The clinical effectiveness of sivelestat in treating sepsis patients with both acute respiratory distress syndrome and septic cardiomyopathy.

BACKGROUND: We aimed to assess the efficacy of the neutrophil elastase inhibitor, sivelestat, in the treatment of sepsis-induced acute respiratory distress syndrome (ARDS) and septic cardiomyopathy (SCM). METHODS: Between January 2019 and December 2021, we conducted a randomized trial on patients who had been diagnosed with sepsis-induced acute respiratory distress syndrome (ARDS) and septic cardiomyopathy (SCM) at Wuhan Union Hospital. The patients were divided into two groups by random envelop method, the Sivelestat group and the Control group. We measured the serum concentrations of Interleukin (IL)-6, IL-8, Tumor necrosis factor-α (TNF-α), and High-mobility group box 1 (HMGB1) at five time points, which were the baseline, 12 h, 24 h, 48 h, and 72 h after admission to the ICU. We evaluated the cardiac function by sonography and the heart rate variability (HRV) with 24-hour Holter recording between the time of admission to the intensive care unit (ICU) and 72 h after Sivelestat treatment. RESULTS: From January 2019 to December 2021, a total of 70 patients were included in this study. The levels of IL-6, IL-8, and TNF-α were significantly lower in the Sivelestat group at different time points (12 h, 24 h, 48 h, and 72 h). HMGB1 levels were significantly lower at 72 h after Sivelestat treatment (19.46 ± 2.63pg/mL vs. 21.20 ± 2.03pg/mL, P = 0.003). The stroke volume (SV), tricuspid annular plane systolic excursion (TAPSE), early to late diastolic transmitral flow velocity (E/A), early (e') and late (a') diastoles were significantly low in the Control group compared with the Sivelestat group. Tei index was high in the Control group compared with the Sivelestat group (0.60 ± 0.08 vs. 0.56 ± 0.07, P = 0.029). The result of HRV showed significant differences in standard deviation of normal-to-normal intervals (SDNN), low frequency (LF), and LF/HF (high frequency) between the two groups. CONCLUSIONS: Sivelestat can significantly reduce the levels of serum inflammatory factors, improve cardiac function, and reduce heart rate variability in patients with Sepsis-induced ARDS and SCM.

Mechanism of microRNA-218-5p in mitochondrial biogenesis of sepsis-induced acute kidney injury by the regulation of PGC-1α.

BACKGROUND: Sepsis-induced acute kidney injury (SI-AKI) is a kind of kidney dysfunction, which brings a lot of suffering. This study aimed to figure out the role of the miR-218-5p/PGC-1α axis in SI-AKI. METHODS: AKI mouse model was established through cecal ligation and puncture. PGC-1α expression was activated using an activator ZLN005 before the serum and tissue samples were collected. Next, pathological structure and apoptosis of kidney tissues were observed. Levels of blood urea nitrogen, serum creatinine and indicators of inflammation and oxidative stress were assessed. Moreover, reactive oxygen species and mitochondrial membrane potential levels, adenosine 5'-triphosphate content and mitochondrial ultrastructure of kidney tissues were observed. HK2 cells were treated by lipopolysaccharide (LPS) to mimic sepsis in vitro, followed by evaluation of cell survival and apoptosis, inflammation and oxidative stress. Subsequently, the binding relation between PGC-1α and miR-218-5p was predicted and validated. Then expression of PGC-1α and miR-218-5p was detected. PGC-1α and miR-218-5p expression were intervened to detect their influences in mitochondrial biogenesis. At last, miR-218-5p was overexpressed in ZLN005 (PGC-1α activating agent) pretreated SI-AKI mice to validate the mechanism. RESULTS: PGC-1α is poorly expressed in SI-AKI, but overexpression of PGC-1α using ZLN005 alleviated SI-AKI injury and promoted mitochondrial biogenesis in AKI mice, and relieved LPS-induced cell injury. PGC-1α is a target of miR-218-5p. Downregulation of miR-218-5p expression in HK2 cells attenuated mitochondrial biogenesis disorder. Inhibition of PGC-1α annulled the role of miR-218-5p silencing in cells. In vivo, miR-218-5p overexpression partly reversed the protective role of ZLN005 in SI-AKI mice. CONCLUSION: miR-218-5p targeted PGC-1α to disrupt mitochondrial biogenesis, thereby exacerbating SI-AKI.

Upregulated microRNA-450b-5p represses the development of acute liver failure via modulation of liver function, inflammatory response, and hepatocyte apoptosis.

OBJECTIVE: It has been evidenced that microRNAs (miRs) exert crucial effects on acute liver failure (ALF), while the detailed function of miR-450b-5p in ALF progression remained obscure. The purpose of this research was to unravel the regulatory mechanism of miR-450b-5p in ALF via modulating Mouse Double Minute 2 protein (MDM2). METHODS: ALF was induced in mice by intraperitoneal injection of d-galactosamine ( d-GalN) and lipopolysaccharide (LPS). Adenoviruses containing overexpressed miR-450b-5p, MDM2 shRNA, and overexpressed MDM2 sequences were utilized to manipulate miR-450b-5p and MDM2 expression in the liver before the mice were treated with d-GalN/LPS-induced ALF. Subsequently, miR-450b-5p and MDM2 expression levels in liver tissues of ALF mice were examined. Serum biochemical parameters of liver function were tested, serum inflammatory factors were assessed, and the histopathological changes and hepatocyte apoptosis in liver tissues were observed. The relation between miR-450b-5p and MDM2 was verified. RESULTS: In ALF mice, miR-450b-5p was low-expressed while MDM2 was high-expressed. The upregulation of miR-450b-5p or downregulation of MDM2 could alleviate liver function, mitigate the serum inflammatory response and pathological changes in liver tissues, as well as inhibit the apoptosis of hepatocytes. MiR-450b-5p targeted MDM2. MDM2 overexpression reversed the repressive effects of elevated miR-450b-5p on ALF. CONCLUSION: The upregulated miR-450b-5p blocks the progression of ALF via targeting MDM2. This study contributes to affording novel therapeutic targets for ALF treatment.

[ACE2 agonist DIZE alleviates lung injury induced by limb ischemia-reperfusion in mice].

This study was aimed to explore the effect of angiotensin converting enzyme 2 (ACE2) agonist diminazene aceturate (DIZE) on acute lung injury (ALI) induced by limb ischemia-reperfusion (LIR) in mice. Male 8-week-old wild-type and hACE2 transgenic ICR mice were randomly divided into 6 groups (6 in each group), including wild-type control (W), wild-type model (WL), wild-type model with DIZE administration (WLD), transgenic control (T), transgenic model (TL), and transgenic model with DIZE administration (TLD) groups. LIR model was established by 4 h reperfusion following 2 h ischemia of bilateral hindlimbs with rubber bands in mice. The WLD and TLD groups were pretreated with DIZE (15 mg/kg, i.p.) for 4 weeks before LIR. At the end of LIR, the mice were sacrificed and lung tissues were sampled. Indexes for evaluating lung injury include organ coefficient and wet/dry weight ratio (W/D), cell count and protein concentration of bronchoalveolar lavage fluid (BALF), as well as morphological change and pathological score were detected. Angiotensin II (Ang II) and Ang (1-7) levels in lung tissue were determined by using ELISA commercial kits. And the protein expressions of angiotensin II type 1 receptor (AT1) and Mas receptor protein in lung tissue were detected by Western blot. The results were as follows: (1) There was obvious lung injury in both the WL and TL groups. The lung injury in the TL group was lighter than that in the WL group. DIZE could attenuate the lung injury in both the two groups. (2) The WL group showed increased Ang II and decreased Ang (1-7) levels, whereas the TL group did not exhibit any changes of these two proteins. DIZE decreased the level of Ang II in both the WL and TL groups, and increased the level of Ang (1-7) in the WL group. (3) In the WL and TL groups, AT1 and Mas receptor protein expressions were up-regulated. DIZE reversed the change of AT1 protein expression, whereas further increased Mas receptor expression in both the two groups. These results suggest that DIZE may improve the renin-angiotensin system homeostasis by regulating ACE2-Ang (1-7)-Mas axis in local lung tissue and play a protective role in LIR-induced ALI in mice.

Oxidative stress promotes myocardial fibrosis by upregulating KCa3.1 channel expression in AGT-REN double transgenic hypertensive mice.

The intermediate-conductance Ca2+-activated K+ (KCa3.1) channels play a pivotal role in the cardiac fibroblast proliferation and inflammatory reaction during the progression of myocardial fibrosis. However, the relationship between KCa3.1 expression and oxidative stress, the important factor of promoting fibrosis, has not been clearly established. This study was designed to investigate whether the role of oxidative stress in promoting myocardial fibrosis is related to KCa3.1 channel by using biochemical approaches. It was found that mean blood pressure, plasma Ang II level, and myocardium malondialdehyde (MDA) content of angiotensinogen-renin (AGT-REN) double transgenic hypertension (dTH) mice were higher than those in wild-type (WT) mice of the same age (4, 8 and 12 months) and were significantly increased with age. However, plasma Ang (1-7) level and myocardium superoxide dismutase (SOD) activity showed a downward trend and were lower than those of the same-aged WT mice (4, 8 and 12 months). In addition, protein expression of myocardium KCa3.1 channel in 4-, 8-, and 12-month-old dTH mice were significantly higher than that of the same-aged WT mice and gradually increased with age. TRAM-34, a blocker of KCa3.1 channel, and losartan mitigated the myocardial structural and functional damage by inhibiting collagen deposition and decreasing the expression of ß-MHC. After intervention of ROS scavenger N-acetyl cysteine (NAC) and NADPH inhibitor apocynin (Apo) in 6-month-old dTH mice for 4 weeks, myocardial oxidative stress level was reduced and KCa3.1 channel protein expression was decreased. Meanwhile, Apo inhibited the myocardium p-ERK1/2/T-ERK protein expression in dTH mice, and after blockage of ERK1/2 pathway with PD98059, the KCa3.1 protein expression was reduced. These results demonstrate for the first time that KCa3.1 channel is likely to be a critical target on the oxidative stress for its promoting role in myocardial fibrosis, and the ERK1/2 pathway may be involved in the regulation of oxidative stress to KCa3.1.

Association between circulating angiotensin-converting enzyme 2 and cardiac remodeling in hypertensive patients.

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) plays a vital role in the pathogenesis of hypertension-induced cardiac remodeling and exhibits cardioprotective properties in hypertensive animal models. Evidence that ACE2 is an important regulator of hypertensive cardiac remodeling in humans has not been addressed directly yet. METHODS: A total of 161 patients with essential hypertension and 47 age- and sex-matched normotensive healthy subjects were consecutively recruited. Serum concentration levels of ACE2 were determined by enzyme-linked immunosorbent assay. Cardiac structural and functional parameters were measured by echocardiography. RESULTS: Serum ACE2 concentrations were higher in hypertensive patients compared to healthy subjects (170.31 [83.50-707.12] pg/ml in patients versus 59.28 [39.71-81.81] pg/ml in healthy subjects, P<0.001). After adjustment for confounders, including age, sex, body mass index, snoring, smoking, duration of hypertension, comorbidities, medication use, mean arterial pressure and N-terminal pro-brain natriuretic peptide, serum ACE2 concentrations were positively correlated with left atrial diameter, left ventricular end-diastolic diameter and left ventricular mass in hypertensive patients. Moreover, multiple regression analyses adjusting for covariates revealed that serum ACE2 concentrations were also independently associated with left ventricular ejection fraction and late diastolic filling velocities of the mitral inflow. CONCLUSIONS: This study reveals an elevated serum concentration of ACE2 and independent associations between serum ACE2 and echocardiographic parameters in hypertensive patients.

Protective role of ACE2-Ang-(1-7)-Mas in myocardial fibrosis by downregulating KCa3.1 channel via ERK1/2 pathway.

The intermediate-conductance Ca2+-activated K+ (KCa3.1) channel plays a vital role in myocardial fibrosis induced by angiotensin (Ang) II. However, as the antagonists of Ang II, the effect of angiotensin-converting enzyme 2 (ACE2)-angiotensin-(1-7)-Mas axis on KCa3.1 channel during myocardial fibrosis remains unknown. This study was designed to explore the function of KCa3.1 channel in the cardioprotective role of ACE2-Ang-(1-7)-Mas. Wild-type (WT) mice, hACE2 transgenic mice (Tg), and ACE2 deficiency mice (ACE2-/-) were administrated with Ang II by osmotic mini-pumps. As the activator of ACE2, diminazene aceturate (DIZE) inhibited increase of blood pressure, collagen deposition, and KCa3.1 protein expression in myocardium of WT mice induced by Ang II. In Tg and ACE2-/- mice, besides the elevation of blood pressure, Ang II induced transformation of cardiac fibroblast into myofibroblast and resulted in augmentation of hydroxyproline concentration and collagen deposition, as well as KCa3.1 protein expression, but the changes in ACE2-/- mice were more obvious than those in Tg mice. Mas antagonist A779 reduced blood pressure, myocardium fibrosis, and myocardium KCa3.1 protein expression by Ang II in Tg mice, but activation of KCa3.1 with SKA-31 in Tg mice promoted the pro-fibrogenic effects of Ang II. Respectively, in ACE2-/- mice, TRAM-34, the KCa3.1 blocker, and Ang-(1-7) inhibited increase of blood pressure, collagen deposition, and KCa3.1 protein expression by Ang II. Moreover, DIZE and Ang-(1-7) depressed p-ERK1/2/t-ERK increases by Ang II in WT mice, and after blockage of ERK1/2 pathway with PD98059, the KCa3.1 protein expression was reduced in WT mice. In conclusion, the present study demonstrates that ACE2-Ang-(1-7)-Mas protects the myocardium from hypertension-induced injury, which is related to its inhibiting effect on KCa3.1 channels through ERK1/2 pathway. Our results reveal that KCa3.1 channel is likely to be a critical target on the ACE2-Ang-(1-7)-Mas axis for its protective role in myocardial fibrosis and changes of KCa3.1 induced by homeostasis of ACE-Ang II-AT1 axis and ACE2-Ang-(1-7)-Mas axis may be a new therapeutic target in myocardial fibrosis.

[In vivo study of the renoprotective effects of EGCG in diabetic db/db mice].

OBJECTIVE: To explore the renoprotective effects of (-)-epigallocatechin-3-gallate (EGCG) and its potential mechanism in type 2 diabetic db/db mice. METHODS: 8-week-old db/db mice (6 h fasting plasma glucose >16.7 mmol/L) were allocated randomly into Control group (non-intervention group, n=8), EGCG A group (50 mg·kg(-1)·d(-1,)n=8), EGCG B group (100 mg·kg(-1)·d(-1,)n=8). Before the study and after the intervention (in the 4(th)and 8(th)week), the body weight, the level of fasting plasma glucose, oral glucose tolerance test (OGTT) were measured and 24 h urine samples were collected. 24 h proteinuria was measured by routine chemical method. The levels of angiotensin Ⅱ(AngⅡ), fasting plasma insulin and urinary 8-OHdG were measured with enzyme-linked immunosorbent assay (ELISA). The protein expression levels of angiotensin Ⅱ type 1 receptor (AT-1R), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit P22-phox, NADPH oxidase subunit P47-phox, phospho-extracellular regulated protein kinases (p-Erk1/2), phospho-P38 mitogen-activated protein kinase (p-P38MAPK), phospho -phosphatidylinositol 3-hydroxy kinase (p-PI3K) and phospho-protein kinase B (p-AKT) were determined by Western blot. The renal pathological changes were examined by the method of PAS (periodic acid-Schiff stain). RESULTS: After 8 weeks of treatment with EGCG, the level of fasting plasma glucose decreased[(14.4±1.0) mmol/L, (14.2±0.7) mmol/L vs. (17.2±0.8) mmol/L]; the level of fasting plasma insulin increased[(13.2±1.2)mU/L, (13.4±1.3) mU/L vs. (9.9±1.0) mU/L]; the area under the curve (AUC) of OGTT decreased[(49.3±1.8) mmol·L(-1)·h(-1,)(44.8±0.7) mmol·L(-1)·h(-1)vs. (60.0±0.8) mmol·L(-1)·h(-1)]; the level of 24 h proteinuria[(8.8±1.0) mg, (8.6±1.1) mg vs. (11.7±1.3) mg]and urinary 8-OHdG[(90±5) ng/d, (78±5) ng/d vs. (118±10) ng/d]decreased; the level of serum Ang-Ⅱ[(498±23) ng/L, (511±19) ng/L vs. (688±17) ng/L]and renal cortex AngⅡ[(367±5) ng/L, (384±10) ng/L vs. (406±7) ng/L]decreased; the expression levels of AT-1R, P22-phox, P47-phox, p-Erk1/2, p-P38MAPK downregulated obviously and the expression levels of p-PI3K, p-AKT increased significantly (P<0.05), and renal pathology improved as compared with the control group. After 8 weeks of treatment with EGCG, the level of urinary 8-OHdG decreased (P=0.007) and the AUC of OGTT also decreased (P=0.01) in EGCG B group when compared with the EGCG A group. CONCLUSION: EGCG protects the kidney in diabetic db/db mice via anti-oxidative stress pathway, as well as inhibiting Erk1/2-P38MAPK pathway and improving PI3K-AKT signaling transduction pathway.

Blocking follistatin-like 1 attenuates bleomycin-induced pulmonary fibrosis in mice.

Progressive tissue fibrosis is a cause of major morbidity and mortality. Pulmonary fibrosis is an epithelial-mesenchymal disorder in which TGF-ß1 plays a central role in pathogenesis. Here we show that follistatin-like 1 (FSTL1) differentially regulates TGF-ß and bone morphogenetic protein signaling, leading to epithelial injury and fibroblast activation. Haplodeletion of Fstl1 in mice or blockage of FSTL1 with a neutralizing antibody in mice reduced bleomycin-induced fibrosis in vivo. Fstl1 is induced in response to lung injury and promotes the accumulation of myofibroblasts and subsequent fibrosis. These data suggest that Fstl1 may serve as a novel therapeutic target for treatment of progressive lung fibrosis.

Molecular cloning and characterization of a gene encoding RING zinc finger ankyrin protein from drought-tolerant Artemisia desertorum.

A RING zinc finger ankyrin protein gene,designated AdZFP1, was isolated from drought-tolerant Artemisia desertorum Spreng by mRNA differential display and RACE. Its cDNA was 1723 bp and encoded a putative protein of 445 amino acids with a predicted molecular mass of 47.9 kDa and an isoelectric point (pI) of 7.49. A typical C3HC4- type RING finger domain was found at the C-terminal region of the AdZFP1 protein,and several groups of ankyrin repeats were found at the N-terminal region. Alignments of amino acid sequence showed that AdZFP1 was 66% identical to the Arabidopsis thaliana putative RING zinc finger ankyrin protein AAN31869. Transcriptional analysis showed that AdZFP1 was inducible under drought stress in root,stem and leaf of the plant.Semi-quantitative reverse- transcriptase-polymerase chain reaction (RT-PCR) analysis showed that the transcript of AdZFP1 was strongly induced by exogenous abscisic acid (ABA) and also by salinity,cold and heat to some extent. Overexpression of the AdZFP1 gene in transgenic tobacco enhanced their tolerance to drought stress.