation of blank group and control group were remarkably increased and the HIF-1alpha mRNA expressions were up-regulated, while the cell proliferation of the treatment groups did not increase and the HIF-1alpha mRNA expressions were not up-regulated. In conclusion, we successfully constructed the recombinant plasmid of RNAi and transfected them into the PASMCs in vitro. The RNAi inhibited the expression of HIF-1alpha mRNA in the PASMCs, and subsequently it remarkably suppressed the proliferation of PASMCs in hypoxia. These results indicate that HIF-1alpha plays a pivotal role in PASMC proliferation.