Zhongguo ying yong sheng li xue za zhi = Zhongguo yingyong shenglixue zazhi = Chinese journal of applied physiology最新文献

Objective: To investigate the effect of SIX2 gene on the proliferation of bovine skeletal muscle satellite cells. Methods: Bovine skeletal muscle satellite cells were used as experimental materials, and the expression of SIX2 gene in bovine skeletal muscle satellite cells was detected by real-time quantitative PCR at 24 h, 48 h, and 72 h of proliferation. The SIX2 gene overexpression vector was constructed by homologous recombination. The SIX2 gene overexpression plasmid and the control empty plasmid were transfected into bovine skeletal muscle satellite cells, and each group had three complex Wells. The cell viability was detected by MTT assay at 24 h, 48 h and 72 h after transfection. At 48 h after transfection, the cell cycle was detected by flow cytometry, and the expressions of cell proliferation marker genes were detected by real-time quantitative PCR (qRT-PCR) and Western blot. Results: With the proliferation of bovine skeletal muscle satellite cells, the expression of SIX2 mRNA was increased. Compared with the control group, the expressions of SIX2 mRNA and protein in the SIX2 gene overexpression plasmid group were increased by 18 and 2.6 times, respectively (P＜0.01). The cell viability of the SIX2 gene overexpression plasmid group was increased (P＜0.01), the proportion of G1 cells was decreased by 24.6%, and the proportion of S phase and G2 phase cells was increased by 20.3% and 4.31%, respectively (P＜0.01). The mRNA and protein expressions of Pax7 gene were increased by 15.84 and 1.22 times, respectively, and the mRNA and protein expressions of proliferation marker genes PCNA and CCNB1 were increased by 4.82, 2.23,1.55 and 1.46 times, respectively (P＜0.01). Conclusion: Overexpression of SIX2 gene promotes the proliferation of bovine skeletal muscle satellite cells.

Objective: To investigate the effects of repeated sevoflurane exposure on hippocampal cell apoptosis and long-term learning and memory ability in neonatal rats and its regulation on PI3K/AKT pathway. Methods: Ninety SD rats were randomly divided into the control group (25% oxygen), the single exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th day after birth), the 3-times exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th, 7th, and 8th day after birth), the 5-times exposure group (inhalation of 3% sevoflurane and 25% oxygen on the 6th, 7th, 8th, 9th and 10th day after birth), and the 5-times exposure + 740Y-P (PI3K activator) group (intraperitoneal injection of 0.02 mg/kg 740Y-P after inhalation of sevoflurane for 5 times) according to the random number table method. Morris water maze was used to measure the learning and memory ability; HE staining and transmission electron microscopy were used to observe the morphological and structural changes of neurons in the hippocampus; TUNEL was used to detect the apoptosis of hippocampal nerve cells; Western blot was used to detect the expressions of apoptosis-related proteins (Caspase-3, Bax, Bcl-2) and PI3K/AKT pathway related proteins in the hippocampus of rats. Results: Compared with the control group and the single exposure group, the learning and memory abilities of rats in the 3-times exposure group and the 5-times exposure group were severely reduced, the morphology and structure of hippocampal neurons were severely damaged, and the apoptosis rate of hippocampal nerve cells was increased (P＜0.05), the expressions of Capase-3 and Bax proteins were significantly increased (P＜0.05), and the expressions of Bcl-2 protein and PI3K/AKT pathway protein were significantly decreased (P＜0.05). With the increase in the number of exposures to sevoflurane, the learning and memory abilities of rats were significantly reduced, the hippocampal neuron cells were severely damaged, the hippocampal neuronal apoptosis rate was significantly increased (P＜0.05), and the expressions of PI3K/AKT pathway proteins were significantly reduced (P＜0.05). Compared with the 5-times exposure group, the learning and memory abilities and hippocampal neuron structure of rats in the 5-times exposure +740Y-P group were restored to a certain extent, and the hippocampal neuronal apoptosis rate, the levels of capase-3 and Bax protein were significantly reduced (P＜0.05), while the expressions of Bcl-2 protein and PI3K/AKT pathway protein were increased significantly (P＜0.05). Conclusion: Repeated exposure to sevoflurane can significantly reduce the learning and memory abilities of neonatal rats and exacerbate hippocampal neuronal apoptosis, which may be mediated by inhibiting the PI3K/AKT pathway.

Objective: To investigate the alleviating effect of hydrogen (H₂) on homocysteine (Hcy) levels and non alcoholic fatty liver in rats with hyperhomocysteinemia (HHcy). Methods: After one week of adaptive feeding, Wistar rats were randomly divided into three groups: the general diet group (CHOW), the high methionine group (HMD), and the high methionine plus hydrogen rich water group (HMD+HRW), with 8 rats in each group. The CHOW group was fed with AIN-93G feed, while the HMD and HMD+HRW groups were fed with AIN-93G+2% methionine feed to construct an HHcy model. The HMD+HRW group was also gavaged with hydrogen rich water (3 ml/animal, twice a day, with a hydrogen concentration of 0.8 mmol/L), and body weight data were recorded. After 6 weeks of feeding, the plasma and liver samples were processed and collected. The plasma homocysteine (Hcy) and lipid contents of each group were measured, and the histological morphology of the liver was observed. The activities of key enzymes in the Hcy metabolism pathway and mRNA expression were detected in the liver. Results: Compared with the CHOW group rats, the Hcy level in the blood of HMD rats was significantly increased significantly (P＜0.05). Pathological tissue sections showed liver enlargement, injury, and fatty liver in the rats; Compared with the HMD group rats, the HMD+HRW group rats showed a significant decrease in Hcy in the blood, reduced liver damage, and increased Hcy metabolism key enzyme activity and mRNA expression in the liver, with statistical differences (P＜0.05). Conclusion: Hydrogen has a significant improvement effect on liver injury induced by HMD diet in HHcy rats, possibly by enhancing the three metabolic pathways of Hcy to reduce excessive Hcy in the body, thereby improving liver metabolic function and symptoms of non-alcoholic fatty liver disease.

Objective: To study the effects of Cistanche deserticola and its active components Cistanche deserticola polysaccharide and Echinacoside on intestinal flora of antibiotic-associated diarrhea (AAD) mice. Methods: Forty-eight Balb/c mice were randomly divided into control (Con) group, AAD Group, inulin (Inu) group, Cistanche deserticola (RCR) group, Cistanche deserticola polysaccharide (RCRDT) group and Echinacoside (Ech) group with 8 mice in each group. The diarrhea model of mice was induced by intragastric administration of lincomycin hydrochloride(3 g/kg) for 7 days, and then treated by intragastric administration of INU(5 g/kg), RCR(5 g/kg), RCRDT(200 mg/kg) and ECH (60 mg/kg),0.2 ml once a day for 7 days, Con group and AAD group were given the same volume of normal saline. By observing general signs of mice, colon HE staining, 16S rDNA high-throughput sequencing analysis, the effects of Cistanche deserticola, Cistanche deserticola polysaccharide and Echinacea glycoside on the imbalance of intestinal flora induced by antibiotics in mice were evaluated. Results: Compared with Con group, AAD group mice lost weight, presented obvious diarrhea symptoms, inflammatory changes in colon tissue and decreased intestinal flora diversity (P＜0.05) indicating the success of the model. Compared with AAD group, the weight and diarrhea of INU, RCR, RCRDT and ECH groups were significantly improved, and the colon pathology of ECH group was restored to normal level. Compared with AAD group, RCR group, RCRDT group and ECH group had significantly decreased intestinal Firmicutes, increased Blautia and Lachnoclostridium, and decreased Clostridium_sensu_stricto_1 (P＜0.05) . In ECH group, the abundance and diversity of intestinal microflora were returned to normal level, and the structure of intestinal microflora was well adjusted, the contents of Bacteroides, Flavonifractor, Agathobacter, Lachnoclostridium and Prevotella-9 were increased (P＜0.01). Conclusion: Both Cistanche deserticola and its active components cistanche deserticola polysaccharide and echinacoside can regulate the intestinal flora imbalance caused by antibiotics and improve the symptoms of AAD, especially echinacoside.

Objective: To investigate the effects of one-time exhaustive exercise on coagulation state in rats and its mechanism. Methods: Forty-eight SD rats were randomly divided into control group and exhaustive exercise group, 24 rats in each group. Rats in exhaustive exercise group were trained with treadmill training for 25～50 min at a time on non-slope treadmill and the initial speed of 5 m/min was uniformly accelerated to 25 m/min until the rats exhausted. Thrombelastography (TEG) was used to monitor the coagulation function of rats after training. The ligation model of inferior vena cava (IVC) was established to evaluate thrombosis. The phosphatidylserine (PS) exposure and Ca²⁺ concentration were detected by flow cytometry. The production of FXa and thrombin was detected by microplate reader. The clotting time was measured by using coagulometer. Results: Compared with the control group, the blood of rats in the exhaustive exercise group exhibited hypercoagulable state. The probability of thrombus formation, weight, length and ratio in the exhaustive exercise group were significantly higher than those in the control group (P＜0.01). The levels of PS exposure and intracellular Ca²⁺ concentration of red blood cells (RBCs) and platelets in the exhaustive exercise group were increased significantly (P＜0.01). The blood clotting time of RBCs and platelets was shortened (P＜0.01), and the production of FXa and thrombin was increased significantly (P＜0.01) in the exhausted exercise group, and both were inhibited by lactadherin (Lact, P＜0.01). Conclusion: The blood of exhaustive exercise rats is in a hypercoagulable state and the risk of thrombosis is increased. The increased PS exposure of RBCs and platelets caused by exhaustive exercise may be an important mechanism of thrombosis.

Objective: To investigate the effects of ACC1 knockdown on human glioma U251 cell migration and its molecular mechanisms. Methods: Human glioma U251 cell line was used. The experiment was carried out in three steps. Experiment 1: knockdown of ACC1 in U251 cells (shACC1) and its control (NC) U251 cells were established by transfection of shACC1 lentivirus and negative control virus. The cell migration was detected by Transwell migration assay and scratch test. Western blot (WB) was performed to detect the levels of ACC1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug proteins. Experiment 2: RT-qPCR and WB were performed to verify the RNA-seq result, upregulation effect of ACC1 knockdown on PAI-1 in U251 cells. The cells then were treated with PAI-1 inhibitor PAI-039, and the cell migration was detected by Transwell migration assay and scratch assay. The protein levels of ACC1, PAI-1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug were examined by WB. Experiment 3: the molecular mechanisms of knocking down ACC1 to increase PAI-1 were explored. The cells were treated with acetyltransferase inhibitor C646, and cell migration was examined by Transwell migration assay and scratch assay. WB was conducted to test the levels of ACC1, H3K9ac, PAI-1, Vimentin, Fibronectin, N-cadherin, E-cadherin and Slug proteins. Each experiment was repeated three times. Results: Experiment 1: lentivirus transfection was performed on glioma U251 cells. Compared with NC group, the expression level of ACC1 in shACC1 group was decreased significantly, indicating that lentivirus transfection was successful (P＜0.01), and the number of migrated cells in shACC1 group was increased significantly (P＜0.01). Migration-related proteins Vimentin, Fibronectin, N-cadherin and Slug were up-regulated, while E-cadherin was down-regulated (P＜0.01). Experiment 2: Compared with NC group, PAI-1 mRNA level in shACC1 group was up-regulated. Compared with control group, cell migration in shACC1+PAI-039 group was decreased (P＜0.01), and migration-related proteins Vimentin, Fibronectin, N-cadherin, and Slug were up-regulated. E-cadherin expression was down-regulated (P＜0.01). Experiment 3: Compared with NC group, the concentration of acetyl-coA and the expression level of H3K9ac in shACC1 group were increased significantly (P＜0.01); After further treatment with histone acetyl transferase inhibitor C646, PAI-1 mRNA level was decreased, cell migration number and H3K9ac expression level were decreased in shACC1+C646 group compared with control group (P＜0.01). Migration-related proteins Vimentin, Fibronectin, N-cadherin and Slug were up-regulated, while E-cadherin was down-regulated (P＜0.01). Conclusion: Knockdown of ACC1 promotes the migration of human glioma U251 cells by increasing histone acetylation which elevates the level of PAI-1.

Objective: To investigate the effects of polystyrene nanoplastics (PS-NPs) exposure during gestation on the growth and neurotoxicity of fetal rats. Methods: Twenty-seven SD pregnant rats were randomly divided into 9 groups with three rats in each group. The experimental group of PS-NPs was given 0.5, 2.5, 10 and 50 mg/kg of PS-NPs suspension with different particle sizes (25 and 50 nm) by gavage, wihe the control group was given ultrapure water by gavage. The time of gavage is from the 1st to the 18th day of pregnancy. The morphological changes of the placenta were observed; compare the number of male and female fetuses, live/dead/absorbed fetuses, body weight, body length, placental weight, and organ coefficients of kidney, liver, brain and intestine of fetal rats; the prefrontal cortex, hippocampus and striatum of the fetal rats were taken to measure related biochemical indicators. Results: Compared with the control group, the placenta of the PS-NPs exposed group was found to have structural damage, which increased in a dose-dependent manner. The area ratio of trophoblast was significantly increased (P＜0.05), and the area ratio of labyrinth was significantly decreased (P＜0.05); In the prefrontal cortex, hippocampus and striatum of fetal rats, the levels of IL-1β, IL -6 and TNF-α were significantly increased in the 10 and 50 mg/kg PS-NPs exposed group (P＜0.05), and more significantly elevated in the 25 nm group than those in the 50 nm group at 10 mg/kg exposure (P＜0.05) the CAT activity was significantly decreased in 2.5, 10 and 50 mg/kg PS-NPs exposure groups (P＜0.05), while the SOD and GSH-Px activities were significantly decreased in 25 nm exposure groups and 2.5, 10 and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05), the MDA content was significantly increased in 10, 50 mg/kg 25 nm PS-NPs exposure groups and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05). Conclusion: Maternal PS-NPs exposure during gestation may affect the growth and development of fetal rats by damaging the placental barrier and produce neurotoxicity in fetal rats, causing oxidative stress and inflammatory responses in various brain regions, and smaller particle sizes and higher doses of polystyrene nanoplastic exposure have more significant neurotoxic effects on the offspring.

Objective: To investigate the effects of adding whole body vibration (WBV) to routine exercise regimen of pulmonary rehabilitation (PR) on bone strength, lung function and exercise ability of elderly patients with stable chronic obstructive pulmonary disease (COPD) complicated with osteoporosis (OP). Methods: Thirty seven elderly patients with stable COPD were randomly divided into control group (group C, n=12, age: 64.6±3.8 years), conventional PR group (PR group, n=12, age: 66.1±4.9 years), and whole body vibration combined PR group (WP group, n=13, age: 65.5±3.3 years). Before intervention, X-ray and computerized tomography bone scan, bone metabolic markers, pulmonary function, cardiopulmonary exercise, 6-minute walking and isokinetic muscle strength were performed, and then intervened for 36 weeks, three times/week, among which group C subjects were given routine treatment, PR group added aerobic running and static weight resistance on the basis of routine treatment, and WP group added WBV on the basis of PR group intervention. After the intervention, the same indicators were detected. Results: Compared with before the intervention, the pulmonary function indexes of each group were significantly improved after the intervention (P＜0.05), and the bone mineral density and bone microstructure indexes of the patients in the WP group were also significantly improved (P＜0.05). Compared with group C and group PR, the bone mineral density, bone microstructure, parathyroid hormone (PTH), insulin-like growth factor-1 (IGF-1), interleukin-6 (IL-6), osteocalcin (OCN) and other bone metabolism indexes, knee flexion, peak extension torque, fatigue index and muscle strength of patients in WP group were significantly improved (P＜0.05). Conclusion: Adding WBV to the conventional PR regimen can improve the bone strength, lung function and exercise capacity of elderly patients with COPD complicated with OP, and may be able to make up for the deficiency of the current conventional PR regimen for insufficient muscle and bone stimulation.