BACKGROUNDThe Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway and the extracellular signal-regulated kinases 1/2 (ERK1/2) pathway are the two major independent signal transduction pathways. However, it has recently been found that STAT3 may be negatively regulated by ERK1/2 in gp130-dependent signaling. Cardiotrophin-1 (CT-1), a potent novel hypertrophic cytokine, depends on gp130 to induce signaling and depends on STAT3 to exert hypertrophic effect. In this study, we examined whether STAT3 activity was negatively regulated by ERK1/2 during CT-1-induced signaling in rat cardiomyocytes and, if so, whether such crosstalk interfered with the hypertrophic effect of CT-1 and, furthermore, whether the mechanism underlying the crosstalk involved phosphorylation of serine 727 (S727) in STAT3.

METHODSThe activities of ERK1/2 and STAT3 were assessed by in-gel kinase assay and Western blot analysis, respectively. The role of S727 phosphorylation in the crosstalk between ERK1/2 and STAT3 was determined by a transient transfection study using a STAT3S727A mutant. Cardiomyocyte hypertrophy was evaluated by the cellular protein-to-DNA ratio and [(3)H]-leucine incorporation.

RESULTSCT-1 simultaneously activated both ERK1/2 and STAT3 in rat cardiomyocytes. Inhibition of ERK1/2 by U0126 resulted in an increase of CT-1-induced tyrosine phosphorylation of STAT3 and, consequently, the protein-to-DNA ratio and [(3)H]-leucine incorporation. Transient transfection of the cells with STAT3S727A had no significant effect on CT-1-induced tyrosine phosphorylation of STAT3.

CONCLUSIONSSTAT3 is activated by CT-1 in rat cardiomyocytes, but full activation is mitigated by the simultaneous activation of ERK1/2. The inhibition of ERK1/2 increases the activity of STAT3, which, in turn, enhances the hypertrophic effect of CT-1. The crosstalk between ERK1/2 and STAT3 is independent of the phosphorylation of the S727 in STAT3. Such crosstalk may contribute to the development of adequate cardiac hypertrophy.

Active Transport, Cell Nucleus ; Animals ; Antigens, CD ; metabolism ; Cardiomegaly ; chemically induced ; metabolism ; Cytokine Receptor gp130 ; Cytokines ; toxicity ; DNA-Binding Proteins ; physiology ; Membrane Glycoproteins ; metabolism ; Mitogen-Activated Protein Kinase 1 ; physiology ; Mitogen-Activated Protein Kinase 3 ; physiology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; STAT3 Transcription Factor ; Trans-Activators ; physiology ; Tyrosine ; metabolism

OBJECTIVES: To study the clinical value of extracorporeal membrane oxygenation (ECMO) in the treatment of persistent pulmonary hypertension of the newborn (PPHN). METHODS: A retrospective analysis was performed on the medical data of 11 neonates with PPHN who were treated with ECMO in the Neonatal Intensive Care Unit of Zhongshan People's Hospital from January 2015 to December 2021, involving the neonates' general information, clinical diagnosis, laboratory results, duration of ECMO treatment, complications during ECMO treatment, length of hospital stay, and outcome. RESULTS: Of the 11 neonates, 10 (91%) had successful weaning from ECMO, and 8 (73%) survived. For the 11 neonates, the mean duration of ECMO treatment was (81±50) hours (range: 26 to 185 hours), the mean duration of ventilator use was (198±105) hours (range: 57 to 392 hours), and the mean length of hospital stay was (22±15) days (range: 2 to 49 days). The oxygenation index and blood lactate level were significantly improved after 24 hours of ECMO treatment among the 11 neonates (P<0.05). Ten neonates had significantly reduced pulmonary artery pressure after 24 hours of ECMO treatment (P<0.05). One neonate had a progressive increase in the pulmonary artery pressure during EMCO treatment, succumbing to death. This neonate was diagnosed with alveolar capillary dysplasia based on the histopathological findings of the lung tissue and whole-exome sequencing results. Among the 11 children, 5 had intracranial hemorrhage, 1 had disseminated intravascular coagulation, 1 had gastric hemorrhage, 2 had pulmonary hemorrhage, 1 had renal insufficiency, and 3 had bleeding at the puncture site during ECMO treatment. CONCLUSIONS ECMO is effective for the treatment of PPHN, however, the high incidence of complications of ECMO treatment suggests that it is important to carefully assess the indications and timing of ECMO treatment and improve the management of ECMO, which can improve the weaning rate and survival rate.
Child ; Extracorporeal Membrane Oxygenation ; Humans ; Hypertension, Pulmonary/therapy* ; Infant, Newborn ; Lung Diseases ; Persistent Fetal Circulation Syndrome/therapy* ; Retrospective Studies ; Treatment Outcome

Objective: To explore the protective effect and mechanisms of Renshen Sinitang and its active ingredients on cardiomyocyte injury induced by pentobarbital sodium. Method: H9C2 cells were sub-cultured with ginsenoside Rb₂ 0.01, 0.1, 1 μmol ·L^-1, Re 0.01, 0.1, 1 μmol·L^-1, isoliquiritigenin 20, 40, 80 μmol·L^-1, glycyrrhetinic acid 10, 20, 40 μmol·L^-1, Renshen Sinitang, 10, 100, 400 mg·L^-1, for 4 h. After treatment with 0.1% of sodium pentobarbital for 30 min, cell viability, lactate dehydrogenase (LDH), lipid peroxide malondialdehyde (MDA), Na⁺-K⁺-adenosine triphosphate(ATP) ase, Ca²⁺-ATPase activity, and real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) were used to detect the expressions of peroxisome proliferative activated receptor-1α (PGC-1α), B-cell lymphoma-2 associated X protein(Bax) and cysteine aspartate-specific protease-3(Caspase-3) mRNA. Result: Renshen Sinitang and its active ingredients have a protective effect on heart failure cell model. Compared with the normal group, the cell survival rate of the model group decreased significantly, while the LDH and MDA contents increased significantly, and the Na⁺-K⁺-ATPase activity increased. Ca²⁺-ATPase activity was significantly decreased, PGC-1α mRNA expression was down-regulated, Bax and Caspase-3 mRNA expressions indicates the modeling(P<0.01). Compared with the model group, each administration group showed a significantly increased cell viability, decreased LDH, MDA content, inhibited Na⁺-K⁺-ATPase activity, increased Ca²⁺-ATPase activity, up-regulated PGC-1α mRNA expression, and inhibited Bax and Caspase-3 mRNA expression (P<0.05, P<0.01). Conclusion: Renshen Sinitang and its active ingredients have a significant protective effect on heart failure cell model, and its mechanisms of action are related to anti-oxidation, improvement of mitochondrial energy metabolism and inhibition of mitochondrial apoptosis pathway.

Objective: To study on the physical and chemical properties of dichroa alkali hydrochloride and to establish a method for the determination of entrapment efficiency of dichroa alkali hydrochloride liposomes. Method: HPLC was used to determine the content of dichroa alkali hydrochloride with mobile phase of acetonitrile-water-triethylamine-glacial acetic acid(9:91:0.35:0.75) and detection wavelength at 265 nm.The oil-water partition coefficient of this compound in different pH range was measured by shake flask method.The stability of the dichroa alkali hydrochloride in phosphate buffer solution with different pH after sterilization at 125℃ for 30 min was investigated.Ammonium sulfate gradient method was used to prepare dichroa alkali hydrochloride liposomes.The microcolumn was prepared by dextran gel and cation exchange resin,respectively.Then the free drug and liposome were separated by centrifugation,the drug content was measured,and the encapsulation efficiency was calculated.The t-test was performed using SPSS 20.0 software,the differences between these two methods were compared. Result: In the pH 6-9,the oil-water partition coefficient of dichroa alkali hydrochloride increased with increasing of pH,which was between 0.016 and 1.44;the recovery rate of dichroa alkali hydrochloride after sterilization was 37.16%-57.91%.Between the dextran gel microcolumn centrifugation and the cation exchange resin microcolumn centrifugation,there was no significant difference in the entrapment efficiency of the liposomes. Conclusion: Dichroa alkali hydrochloride is suitable for preparation of liposomes.However,its stability is not ideal,so the experimental temperature should be strictly controlled in the preparation process.Dextran gel microcolumn centrifugation and cation exchange resin microcolumn centrifugation can be used to determine the entrapment efficiency of dichroa alkali hydrochloride liposomes,and the cation exchange resin microcolumn centrifugation is suggested after comparison.

Objective:Compare the effects of 3 administration methods (tracheal perfusion, tail vein injection and aerosol inhalation) with bleomycin (BLM) in inducing pulmonary fibrosis in rats, in order to find out the optimal administration methods. Method:Eighty sprague-dawley (SD) male rats with SPF were randomly divided into aerosol inhalation blank group, single tracheal perfusion group(10 mg·kg^-1), multiple tracheal perfusion group(5 mg·kg^-1), single intravenous injection group(150 mg·kg^-1), multiple intravenous injection group(50 mg·kg^-1), single aerosol inhalation group (30 min)and multiple aerosol inhalation group(30 min). The mortality and body weight of rats in each group were observed at 7 d, 14 d and 28 d after the administration. And 28 days later after the administration, the lung coefficients of rats in each group were observed, paraffin sections were prepared, hematoxylin-eosin staining (HE) and Masson staining were performed, and the contents of hydroxyproline (HYP) and plasminogen activator inhibitor-1 (PAI-1) in lung tissues were detected by enzyme-linked immunosorbent assay (ELISA), so as to evaluate the alveoli inflammation and pulmonary fibrosis of rats in each group. Result:Compared with the aerosol inhalation blank group, the rats in the trachea perfusion group had the highest mortality among the drug treatment groups. The pulmonary coefficients of rats in the multiple intravenous injection group and the multiple inhalation group were significantly higher than those in the blank group(P<0.05,P<0.01). The multiple inhalation group was higher than the other model group and the single atomization model group. The results of HE and Masson staining showed thickening of pulmonary septum and higher degree of pulmonary interstitial fibrosis in tracheal perfusion group, intravenous injection group and multiple inhalation group. The degree of pulmonary fibrosis in the multiple inhalation group was more obvious than that in other groups. The results of ELISA showed that the levels of HYP and PAI-1 in lung tissues of rats in aerosol inhalation group and tracheal perfusion group were significantly higher than those in control group(P<0.05). The multiple inhalation group and the single atomization inhalation group were significantly higher than other modules. Conclusion:Bleomycin was inhaled repeatedly to establish pulmonary fibrosis model. The pathological injury and physiological indexes of the model rats were relatively stable, which conforms with the evolution process of pulmonary fibrosis.

Objective: To clarify the antitussive, expectorant, antipyretic and anti-inflammatory effects of Tanreqing inhalation solution, and provide basis and data support for further research and development of this preparation. Method: The methods of cough induced by ammonia and tracheal phenol red excretion were used to observe the antitussive and expectorant effects of Tanreqing inhalation solution in mice. The fever model of rats was established by intraperitoneal injection of bacterial lipopolysaccharide(LPS) to observe the antipyretic effect of the Tanreqing inhalation solution, the acute pneumonia model of rats was established by atomizing LPS inhalation, and the anti-inflammatory effect of Tanreqing inhalation solution was observed. Result: Tanreqing inhalation solution could reduce the number of coughs in mice induced by ammonia water, increase the amount of phenol red excretion in mouse trachea, decrease the levels of body temperature and its related regulatory factors of prostaglandin E₂(PGE₂) and cyclic adenosine monophosphate(cAMP) of rats induced by LPS, decrease the white blood cell(WBC) count and the neutrophil ratio(NEUT) in bronchoalveolar lavage fluid(BALF) of rats with LPS-induced acute pneumonia, and reduce the levels of nuclear transcription factor-κB(NF-κB) and interleukin-1β(IL-1β) in lung tissue. Conclusion: Tanreqing inhalation solution has obvious antitussive, expectorant, antipyretic and anti-inflammatory effects, which is worthy of further development and promotion.