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

Objective: To explore the changes in the excitatory/inhibitory (E/I) balance of pyramidal neurons in prefrontal cortex and hippocampus in mice with anxiety disorder induced by chronic unpredictable mild stress (CUMS). Methods: Twenty-four C57/BL6 male mice were randomly divided into control group (CTRL) and model group (CUMS), with 12 mice in each group. The mice in CUMS group were subjected to 21 days of stress, including restraint for 1 h, reversed day/night cycle for 24 h, forced warm water bath for 5 min, water/food deprivation for 24 h, housing in wet sawdust for 18 h, shaking the cage for 30 min, noise for 1 h, and social stress for 10 min. CTRL group mice were fed normally. Anxiety-related behavioral tests and whole-cell recording tests were performed after modeling. Results: Compared with CTRL group, the time of spent in the central arena of CUMS group was reduced significantly in open field test (P＜0.01), the time and number of entering the open arms were decreased significantly in elevated plus maze test (P＜0.01), and the time of staying in the closed arms was increased significantly in CUMS group (P＜0.01). The sEPSC frequency, capacitance and E/I ratio of dlPFC, mPFC and vCA1 pyramidal neurons of mice in CUMS group were increased significantly (P＜0.01), while sEPSC amplitude, sIPSC frequency, amplitude and capacitance were not significantly changed (P＞0.05). The frequency, amplitude, capacitance and E/I ratio of sEPSC and sIPSC of dCA1 pyramidal neurons were not significantly changed (P＞0.05). Conclusion: The anxiety-like behavior of CUMS-induced mice may be the result of the participation of multiple brain regions, which is mainly related to the increase of the excitability of pyramidal neurons in dlPFC, mPFC and vCA1 brain regions, but seems to have little relationship with dCA1 brain regions.

Objective: To study the effects of estradiol (E2) on alleviating myocardial ischemia/reperfusion(I/R) injury through estrogen receptorβ(ERβ) mediated extracellular regulated protein kinases(ERK) pathway activation. Methods: Eighty-four adult female SD rats were ovariectomized and randomly divided into control group, NC siRNA adeno-associated virus (AAV) group received sham operation, the myocardial I/R injury model was prepared by ligation of the left anterior descending coronary artery in I/R group, E2+I/R group, NC siRNA AAV+I/R group, NC siRNA AAV+E2+I/R group and ERβ-siRNA AAV+E2+I/R group. E2+I/R group, NC siRNA AAV+E2+I/R group and ERβ-siRNA AAV+E2+I/R group were treated with E2 0.8 mg/kg by gavage for 60 days before modeling. NC siRNA AAV+I/R group, NC siRNA AAV+E2+I/R group, and ERβ-siRNA AAV+E2+I/R group were treated with AAV by caudal vein injection 24 h before modeling. After 120 min of reperfusion, the contents of serum lactate dehydrogenase (LDH), phosphocreatine kinase (CK), phosphocreatine kinase isoenzyme (CK-MB), myocardial infarction area and the expressions of ERβ, p-ERK, the contents of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1 β), malondialdehyde (MDA) and total antioxidant capacity (T-AOC) in myocardium were measured. Results: The contents of serum LDH, CK, CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 β, MDA in myocardium of I/R group were higher than those of the control group, the expression levels of ERβ and p-ERK and the content of T-AOC were lower than those in the control group (P＜0.05). The contents of serum LDH, CK and CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 β and MDA in myocardium of E2+I/R group were lower than those of the I/R group, the expression levels of ERβ and p-ERK and the content of T-AOC were higher than those of the I/R group(P＜0.05). After knockdown ERβ by caudal vein injection of ERβ-siRNA AAV, the contents of serum LDH, CK and CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 β and MDA in myocardium of ERβ-siRNA AAV+E2+I/R group were higher than those of NC-siRNA AAV+E2+I/R, the expression levels of ERβ and p-ERK and the content of T-AOC were lower than those of NC-siRNA AAV+E2+I/R(P＜0.05). Conclusion: E2 has protective effects on myocardial I / R injury in ovariectomized rats, which are related to the promotion of ERβ mediating the activation of ERK pathway, reducing inflammatory and oxidative stress responses.

Objective: To investigate the effects of glutamate aspartate transporter (GLAST)deletion on the normal auditory function of mice.

Methods: We hybridized GLAST^+/- mice with C57BL/6J background and identified the genotypes of their offspring by agarose gel electrophoresis. 9-10-week-old mice were selected to detect the expression of GLAST protein in the cochlea by immunofluorescence staining and to verify the knockout results(n=3). The changes in weight from 7 days to 30 days after birth and the 30-day body length of male and female mice were compared(n=8). The auditory brainstem response(ABR) was used to detect the auditory threshold and the amplitude of wave I in 9-10-week-old male and female mice(n=5).

Results: Male GLAST^-/- mice had shown significantly lower weight and body length compared to male GLAST^+/+ and GLAST^+/- mice(P＜0.01), and male GLAST^-/- mice showed significant differences compared to GLAST^+/+ from P7 to P30 statistical time. Male GLAST^-/- mice exhibited a significant reduction in weight after P15 compared to male GLAST^+/- mice. In contrast, no significant differences in weight and body length were observed in female GLAST^-/- mice compared with female GLAST^+/+ and GLAST^+/- mice. There was no difference in the hearing threshold detected by ABR between the three genotypes in both male and female mice, but the amplitude of wave I in GLAST^-/- mice was significantly lower than that in male GLAST^+/+ mice(P＜0.01). In contrast, the amplitude of wave I in females was reduced throughout the stimulus intensity but was most significant only at high-intensity stimulation (e.g.80 dB, 90 dB) (P＜0.05).

Conclusion: GLAST knockout affects the normal growth and development of male mice, and decreases the amplitude of wave I, but do not change the threshold, suggesting that GLAST knockout may lead to synaptic pathological changes, and there are gender differences in this effect.

Objective: To analyze the molecular mechanisms of skeletal muscle cells apoptosis induced by heavy-load exercise with Omi as the entry point.

Methods: One hundred and twenty-six adult SD rats were randomly divided into five groups: control group(C), eccentric exercise group (E), simple blocking group (U), DMSO group (D) and exercise block group (EU). In addition to the C group, the other four groups were randomly divided into 0 h after experiment, 12 h after experiment, 24 h after experiment, 48 h after experiment and 72 h after experiment with 6 rats in each group. E and EU group were submitted to a heavy-load exercise on a treadmill down a 16° decline, 16 m/min for 90 minutes. U, D and EU group were one-time intervened with drugs. U and EU groups were intraperitoneally injected with 1.5 μmol/kg ucf-101, D group were intraperitoneally injected with 1.5 μmoL/kg 0.5% DMSO. The rats were sacrificed in batches at different time points after experiment, then the soleus were saved to detect the Caspase-3,-8,-9,-12 activities and protein expressions of Omi and XIAP.

Results: Compared with group C, the mitochondrial distribution and morphology appeared the typical ultrastructure pathological changes, the opening degree of MPTP was increased significantly (P＜0.01) or (P＜0.05), protein expressions of Omi and XIAP were increased significantly (P＜0.01 or P＜0.05), the activities of Caspase-9 and Caspase-3 were increased significantly (P＜0.01 or P＜0.05) in group E. Compared with group C, there was no significant difference in XIAP protein and caspase-9, - 3 activities in group U and Group D. The change trend of XIAP protein and Caspase-9, - 3 activities was the same as those between EU group and E group, but the change range of XIAP protein in EU group was significantly higher than that in E group (P＜0.01), and the change ranges of caspase-9, - 3 activities in EU group were significantly lower than those in E group (P＜0.01).

Conclusion: A single heavy-load exercise can induce changes in the mitochondria morphology and structure in rats, open the high permeability of MPTP, and improve the expression of Omi protein, then through its downstream XIAP-Caspase pathway, start the mitochondrial apoptosis pathway mediated by caspase-9, and finally lead to myocyte apoptosis. The inhibition of Omi can reduce the cell apoptosis level of motor induced skeletal muscle cells.

Objective: To investigate the effects of down-regulating MDR1 gene expression by CRISPRi on enhancing the sensitivity of lung adenocarcinoma A549/DDP cells to cisplatin.

Methods: The potential CRISPRi interference sites on the MDR1 gene promoter were predicted by bioinformatics software, and the interference fragments were designed and constructed. The mRNA and protein expression levels of MDR1 gene in each group of cells were detected by qRT-PCR and Western blot methods, and the recombinant vectors with high interference efficiency were screened. Human lung cancer A549/DDP cells were divided into three groups: A549/DDP, Scrambed and sgRNA-MDR1-1, with three multiple holes in each group. After each vector was transfected into the cells for 48 h, the efflux of cells in each group was detected by flow cytometry, the IC₅₀ value of cells in each group was detected by MTT method, and the cell morphology of cells treated with cisplatin was observed under laser confocal microscope.

Results: After sequencing and comparison, two kinds of CRISPRi recombinant vectors interfering with MDR1 gene transcription were constructed successfully. After transfection of A549/DDP cells, the mRNA and protein levels of MDR1 gene in all transfection groups were decreased significantly (P＜ 0.01). Among them, the interference efficiency of sgRNA-MDR1-1 was the highest, and the interference efficiency of mRNA and protein was 60% and 51%, respectively. After transfection of sgRNA-MDR1-1 vector, compared with the control group, the efflux ability of cells was decreased (P＜0.01), the IC₅₀ value of cells to cisplatin was decreased significantly (P＜0.01), and the intracellular chromatin gathered and marginalized, and apoptotic bodies appeared.

Conclusion: CRISPRi interference with MDR1 gene in drug-resistant A549/DDP cells can significantly enhance the sensitivity to cisplatin.

Objective: To investigate the effects of rhein on proliferation and apoptosis of gastric cancer cell line HGC-27 and its related mechanisms.

Methods: Human gastric cancer cells HGC-27 were treated with 0, 5, 10 or 20 mg/L rhein respectively for 24, 48 and 72 h in vitro, three duplicate wells were set in each group. The proliferation activity of HGC-27 cells was detected with CCK-8 method, the growth status of HGC-27 cells was observed by small high-content microscope, hoechst staining was used to analyze the karyotype of HGC-27 cells. Mitochondrial membrane potential was detected by JC-1 staining and flow cytometry, cell cycle was analyzed with flow cytometry, the levels of mRNA transcribing of bcl-2, bax, caspase-3, jak1, jak2, stat3 and notch genes were investigated with RT-qPCR method. Protein expressions were determined by Western blot.

Results: Compared with HGC-27 cells treated with 0 mg/L rhein, HGC-27 cells treated with 5, 10 and 20 mg/L rhein for 24 h showed decreased mitochondrial membrane potential ( P＜0.01), the cell proliferation activity was inhibited and apoptosis was induced. The effects were enhanced with the increase of rhein concentration and the extension of treatment time, but the cell cycle did not change significantly, and the expressions of bcl-2, jak1, jak2, stat3 and notch genes were down-regulated. The expression levels of bax and caspase-3 genes were increased significantly ( P＜0.01).

Conclusion: Rhein can induce apoptosis of HGC-27 cells by influencing NOTCH/JAK/STAT signaling pathway, and has anti-gastric cancer effect.

Objective: To investigate the protective effects and possible mechanisms of ferulic acid on diabetic nephropathy by observing the effects of ferulic acid on the level of inflammation and autophagy in glomerular mesangial cells induced by high glucose.

Methods: SV40 MES 13 cells were cultured and randomly divided into the following groups: normal group (Control, 5.6 mmol/L glucose), mannitol group (Man, 30 mmol/L mannitol), high glucose group (HG, 30 mmol/L glucose), ferulic acid group (FA, 30 mmol/L glucose + 12.5, 25, 50, 100, 200 μmol/L ferulic acid), and the proliferation of SV40 MES 13 cells in each group was observed by MTT method. The levels of tumour necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and interleukin 1β(IL-1β)in cell supernatant were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of NLRP3, IL-1β, LC3-II/I and p62 proteins in SV40 MES 13 cells were detected by Western blot.

Results: ①The proliferative activity of SV40 MES 13 cells was significantly higher in the HG group compared to the control group (P＜0.01), while the proliferative activity of SV40 MES 13 cells was decreased to different degrees in the FA group compared to the HG group (P＜0.05～0.01). ②Compared to the control group, the levels of TNF-α, MCP-1 and IL-1β were increased significantly in the cell supernatant of HG group (P＜0.01). Compared with the HG group, the levels of TNF-α, MCP-1 and IL-1β were decreased significantly in the FA group (P＜0.01). ③Compared with the control group, LC3-II/Ⅰ protein expression was decreased in the HG group, while the levels of p62, NLRP3 and IL-1β protein were increased significantly (P＜0.01). Compared with the HG group, the expression of LC3-II/Ⅰ protein was elevated significantly (P＜0.05) in the FA group, while the levels of p62, NLRP3 and IL-1β protein in the FA group were decreased significantly (P＜ 0.01).

Conclusion: FA can inhibit the abnormal proliferation of SV40 MES 13 cells induced by high glucose. FA can protect glomerular mesangial cells by inhibiting inflammation and increasing the level of autophagy.

Objective: To investigate the effects of sphingosine-1-phosphate (S1P) on cardiac hypertrophic response in H9c2 cells.

Methods: H9c2 cells were randomly divided into four groups: normal control group, S1P (1 μmol/L) treated group, Phenylephrine (PE) (100 μmol/L) treated group, PE (100 μmol/L) treated group combined with S1P (1 μmol/L) treatment. Each group has 3 duplicated wells. After 24 hours, the size of H9c2 cells in each group was detected by Actin-Trakcer Green immunofluorescence staining. Transcriptional levels of hypertrophic markers ( ANP, BNP and β-MHC) in H9c2 cells were determined by real-time PCR. Western blot was performed to examine the expression level of ANP in each group. Then H9c2 cells were randomly divided into five groups: normal control group, PE (100 μmol/L) treated group, PE (100 μmol/L) with S1P low-dose (0.1 μmol/L) treated group, PE (100 μmol/L) with S1P middle-dose (1 μmol/L) treated group and PE (100 μmol/L) with S1P high-dose (10 μmol/L) treated group. Each group has 3 duplicated wells. After 24 hours, Western blot was performed to examine the expressions of phosphorylated Janus kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3) under low, medium and high concentrations of S1P. Each experiment was repeated three times.

Results: Compared with normal control group, the surface area of H9c2 cells in PE group was increased significantly (P＜0.05), meanwhile, the transcription levels of ANP, BNP and β-MHC were increased significantly (all P＜0.05), and the expression of ANP was also increased significantly (P＜0.05) in PE group. While compared with PE group, the surface area of H9c2 cells in PE + S1P group was decreased significantly (P＜0.05), the transcription levels of ANP, BNP and β-MHC and the expression of ANP were also decreased significantly (all P＜0.05) in PE + S1P group. After treated with PE and different concentrations of S1P, the expressions of p-JAK2 and p-STAT3 were increased significantly compared with the normal control group and PE group (P＜0.05), in a dose-dependent manner.

Conclusion: S1P could protect H9c2 cells against hypertrophic response induced by PE, which may be achieved by activating JAK2/STAT3 signal pathway.