Objective To establish a weightlessness simulation animal model using miniature pigs, leveraging the characteristic of multiple systems’ tissue structures and functions similar to those of humans, and to observe pathophysiological changes, providing a new method for aerospace research. Methods Nine standard-grade miniature pigs were selected and randomly divided into an experimental group (n=7) and a control group (n=2). The experimental group was fixed using customized metal cages, with canvas slings suspending their hind limbs off the ground, and the body positioned at a -20° angle relative to the ground to simulate unloading for 30 days (24 hours a day). Data on body weight, blood volume, and blood biochemistry indicators were collected at different time points for statistical analysis of basic physiological changes. After the experiment, the miniature pigs were euthanized and tissue samples were collected for histopathological observation of the cardiovascular, skeletal and muscle systems HE and Masson staining. Statistical analysis was also conducted on the thickness of arterial vessels and the diameter of skeletal muscle fibers. Additionally, western blotting was employed to detect the expression levels of skeletal muscle atrophy-related proteins, including muscle-specific RING finger protein 1 (MuRf-1) and muscle atrophy F-box (MAFbx, as known as Atrogin-1), while immunohistochemistry was used to detect the expression of glial fibrillary acidic protein (GFAP), an indicator of astrocyte activation in the brain, reflecting the pathophysiological functional changes across systems. Results After hindlimb unloading, the experimental group showed significant decreases in body weight (P<0.001) and blood volume (P<0.01). During the experiment, hemoglobin, hematocrit, and red blood cell count levels significantly decreased (P<0.05) but gradually recovered. The expression levels of alanine aminotransferase and γ-glutamyltransferase initially decreased (P<0.05) before rebounding, while albumin significantly decreased (P<0.001) and globulin significantly increased (P<0.01). Creatinine significantly decreased (P<0.05). The average diameter of gastrocnemius muscle fibers in the experimental group significantly shortened (P<0.05), with a leftward shift in the distribution of muscle fiber diameters and an increase in small-diameter muscle fibers. Simultaneously, Atrogin-1 expression in the gastrocnemius and paravertebral muscles significantly increased (P<0.05). These changes are generally consistent with the effects of weightlessness on humans and animals in space. Furthermore, degenerative changes were observed in some neurons of the cortical parietal lobe, frontal lobe, and hippocampal regions of the experimental group, with a slight reduction in the number of Purkinje cells in the cerebellar region, and a significant enhancement of GFAP-positive signals in the hippocampal area (P<0.05). Conclusion Miniature pigs subjected to a -20° angle hind limb unloading for 30 days maybe serve as a new animal model for simulating weightlessness, applicable to related aerospace research.

Peptide‒drug conjugates (PDCs) are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable linker. As an emerging prodrug strategy, PDCs not only preserve the function and bioactivity of the peptides but also release the drugs responsively with the cleavable property of the linkers. Given the ability to significantly improve the circulation stability and targeting of drugs in vivo and reduce the toxic side effects of drugs, PDCs have already been extensively applied in drug delivery. Herein, we review the types and mechanisms of peptides, linkers and drugs used to construct PDCs, and summarize the clinical applications and challenges of PDC drugs.

Diabetic kidney disease (DKD) is the most common complication of diabetes mellitus (DM). Qianjin Wenwu decoction (QWD), a well-known traditional Korean medicine, has been used for the treatment of DKD, with satisfactory therapeutic effects. This study was designed to investigate the active components and mechanisms of action of QWD in the treatment of DKD. The results demonstrated that a total of 13 active components in five types were found in QWD, including flavonoids, flavonoid glycosides, phenylpropionic acids, saponins, coumarins, and lignins. Two key proteins, TGF-β1 and TIMP-1, were identified as the target proteins through molecular docking. Furthermore, QWD significantly suppressed Scr and BUN levels which increased after unilateral ureteral obstruction (UUO). Hematoxylin & eosin (H&E) and Masson staining results demonstrated that QWD significantly alleviated renal interstitial fibrosis in UUO mice. We also found that QWD promoted ECM degradation by regulating MMP-9/TIMP-1 homeostasis to improve renal tubulointerstitial fibrosis and interfere with the expression and activity of TGF- β1 in DKD treatment. These findings explain the underlying mechanism of QWD for the treatment of DKD, and also provide methodological reference for investigating the mechanism of traditional medicine in the treatment of DKD.
Rats ; Mice ; Animals ; Ureteral Obstruction/metabolism* ; Kidney/metabolism* ; Tissue Inhibitor of Metalloproteinase-1/metabolism* ; Molecular Docking Simulation ; Rats, Sprague-Dawley ; Kidney Diseases/drug therapy* ; Extracellular Matrix/metabolism* ; Flavonoids/metabolism* ; Fibrosis

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/ kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 μM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7rNLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

OBJECTIVE: To investigate the biological function of Cysteine rich (CysR) domain of a disintegrin and metalloprotease with thrombospondin type 1 repeats-13 (ADAMTS13) on cleavage of von Willebrand factor (vWF) and provide experimental evidence for exploring the pathogenesis of thrombotic thrombocytopenic purpura (TTP). METHODS: The six amino acids (EDGTLS) in ADAMTS13 CysR domain were point mutated one by one, and the mutant ADAMTS13 proteins were expressed and purified. The cleavage products of vWF polymer by wild-type or mutant ADAMTS13 under denaturing condition or shear stress were separated by 1% SeaKem HGT agarose gel and detected by Western blot. RESULTS: The mutant ADAMTS13 plasmids (M1: Glu515Ala; M2: Asp516Ala; M3: Gly517Ala; M4: Thr518Ala; M5: Leu519Ala; M6: Ser520Ala) were successfully constructed and the proteins of wild-type and mutant ADAMTS13 were purified. Wild-type ADAMTS13 almost completely cleaved the vWF polymer under denaturing condition, while the cleavage activity of M1 mutant was significantly reduced in the same condition (P<0.01). The cleavage activity of M1 mutant of ADAMTS13 was also significantly reduced compared with that of the wild-type under shear stress (P<0.01). The activity of M1 mutant to cleave the FRETS-vWF73 was dramatically reduced compared with that of wild-type ADAMTS13. However, the binding ability of M1 mutant to vWF was similar with that of wild-type ADAMTS13. CONCLUSION The CysR domain of ADAMTS13 plays an important role in the digestion of vWF under denaturing condition and shear stress. The Glu515 amino acid residue might be an important site for substrate recognition.
ADAM Proteins ; ADAMTS13 Protein/genetics* ; Humans ; Purpura, Thrombotic Thrombocytopenic/genetics* ; von Willebrand Factor/genetics*

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 µM) and BQ788 (0.3 µM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 µM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 µM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxiaactivated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 µM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 µM) and LY294002 (10.0 µM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 µM) and BQ788 (0.3 µM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 µM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 µM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxiaactivated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 µM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 µM) and LY294002 (10.0 µM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

ObjectiveTo investigate the correlation of miR-181c expression in peripheral blood mononuclear cells (PBMCs) with interferon-γ (IFN-γ), chemokine (C-X-C motif) ligand 10 (CXCL10), and Toll-like receptor 4 (TLR4) in children with autoimmune hepatitis (AIH). MethodsA total of 27 children with AIH who were admitted to The Affiliated Hospital of Yanbian University from March 2015 to May 2019 were enrolled as AIH group, and 30 healthy children who underwent physical examination during the same period of were enrolled as control group. The expression of miR-181c in PBMCs and the expression of IFN-γ, CXCL10, and TLR4 were measured for the two groups. The t-test was used for comparison of normally distributed continuous data between two groups, and the Wilcoxon rank-sum test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. The Pearson correlation coefficient was used to investigate the correlation of miR-181c expression with each index, and a logistic regression analysis was used to investigate the influence of each factor on AIH. ResultsCompared with the control group, the AIH group had significantly higher levels of the liver function parameters aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), and total bilirubin (TBil) (t=14.445,20.064，11.728,13.822, all P＜0.001). The AIH group also had significantly higher levels of IgA, IgM, and IgG than the control group (t=7.772, 5147, and 6771, all P＜0.05). The AIH group had significantly lower relative expression of miR-181c in PBMCs than the control group (0.784±0173 vs 1.106±0.224, t=5.819, P＜0.05). Compared with the control group, the AIH group had significantly higher levels of IFN-γ and CXCL10 and mRNA expression of TLR4 (t=6.949, 12.303, and 13.835, all P＜0.05). The correlation analysis showed that in the children with AIH, the expression of miR-181c in PBMCs was negatively correlated with IFN-γ, CXCL10, TLR4, AST, ALT, GGT, TBil, and IgG (r=-0.316, -0.348, -0.322, -0.427, -0.442, -0.408, -0.396, and -0.321, all P＜0.05). The univariate logistic regression analysis showed that AST, ALT, GGT, TBil, IFN-γ, CXCL10, TLR4 mRNA, and miR-181c were all included in the regression model (all P＜0.05) and were the influencing factors for the onset of AIH. ConclusionChildren with AIH have downregulated expression of miR-181c in PBMCs, which is closely associated with IFN-γ, CXCL10, and TLR4, suggesting that miR-181c may affect the development of AIH in children by regulating the immune system.

Objective    To define the patient characteristics and perioperative management, and to define the mortality and its risk factors after arterial switch operation (ASO). Methods    We conducted a bidirectional cohort study with 571 consecutive patients undergoing ASO from 1997 to 2016 in our hospital. We enrolled patients who underwent ASO before 2012 retrospectively and after 2012 prospectively and followed up all the patients prospectively. Demographic characteristics, clinical information and mortality of these patients were summarized. Joinpoint regression analysis was used to identify the time trend of the overall mortality. Kaplan-Meier survival analysis was used to evaluate the mid- and long-term survival rate after ASO. Cox proportional hazards regression models were used to explore the potential factors associated with mortality. The cumulative incidence of complications after ASO was predicted using competing risk models. Results    Several aspects of patients’ characteristics and perioperative management in our center differed from those in the developed countries. The overall mortality and in-hospital mortality after ASO was 16.3% and 15.1%, respectively. The overall cumulative survival rate at 5, 10 and 15 years after ASO was 83.3%, 82.8% and 82.8%, respectively. A significant decrease of overall mortality from 1997 to 2016 was observed. Independent risk factors of mortality included earlier ASO (1997-2006), single or intramural coronary anatomy and longer cardiopulmonary bypass time. Ten years after ASO, re-intervention, arrhythmia, pulmonary and anastomotic stenosis were the most common complications with a cumulative incidence over 10%. Conclusion    Significant improvements in the results of the ASO were observed and the postoperative mortality rate is close to reports from developed countries. Nonetheless, we have identified the need for further improvement in the early and late postoperative periods after ASO. Pulmonary stenosis, anastomotic stenosis and arrhythmia should be paid attention to during the long-term follow-up after ASO.

In current study, we aimed to investigate whether the gentiopicroside (GPS) derived from Gentiana manshurica Kitagawa could block the progression of alcoholic hepatic steatosis to fibrosis induced by chronic ethanol intake. C57BL/6 mice were fed an ethanol- containing Lieber-DeCarli diet for 4 weeks. LX-2 human hepatic stellate cells were treated with GPS 1 h prior to transforming growth factor-β (TGF-β) stimulation, and murine hepatocyte AML12 cells were pretreated by GPS 1 h prior to ethanol treatment. GPS inhibited the expression of type I collagen (collagen I), α-smooth muscle actin (α-SMA) and tissue inhibitor of metal protease 1 in ethanol-fed mouse livers with mild fibrosis. In addition, the imbalanced lipid metabolism induced by chronic ethanol-feeding was ameliorated by GPS pretreatment, characterized by the modulation of lipid accumulation. Consistently, GPS inhibited the expression of collagen I and α-SMA in LX-2 cells stimulated by TGF-β. Inhibition of lipid synthesis and promotion of oxidation by GPS were also confirmed in ethanol-treated AML12 cells. GPS could prevent hepatic steatosis advancing to the inception of a mild fibrosis caused by chronic alcohol exposure, suggesting GPS might be a promising therapy for targeting the early stage of alcoholic liver disease.