Liraglutide inhibits receptor for advanced glycation end products (RAGE)/reduced form of nicotinamide-adenine dinucleotide phosphate (NAPDH) signaling to ameliorate non-alcoholic fatty liver disease (NAFLD) in vivo and vitro.

The study was designed to investigate the effects of liraglutide and reveal its action mechanism associated with RAGE/NAPDH in NAFLD. The liver tissue was collected for HE, Masson, and ROS staining. Apoptosis levels were detected through TUNEL staining and ROS levels were evaluated through ROS staining. The expression levels of c-Jun N-terminal kinase (JNK) and transforming growth factor-ß (TGF-ß) were detected through Western blot. JNK and the expression of Collagenα1, Collagenα2 and connective tissue growth factor (CTGF) were detected through RT-qPCR and Western blot and the expression in mouse liver stellate cells (JS-1) cells were evaluated through immunofluorescence staining. We detected the effects of liraglutide on NAFLD in high-fat diet (HFD)-fed mice. Liraglutide treatment improved bridging fibrosis and liver function, as well as lessening ROS levels and the protein levels of RAGE, NOX1, NOX2 and NOX4. In PA and H2O2-induced AML12 cells, liraglutide treatment was able to decrease cell apoptosis, ROS levels and the levels of inflammatory factors including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6, while it effects were reversed by the induction of RAGE overexpression or NOX2 overexpression. In JS-1 cells treated with medium culturing AML12 cells, liraglutide markedly suppressed cell proliferation and activation, while RAGE overexpression or NOX2 overexpression blunted these effects of liraglutide. Taken together, liraglutide exerts a protective role in improving liver injury caused by HFD, which could be related to decreased apoptosis and oxidative stress of liver cells, as well as decreased proliferation and activation of hepatic stellate cells through RAGE/NOX2.

Liraglutide blocks the proliferation, migration and phenotypic switching of Homocysteine (Hcy)-induced vascular smooth muscle cells (VSMCs) by suppressing proprotein convertase subtilisin kexin9 (PCSK9)/ low-density lipoprotein receptor (LDLR).

Liraglutide, a glucagon-like peptide 1 (GLP1) receptor agonist, is known to inhibit the atherosclerosis of apoE mice and suppress the cellular behaviors of VSMCs induced by AngII. This study aimed to explore whether liraglutide can reduce the proliferation, invasion and phenotypic transformation of VSMCs induced by Hcy and the underlying mechanism. Hcy was used to induce the proliferation of VSMCs, and liraglutide was then used to expose the cells for assessing cell proliferation. Afterward, the cell migration and phenotypic switch were evaluated to observe the effects of liraglutide. Meanwhile, the expression of PCSK9 and LDLR was detected. After overexpressing PCSK9, the changes in proliferation, cell migration and phenotypic switch were estimated again. Hcy promoted cell proliferation of VSMCs, whereas liraglutide blocked the proliferation, migration and phenotypic switch of Hcy-induced VSMCs. Furthermore, the expression of PCSK9 was downregulated and LDLR expression was upregulated after liraglutide administration in Hcy-induced VSMCs. After overexpressing PCSK9, the proliferation, migration and phenotypic switch of Hcy-induced VSMCs were enhanced. Liraglutide blocked the proliferation, migration and phenotypic switching of Hcy-induced VSMCs by suppressing PCSK9/LDLR. This finding provided the basis for the future application of liraglutide as an effective drug for therapeutic strategy in targeting AS.

lncRNA HAND2-AS1 inhibits cancer cell proliferation, migration and invasion by downregulating ROCK1 in HPV-positive and negative cervical squamous cell carcinoma.

Long non-coding (lnc)RNA HAND2 antisense RNA 1 (HAND2-AS1) exhibited tumor suppression activity in different types of cancer. However, its role in cervical squamous cell carcinoma (CSCC), which is frequently diagnosed among females, has not been elucidated. The current study revealed that lncRNA HAND2-AS1 was downregulated, while Rho-associated protein kinase 1 (ROCK1) was upregulated in serum of human papillomavirus (HPV)-positive and -negative patients with CSCC compared with healthy controls. Correlation analysis revealed that the expression levels of lncRNA HAND2-AS1 were negatively correlated with the expression levels of ROCK1 in HPV-positive and -negative patients with CSCC but not in healthy controls. Downregulation of lncRNA HAND2-AS1 distinguished patients with CSCC from healthy controls. Additionally, lncRNA HAND2-AS1 overexpression led to reduced expression levels of ROCK1 in HPV-positive and -negative human CSCC cell lines but not in normal cervical cell lines. ROCK1 overexpression did not significantly affect the expression of lncRNA HAND2-AS1 in all the cell lines investigated. lncRNA HAND2-AS1 overexpression inhibited, while ROCK1 overexpression promoted the proliferation, migration and invasion of HPV-positive and -negative human CSCC cell lines but not normal cervical cell lines. ROCK1 overexpression attenuated the effects of lncRNA HAND2-AS1 overexpression on cancer cell proliferation, migration and invasion. lncRNA HAND2-AS1 may inhibit cancer cell proliferation, migration and invasion by downregulating ROCK1 in HPV-positive and -negative CSCC.

Increased expression of 78 kD glucose-regulated protein promotes cardiomyocyte apoptosis in a rat model of liver cirrhosis.

AIMS: This study was to investigate the role and underlying mechanism of 78 kD glucose-regulated protein (GRP78) in cardiomyocyte apoptosis in a rat model of liver cirrhosis. METHODS: A rat model of liver cirrhosis was established with multiple pathogenic factors. A total of 42 male SD rats were randomly divided into the liver cirrhosis group and control group. Cardiac structure analysis was performed to assess alterations in cardiac structure. Cardiomyocytes apoptosis was detected by TdT-mediated dUTP nick end labeling method. Expression of GRP78, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, nuclear factor kappa-light-chain-enhancer of activated B cells p65 subunit (NF-κB p65) and B cell lymphoma-2 (Bcl-2) was detected by immunohistochemical staining. RESULTS: The ratios of left ventricular wall thickness to heart weight and heart weight to body weight were significantly increased with the progression of liver cirrhosis (P < 0.05). Apoptosis index of cardiomyocytes was significantly increased with the progression of liver cirrhosis (P < 0.05). The expression levels of GRP78, CHOP and caspase-12 were significantly increased in the progression of liver cirrhosis (P < 0.05). The expression levels of NF-κB p65 and Bcl-2 were highest in the 4-wk liver cirrhosis, and they were decreased in the 6-wk and 8-wk in the progression of liver cirrhosis. GRP78 expression levels were positively correlated with apoptosis index, CHOP and caspase-12 expression levels (P < 0.05). CHOP expression levels were negatively correlated with NF-κB p65 and Bcl-2 expression levels (P < 0.05). CONCLUSION: Increased expression of GRP78 promotes cardiomyocyte apoptosis in rats with cirrhotic cardiomyopathy.

Glucose-regulated protein 78 may play a crucial role in promoting the pulmonary microvascular remodeling in a rat model of hepatopulmonary syndrome.

OBJECTIVE: This study is to investigate the role of glucose-regulated protein 78 (GRP78) in the pulmonary microvascular remodeling during hepatopulmonary syndrome (HPS) development. METHODS: The rat models with liver cirrhosis and HPS were induced by multiple pathogenic factors for 4 to 8 wk. The concentrations of alanine transferase (ALT) and endotoxin in plasma were detected in the models, followed by the detection of GRP78 expression. RT-PCR, quantitative real-time PCR and Western blotting were employed to assess the mRNA and protein expression levels of vascular endothelial growth factor (VEGF), respectively. Immunohistochemistry staining was used to examine the expression of a specific vascular marker, factor VIII-related antigen (FVIII-RAg), and several cell proliferation- and apoptosis-related proteins, including CHOP/GADD153, caspase-12, Bcl-2 and nuclear factor (NF)-κB. RESULTS: The levels of endotoxin and ALT in plasma were gradually increased as the disease progressed, so did GRP78, which were in a positive correlation. The expression levels of VEGF (both mRNA and protein) and FVIII-RAg were significantly elevated in the HPS models, indicating active angiogenesis, which was also positively correlated with GRP78 expression. Furthermore, the expression levels of the pro-apoptotic proteins of CHOP/GADD153 and caspase-12 were dramatically decreased, while the anti-apoptotic proteins of Bcl-2 and NF-κB were significantly elevated, in the HPS models. There were also close correlation between these proteins and GRP78. CONCLUSIONS: Over-expression of GRP78 in lungs may be the critical pathogenic factor for HPS. Through promoting cell proliferation and survival and inhibiting apoptosis, GRP78 may promote the pulmonary microvascular remodeling in HPS pathogenesis. Our results provide a potential therapeutic target for clinical prevention and treatment for HPS and related complications.

[Effect of ischemic postconditioning on the expression of myocardium matrix metalloproteinase-2 induced by ischemia/reperfusion in rats].

OBJECTIVE: To investigate the effect of ischemic postconditioning on the expression of rat myocardium matris metalloproteinase-2 (MMP-2) induced by ischemia/reperfusion (I/R) and relationship between its expression and interstitium and the effect on left ventricular function. METHODS: Twenty-four rats were randomly divided into 3 groups (n = 8): sham control (SC) group, ischemic/reperfusion (I/R) group and ischemic postconditioning (IPTC) group. The left ventricular peak systolic pressure and its derivate (+/- dp/dt) were calculated; The amount of myocardium collagenous were determined; The vitality of superoxide dismutase (SOD) and content of malondialdehyde (MDA) of plasma were detected; The activity of myocardium MMP-2 was measured by Western blot and RT-PCR. RESULTS: As compared with I/R group, IPTC could lower the expression of MMP-2, ameliorate left ventricular function and increase the content of myocardium collagenous. In the meantime, the vitality of superoxide dismutase (SOD) of plasma were greatly enhanced and the content of malondialdehyde (MDA) of plasma were reduced in IFC group. CONCLUSION: Protective effect of IPIC on myocardium may be due to reduce free radical, lower expression of MMP-2 and protect myocardial interstitium. MMPs plays an important role in the myocardial protection provided by IPTC.

Expression of the 78 kD glucose-regulated protein is induced by endoplasmic reticulum stress in the development of hepatopulmonary syndrome.

OBJECTIVE: This study is to explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats. METHODS: The rat model of liver cirrhosis and HPS were induced with multiple pathogenic factors. Hematoxylin and eosin (H & E) staining was performed to detect the pathological changes of the lung and liver tissues. The levels of alanine transferase (ALT), endotoxin, and tumor necrosis factor-α (TNF-α) in plasma and TNF-α and malondialdehyde (MDA) in lung tissues were detected. RT-PCR and Western blotting were conducted to detect the mRNA and protein expression levels of GRP78 in lungs. RESULTS: The plasma endotoxin level was gradually increased as HPS developed, and the mRNA and protein expression levels of GRP78 in lungs were also increased as the disease progressed. The levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in lung tissues were gradually increased along with the disease progression, with a strong positive correlation. Compared with controls, the plasma TNF-α level and the mRNA and protein expression levels of GRP78 in lung tissues were significantly higher in rats with HPS. The levels of endotoxin and ALT in plasma and the level of MDA in lungs were significantly higher in rats with HPS than controls. CONCLUSIONS: The increased GRP78 expression is indicative of endoplasmic reticulum stress response during HPS, which may play an important role in the disease pathogenesis.