Effect of preoperative inspiratory muscle training on postoperative outcomes in patients undergoing cardiac surgery: A systematic review and meta-analysis.

BACKGROUND: Cardiovascular disease is the most prevalent disease worldwide and places a great burden on the health and economic welfare of patients. Cardiac surgery is an important way to treat cardiovascular disease, but it can prolong mechanical ventilation time, intensive care unit (ICU) stay, and postoperative hospitalization for patients. Previous studies have demonstrated that preoperative inspiratory muscle training could decrease the incidence of postoperative pulmonary complications. AIM: To explore the effect of preoperative inspiratory muscle training on mechanical ventilation time, length of ICU stay, and duration of postoperative hospitalization after cardiac surgery. METHODS: A literature search of PubMed, Web of Science, Cochrane Library, EMBASE, China National Knowledge Infrastructure, WanFang, and the China Science and Technology journal VIP database was performed on April 13, 2022. The data was independently extracted by two authors. The inclusion criteria were: (1) Randomized controlled trial; (2) Accessible as a full paper; (3) Patients who received cardiac surgery; (4) Preoperative inspiratory muscle training was implemented in these patients; (5) The study reported at least one of the following: Mechanical ventilation time, length of ICU stay, and/or duration of postoperative hospitalization; and (6) In English language. RESULTS: We analyzed six randomized controlled trials with a total of 925 participants. The pooled mean difference of mechanical ventilation time was -0.45 h [95% confidence interval (CI): -1.59-0.69], which was not statistically significant between the intervention group and the control group. The pooled mean difference of length of ICU stay was 0.44 h (95%CI: -0.58-1.45). The pooled mean difference of postoperative hospitalization was -1.77 d in the intervention group vs the control group [95%CI: -2.41-(-1.12)]. CONCLUSION: Preoperative inspiratory muscle training may decrease the duration of postoperative hospitalization for patients undergoing cardiac surgery. More high-quality studies are needed to confirm our conclusion.

Celastrol attenuates hepatitis C virus translation and inflammatory response in mice by suppressing heat shock protein 90ß.

Hepatitis C virus (HCV) infection is one of the major factors to trigger a sustained hepatic inflammatory response and hence hepatocellular carcinoma (HCC), but direct-acting-antiviral (DAAs) was not efficient to suppress HCC development. Heat shock protein 90 kDa (HSP90) is highly abundant in different types of cancers, and especially controls protein translation, endoplasmic reticulum stress, and viral replication. In this study we investigated the correlation between the expression levels of HSP90 isoforms and inflammatory response marker NLRP3 in different types of HCC patients as well as the effect of a natural product celastrol in suppression of HCV translation and associated inflammatory response in vivo. We identified that the expression level of HSP90ß isoform was correlated with that of NLRP3 in the liver tissues of HCV positive HCC patients (R2 = 0.3867, P < 0.0101), but not in hepatitis B virus-associated HCC or cirrhosis patients. We demonstrated that celastrol (3, 10, 30 µM) dose-dependently suppressed the ATPase activity of both HSP90α and HSP90ß, while its anti-HCV activity was dependent on the Ala47 residue in the ATPase pocket of HSP90ß. Celastrol (200 nM) halted HCV internal ribosomal entry site (IRES)-mediated translation at the initial step by disrupting the association between HSP90ß and 4EBP1. The inhibitory activity of celastrol on HCV RNA-dependent RNA polymerase (RdRp)-triggered inflammatory response also depended on the Ala47 residue of HSP90ß. Intravenous injection of adenovirus expressing HCV NS5B (pAde-NS5B) in mice induced severe hepatic inflammatory response characterized by significantly increased infiltration of immune cells and hepatic expression level of Nlrp3, which was dose-dependently ameliorated by pretreatment with celastrol (0.2, 0.5 mg/kg, i.p.). This study reveals a fundamental role of HSP90ß in governing HCV IRES-mediated translation as well as hepatic inflammation, and celastrol as a novel inhibitor of HCV translation and associated inflammation by specifically targeting HSP90ß, which could be developed as a lead for the treatment of HSP90ß positive HCV-associated HCC.

Postoperative Pulmonary Complications in Patients With Transcatheter Tricuspid Valve Implantation-Implications for Physiotherapists.

Objectives: To investigate the incidence of postoperative pulmonary complications (PPCs) and short-term recovery after transcatheter tricuspid valve implantation (TTVI). Methods: A total of 17 patients diagnosed with severe tricuspid regurgitation who received a LuX-valve TTVI were included in this study. Spirometry lung function, maximal inspiratory pressure (MIP), and 6-min walk test distance (6MWD) were recorded. Prior to surgery, patients were stratified into high or low pulmonary risk groups based on published predefined criteria. A physiotherapist provided all patients with education on thoracic expansion exercises, effective cough and an inspiratory muscle training protocol at 50% of MIP for 3 days preoperatively. All patients received standard post-operative physiotherapy intervention including positioning, thoracic expansion exercises, secretion removal techniques and mobilization. Patients were assessed for PPCs as defined by the Melbourne-Group Score-version 2. Clinical characteristics and hospital stay, cost, functional capacity, and Kansas City Cardiomyopathy Questionnaire (KCCQ) heart failure score were recorded at admission, 1-week, and 30-days post-op. Results: The mean (SD) age of the 17 patients was 68.4 (8.0) years and 15 (88%) were female. Pre-surgical assessment identified 8 patients (47%) at high risk of PPCs. A total of 9 patients (53%) developed PPCs between the 1st and 3rd day post-surgery, and 7 of these 9 patients were amongst the 8 predicted as "high risk" prior to surgery. One patient died before the 30 day follow up. Pre-operative pulmonary risk assessment score, diabetes mellitus, a low baseline MIP and 6MWD were associated with a high incidence of PPCs. Compared to those without PPCs, patients with PPCs had longer ICU and hospital stay, and higher hospitalization cost. At 30 days post-surgery, patients without PPCs maintained higher MIP and 6MWD compared to those with PPCs, but there were no significant between-group differences in other lung function parameters nor KCCQ. Conclusion: This is the first study to report the incidence of PPCs post TTVI. Despite a 3-day prehabilitation protocol and standard post-operative physiotherapy, PPCs were common among patients after TTVI and significantly impacted on hospital and short-term recovery and outcomes. In the majority of patients, PPCs could be accurately predicted before surgery. A comprehensive prehabilitation program should be considered for patients prior to TTVI. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [ChiCTR2000039671].

A Potent Multi-functional Neuroprotective Derivative of Tetramethylpyrazine.

Neurodegenerative disorders are one of the leading causes of death among the elderly. Therapeutic approaches with a single target have proven unsuccessful in treating these diseases. Structural combination of multi-functional compounds may lead to a molecule with multiple properties. In this study, we designed and synthesized T-006, a novel analog derived from two multi-functional neuroprotective chemicals, tetramethylpyrazine and J147. The methoxyphenyl group of J147 was replaced by tetramethylpyrazine. Bioactivity evaluation showed that T-006 at very low concentrations had multi-functional neuroprotective effects including rescuing iodoacetic acid-induced neuronal loss, preventing oxidative stress-induced neurotoxicity and reducing glutamate-induced excitotoxicity in vitro. Most importantly, T-006 significantly ameliorated memory impairments in APP/PS1 transgenic mice. These multiple functions of a single molecule suggest that T-006 is a promising novel neuroprotective agent for treating various neurodegenerative disorders, including and in particular Alzheimer's disease.

SIRT1 Protects Against Oxidative Stress-Induced Endothelial Progenitor Cells Apoptosis by Inhibiting FOXO3a via FOXO3a Ubiquitination and Degradation.

Cell loss due to apoptosis induced by oxidative stress is a major hurdle for endothelial progenitor cells (EPCs)-based therapy. Sirtuin 1 (SIRT1) plays important roles in many pathophysiological processes by deacetylating various substrates, including forkhead transcription factor (FOXO). However, after deacetylation, the fate of FOXO protein remains to be explored. In the present study, we investigated whether SIRT1 exerted a protective effect on hydrogen peroxide (H(2)O(2))-induced EPCs apoptosis and, if so, what the underlying mechanism might be. EPCs were isolated and obtained from human umbilical cord blood by density gradient centrifugation and identified by morphology, tube formation ability, cell surface markers, and the ability to take up acetylated low-density lipoprotein (Dil-Ac-LDL) and bind ulex europaeus agglutinin 1 (FITC-UEA-1). Immunofluorescence showed that SIRT1 is localized in the nucleus of EPCs in the presence or absence of H(2)O(2). SIRT1 protein level in EPCs was increased by the treatment with H(2)O(2) for 24 h. Incubation of EPCs with H(2)O(2) dose dependently induced EPCs apoptosis. SIRT1 overexpression reduced the rate of EPCs apoptosis induced by H(2)O(2), whereas SIRT1 downregulation and EX527, a specific SIRT1 inhibitor, exerted the opposite effect. SIRT1 overexpression decreased the total FOXO3a protein expression, whereas SIRT1 downregulation and EX527 increased the amount of FOXO3a protein. SIRT1 reduced FOXO3a transcriptional activity according to Bim expression. Co-immunoprecipitation assay showed that SIRT1 could bind to FOXO3a, reduce its acetylation level and increase its ubiquitination level. To sum up, our work demonstrated that SIRT1 had a pivotally protective role in the regulation of EPCs apoptosis induced by H(2)O(2) and that SIRT1 protected against apoptosis by inhibiting FOXO3a via FOXO3a ubiquitination and subsequent degradation.

A novel tetramethylpyrazine bis-nitrone (TN-2) protects against 6-hydroxyldopamine-induced neurotoxicity via modulation of the NF-κB and the PKCα/PI3-K/Akt pathways.

INTRODUCTION: The natural product tetramethylpyrazine (TMP) has a variety of biologic activities, including neuroprotection. Nitrones are powerful free radical scavengers. We have designed and synthesized a TMP derivative, TN-2, which is armed with two nitrone moieties. AIMS: In this study, we investigated the neuroprotective effect of TN-2 against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro and in zebrafish. METHODS: PC12 cells, zebrafish and rats were exposed to 6-OHDA challenge. MTT assay, LDH release, Hoechst staining, DAF-FM staining, luciferase reporter construct transfection, and western blotting were applied to detect cell viability, apoptosis, intracellular nitric oxide (NO), NF-κB transcriptional activity and proteins expression. In zebrafish, whole-mount staining and real-time PCR were performed to quantify dopaminergic neurons and mRNA expression. Hematoxylin and eosin staining and immunohistochemistry for glial fibrillary acidic protein were used to detect the astrocyte activation in the unilateral 6-OHDA rat model. RESULTS: TN-2 but not TMP exhibited potent neuroprotective effect against 6-OHDA-induced apoptosis in PC12 cells. Moreover, TN-2 prevented dopaminergic neuron loss and suppressed mRNA expression of pro-inflammatory genes, including IL-1ß, TNF-α and COX-2, in 6-OHDA-treated zebrafish. TN-2 remarkably attenuated microglial/astrocyte activation in the unilateral 6-OHDA rat model. The mechanistic study demonstrated that TN-2 inhibited over-production of intracellular NO and protein expression of inducible nitric oxide synthase through down-regulating NF-κB activity. Additionally, the PKCα/PI3-K/Akt pathway was also involved in the neuroprotection of TN-2. CONCLUSION: These results suggest that TN-2 protected against 6-OHDA-induced neurotoxicity via modulating the NF-κB-medicated neuroinflammation and PKCα/PI3-K/Akt pathways.

Sunitinib produces neuroprotective effect via inhibiting nitric oxide overproduction.

BACKGROUND: Sunitinib is an inhibitor of the multiple receptor tyrosine kinases (RTKs) for cancer therapy. Some sunitinib analogues could prevent neuronal death induced by various neurotoxins. However, the neuroprotective effects of sunitinib have not been reported. METHODS: Cerebellar granule neurons (CGNs) and SH-SY5Y cells were exposed to low-potassium and MPP(+) challenges, respectively. MTT assay, FDA/PI staining, Hoechst staining, DAF-FM, colorimetric nitric oxide synthase (NOS) activity assay, and Western blotting were applied to detect cell viability, NO production, NOS activity, and neuronal NOS (nNOS) expression. Short hairpin RNA was used to decrease nNOS expression. In vitro NOS enzyme activity assay was used to determine the direct inhibition of nNOS by sunitinib. RESULTS: Sunitinib prevented low-potassium-induced neuronal apoptosis in CGNs and MPP(+) -induced neuronal death in SH-SY5Y cells. However, PTK787, another RTK inhibitor, failed to decrease neurotoxicity in the same models. Sunitinib reversed the increase in NO levels, NOS activity, and nNOS expression induced by low potassium or MPP(+) . Knockdown of nNOS expression partially abolished the neuroprotective effects of sunitinib. Moreover, sunitinib directly inhibited nNOS enzyme activity. CONCLUSIONS: Sunitinib exerts its neuroprotective effects by inhibiting NO overproduction, possibly via the inhibition of nNOS activity and the decrease in nNOS expression.

Hydrogen peroxide induced impairment of endothelial progenitor cell viability is mediated through a FoxO3a dependant mechanism.

OBJECTIVES: Increased oxidative stress has been suggested to contribute to the functional impairment of endothelial progenitor cells (EPCs). The Forkhead box O transcription factors (FoxOs) are critical regulators involved in various cellular processes including cell apoptosis. Here, we investigated whether FoxOs are required in oxidative stress induced EPC apoptosis. METHODS AND RESULTS: EPCs were cultured from cord blood derived mononuclear cells and treated with hydrogen peroxide (H2O2) for induction of oxidative stress. Incubation with H2O2 dose dependently reduced viability and increased apoptosis in EPCs. Western blotting showed that EPCs predominantly expressed FoxO3a and the expression was markedly increased upon H2O2 treatment. Transduction with adenoviral vectors expressing either a wide-type or a non-phosphorylatable, constitutively active mutant of FoxO3a led to further increased apoptosis of EPCs after H2O2 treatment. Conversely, FoxO3a silencing rescued EPCs from these H2O2 induced deleterious effects. Overexpression of FoxO3a also increased the level of the pro-apoptotic protein Bim, whereas FoxO3a silencing downregulated H2O2 induced Bim expression. Furthermore, Matrigel assay demonstrated that FoxO3a overexpression significantly impaired the tube forming ability of EPCs, whereas its silencing completely protected EPCs from H2O2 induced decrease of capillary formation. CONCLUSIONS: These data suggest that oxidative stress induced impairment of EPC survival is mediated through a FoxO3a dependant mechanism, possibly by transcriptional regulation of Bim. Our data indicate FoxO3a as a potential therapeutic target for improvement of EPC number and function in patients with ischemic heart disease.

Delivery of therapeutic AGT shRNA by PEG-Bu for hypertension therapy.

Gene silencing by RNA interference (RNAi) is a promising approach for gene therapy. However, up to today, it is still a major challenge to find safe and efficient non-viral vectors. Previously, we reported PEI-Bu, a small molecular weight PEI derivative, as an efficient non-viral carrier. However, like many PEI-based polymers, PEI-Bu was too toxic. In order to reduce cytotoxicity while maintain or even enhance transfecion efficiency, we modified PEI-Bu with poly(ethylene glycol) (PEG) to obtain PEG-Bu, and used it to delivery a theraputic short hairpin RNA (shRNA) targeting angiotensinogen (AGT) to normal rat liver cells (BRL-3A), which was a key target for the treatment of hypertension. The structure of PEG-Bu was confirmed by proton nuclear magnetic resonance ((1)H-NMR). Gel permeation chromatography (GPC) showed that the weight average molecular weight (Mw) of PEG-Bu was 5880 Da, with a polydispersity of 1.58. PEG-Bu could condense gene cargo into spherical and uniform nanoparticles with particle size (65-88 nm) and zeta potential (7.3-9.6 mV). Interestingly and importantly, PEG-Bu displayed lower cytotoxicity and enhanced tranfection efficiency than PEI-Bu after PEGylation in both normal cells BRL-3A and tumor cells HeLa. Moreover, PEG-Bu could efficiently delivery AGT shRNA to knockdown the AGT expression. To sum up, PEG-Bu would be a promising non-viral vector for delivering AGT shRNA to BRL-3A cells for hypertension therapy.

A novel andrographolide derivative AL-1 exerts its cytotoxicity on K562 cells through a ROS-dependent mechanism.

Andrographolide-lipoic acid conjugate (AL-1) is a new in-house synthesized chemical entity, which was derived by covalently linking andrographolide with lipoic acid. However, its anti-cancer effect and cytotoxic mechanism remains unknown. In this study, we found that AL-1 could significantly inhibit cell viability of human leukemia K562 cells by inducing G2/M arrest and apoptosis in a dose-dependent manner. Thirty-one AL-1-regulated protein alterations were identified by proteomics analysis. Gene ontology and ingenuity pathway analysis revealed that a cluster of proteins of oxidative redox state and apoptotic cell death-related proteins, such as PRDX2, PRDX3, PRDX6, TXNRD1, and GLRX3, were regulated by AL-1. Functional studies confirmed that AL-1 induced apoptosis of K562 cells through a ROS-dependent mechanism, and anti-oxidant, N-acetyl-L-cysteine, could completely block AL-1-induced cytotoxicity, implicating that ROS generation played a vital role in AL-1 cytotoxicity. Accumulated ROS resulted in oxidative DNA damage and subsequent G2/M arrest and mitochondrial-mediated apoptosis. The current work reveals that a novel andrographolide derivative AL-1 exerts its anticancer cytotoxicity through a ROS-dependent DNA damage and mitochondrial-mediated apoptosis mechanism.

[Inhibitory effect of TBN on platelet aggregation in rabbit].

OBJECTIVE: To investigate the inhibitory effect of TBN on rabbit platelet aggregation in vitro and in vivo, and compare with tetramethylpyrazine (TMP). METHODS: To seek out the maximum of platelet aggregation (expressed in percentage) within 5 minutes which was induced by ADP, PAF and AA according to the Born turbidimetric method with a Platelet-Aggregometer. RESULTS: TBN significantly inhibited platelet aggregation induced by ADP, PAF and AA both in vitro and in vivo. TBN was more active than TMP. CONCLUSION: TBN has significant activity inhibiting platelet aggregation induced by ADP, PAF and AA in vitro and in vivo.