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 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.

Objective: To investigate the effect of hydroxysafflower yellow A (HSYA) on pulmonary fibrosis induced by bleomycin in mice and transforming growth factor β 1(TGF-β1) /Smad signal transduction pathway regulation.

Methods: The pulmonary fibrosis model was prepared by intranasal injection of bleomycin 50 μl (15 mg/kg). ICR mice were randomly divided into control group, model group, HSYA group(6 mg/kg) and dexamethasone (Dex) group(3 mg/kg), with 15 mice in each group. From the next day of modeling, HSYA and Dex groups were intraperitoneally injected with corresponding drugs, while the control group and model group were intraperitoneally injected with the same volume of normal saline, once a day, for 28 consecutive days. After 4 weeks, the mice were sacrificed and the lungs were collected. HE and Masson staining were used to observe the pathological damage of lung tissue; Immunohistochemistry, RT-qPCR and Western blot were used to detect the expressions of TGF-β1/Smad signaling pathway in lung tissues.

Results: Compared with the control group, the model group showed severe alveolitis and pulmonary fibrosis. The mRNA and protein expressions of TGF-β1 and Smad3 in lung tissues were increased significantly (P＜0.01), while the mRNA and protein expressions of Smad7 were decreased significantly (P＜0.01). Compared with the model group, the degree of alveolitis and pulmonary fibrosis in the HSYA and Dex groups was reduced significantly. The mRNA and protein expressions of TGF-β1 and Smad3 in lung tissues of HSYA and Dex groups were decreased significantly (P＜0.01), while the mRNA and protein expressions of Smad7 were increased significantly(P＜0.01).

Conclusion: HSYA can alleviate the pathogenesis of pulmonary fibrosis, and its mechanism may be related to the regulation of TGF-β1/Smad signaling pathway.

Objective: To investigate the effects of silent information regulator 1 (SIRT1) in amygdala on depression-like behaviors in rats using chronic restraint stress (CRS) as a model of depression.

Methods: Sixty male SD rats were randomly divided into six groups (n=10 per group): control group (Control), chronic restraint stress group (CRS), CRS + fluoxetine-treated group (CRS + FLU), CRS + saline-treated group (CRS + NaCl), CRS + SIRT1-overexpression group (CRS + AAV-SIRT1), and CRS + empty vector group (CRS + AAV-EGFP). Except for the control group, rats from the other groups were exposed to chronic restraint stress for 21 days. After the modeling, rats in fluoxetine-treated group and saline-treated group were, respectively, treated with fluoxetine (10 mg/kg) or saline (10 mg/kg) by gavage every day for 3 weeks; AAV-SIRT1 or AAV-EGFP was, respectively, stereotaxically injected into the amygdala of rats in SIRT1-overexpression group and empty vector group, and the virus was expressed for 3 weeks. Rats in normal control group and CRS model group were not given any drug treatment. The depression-like behaviors of rats in each group were evaluated by sugar preference test (SPT), open field test (OFT) and forced swimming test (FST). SIRT1 expression in amygdala of rats was assessed by using immunoblot blotting. The number of SIRT1-positive cells in amygdala of rats was detected by immunofluorescence technique.

Results: Compared with the normal control group, the level of SIRT1 protein and the number of SIRT1⁺ cells in amygdala of the CRS-exposed rats were decreased significantly (P＜0.01), and CRS-exposed rats showed a significant decrease in sucrose preference (P＜0.01), less total horizontal distance (P＜0.01) and less time entered the center field (P＜0.01) in the OFT, a significant increase in the immobility time of the FST (P＜0.01). Fluoxetine treatment (P＜0.05, P＜0.01) or SIRT1 overexpression (P＜0.01) partially reversed the down-regulation of SIRT1 protein and SIRT1⁺ cells in amygdala of CRS-exposed rats and significantly improved the depression-like behaviors of CRS rats.

Conclusion: Fluoxetine treatment partially reversed the down-regulation of SIRT1 level and the number of SIRT1⁺ in CRS rats, and significantly improved the depression-like behaviors. The antidepressant effect of fluoxetine treatment may be related to the up-regulation of SIRT1 in the amygdala of CRS-exposed rats.

Objective: To investigate the protective effects of Polygonatum odoratum polysaccharides (POP) on alcohol-induced injury of HepG2 cells and its potential molecular mechanisms. Methods: After screening the appropriate concentration of alcohol-treated HepG2 cells and the intervention concentration of POP by MTT method, HepG2 cells were divided into three groups according to different intervention concentrations (200 μg/L, 400 μg/L and 600 μg/L) of POP, and the blank group without POP. After pretreated for 1 h, HepG2 cells were treated with 4% alcohol for 24 h. The activities of intracellular alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and the levels of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF- α) were measured. The protein expressions of Kelch-like epichlorohydrin-associated protein-1 (Keap1), phosphorylated nuclear factor E2-related factor 2 (p-Nrf2), phosphoamide adenine dinucleotide quinone oxidoreductase -1 (NQO1), B lymphocyte tumor-2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase 3 were detected. Results: Compared with the HepG2 cells treated with 4% alcohol, POP at the various concentrations could effectively down-regulate the activities of ALT and AST in HepG2 cells induced by alcohol (P＜0.05). The levels of IL-1β and TNF-α in the 200 μg/L POP treated group were decreased significantly (P＜0.05), while the level of GSH was increased significantly (P＜0.01). The levels of ROS, MDA, IL-1β and TNF-α in the 400 μg/L and 600 μg/L POP treated groups were decreased significantly (P＜0.05 or P＜0.01), while the GSH level was increased significantly (P＜0.01). POP effectively up-regulated the expressions of p-Nrf2 and NQO1 protein in HepG2 cells induced by alcohol, and also down-regulated the Bax/Bcl-2 index (P＜0.05), and inhibited the protein expressions of Keap1 and cleaved-caspase-3 (P＜0.05). Conclusion: POP can improve alcohol-induced oxidative stress injury in HepG2 cells by regulating the Nrf2/Keap1 pathway, thereby reducing the inflammatory index and apoptosis level of HepG2 cells. Among them, 400 μg/L and 600 μg/L POP have better intervention effects.

Objective: To investigate the effects of ferrostatin-1 (Fer-1) on cardiomyocyte hypoxia/reoxygenation injury and its mechanisms.

Methods: The original generation of myocardial cells were extracted from 1～3 d newborn SD rats, which were randomly divided into normal control group (control), hypoxia reoxygenation (H/R) group and hypoxia reoxygenation + iron death inhibitors group (H/R + Fer-1). After 52 h of culture, cells in H/R group were added with 4 mmol/L Na₂S₂O₄ solution. After 1 h of hypoxia, cells were reoxygenated with DMEM medium containing 10% calf serum for 3 h.The H/R+ Fer-1 group was pretreated with Fer-1 (2 μmol/L) for 24 h and then subjected to hypoxia and reoxygenation. The release rate of lactate dehydrogenase (LDH) was measured by UV spectrophotometry, the cell survival rate was measured by CCK-8 method, SOD was measured by xanthine oxidase method, MDA was measured by chemical coloration, and the changes of mitochondrial membrane potential and reactive oxygen species (ROS) were observed by immunofluorescence. Western blot was used to detect the expressions of ACSL4 and GPX4.

Results: Compared with the control group, the cell activity, SOD release and MMP level were decreased (P＜0.05), the levels of LDH, MDA and ROS were increased (P＜0.05), the protein expression of ACSL4 was increased (P＜0.05), and the protein expression of GPX4 was decreased (P＜0.05) in H/R group. Compared with the H/R group, the cell activity, SOD release and MMP level were increased (P＜0.05), the level of LDH, MDA and ROS were decreased (P＜0.05), the protein expression of ACSL4 was decreased (P＜0.05), and the protein expression of GPX4 was increased (P＜0.05) in H/R+Fer-1 group.

Conclusion: Fer-1 can inhibit the production of intracellular reactive oxygen species by regulating ACSL4 and GPX4, thereby alleviating the hypoxia and reoxygenation injury of primary cardiomyocytes caused by iron death.

Objective: To investigate the effects and related molecular mechanisms of Astragalin on undifferentiated gastric cancer cell HGC-27.

Methods: Astragalin was used to treat HGC-27 cells, the cell proliferation activity was detected by CCK-8 method, the cell morphology was observed under inverted microscope, hoechst 33342 and JC-1 staining were used to observe the changes of nucleus formation and mitochondrial membrane potential, the cell cycle and apoptosis rate were detected by flow cytometry, the reverse transcription level of the gene was analyzed by the second-generation sequencer.

Results: Astragalin inhibited the proliferation of HGC-27 significantly (P＜0.01), down-regulated mitochondrial membrane potential, induced cell apoptosis, blocked the cell cycle in G1 prophase. At the same time, Astragalin up-regulated the transcription levels of genes bax and bad, down-regulated the transcription levels of genes egf, egfr, pik3cb, pdk1, akt3 and bcl-2. Western blot analysis also showed that the expressions of PI3K and Akt protein were decreased, and the proportion of Bax and BCL-2 protein was increased significantly (P＜0.01).

Conclusion: The apoptosis of undifferentiated gastric cancer cell line HGC-27 can be induced by Astragalin through inhibition of EGFR/PDK/Akt signaling pathway, and the cell cycle can be blocked in G1 phase, which has a certain therapeutic effect on undifferentiated gastric cancer.

Objective: To investigate the effects and molecular mechanisms of miR-125b-5p on cognitive dysfunction caused by traumatic brain injury (TBI).

Methods: The rats were randomly divided into control group, TBI group (model group), NC Agomir group (false negative group) and miR-125b-5p agomir group (high expression group), with 5 rats in each group. The false negative group and the high expression group were injected with NC agomir and miR-125b-5p agomir, respectively. The brain injury model was established by modified Feeney method except control group. Animal behavioral experiments were utilized for evaluation of the motor coordination, learning and memory and the degree of nerve damage in rats; and enzyme-linked immunosorbent assays (ELISA) and Western blot (WB) were used for determination of the expression levels of inflammatory factors and nerve-related factors in the hippocampus of rats in each group respectively. Finally, combined with bioinformatics, downstream target genes of miR-125b-5p were predicted and verified by reverse transcription polymerase chain reaction (RT-PCR) and WB.

Results: Compared with control group, mir-125b-5p expression level, motor coordination ability, learning and memory ability, brain-derived neurotrophic factor(BDNF) and nerve growth factor(NGF) expression levels of rats in model group and false negative group were decreased significantly, the MNSS score, the expressions of interleukins (IL-1β, IL 6), tumor necrosis factor-α(TNF-α) and glial fibrillary acid protein(GFAF) were increased significantly (P＜0.01);However, compared with model group and false negative group, the above situation of rats in high expression group was opposite (P＜0.01). Bioassay showed that MMP-15 was the downstream target gene of miR-125b-5p. Compared with the control group, the expression of MMP-15 in model group and false negative group was increased significantly (P＜0.01);Compared with model group and false negative group, the expression of MMP-15 in high expression group was decreased significantly (P＜0.01) .

Conclusion: miR-125b-5p can improve cognitive dysfunction induced by TBI in rats, which may be related to regulating the expression level of MMP-15, thereby inhibiting the neuroinflammatory response after TBI and promoting neuronal regeneration.

Objective: To investigate the protective effects of three Polyphenolic compounds on intestinal microbial communities in mice exposed intermittent plateau hypoxia.

Methods: In this study, 60 healthy male Balb/c mice were randomly divided into plain control group, plateau control group, primary anthocyanin intervention group, quercetin intervention group and resveratrol intervention group, 12 mice in each group. Primary anthocyanin, quercetin and resveratrol were administrated by gavage at the doses of 50, 100 and 20 mg/kg in pharmacological intervention group, respectively. After exposure of the mice to simulation plateau-condition for 30 days, the serum samples were collected for DAO testing, sterile feces were collected in mice, and the diversity and genus level of the mouse gut bacteria were detected by using 16S rRNA technology. Ileum tissue was fixed and stained with HE.

Results: HE staining showed that the plateau control group had significant damage to the intestinal tissue structure compared to the plain control group, and the serum DAO concentration was increased (P＜0.05), but there was no statistical difference in the abundance and diversity of intestinal flora species. Contrast to simulated intermittent plateau hypoxia group, the structure of the intestine tissue and the level of DAO in the quercetin intervention group and resveratrol intervention group were improved(P＜0.05), the abundance and α diversity of the intestinal flora were decreased, the relative abundance of Bacteroidetes was reduced(P＜0.05), and the Firmicutes was increased. Concomitantly, significant decreases in relative abundance were observed for Corynebacterium glutamicum and Lactobacillus reuteri(P＜ 0.05).

Conclusion: Quercetin and resveratrol showed some degree of protection to mice intestinal microbial communities, and increased the diversity and the abundance of the dominant flora and inhibited the growth of conditional pathogenic bacteria.

Objective: To study the protective effects of Lycium ruthenicum Murr. juice on alcoholic liver injury in rats and explore the regulatory mechanism of toll-like receptors 4 (TLR4)/p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway in this process. Methods: Sixty male SD rats were randomly divided into control group (C), model group (M), low-dose Lycium ruthenicum Murr. juice group (LLM), medium-dose Lycium ruthenicum Murr. juice group (MLM) and high-dose Lycium ruthenicum Murr. juice group (HLM), 12 rats in each group. The group M, LLM, MLM and HLM were treated with 20 ml/kg (8 g/(kg·d)) ethanol (400 g/L) intragastrically and the gavage was divided into two sessions, group C was treated with an equal volume of distilled water at the same time point. Four hours before the first alcohol gavage session, rats in each dose group of Lycium ruthenicum Murr. juice were administered with 2.4, 4.8, 9.6 ml/(kg·d) Lycium ruthenicum Murr. juice respectively, and the other groups were given equal volume of distilled water at the corresponding time points. Four weeks later, the rats were sacrificed 24 hours after the end of the last experiment, blood and liver were collected. The liver index was calculated. The morphology of the liver was observed by HE staining. The expressions of hepatic TLR4, p38 MAPK and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) were detected by immunohistochemistry. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by colorimetry. The levels of hepatic tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-10 (IL-10) and interleukin-18 (IL-18) were detected by enzyme linked immunosorbent assay. Results: Compared with group C, the alcoholic liver injury model was established successfully in Group M. Compared with group M, related indicators in each dose group of Lycium ruthenicum Murr. juice were improved, the improvement of hepatic morphology in group HLM was the most significant, the liver index, the levels of serum ALT, AST and hepatic TLR4, p38 MAPK/p-p38 MAPK ratio, TNF-α, IL-1β, IL-18 were decreased (P＜ 0.05 or P＜0.01), while the level of hepatic IL-10 was increased (P＜0.01). Comparison among the dose groups of Lycium ruthenicum Murr. juice, the levels of liver index, serum AST and hepatic TLR4, p38 MAPK/p-p38 MAPK ratio, TNF-α, IL-18 in HLM were lower than those in LLM (P＜0.05 or P＜0.01); the level of hepatic IL-10 in HLM was higher than that in LLM and MLM (P＜0.05 or P＜0.01); the other indicators in each dose group had no statistical difference (P＞0.05). Conclusion: Lycium ruthenicum Murr. juice can improve the inflammatory stress by regulating TLR4/p38 MAPK signaling pathway, relieve alcoholic liver injury in rats, and the effect of high-dose group is better than the others.

Objective: To study the effects of aerobic exercise training on renal fibrosis in spontaneously hypertensive rats (SHR), and to explore the protective effect of exercise on renal damage in hypertensive rats. Methods: Eight-week-old male SHR and Wistar Kyoto rats of the same age (WKY) were randomly divided into 4 groups (n=6): sedentary WKY control group (WKY-S), sedentary SHR control group (SHR-S), low-intensity exercise group (SHR-L) and medium-intensity exercise group (SHR-M). SHR-L group and SHR-M group were set at a slope of 0° at 14 m/min (35% of the maximum aerobic speed) and 20 m/min (50% of the maximum aerobic speed), running on a sports treadmill for 14 weeks, 5 times a week, and 60 min each time. WKY-S and SHR-S groups were kept quietly. Blood pressure was measured 72 hours after exercise training. And the serum levels of creatinine (Scr) and BUN were detected. The morphology of renal tissue was observed by hematoxylin and eosin (HE) staining. The collagen deposition of renal tissue was observed by Masson staining, and the renal collagen volume fraction (CVF) was calculated. Results: Compared with WKY-S group, blood pressure, serum Scr and BUN, kidney CVF levels and AngⅡ, AT1R, TGF-β, α-SMA, CTGF expressions in SHR-S group were increased significantly (P＜0.05). Compared with SHR-S group, blood pressure, serum Scr and BUN, kidney CVF level and AngⅡ, AT1R, TGF-β, α-SMA, CTGF expressions in SHR-L and SHR-M groups were decreased significantly (P＜0.05) and the decreasing trend was more obvious in SHR-M group (P＜0.05). Conclusion: Aerobic exercise can improve renal fibrosis and renal function in spontaneously hypertensive rats by inhibiting the AngⅡ-AT1R-TGF-β pathway.