Design and synthesis of novel poly (aryl ether ketones) containing trifluoromethyl and trifluoromethoxy groups.

The high-frequency and high-speed communication in the 5 G era puts forward requirements for the dielectric properties of polymers. Introducing fluorine into poly(ary ether ketone) can improve its dielectric properties. In this work, by introducing the fluorine group strategy, we successfully designed and synthesized three novel trifluoromethyl (-CF3) or trifluoromethoxy (-OCF3)-containing bisphenol monomers and their F-substitution PEK-based polymers (PEK-Ins). All these PEK-Ins exhibited good thermal, mechanical and dielectric properties. The T d5% of the three polymers is all higher than 520℃. The free volume fraction of novel polymers increased from 3.75% to 5.72%. Among the three polymers, exhibited the lowest dielectric constant of the films is 2.839, and the dielectric loss is 0.0048, ascribing to the increasing free volume. The Young's modulus of the polymer film is as high as 2.9 GPa and the tensile strength is as high as 84 MPa. PEK-Ins reduced the dielectric constant by introducing a low fluorine content. This study provides a new way to design PEK to synthesize low dielectric constant polymers.

Heme Oxygenase-1 Inhibits the Proliferation of Hepatic Stellate Cells by Activating PPARγ and Suppressing NF-κB.

BACKGROUND: Hepatic stellate cells (HSCs) are reported to play significant roles in the development of liver fibrosis. Heme oxygenase-1 (HO-1) is a key rate-limiting enzyme, which could decrease collagen synthesis and liver damage. Nevertheless, it was yet elusive towards the function and mechanism of HO-1. METHODS: An HO-1 inducer Hemin or an HO-1 inhibitor ZnPP-IX was used to treat the activated HSC-T6, respectively. MTT assay was adopted to detect cell proliferation. Immunocytochemical staining was employed to test the levels of alpha-smooth muscle actin (α-SMA), peroxisome proliferator-activated receptor-γ (PPARγ), and nuclear factor-kappa B (NF-kappa B) levels in HSC-T6. HO-1, PPARγ, and NF-κB expression levels were measured by qRT-PCR and Western blotting. ELISA was then used to detect the levels of transforming growth factor- (TGF-) beta 1 (TGF-ß1), interleukin-6 (IL-6), serum hyaluronic acid (HA), and serum type III procollagen aminopeptide (PIIIP). RESULTS: HSC-T6 proliferation was inhibited in Hemin-treated HSCs. The levels of α-SMA, HA, and PIIIP and the production of ECM were lower in Hemin-treated HSCs, whereas those could be rescued by ZnPP-IX. NF-κB activation was decreased, but PPARγ expression was increased after HO-1 upregulation. Furthermore, the levels of TGF-ß1 and IL-6, which were downstream of activated NF-κB in HSC-T6, were reduced. The PPAR-specific inhibitor GW9662 could block those mentioned effects. CONCLUSIONS: Our data demonstrated that HO-1 induction could inhibit HSC proliferation and activation by regulating PPARγ expression and NF-κB activation directly or indirectly, which makes it a promising therapeutic target for liver fibrosis.

Expression of microRNA-21 in osteoporotic patients and its involvement in the regulation of osteogenic differentiation.

Expression of microRNA-21 in bone tissue and serum of patients with osteoporosis (OP) and its involvement in the regulation of osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) were investigated. Bone tissue and serum were collected from 48 patients with OP and 48 normal subjects. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of six microRNAs. Among these microRNAs, the expression level of microRNA-21 in bone tissue and serum of OP patients was the lowest. In addition, BMSCs of SD rats were isolated and cultured. Subculture was performed 3 times, transfection of microRNA-21 was performed and osteogenic differentiation was induced. Control group [negative control (NC)] was transfected with microRNA-21 mimics followed by osteogenic induction. Experimental groups were transfected with microRNA-21 analogue (mimics) and microRNA-21 inhibitor (inhibitor) followed by osteogenic induction. Ten days after osteogenic induction, alkaline phosphatase (ALP) staining and alizarin red staining were performed to measure the mineralized stained area and the number of mineralized nodules in each treatment group. RT-qPCR was used to detect the expression of osteogenic genes in each group of cells. RT-qPCR results showed that microRNA-21 expression was lower in bone tissue and serum of patients with OP than that of normal subjects. Moreover, compared with control group, BMSCs showed increased stained mineralized areas, deeper color and increased number of mineralized nodules. In addition, increased mRNA expression of osteogenic genes was evident after microRNA-21 mimics transfection and osteogenic induction (p<0.05). Compared with control group, BMSCs showed decreased stained mineralized areas, lighter color, decreased number of mineralized nodules, and decreased mRNA expression of osteogenic genes after microRNA-21 inhibitor transfection and osteogenic induction (p<0.05). MicroRNA-21 is expressed at low level in bone tissue and serum in patients with OP, and microRNA-21 can promote osteogenic differentiation of BMSCs. Our study provided theoretical basis for drug treatment of OP.

Heme oxygenase-1 exerts pro-apoptotic effects on hepatic stellate cells in vitro through regulation of nuclear factor-κB.

Heme oxygenase-1 (HO-1) is an antioxidant and cytoprotective protein, which has been proven to alleviate the proliferation of hepatic stellate cells (HSCs) and the development of liver fibrosis. However, the role of HO-1 in HSC apoptosis remains unclear. The aim of the present study was to investigate the effect of HO-1 on HSC apoptosis and its possible underlying mechanisms. HSCs-T6 were incubated with different concentrations of hemin (HO-1 chemical inducer) and Znpp-IX (HO-1 chemical inhibitor) for 12, 24 and 48 h. Cell viability was determined using an MTT assay. HSCs were classified into 4 groups as follows: Control, hemin, Znpp-IX and hemin+Znpp-IX co-treatment groups. Apoptosis was quantitatively measured by Annexin V/propidium iodide double staining and a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The mRNA and protein expression of HO-1, α-smooth muscle actin, B-cell lymphoma (Bcl)-2, caspase-3 and nuclear factor (NF)-κB p65 were measured using quantitative polymerase chain reaction and western blotting. The levels of tumor growth factor (TGF)-ß and interleukin (IL)-6 in HSC supernatants were examined by ELISA. The results demonstrated that HO-1 exerted antiproliferative effects on HSCs in a time- and concentration-dependent manner. Increasing HO-1 expression induced HSC apoptosis in vitro as demonstrated by a significant decrease in Bcl-2 and an increase in caspase-3 expression. Additionally, the expression of NF-κB p65 and its downstream inflammatory factors TGF-ß and IL-6 in the HO-1 overexpression group was significantly decreased compared with the control group. Therefore, the present study provided evidence that HO-1 serves an anti-fibrosis role in the liver by enhancing HSC apoptosis, which was partially associated with the regulation of NF-κB and its downstream effectors.

ERß compensates for the absence of ERα function to promote osteoblast viability by inhibition of SOST signaling.

Estrogen receptors α and ß (ERα and ERß) serve key functions in bone development and maintenance, and in the metabolism of bone mineral. ERß and ERα form heterodimers, and ERß negatively regulates the transactivation of ERα. ERß also inhibits recruitment of ERα to the estrogen-responsive promoters. However, the relationship of ERα and ERß in the regulation of osteoblast viability and differentiation remains unclear. The present study aimed to investigate whether ERß plays a role in balancing ERα activity in osteoblast cells. Downregulation of ERα by short hairpin RNA (shRNA) was found to significantly increase cell cycle arrest at G1 phase (P<0.01). In addition, this effect was found to be significantly enhanced by downregulation of ERß (P<0.05). Inversely, ERα-knocked down osteoblasts were treated with ERß agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) to activate ERß. It was found that activation of ERß significantly rescued the arrest of cell cycle induced by the downregulation of ERα (P<0.05). Furthermore, downregulation of ERα was found to significantly inhibit cell viability (P<0.01), and knockdown of ERß was found to have a significant synergic effect with ERα downregulation on the inhibition of cell viability (P<0.01). Treatment with ERß agonist DPN significantly rescued the effects of downregulation of ERα on cell viability (P<0.01). It was also demonstrated that the synergic effects of ERα and ERß deletion was via upregulation of SOST gene expression, and the subsequent inhibition of OPG and Runx2 gene expression. Thus, ERß may serve a function in balancing osteoblast viability and differentiation induced by ERα.

CXCR2 is involved in pulmonary intravascular macrophage accumulation and angiogenesis in a rat model of hepatopulmonary syndrome.

Hepatopulmonary syndrome (HPS) is a lung complication in various liver diseases, with high incidence, poor prognosis and no effective non-surgical treatments in patients with hepatocirrhosis. Therefore, assessing HPS pathogenesis to explore proper therapy strategies is clinically relevant. In the present study, male Sprague-Dawley rats underwent sham operation or common bile duct ligation (CBDL). Two weeks post-surgery, the following groups were set up for 2 weeks of treatment: sham + normal saline, CBDL + CXCR2 antagonist SB225002, CBDL + tumour necrosis factor α (TNF-α) antagonist PTX and CBDL + normal saline groups. Liver and lung tissues were collected after mean arterial pressure (MAP) and portal venous pressure (PVP) measurements. Haematoxylin and eosin (H&E) staining (lung) and Masson staining (liver) were performed for pathological analyses. Finally, pulmonary tissue RNA and total protein were assessed for target effectors. The mRNA and protein levels of CXCR2 were significantly increased in the pulmonary tissue of CBDL rats. What's more, CXCR2 inhibition by SB225002 reduced the expression of CD68 and von Willebrand factor (vWf) in CBDL rats. Importantly, CXCR2 inhibition suppressed the activation of Akt and extracellular signal-regulated kinase (ERK) in CBDL rats. Antagonization of TNF-α with PTX down-regulated the expression of CXCR2. During HPS pathogenesis in rats, CXCR2 might be involved in the accumulation of pulmonary intravascular macrophages and angiogenesis, possibly by activating Akt and ERK, with additional regulation by TNF-α that enhanced pulmonary angiogenesis by directly acting on the pulmonary tissue. Finally, the present study may provide novel targets for the treatment of HPS.

Cavernous hemangiomas of the temporalis muscle with prominent formation of phleboliths: Case report and review of the literature.

RATIONALE: Hemangiomas are benign tumors characterized by an abnormal proliferation of blood vessels, most often occur in the skin and subcutaneous tissue, intramuscular hemangioma, a distinctive type of hemangioma within the skeletal muscle, account for <1% of all hemangiomas, temporalis muscle is a very uncommon site, cavernous hemangioma of the temporalis muscle with prominent formation of phleboliths is rare reported. PATIENT CONCERNS: A 62-year-old man presented with a slowly increased mass in his right temporal fossa. DIAGNOSES: Computed tomography (CT) scan showed the lesion across the zygomatic arch, with many calcified nodules differ in sizes and no erosion to the bone, magnetic resonance imaging (MRI) showed an oval lesion with hypointense and isointense on T2-weighted imaging within the temporal muscle, and preoperation diagnosis was hemangioma. INTERVENTIONS: The tumor was resected under general anesthesia. OUTCOMES: The mass was excised completely, and the histopathology examination confirmed the diagnosis of cavernous hemangioma with prominent formation of phleboliths. The patient recovered very well without dysfunctions. LESSONS: Cavernous hemangioma should be suspected when mass occurs in this region. CT and MRI are important for the early diagnosis of tumor, and resection the tumor completely is recommended.

HBsAg seroclearance or seroconversion induced by peg-interferon alpha and lamivudine or adefovir combination therapy in chronic hepatitis B treatment: a meta-analysis and systematic review.

BACKGROUND AND AIMS: Seroclearance or seroconversion of hepatitis B surface antigen (HBsAg) is generally considered as the clinical endpoint. The purpose of the present meta-analysis was to evaluate pegylated interferon alpha (PEG-IFNα) with or without lamivudine (LAM) or adefovir (ADV) combination treatment in HBsAg seroclearance or seroconversion with CHB. METHODS: Randomized controlled trials of adults with CHB prior to May 30th 2015, with 48-52 weeks of PEG-IFNα and LAM or ADV combination therapy or monotherapy, were included. Review Manager Software 5.2.0 was used for meta-analysis. RESULTS: No statistical difference was noticed in HBsAg seroclearance (9.9% vs 7.1%, OR = 1.47, 95% CI 0.75, 2.90; p = 0.26) or observed in HBsAg seroconversion (4.2% vs 3.7%, OR = 1.17, 95% CI 0.57, 2.37; p = 0.67) between PEG-IFNα + LAM and PEG-IFNα + placebo for 24-26 weeks follow-up after treatment on hepatitis B e antigen (HBeAg)-positive CHB. Statistical difference was not showed in HBsAg disappearance (10.5% vs 6.4%, OR = 1.68, 95% CI 0.75, 3.76; p = 0.21) but was demonstrated in HBsAg seroconversion (6.3% vs 0%, OR = 7.22, 95% CI 1.23, 42.40; p = 0.03) between PEG-IFNα + ADV and PEG-IFNα for 48-52 weeks treatment on HBeAg-positive CHB By systematical evaluation, there were no differences in HBsAg disappearance and seroconversion between PEG-IFNα + placebo and PEG-IFNα + LAM for 48-52 weeks treatment on HBeAg-positive CHB. There were no differences in HBsAg disappearance and seroconversion between PEG-IFNα + placebo and PEG-IFNα + LAM during 24 weeks to 3 years follow-up after treatment on HBeAg-negative CHB by systematical evaluation. CONCLUSION: The combination between PEG-IFNα and LAM or ADV was not superior to monotherapy of PEG-IFNα in terms of HBsAg seroclearance or seroconversion.

Effect of artesunate supplementation on bacterial translocation and dysbiosis of gut microbiota in rats with liver cirrhosis.

AIM: To evaluate the effect of artesunate (AS) supplementation on bacterial translocation (BT) and gut microbiota in a rat model of liver cirrhosis. METHODS: Fifty-four male Sprague-Dawley rats were randomly divided into a normal control group (N), a liver cirrhosis group (M) and a liver cirrhosis group intervened with AS (MA). Each group was sampled at 4, 6 and 8 wk. Liver cirrhosis was induced by injection of carbon tetrachloride (CCl4), intragastric administration of 10% ethanol, and feeding a high fat diet. Rats in the MA group were intragastrically administered with AS (25 mg/kg body weight, once daily). Injuries of the liver and intestinal mucosa were assessed by hematoxylin-eosin or Masson's trichrome staining. Liver index was calculated as a ratio of the organ weight (g) to body weight (g). The gut microbiota was examined by automated ribosomal intergenic-spacer analysis of fecal DNA. BT was assessed by standard microbiological techniques in the blood, mesenteric lymph nodes (MLNs), liver, spleen, and kidney. RESULTS: Compared to group N, the body weight was reduced significantly in groups M and MA due to the development of liver cirrhosis over the period of 8 wk. The body weight was higher in group MA than in group M. The liver indices were significantly elevated at 4, 6 and 8 wk in groups M and MA compared to group N. AS supplementation partially decreased the liver indices in group MA. Marked histopathologic changes in the liver and small intestinal mucosa in group M were observed, which were alleviated in group MA. Levels of pro-inflammatory interleukin-6 and tumor necrosis factor-α were significantly elevated at 8 wk in ileal homogenates in group M compared to group N, which were decreased after AS supplementation in group MA. The dysbiosis of gut microbiota indicated by the mean diversity (Shannon index) and mean similarity (Sorenson index) was severe as the liver cirrhosis developed, and AS supplementation had an apparent intervention effect on the dysbiosis of gut microbiota at 4 wk. The occurrence of BT was increased in the liver of group M compared to that of group N. AS supplementation reduced BT in group MA at 8 wk. BT also occurred in the MLNs, spleen, and kidney, which was reduced by AS supplementation. BT was not detected in the blood in any group. CONCLUSION: Dysbiosis of gut microbiota, injury of intestinal mucosal barrier and BT occurred as liver cirrhosis progressed, which might enhance inflammation and aggravate liver injury. AS may have other non-antimalarial effects that modulate gut microbiota, inhibit BT and alleviate inflammation, resulting in a reduction in CCl4, alcohol and high fat-caused damages to the liver and intestine.

Enhanced expression of glucose-regulated protein 78 correlates with malondialdehyde levels during the formation of liver cirrhosis in rats.

The aim of the present study was to explore the role of glucose-regulated protein 78 (GRP78) in the development of liver cirrhosis promoted by intestinal endotoxemia in rats. Fifty-one male Wistar rats were randomly divided into the liver cirrhosis 4-week, 6-week and 8-week groups and the normal control group at each time point. Liver cirrhosis was induced by employing multiple pathogenic factors in the rats. Blood and liver tissues were collected. The levels of alanine aminotransferase (ALT), homocysteine, endotoxin and tumor necrosis factor-α (TNF-α) in the plasma, and TNF-α, malondialdehyde (MDA) and procollagen type III peptide (PIIIP) in the liver tissues were determined. The mRNA and protein expression levels of GRP78 in the liver were detected using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Morphological changes were observed through hematoxylin and eosin and van Gieson staining of the liver. Liver cirrhosis caused marked histopathological changes to the livers of the rats. Following significant increases in the levels of ALT, homocysteine, endotoxin and TNF-α in the plasma, and TNF-α, MDA and PIIIP in the liver tissues of all experimental groups with the progression of liver cirrhosis, the mRNA and protein expression levels of GRP78 also gradually increased. In addition, correlation analysis indicated that the enhanced expression of GRP78 correlated with the MDA levels of the rats during the formation of liver cirrhosis.

In vitro drug susceptibility of 40 international reference rapidly growing mycobacteria to 20 antimicrobial agents.

Rapidly growing mycobacteria (RGM) are human pathogens that are relatively easily identified by acid-fast staining but are proving difficult to treat in the clinic. In this study, we performed susceptibility testing of 40 international reference RGM species against 20 antimicrobial agents using the cation-adjusted Mueller-Hinton (CAMH) broth microdilution based on the minimum inhibitory concentration (MIC) assay recommended by the guidelines of the Clinical and Laboratory Standards Institute (CLSI). The results demonstrated that RGM organisms were resistant to the majority of first-line antituberculous agents but not to second-line fluoroquinolones or aminoglycosides. Three drugs (amikacin, tigecycline and linezolid) displayed potent antimycobacterial activity against all tested strains. Capreomycin, levofloxacin and moxifloxacin emerged as promising candidates for the treatment of RGM infections, and cefoxitin and meropenem were active against most strains. Mycobacterium chelonae (M. chelonae), M. abscessus, M. bolletii, M. fortuitum, M. boenickei, M. conceptionense, M. pseudoshottsii, M. septicum and M. setense were the most resistant RGM species. These results provide significant insight into the treatment of RGM species and will assist optimization of clinical criteria.

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.

[Protective effect of tanshinol on the hepatopulmonary syndrome in rat].

OBJECTIVE: To explore the mechanism of tanshinol on alleviate the inflammatory injury of lung tissue in rat hepatopulmonary syndrome (HPS). METHODS: SD rats were randomly divided into normal control group (n = 8), hepatopulmonary syndrome (HPS) group (n = 11) and tanshinol intervention group (n = 9). HE staining was used to observe the histopathology changes of pulmonary and hepatic tissues, and to count the number of macrophages in lung tissues. The activity of alanine transferase (ALT) and concentrations of endotoxin, tumor necrosis factor-a (TNF-alpha) and homocystein (Hcy) in plasma were detected. The concentrations of TNF-alpha, nitric oxide (NO) and malondialdehyde (MDA) and the activity of inducible nitric oxide synthase (iNOS) in the lung tissues were measured, respectively. RESULTS: Thickened alveolar septum and increased macrophages were observed in lungs in HPS rat. After administered with tanshinol, the pulmonary pathological changes were alleviated and the number of macrophages in lung tissue was decreased compared with HPS group. The activity of ALT and the concentrations of endotoxin, TNF-alpha and Hcy in plasma ,and TNF-alpha, iNOS, NO and MDA in lung tissue in HPS group were higher than those of normal control group; meanwhile, those tanshinol group were less those that of HPS group. CONCLUSION: Tanshinol may play an important role in delaying the development of HPS through protecting liver or directly antagonizing the effect of intestinal endotoxemia so as to alleviate the inflammatory reaction in lung tissue.

[A method for primary culture of pulmonary microvascular endothelial cells].

OBJECTIVE: To explore a simple and practical method of primarily culturing rat pulmonary microvascular endothelial cells (PMECs) in vitro, and observe the cell growth status and identify the PMECs. METHODS: Wistar rats (n=40, aged 4-5 weeks) were sacrificed to take the lung tissue. After removal of pleura, the peripheral lung tissues were cut into pieces (1 mm(3)) in aseptic condition. The endothelial cells were cultured in the DMEM medium containing heparin sodium and in the RPMI1640 medium supplemented with special additives or not, respectively. Cell growth and morphology was observed under an inverted microscope. The expression of CD31 in cells was detected by immunofluorescence staining. RESULTS: After incubation for 24 hours, PMECs in the medium containing special additives were the most in number and purity compared with the other two culture systems. At 24 hours, endothelial cells migrated from the lung tissue, and at 14 days, the cells aggregated and grew obviously, exhibiting a polygon shape, being tightly arranged and paving the base of Petri dish. After sub-culturing, the cells spread much more and most cells became spindle shaped, which showed a tendency of endothelial cell angiogenesis in vitro. CD31 was positive in immunofluorescence staining. CONCLUSION: The adherent culture method of tissue explants in the medium added by the special additives was proved to a good method to obtain a high-purity rat PMECs in vitro.

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.

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.

Oxygen consumption and usage during physical exercise: the balance between oxidative stress and ROS-dependent adaptive signaling.

The complexity of human DNA has been affected by aerobic metabolism, including endurance exercise and oxygen toxicity. Aerobic endurance exercise could play an important role in the evolution of Homo sapiens, and oxygen was not important just for survival, but it was crucial to redox-mediated adaptation. The metabolic challenge during physical exercise results in an elevated generation of reactive oxygen species (ROS) that are important modulators of muscle contraction, antioxidant protection, and oxidative damage repair, which at moderate levels generate physiological responses. Several factors of mitochondrial biogenesis, such as peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), mitogen-activated protein kinase, and SIRT1, are modulated by exercise-associated changes in the redox milieu. PGC-1α activation could result in decreased oxidative challenge, either by upregulation of antioxidant enzymes and/or by an increased number of mitochondria that allows lower levels of respiratory activity for the same degree of ATP generation. Endogenous thiol antioxidants glutathione and thioredoxin are modulated with high oxygen consumption and ROS generation during physical exercise, controlling cellular function through redox-sensitive signaling and protein-protein interactions. Endurance exercise-related angiogenesis, up to a significant degree, is regulated by ROS-mediated activation of hypoxia-inducible factor 1α. Moreover, the exercise-associated ROS production could be important to DNA methylation and post-translation modifications of histone residues, which create heritable adaptive conditions based on epigenetic features of chromosomes. Accumulating data indicate that exercise with moderate intensity has systemic and complex health-promoting effects, which undoubtedly involve regulation of redox homeostasis and signaling.

Heme oxygenase-1 prevents liver fibrosis in rats by regulating the expression of PPARγ and NF-κB.

AIM: To investigate the effects of heme oxygenase (HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and nuclear factor-kappa B (NF-κB) in rats. METHODS: Sixty Wistar rats were used to construct liver fibrosis models and were randomly divided into 5 groups: group A (normal, untreated), group B (model for 4 wk, untreated), group C (model for 6 wk, untreated), group D [model for 6 wk, treated with zinc protoporphyrin IX (ZnPP-IX) from week 4 to week 6], group E (model for 6 wk, treated with hemin from week 4 to week 6). Next, liver injury was assessed by measuring serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and albumin levels. The degree of hepatic fibrosis was evaluated by measuring serum hyaluronate acid (HA), type IV collagen (IV-C) and by histological examination. Hydroxyproline (Hyp) content in the liver homogenate was determined. The expression levels of alpha-smooth muscle actin (α-SMA) in liver tissue were measured by real-time quantitative polymerase chain reaction (RT-PCR). The expression levels of PPARγ and NF-κB were determined by RT-PCR and Western blotting. RESULTS: The expression of HO-1 increased with the development of fibrosis. Induction of HO-1 by hemin significantly attenuated the severity of liver injury and the levels of liver fibrosis as compared with inhibition of HO-1 by ZnPP-IX. The concentrations of serum ALT, AST, HA and IV-C in group E decreased compared with group C and group D (P < 0.01). Amount of Hyp and α-SMA in the liver tissues in group E decreased compared with group C (0.62 ± 0.14 vs 0.84 ± 0.07, 1.42 ± 0.17 vs 1.84 ± 0.17, respectively, P < 0.01) and group D (0.62 ± 0.14 vs 1.11 ± 0.16, 1.42 ± 0.17 vs 2.56 ± 0.37, respectively, P < 0.01). The expression of PPARγ at levels of transcription and translation decreased with the development of fibrosis especially in group D; and it increased in group E compared with groups C and D (0.88 ± 0.15 vs 0.56 ± 0.19, 0.88 ± 0.15 vs 0.41 ± 0.11, respectively, P < 0.01). The expression of NF-κB increased with the development of fibrosis especially in group D; and it decreased in group E compared with groups C and D (1.43 ± 0.31 vs 1.89 ± 0.29, 1.43 ± 0.31 vs 2.53 ± 0.54, respectively, P < 0.01). CONCLUSION: Our data demonstrate a potential mechanism that HO-1 can prevent liver fibrosis by enhancing the expression of PPARγ and decreasing the expression of NF-κB in liver tissues.

The effects of aging, physical training, and a single bout of exercise on mitochondrial protein expression in human skeletal muscle.

Aging results in a significant decline in aerobic capacity and impaired mitochondrial function. We have tested the effects of moderate physical activity on aerobic capacity and a single bout of exercise on the expression profile of mitochondrial biogenesis, and fusion and fission related genes in skeletal muscle of human subjects. Physical activity attenuated the aging-associated decline in VO2 max (p<0.05). Aging increased and a single exercise bout decreased the expression of nuclear respiratory factor-1 (NRF1), while the transcription factor A (TFAM) expression showed a strong relationship with VO(2max) and increased significantly in the young physically active group. Mitochondrial fission representing FIS1 was induced by regular physical activity, while a bout of exercise decreased fusion-associated gene expression. The expression of polynucleotide phosphorylase (PNPase) changed inversely in young and old groups and decreased with aging. The A2 subunit of cyclic AMP-activated protein kinase (AMPK) was induced by a single bout of exercise in skeletal muscle samples of both young and old subjects (p<0.05). Our data suggest that moderate levels of regular physical activity increases a larger number of mitochondrial biogenesis-related gene expressions in young individuals than in aged subjects. Mitochondrial fission is impaired by aging and could be one of the most sensitive markers of the age-associated decline in the adaptive response to physical activity.

Age-associated neurodegeneration and oxidative damage to lipids, proteins and DNA.

Lipids, proteins and DNA in the central nervous system have a high sensitivity to oxidative stress. Reactive oxygen species (ROS)-induced damage increases with aging, especially in the last quarter of the life span. The so called base level of oxidative modification of lipids could be important to cell signaling, and membrane remodeling, but the ROS-mediated post translation modifications of proteins could be important to the homeostasis of protein turnover. Low levels of 8-oxo-7,8-dihydroguanine (8-oxoG) might be necessary for transcription. A high level of accumulation of lipid peroxidation, oxidative protein damage or 8-oxoG, on the other hand, accelerates the progress of aging and neurodegenerative diseases. Therefore, agents that induce the activity of repair enzymes, such as Ca(2(+))-independent phospholipase A(2) (iPLA(2)beta), methionine sulfoxide reductase, and 8-oxoguanine DNA glycosylase, or the activity of enzymes that could prevent the accumulation of oxidized, toxic proteins, such as proteasome, Lon protease, neprilysin or insulin degrading enzyme, may act as potential therapeutic tools to slow the aging process and the progress of neurodegenerative diseases.