Cellular senescence contributes to mechanical ventilation-induced diaphragm dysfunction by upregulating p53 signalling pathways.

BACKGROUND: Mechanical ventilation can cause acute atrophy and injury in the diaphragm, which are related to adverse clinical results. However, the underlying mechanisms of ventilation-induced diaphragm dysfunction (VIDD) have not been well elucidated. The current study aimed to explore the role of cellular senescence in VIDD. METHODS: A total of twelve New Zealand rabbits were randomly divided into 2 groups: (1) spontaneously breathing anaesthetized animals (the CON group) and (2) mechanically ventilated animals (for 48 h) in V-ACV mode (the MV group). Respiratory parameters were collected during ventilation. Diaphragm were collected for further analyses. RESULTS: Compared to those in the CON group, the percentage and density of sarcomere disruption in the MV group were much higher (p < 0.001, both). The mRNA expression of MAFbx and MuRF1 was upregulated in the MV group (p = 0.003 and p = 0.006, respectively). Compared to that in the CON group, the expression of MAFbx and MuRF1 detected by western blotting was also upregulated (p = 0.02 and p = 0.03, respectively). Moreover, RNA-seq showed that genes associated with senescence were remarkably enriched in the MV group. The mRNA expression of related genes was further verified by q-PCR (Pai1: p = 0.009; MMP9: p = 0.008). Transverse cross-sections of diaphragm myofibrils in the MV group showed more intensive positive staining of SA-ßGal than those in the CON group. p53-p21 axis signalling was elevated in the MV group. The mRNA expression of p53 and p21 was significantly upregulated (p = 0.02 and p = 0.05, respectively). The western blot results also showed upregulation of p53 and p21 protein expression (p = 0.03 and p = 0.05, respectively). Moreover, the p21-positive staining in immunofluorescence and immunohistochemistry in the MV group was much more intense than that in the CON group (p < 0.001, both). CONCLUSIONS: In a rabbit model, we demonstrated that mechanical ventilation in A/C mode for 48 h can still significantly induce ultrastructural damage and atrophy of the diaphragm. Moreover, p53-dependent senescence might play a role in mechanical ventilation-induced dysfunction. These findings might provide novel therapeutic targets for VIDD.

PEEP application during mechanical ventilation contributes to fibrosis in the diaphragm.

BACKGROUND: Positive end-expiratory airway pressure (PEEP) is a potent component of management for patients receiving mechanical ventilation (MV). However, PEEP may cause the development of diaphragm remodeling, making it difficult for patients to be weaned from MV. The current study aimed to explore the role of PEEP in VIDD. METHODS: Eighteen adult male New Zealand rabbits were divided into three groups at random: nonventilated animals (the CON group), animals with volume-assist/control mode without/ with PEEP 8 cmH2O (the MV group/ the MV + PEEP group) for 48 h with mechanical ventilation. Ventilator parameters and diaphragm were collected during the experiment for further analysis. RESULTS: There was no difference among the three groups in arterial blood gas and the diaphragmatic excursion during the experiment. The tidal volume, respiratory rate and minute ventilation were similar in MV + PEEP group and MV group. Airway peak pressure in MV + PEEP group was significantly higher than that in MV group (p < 0.001), and mechanical power was significantly higher (p < 0.001). RNA-seq showed that genes associated with fibrosis were enriched in the MV + PEEP group. This results were further confirmed on mRNA expression. As shown by Masson's trichrome staining, there was more collagen fiber in the MV + PEEP group than that in the MV group (p = 0.001). Sirius red staining showed more positive staining of total collagen fibers and type I/III fibers in the MV + PEEP group (p = 0.001; p = 0.001). The western blot results also showed upregulation of collagen types 1A1, III, 6A1 and 6A2 in the MV + PEEP group compared to the MV group (p < 0.001, all). Moreover, the positive immunofluorescence of COL III in the MV + PEEP group was more intense (p = 0.003). Furthermore, the expression of TGF-ß1, one of the most potent fibrogenic factors, was upregulated at both the mRNA and protein levels in the MV + PEEP group (mRNA: p = 0.03; protein: p = 0.04). CONCLUSIONS: We demonstrated that PEEP application for 48 h in mechanically ventilated rabbits will cause collagen deposition and fibrosis in the diaphragm. Moreover, activation of the TGF-ß1 signaling pathway and myofibroblast differentiation may be the potential mechanism of this diaphragmatic fibrosis. These findings might provide novel therapeutic targets for PEEP application-induced diaphragm dysfunction.

Shenmai injection improves doxorubicin cardiotoxicity via miR-30a/Beclin 1.

BACKGROUND: Shenmai Injection (SMI) has been widely used in the treatment of cardiovascular diseases and can reduce side effects when combined with chemotherapy drugs. However, the potential protective mechanism of SMI on the cardiotoxicity caused by anthracyclines has not been clear. METHODS: We used network pharmacology methods to collect the compound components in SMI and myocardial injury targets, constructed a 'drug-disease' target interaction network relationship diagram, and screened the core targets to predict the potential mechanism of SMI in treating cardiotoxicity of anthracyclines. In addition, the rat model of doxorubicin cardiotoxicity was induced by injecting doxorubicin through the tail vein. The rats were randomized in the model group, miR-30a agomir group, SMI low-dose group, SMI high-dose group，and the control group. The cardiac ultrasound was used to evaluate the structure and function of the rat heart. HE staining was used to observe the pathological changes of the rat myocardium. Transmission electron microscopy was used to observe myocardial autophagosomes. The expression of miR-30a and Beclin 1 mRNA in the rat myocardium was detected by RT-qPCR. Western Blot detected the expression of LC3-II/LC3-I and p62 protein. RESULTS: The network pharmacological analysis found that SMI could act synergistically through multiple targets and multiple pathways, which might exert a myocardial protective effect through PI3K-Akt signaling pathways and cancer microRNAs. In vivo, compared with the control group, the treatment group could improve the cardiac structure and function, and reduce myocardial pathological damage and the number of autophagosomes. The expression of miR-30a in the myocardium of rats in miR-30a agomir group and SMI group increased (P < 0.01)，Beclin 1 mRNA was decreased (P < 0.01)，LC3-Ⅱ/LC3-I protein was decreased (P < 0.01 or P < 0.05)，and p62 protein was increased (P < 0.01 or P < 0.05). CONCLUSIONS: SMI has the characteristics of multi-component, multi-target, and multi-pathway. It can inhibit myocardial excessive autophagy by regulating the expression of miR-30a/Beclin 1 and alleviate the myocardial injury induced by doxorubicin.

The emerging role of circular RNAs in cardiovascular diseases.

Cardiovascular disease (CVD) is one of the vital causes of morbidity and mortality, and the number of deaths from CVD has increased worldwide. Circular RNAs (circRNAs) is a novel type of endogenous noncoding RNA, which can form covalent closed continuous rings and are highly expressed in the eukaryotic transcriptome. In recent years, research on circRNAs have been increasing and the researchers have also become cumulatively aware of the association between circRNAs and CVD. This review highlights the biogenesis and functions of circRNAs and the role in cardiovascular diseases.

TMA/TMAO in Hypertension: Novel Horizons and Potential Therapies.

Hypertension is the most prevalent chronic disease and a risk factor for various diseases. Although its mechanisms and therapies are constantly being updated and developed, they are still not fully clarified. In recent years, novel gut microbiota and its metabolites have attracted widespread attention. It is strongly linked with physiological and pathological systems, especially TMA and TMAO. TMA is formed by intestinal microbial metabolism of choline and L-carnitine and converted into TMAO by FMO3. This paper collected and collated the latest researches and mainly discussed the following four parts. It introduced gut microbiota; provided a focus on TMA, TMA-producing bacteria, and TMAO; summarized the alternations in hypertensive patients and animals; discussed the mechanisms of TMAO with two respects; and summarized the regulatory factors may be as new interventions and therapies of hypertension. And, more relevant studies are still prospected to be accomplished between hypertension and TMA/TMAO for further clinical services.

Roles of Biomarkers in Myocardial Fibrosis.

Myocardial fibrosis is observed in various cardiovascular diseases and plays a key role in the impairment of cardiac function. Endomyocardial biopsy, as the gold standard for the diagnosis of myocardial fibrosis, has limitations in terms of clinical application. Therefore, biomarkers have been recommended for noninvasive assessment of myocardial fibrosis. This review discusses the role of biomarkers in myocardial fibrosis from the perspective of collagen.

Morphological and Functional Characteristics of Animal Models of Myocardial Fibrosis Induced by Pressure Overload.

Myocardial fibrosis is characterized by excessive deposition of myocardial interstitial collagen, abnormal distribution, and excessive proliferation of fibroblasts. According to the researches in recent years, myocardial fibrosis, as the pathological basis of various cardiovascular diseases, has been proven to be a core determinant in ventricular remodeling. Pressure load is one of the causes of myocardial fibrosis. In experimental models of pressure-overload-induced myocardial fibrosis, significant increase in left ventricular parameters such as interventricular septal thickness and left ventricular posterior wall thickness and the decrease of ejection fraction are some of the manifestations of cardiac damage. These morphological and functional changes have a serious impact on the maintenance of physiological functions. Therefore, establishing a suitable myocardial fibrosis model is the basis of its pathogenesis research. This paper will discuss the methods of establishing myocardial fibrosis model and compare the advantages and disadvantages of the models in order to provide a strong basis for establishing a myocardial fibrosis model.

Prevention and treatment of chronic heart failure through traditional Chinese medicine: Role of the gut microbiota.

In recent years, although the concept and means of modern treatment of chronic heart failure(CHF) are continually improving, the readmission rate and mortality rate are still high. At present, there is evidence that there is a link between gut microbiota and heart failure, so the intervention of gut microbiota and its metabolites is expected to become a potential new therapeutic target in heart failure. Traditional Chinese medicine(TCM) has apparent advantages in stabilizing the disease, improving heart function, and improving the quality of life. It can exert its effect by operating in the gut microbiota and is an ideal intestinal micro-ecological regulator. Therefore, this article will mainly discuss the advantages of traditional Chinese medicine in treating CHF, the relationship between traditional Chinese medicine and gut microbiota, the relationship between CHF and gut microbiota, and the ways of regulating gut microbiota by traditional Chinese medicine to prevent and treat CHF. It will specify the target and mechanism of traditional Chinese medicine treating heart failure by acting gut microbiota and provide ideas for the treatment of heart failure.

Anti-tumor effect of Scutellaria barbata D. Don extracts on ovarian cancer and its phytochemicals characterisation.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellaria barbata D. Don is a widely used medicinal herb in China. It possess various medicinal properties including antioxidative, anti-inflammatory and anti-cancer effects. The aim of this study was to explore whether Scutellaria barbata D. Don could inhibit the growth of ovarian cancer cells in vitro and further investigate the underlying mechanisms. MATERIALS AND METHODS: Effects of Scutellaria barbata D. Don on the viability of ovarian cancer A2780 cells were measured by MTT assay. Apoptosis was measured by cell morphologic observation through DAPI staining and Annexin V-FITC staining assay for apoptosis analysis. The migration of ovarian cancer cells which exposed to Scutellaria barbata D. Don were measured by wound healing and transwell chamber assays. The protein levels of caspase 3/9, Bcl-2 and MMP-2/9 in human ovarian cancer cells treated with Scutellaria barbata D. Don were assessed by western blotting analysis. The potential bioactive compounds were characterized by HPLC-Q-TOF-MS. RESULTS: The present study was to investigate the anticancer effects of crude extracts from Scutellaria barbata D. Don on ovarian cancer A2780 cells by MTT, DAPI staining, wound healing assay, transwell migration assay and western blotting analysis. Our study showed that Scutellaria barbata D. Don reduced the viability of A2780 cells and induced apoptosis by down-regulated Bcl-2 protein and increased Caspase 3/9 proteins. Furthermore, migration of A2780 cells were significantly inhibited by Scutellaria barbata D. Don and the underlying mechanism may be related to the decrease of MMP-2/9. The main constituents from Scutellaria barbata D. Don were identified to be thirteen flavonoids. A HPLC-Q-TOF-MS analysis of Scutellaria barbata D. Don indicated the presence of 14 flavonoids compounds, which may contribute to the anticancer activity of the Scutellaria barbata D. Don. CONCLUSIONS: Scutellaria barbata D. Don could inhibit proliferation and induce apoptosis in A2780 cells through mitochondrial pathway. Moreover, the inhibitory effect of Scutellaria barbata D. Don on the migration of ovarian cancer cells was associated with the down-regulation of MMP-2/9 expression. These findings could shed a light on the therapy of ovarian cancer.