Salubrinal protects against tunicamycin and hypoxia induced cardiomyocyte apoptosis via the PERK-eIF2α signaling pathway

Objectives This study examined the protective effect of salubrinal and the mechanism underlying this protection on tunicamycin (TM)- and hypoxia-induced apoptosis in rat cardiomyocytes. Methods Neonatal rat cardiomyocytes were cultured from the ventricles of 1-day-old Wistar rats. Cells were exposed to different concentrations of salubrinal (10, 20, and 40 μmol/L) for 30 minutes followed by TM treatment or hypoxia for 36 hours. Apoptosis was measured by a multiparameter HCS (high content screening) apoptosis assay, TUNEL assay and flow cytometry. The phosphorylation of eukaryotic translation initiation factor 2 subunit alpha (p-eIF2α) and the expression of cleaved caspase-12 were determined by western blotting. C/EBP homologous protein (CHOP) was detected by immunocytochemistry. Results HCS, TUNEL assays and flow cytometry showed that salubrinal protected against apoptosis induced by TM or hypoxia. Western blotting showed that salubrinal protected cardiomyocytes against apoptosis by inducing eIF2α phosphorylation and down-regulating the expression of the endoplasmic reticulum stress-mediated apoptotic proteins, CHOP and cleaved caspase-12. Conclusions Our study suggests that salubrinal protects rat cardiomyocytes against TM- or hypoxia-associated apoptosis via a mechanism involving the inhibition of ER stress-mediated apoptosis.     

Mir-217 promotes inflammation and fibrosis induced by high glucose in rat glomerular mesangial cells via Sirt1/HIF-1α signal pathway

<正>Objective To explore the roles of MircroRNA-217(Mir-217),silent information regulator 1(Sirt1),and hypoxia-inducible factor-1α(HIF-1α)in high glucoseinduced inflammation and fibrosis in rat glomerular mesangial cells(RMCs).Methods RMCs were pre-incubated with a Sirt1 activator resveratrol prior to high glucose treatment or transfected with Sirt1 small interfering RNA     

ΔNp63α mediates proliferation and apoptosis in human gastric cancer cells by the regulation of GATA-6

The oncogenic isoform of the p63 protein, ΔNp63α, has been found to be overexpressed in numerous human squamous cell carcinomas. However, the role of ΔNp63α in human gastric cancer remains unknown. To evaluate this role, we screened a panel of gastric cancer cell lines for ΔNp63α expression and found that they are correlated with the differentiation status of the cell lines. Using the MKN28 gastric cancer cell line for loss-of-function or gain-of-function of ΔNp63α in our experiments, we observed that forced expression of ΔNp63α promoted cell proliferation as assessed by the MTT and colony formation assays, and increased the GATA-6 expression. In contrast, down-regulation of ΔNp63α via small interfering RNA suppressed cell proliferation, induced cell apoptosis, and reduced the expression of GATA-6. In conclusion, our data suggest that ΔNp63α plays an important role in cell growth and proliferation of gastric cancer cells, which may be associated with the regulation of GATA-6 expression. This is the first study exploring the biological functions and the underlying mechanism of ΔNp63α during gastric cancer development. It also identifies potential targets for anti-tumor treatment.     

15-deoxy-Δ12,14 -prostaglandin J2 reduces recruitment of bone marrow-derived monocyte/macrophages in chronic liver injury in mice

15-Deoxy-Δ(12,14) -Prostaglandin J(2) (15d-PGJ(2) ), a natural peroxisome proliferator-activated receptor gamma (PPAR-γ) ligand, has been implicated as a new antiinflammatory compound with possible clinical applications. Based on this concept, this study was designed to evaluate the effects of 15d-PGJ(2) on bone marrow-derived monocyte/macrophage (BMM) migration, phagocytosis, and cytokine expression after liver injury using mouse models induced by cholestasis or carbon tetrachloride. Mice were lethally irradiated and received bone marrow transplants from enhanced green fluorescent protein transgenic mice. Our results showed that recruitment of BMM was significantly increased during chronic liver injury, and that 15d-PGJ(2) administration reduced BMM, but not neutrophil, dendritic, or T cell migration toward the damaged liver, involving reactive oxygen species generation and independently of PPAR-γ. Moreover, 15d-PGJ(2) inhibited the phagocytic activity of BMM and down-regulated inflammatory cytokine expression in vivo and in vitro. Accordingly, hepatic inflammation and fibrosis were strikingly ameliorated after 15d-PGJ(2) administration. CONCLUSION: Our findings strongly suggest the antiinflammation and antifibrogenic potential of 15d-PGJ(2) in chronic liver diseases.     

Role of rivaroxaban in sunitinib-induced renal injuries via inhibition of oxidative stress-induced apoptosis and inflammation through the tissue nacrosis factor-α induced nuclear factor-κappa B signaling pathway in rats

Journal of Thrombosis and Thrombolysis - Rivaroxaban (RIVA) inhibits factor Xa and exhibits antithrombotic and anti-inflammatory activities by inhibiting several cellular signaling molecules....     

Rac1 mediates sex difference in cardiac tumor necrosis factor-α expression via NADPH oxidase-ERK1/2/p38 MAPK pathway in endotoxemia

The purpose of this study was to investigate the role of Rac1 and estrogen in sex difference of cardiac tumor necrosis factor-alpha (TNF-α) expression during endotoxemia. Endotoxemia was induced in male and female mice by peritoneal injection of lipopolysaccharide (LPS, 4 mg/kg). Compared with female mice, male mice produced more TNF-α in the heart 4 h after LPS treatment, which were correlated with higher Rac1 and NADPH oxidase activity, more phosphorylation of ERK1/2 and p38 MAPK, and up-regulation of toll-like receptor-4 (TLR-4) expression in male mice. Cardiac specific Rac1 knockout or administration of 17β-estradiol down-regulated Rac1 expression, attenuated gp91^phox-NADPH oxidase expression and activity, decreased phosphorylation of ERK1/2/p38 MAPK and inhibited cardiac TNF-α expression induced by LPS, suggesting an important role of Rac1 and estrogen in LPS-stimulated TNF-α expression in the heart. More importantly, the sex difference in TNF-α expression was abrogated by Rac1 knockout or gp91^phox knockout and by administration of apocynin or N-acetylcysteine in LPS-stimulated mice. To investigate the functional significance of sex difference in endotoxemia, heart function was measured in isolated hearts with a Langendorff system. Male mice exhibited worse myocardial dysfunction compared with female in endotoxemia. Treatment of male mice with 17β-estradiol attenuated myocardial dysfunction during endotoxemia. In conclusion, LPS induces Rac1 activation, which contributes to NADPH oxidase activity and phosphorylation of ERK1/2/p38 MAPK, leading to TNF-α expression in the heart. The sex difference in TNF-α expression is estrogen-dependent and mediated via Rac1 dependent NADPH oxidase/ERK1/2 and p38 MAPK pathway in LPS-stimulated hearts.     

Thrombomodulin domain 1 ameliorates diabetic nephropathy in mice via anti-NF-κB/NLRP3 inflammasome-mediated inflammation, enhancement of NRF2 antioxidant activity and inhibition of apoptosis

Aims/hypothesis

Chronic inflammatory processes have been increasingly shown to be involved in the pathogenesis of diabetes and diabetic nephropathy. Recently, we demonstrated that a lectin-like domain of thrombomodulin (THBD), which is known as THBD domain 1 (THBDD1) and which acts independently of protein C activation, neutralised an inflammatory response in a mouse model of sepsis. Here, therapeutic effects of gene therapy with adeno-associated virus (AAV)-carried THBDD1 (AAV-THBDD1) were tested in a mouse model of type 2 diabetic nephropathy.

Methods

To assess the therapeutic potential of THBDD1 and the mechanisms involved, we delivered AAV-THBDD1 (10¹¹ genome copies) into db/db mice and tested the effects of recombinant THBDD1 on conditionally immortalised podocytes.

Results

A single dose of AAV-THBDD1 improved albuminuria, renal interstitial inflammation and glomerular sclerosis, as well as renal function in db/db mice. These effects were closely associated with: (1) inhibited activation of the nuclear factor κB (NF-κB) pathway and the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome; (2) promotion of nuclear factor (erythroid-derived 2)-like 2 (NRF2) nuclear translocation; and (3) suppression of mitochondria-derived apoptosis in the kidney of treated mice.

Conclusions/interpretation

AAV-THBDD1 gene therapy resulted in improvements in a model of diabetic nephropathy by suppressing the NF-κB–NLRP3 inflammasome-mediated inflammatory process, enhancing the NRF2 antioxidant pathway and inhibiting apoptosis in the kidney.     

Effects of Angiotensin Ⅱ and Valsartan on the Expression of ATR1/ATR2 Receptors,eNOS in Vascular Endothelial Cells

Background Angiotensin Ⅱ type 1 receptor (ATR1) / Angiotensin Ⅱ type 2 receptor (ATR2) usually interact with each other in their expression and physiological functions, and nitric oxide (NO) is always involved in ATR1 / ATR2 regulation in vivo. Endothelial cells play a crucial role in the maintenance of vascular function and in the prevention of cardiovascular diseases. Objectives To investigate the effects of angiotensin Ⅱ (Ang Ⅱ) and ATR1 blocker valsartan on ATR1, ATR2 expression and their relation with endothelial nitric oxide synthase (eNOS) expression, and NO production in cultured vascular endothelial cells. Methods Human umbilical vein endothelial cell line (HUVEC) and bovine aortic endothelial cell (BAEC) were used. BAEC were isolated from aorta of newborn calf by enzyme digestion and cells of 3-5 passages were used. Cells were incubated with vehicle, Ang Ⅱ, valsartan, or Ang Ⅱ plus valsartan respectively for various periods. ATR1, ATR2, eNOS expression and NO production were detected. Results Incubation with AngⅡ or valsartan apparently downregulated ATR1 mRNA and protein expression in vascular endothelial cells, and the combination effect of the two drugs were more apparent. Ang Ⅱ showed a transient slightly promotive effect on eNOS and NO generation in BAEC and an apparently inhibitory effect with prolonged incubation, while valsartan can apparently reverse those effects. Conclusions Both Ang Ⅱ and valsartan downregulated the expression of ATR1 in vascular endothelial cells. The synergistic effect of the two drugs was more apparent. Prolonged incubation with Ang Ⅱ can apparently inhibit eNOS expression and NO production in endothelial cells, while valsartan can apparently reverse that inhibitory effect.     

Allyl isothiocyanate ameliorates lipid accumulation and inflammation in nonalcoholic fatty liver disease via the Sirt1/AMPK and NF-κB signaling pathways

BACKGROUND Allyl isothiocyanate(AITC),a classic anti-inflammatory and antitumorigenic agent,was recently identified as a potential treatment for obesity and insulin resistance.However,little is known about its direct impact on the liver.AIM To investigate the effect and underlying mechanism of AITC in nonalcoholic fatty liver disease(commonly referred to as NAFLD).METHODS To establish a mouse and cellular model of NAFLD,C57BL/6 mice were fed a high fat diet(HFD)for 8 wk,and AML-12 cells were treated with 200μM palmitate acid for 24 h.For AITC treatment,mice were administered AITC(100 mg/kg/d)orally and AML-12 cells were treated with AITC(20μmol/L).RESULTS AITC significantly ameliorated HFD-induced weight gain,hepatic lipid accumulation and inflammation in vivo.Furthermore,serum alanine aminotransferase and aspartate aminotransferase levels were markedly reduced in AITC-treated mice.Mechanistically,AITC significantly downregulated the protein levels of sterol regulatory elementbinding protein 1(SREBP1)and its lipogenesis target genes and upregulated the levels of proteins involved in fatty acidβ-oxidation,as well as the upstream mediators Sirtuin 1(Sirt1)and AMPactivated protein kinaseα(AMPKα),in the livers of HFD-fed mice.AITC also attenuated the nuclear factor kappa B(NF-κB)signaling pathway.Consistently,AITC relieved palmitate acid-induced lipid accumulation and inflammation in AML-12 cells in vitro through the Sirt1/AMPK and NF-κB signaling pathways.Importantly,further studies showed that the curative effect of AITC on lipid accumulation was abolished by siRNA-mediated knockdown of either Sirt1 or AMPKαin AML-12 cells.CONCLUSION AITC significantly ameliorates hepatic steatosis and inflammation by activating the Sirt1/AMPK pathway and inhibiting the NF-κB pathway.Therefore,AITC is a potential therapeutic agent for NAFLD.     

The relationship between the production and the anti-gonadotrophic action of prostaglandin F2α in luteal cells from the marmoset monkey (Callithrix jacchus) in the early and mid-luteal phase

To address the potential luteolytic role for prostaglandin F_2α (PGF_2α) in the corpus luteum of the common marmoset monkey (Callithrix jacchus), the ability of marmoset luteal cells, maintained in monolayer culture, to produce PGF_2α was determined in vitro in the presence and absence of human chorionic gonadotrophin (hCG) and other established pharmacological modulators of PGF_2α synthesis. We also assessed the effects of the PGF_2α analogue, cloprostenol, on progesterone output from luteal cells isolated in the early luteal phase versus the mid-luteal phase (days 3 and 14 post ovulation, respectively). Cloprostenol had no effect on progesterone output from luteal cells isolated on day 3 of the luteal phase, whereas it significantly inhibited both basal and hCG-stimulated progesterone synthesis by day 14 luteal cells during the culture period 48-72 h (P < 0.001). Intra-luteal PGF_2α concentrations were 5-fold higher in luteal cells isolated in the early luteal phase than in mid-luteal phase cells (16.5 ± 3.5 versus 3.5 ± 0.6 pmol/10⁵ cells). While PGF_2α production was unaffected by hCG in vitro, it was decreased by indomethacin (1000 ng/ml) (P < 0.05) and stimulated by the calcium ionophore A23187 (10 μmol/l) (P < 0.05) in luteal cells from both stages of the luteal phase. Phospholipase A₂ did not influence PGF_2α production by day 3 luteal cells whereas at 10 IU/ml, it significantly stimulated PGF_2α production by day 14 luteal cells (P < 0.05). Hence, the timing of luteolysis in the common marmoset monkey appears to involve changes in both the luteal cell response to and production of PGF_2α.     

Regulation of the release of tumour necrosis factor (TNF)α and soluble TNF Receptor by γ irradiation and interferon γ in Ewing's sarcoma/peripheral primitive neuroectodermal tumour cells

This study analyses the production of tumour necrosis factor (TNF) and soluble TNF receptor (sTNF-R) before and after exposure to irradiation and interferon (IFN) in 12 cell lines derived from Ewing's sarcoma (ES)/peripheral primitive neuroectodermal tumours (pPNET). Supernatants from ES/pPNET cell cultures were tested in a TNF-specific amplified enzyme-linked immunosorbent assay (ELISA), a bioassay, and sTNF-R_p55 and sTNF-R_p75 ELISA. The tumour cell lines released minimal amounts of TNF, prominent amounts of sTNF-R_p55 (7/12 cell lines) and no sTNF-R_p75. Exposure to irradiation (5 Gy) either induced (3/12) cell lines) or up-regulated (3/12 cell lines) TNF release without changing sTNF-R_p55 and sTNF-R_p75 levels. Priming of cultures with recombinant human IFN (rhIFN) markedly enhanced TNF secretion in the radiation-responsive cell lines and had no influence on sTNF-R_p55 and sTNF-R_p75 levels. rhIFN affected the magnitude rather than the sensitivity of the radiation response. The TNF secreted was bioactive, as shown by its cytotoxic effect of WEHI-164 cells, and neutralization of its activity by anti-TNF monoclonal antibody. Herbimycin A (a tyrosine-specific protein kinase inhibitor) but not calphostin C (a protein kinase C inhibitor), H89 (a protein kinase A inhibitor), AACOCF3 (a specific inhibitor of phospholipase A₂) and MK-886 (a specific inhibitor of 5-lipoxygenase) abrogated -irradiation-stimulated TNF release. The antioxidantsN-acetylcysteine, nordihydroguaiaretic acid and mepacrine dose-dependently inhibited -irradiation-mediated TNF production. Collectively our findings indicate that IFN priming potentiates the secretion of bioactive TNF by ES/pPNET cells in response to irradiation without affecting sTNF-R release. The data suggest a requirement for protein tyrosine kinase activity and a role for reactive oxygen species in the -irradiation-mediated intracellular signalling pathway leading to TNF production.     

Non-SMC condensin Ⅰ complex subunit D2 and non-SMC condensin Ⅱ complex subunit D3 induces inflammation via the IKK/NF-κB pathway in ulcerative colitis

BACKGROUND Ulcerative colitis(UC) is a chronic, nonspecific intestinal inflammatory disease with undefined pathogenesis. Non-SMC condensin I complex subunit D2(NCAPD2) and non-SMC condensin II complex subunit D3(NCAPD3) play pivotal roles in chromosome assembly and segregation during both mitosis and meiosis. To date, there has been no relevant report about the functional role of NCAPD2 and NCAPD3 in UC.AIM To determine the level of NCAPD2/3 in intestinal mucosa and explore the mechanisms of NCAPD2/3 in UC.METHODS Levels of NCAPD2/3 in intestinal tissue were detected in 30 UC patients and 30 healthy individuals with in situ hybridization(ISH). In vitro, NCM60 cells were divided into the NC group, model group, si-NCAPD2 group, si-NCAPD3 group and si-NCAPD2+si-NCAPD3 group. Inflammatory cytokines were measured by ELISA, IKK and NF-κB were evaluated by western blot, and IKK nucleation and NF-κB volume were analyzed by immunofluorescence assay.RESULTSCompared with expression in healthy individuals, NCAPD2 and NCAPD3 expression in intestinal tissue was significantly upregulated(P 0.001) in UC patients. Compared with levels in the model group, IL-1β, IL-6 and TNF-α in the si-NCAPD2, si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups were significantly downregulated(P 0.01). IKK and NF-κB protein expression in the si-NCAPD2,si-NCAPD3 and si-NCAPD2+si-NCAPD3 groups was significantly decreased(P 0.01). Moreover, IKK nucleation and NF-κB volume were suppressed upon siNCAPD2, si-NCAPD3 and si-NCAPD2+ si-NCAPD3 transfection.CONCLUSION NCAPD2/3 is highly expressed in the intestinal mucosa of patients with active UC. Overexpression of NCAPD2/3 promotes the release of pro-inflammatory cytokines by modulating the IKK/NF-κB signaling pathway.