Ethanol Withdrawal Alters the Oxidative State of the Heart Through AT1-Dependent Mechanisms.

AIMS: We investigated the cardiac effects of ethanol withdrawal and the possible role of AT1 receptors in such response. METHODS: Male Wistar rats were treated with increasing doses of ethanol (3 to 9%, vol./vol.) for 21 days. The cardiac effects of ethanol withdrawal were investigated 48 h after abrupt discontinuation of ethanol. Some animals were orally treated with losartan (10 mg/kg/day), a selective AT1 receptor antagonist. RESULTS: Ethanol withdrawal did not affect serum levels of creatine kinase (CK)-MB. Losartan prevented ethanol withdrawal-induced increase in superoxide anion (O2•-) production in the left ventricle (LV). However, ethanol withdrawal did no alter the levels of thiobarbituric acid reactive substances (TBARS) or the expression of Nox1, Nox2 or Nox4 were found in the LV. Ethanol withdrawal reduced the concentration of hydrogen peroxide (H2O2) in the LV and this response was prevented by losartan. Ethanol withdrawal increased catalase activity in the LV and losartan attenuated this response. No changes on superoxide dismutase (SOD) activity or expression were detected in the LV during ethanol withdrawal. The expression of AT1, AT2 or angiotensin converting enzyme (ACE) was not affected by ethanol withdrawal. Similarly, no changes on the expression of ERK1/2, SAPK/JNK, COX-1 or COX-2 were found in the LV during ethanol withdrawal. CONCLUSIONS: Ethanol withdrawal altered the cardiac oxidative state through AT1-dependent mechanisms. Our findings showed a role for angiotensin II/AT1 receptors in the initial steps of the cardiac effects induced by ethanol withdrawal.

Identification of JNK1 as a predicting biomarker for ABT-199 and paclitaxel combination treatment.

Targeting Bcl-2 with ABT-199 (Venetoclax) shows limited single-agent activity against many cancers in both preclinical and clinical investigations. Combination therapies have attracted great attention. The principal purpose of this study was to investigate the mechanism of synergism between ABT-199 and paclitaxel. Moreover, we analyzed the biomarker to identify tumors which are most likely to respond to this combination. We evaluated the effect of this combination in a panel of nine cancer cell lines including cervical cancer, lung cancer, ovarian cancer, lymphoma, leukemia and breast cancer. Combination index (CI) assay showed that four of nine call lines exhibited synergistic respond to ABT-199/paclitaxel combination due to enhanced intrinsic apoptosis. However, paclitaxel-induced Bcl-2 phosphorylation impaired the synergistic effect by impeding the freeing of Bax and Bim by ABT-199 because ABT-199 cannot hit phosphorylated Bcl-2 (pBcl-2). By means of a correlation analysis of JNK level with CI value in combination with overexpressing or silencing JNK protein in cancer cells, we identified basal JNK1 level as a potential biomarker for predicting the level of pBcl-2 upon paclitaxel treatment, and thus for predicting a synergistic response. A cut-off value of 0.37 for relative JNK1 expression level was determined using receiver operating characteristic (ROC) analysis to distinguish between synergistic and non-synergistic response cancers. A more accurate and valid cut-off value for JNK1 will be gained based on a large-scale clinical samples analysis.

Berberine Ameliorates Hepatic Steatosis and Suppresses Liver and Adipose Tissue Inflammation in Mice with Diet-induced Obesity.

Increasing evidence demonstrates that berberine (BBR) is beneficial for obesity-associated non-alcoholic fatty liver disease (NAFLD). However, it remains to be elucidated how BBR improves aspects of NAFLD. Here we revealed an AMP-activated protein kinase (AMPK)-independent mechanism for BBR to suppress obesity-associated inflammation and improve hepatic steatosis. In C57BL/6J mice fed a high-fat diet (HFD), treatment with BBR decreased inflammation in both the liver and adipose tissue as indicated by reduction of the phosphorylation state of JNK1 and the mRNA levels of proinflammatory cytokines. BBR treatment also decreased hepatic steatosis, as well as the expression of acetyl-CoA carboxylase and fatty acid synthase. Interestingly, treatment with BBR did not significantly alter the phosphorylation state of AMPK in both the liver and adipose tissue of HFD-fed mice. Consistently, BBR treatment significantly decreased the phosphorylation state of JNK1 in both hepatoma H4IIE cells and mouse primary hepatocytes in both dose-dependent and time-dependent manners, which was independent of AMPK phosphorylation. BBR treatment also caused a decrease in palmitate-induced fat deposition in primary mouse hepatocytes. Taken together, these results suggest that BBR actions on improving aspects of NAFLD are largely attributable to BBR suppression of inflammation, which is independent of AMPK.

Phloretin induces apoptosis of non-small cell lung carcinoma A549 cells via JNK1/2 and p38 MAPK pathways.

Phloretin (Ph) existing in apples, pears and various vegetables is known to have antitumor activities in several cancer cell lines. However, little is known about its effect on human lung cancer cells. The aim of the present study was to see whether Ph could induce apoptosis of non-small cell lung cancer (NSCLC) cells, and explore the possible underlying mechanism of action. We found that Ph markedly induced cell apoptosis of NSCLC cell line A549, and inhibited the migration of A549 cells in a dose-dependent manner. The expression level of BAX, cleaved caspase-3 and -9, and degraded form of PARP was increased and Bcl-2 was decreased after Ph treatment. In addition, the phosphorylation of P38 MAPK, ERK1/2 and JNK1/2 was increased in a dose­dependent manner in parallel with Ph treatment. Inhibition of P38 MAPK and JNK1/2 by specific inhibitors significantly abolished the Ph-induced activation of the caspase-3 and -9. In vivo tumor-suppression assay further indicated that Ph (20 mg/kg) displayed a more significant inhibitory effect on A549 xenografts in tumor growth. All these findings indicate that Ph is able to inhibit NSCLC A549 cell growth by inducing apoptosis through P38 MAPK and JNK1/2 pathways, and therefore may prove to be an adjuvant to the treatment of NSCLC.

Hypoxic response contributes to altered gene expression and precapillary pulmonary hypertension in patients with sickle cell disease.

BACKGROUND: We postulated that the hypoxic response in sickle cell disease (SCD) contributes to altered gene expression and pulmonary hypertension, a complication associated with early mortality. METHODS AND RESULTS: To identify genes regulated by the hypoxic response and not other effects of chronic anemia, we compared expression variation in peripheral blood mononuclear cells from 13 subjects with SCD with hemoglobin SS genotype and 15 subjects with Chuvash polycythemia (VHL(R200W) homozygotes with constitutive upregulation of hypoxia-inducible factors in the absence of anemia or hypoxia). At a 5% false discovery rate, 1040 genes exhibited >1.15-fold change in both conditions; 297 were upregulated and 743 downregulated including MAPK8 encoding a mitogen-activated protein kinase important for apoptosis, T-cell differentiation, and inflammatory responses. Association mapping with a focus on local regulatory polymorphisms in 61 patients with SCD identified expression quantitative trait loci for 103 of these hypoxia response genes. In a University of Illinois SCD cohort, the A allele of a MAPK8 expression quantitative trait locus, rs10857560, was associated with precapillary pulmonary hypertension defined as mean pulmonary artery pressure ≥25 mm Hg and pulmonary capillary wedge pressure ≤15 mm Hg at right heart catheterization (allele frequency, 0.66; odds ratio, 13.8; n=238). This association was confirmed in an independent Walk-Treatment of Pulmonary Hypertension and Sickle Cell Disease With Sildenafil Therapy cohort (allele frequency, 0.65; odds ratio, 11.3; n=519). The homozygous AA genotype of rs10857560 was associated with decreased MAPK8 expression and present in all 14 of the identified precapillary pulmonary hypertension cases among the combined 757 patients. CONCLUSIONS: Our study demonstrates a prominent hypoxic transcription component in SCD and a MAPK8 expression quantitative trait locus associated with precapillary pulmonary hypertension.

Roles of phosphorylated JNK in esophageal squamous cell carcinomas of Kazakh ethnic.

The c-Jun NH2 -terminal kinase (JNK) signal pathway has been implicated in the growth, cellular proliferation, and apoptosis in many kinds of carcinomas. However, the role of JNK in the development of esophageal squamous cell carcinomas (ESCCs) is unknown. To investigate the role of JNK in ESCC, in vitro, esophageal cancer cell line Eca109 was pretreated using SP600125, JNK specific inhibitor, then was subjected to MTT assay to examine cellular proliferation, flow cytometric analysis to detect apoptosis and cell cycle, and wound healing assay to evaluate cell migration. Meanwhile, the mRNA and protein expression of JNK in Eca109 cells pretreated with SP600125 were examined by real-time quantitative reverse transcription PCR (qRT-PCR) and Western blotting, respectively. In vivo, 12 paired of fresh ESCC and normal adjacent tissues (NAT) from Kazakh patients were used to validate the expression of JNK by qRT-PCR and Western blotting. Furthermore, to reconfirm the expression trend of activation JNK (p-JNK), enlarged 72 paired of Kazakh's ESCC and NAT were subjected to immunohistochemistry. Our results showed that the suppression of p-JNK could lead to apoptosis and reduce proliferation in Eca109 cells. However, there was an elevated expression of p-JNK protein in NAT compared with ESCC tissues, and there was significant difference between p-JNK expression and pathological differentiation (P < 0.05) in Kazakh populations. Together, all the data we obtained in the present study indicated that the p-JNK MAPK pathway was involved in pathogenesis of Kazakh's ESCC, and played a different roles in carcinogenesis and development of Kazakh's ESCC.

Inhibition of apolipoprotein A-I expression by TNF-alpha in HepG2 cells: requirement for c-jun.

Tumor necrosis factor alpha (TNF α) signals in part through the mitogen activated protein (MAP) kinase c-jun-N-terminal kinase (JNK). Activation of JNK has been shown to promote insulin resistance and dyslipidemia, including reductions in plasma high-density lipoprotein (HDL) and apolipoprotein A-I (apo A-I). To examine how TNF α-mediated JNK activation inhibits hepatic apo A-I production, the effects of c-jun activation on apo A-I gene expression were examined in HepG2 cells. Apo A-I gene expression and promoter activity were measured by Northern and Western blotting and transient transfection. Transient transfection and siRNA were used to specifically over-express or knockout c-jun, c-jun-N-terminal kinase-1 and -2 (JNK1 and JNK2, respectively) and mitogen-activated protein kinase-4 (MKK4). TNF α-treatment of HepG2 cells induced rapid phosphorylation of c-jun on serine 63. In cells treated with phorbol-12-myristate-13-acetate (PMA), apo A-I gene promoter activity was inhibited and apo A-I mRNA content and apo A-I protein secretion decreased. Likewise, over-expression of JNK1 and JNK2 inhibited apo A-I promoter activity. Over-expression of constitutively active MKK4, an upstream protein kinase that directly activates JNK, also inhibited apo A-I promoter activity, while over-expression of a dominant-negative MKK4 de-repressed apo A-I promoter activity in TNF α-treated cells. Inhibition of c-jun synthesis using siRNA but not a control siRNA prevented TNF α-mediated inhibition of apo A-I. These results suggest that the MKK4/JNK/c-jun signaling pathway mediates TNF α-dependent inhibition of apo A-I synthesis.

Myc inhibition impairs autophagosome formation.

Autophagy, a major clearance route for many long-lived proteins and organelles, has long been implicated in cancer development. Myc is a proto-oncogene often found to be deregulated in many cancers, and thus is an attractive target for design of cancer therapy. Therefore, understanding the relationship between anti-Myc strategies and autophagy will be important for development of effective therapy. Here, we show that Myc depletion inhibits autophagosome formation and impairs clearance of autophagy substrates. Myc suppression has an inhibitory effect on autophagy via reduction of c-Jun N-terminal kinase 1 (JNK1) and B-cell lymphoma 2 (Bcl2) phosphorylation. Additionally, the decrease in JNK1 phosphorylation observed with Myc knockdown is associated with a reduction in ROS production. Our data suggest that targeting Myc in cancer therapy might have the additional benefit of inhibiting autophagy in the case of therapy resistance associated with chemotherapy-induced autophagy.

WNT5A/JNK signaling regulates pancreatic cancer cells migration by Phosphorylating Paxillin.

BACKGROUND: Expression of WNT5A associated with aggressive tumor biology and poor clinical outcome of various types of cancer. However its function in the metastasis property of pancreatic cells still needs to be elucidated. METHODS: We detected the expressions of WNT5A, JNK1/p-JNK1 and Paxillin/p-Paxillin in cancer and the para-carcinoma tissues of pancreatic cancer. To understand how WNT5A/JNK signaling affects pancreatic cancer cell migration through the phosphorylation of cellular substrates of Paxillin, In vitro, we knocked down the WNT5A in PANC1, Capan-2 and HT1080 cell lines, and then tested the expression of JNK1. We detected the proteins of phosphorylation of Paxillin after JNK1 was inhibited and then the cells migration assay was evaluated. Moreover, JNK1 functionally phosphorylates serine178 on paxillin in vitro was detected .At last we subsequently observed whether WNT5A/JNK signaling modulates some molecule expressions relevant to focal adhesion (FA) formation and mesenchymal transition (EMT) and cell cycle. RESULTS: WNT5A, p-JNK1 and p-Paxillin were highly expressed in early stage of tumor tissues. In vitro, WNT5A/JNK signaling promotes cell migration in pancreatic cancer by phosphorylating serine178 on Paxillin, an FA adaptor, which means WNT5A may regulate FA's function.WNT5A up-regulates the molecule's expressions relevant to cell adhesion through the phosphorylation of JNK1, including MMP1, MMP2, ICAM and CD44. In addition, WNT5A/JNK signaling promoted the mRNA expressions of vimentin, but decreased in E-Cadherin expression, which suggested its regulatory effects on the EMT processes. WNT5A/JNK signaling didn't modulate cell proliferation. CONCLUSION: WNT5A/JNK signaling initiate cell migration of pancreatic cancer through activation of Paxillin, which suggested WNT5A has the potency of being an effective therapeutic target for the metastasis of pancreatic cancer.

Expression of NFkB1, GADD45A and JNK1 in salivary gland carcinomas of different histotypes.

The class of salivary gland tumours is very heterogenous, both in a histopathological and clinical sense. Since they are uncommon lesions, their clinical management is still problematic. Molecular mechanisms underlying the development of these cancer types may be fundamental for the diagnosis, treatment and prognosis of this disease. In this study, the gene expression of nuclear factor-kappa B (NKkB1/p65), c-Jun N-terminal kinase (JNK1) and growth arrest and DNA damage (GADD45A), which all play an important role in inflammatory and cell survival mechanisms, was assessed in benign and malignant neoplasms of the salivary gland. The absolute mRNA content of paraffin embedded samples of salivary gland cancer was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using specific primers for NFkB1, GADD45A and JNK1. Expression values (relative to HPRT) were statistically evaluated. Among the detected alterations in gene expression, the only difference reaching statistical significance was in the case of NFkB1 in adenocystic carcinomas (p=0.05). Given the importance of these signalling mechanisms in the biology of tumorigenesis, these results may be implemented in further research and these genes might become targets for innovative diagnostic and therapeutic strategies.

Characterization of an acute muscle contraction model using cultured C2C12 myotubes.

A cultured C2C12 myotube contraction system was examined for application as a model for acute contraction-induced phenotypes of skeletal muscle. C2C12 myotubes seeded into 4-well rectangular plates were placed in a contraction system equipped with a carbon electrode at each end. The myotubes were stimulated with electric pulses of 50 V at 1 Hz for 3 ms at 997-ms intervals. Approximately 80% of the myotubes were observed to contract microscopically, and the contractions lasted for at least 3 h with electrical stimulation. Calcium ion (Ca²âº) transient evoked by the electric pulses was detected fluorescently with Fluo-8. Phosphorylation of protein kinase B/Akt (Akt), 5' AMP-activated protein kinase (AMPK), p38 mitogen-activated protein kinase (p38), and c-Jun NH2-terminal kinase (JNK)1/2, which are intracellular signaling proteins typically activated in exercised/contracted skeletal muscle, was observed in the electrically stimulated C2C12 myotubes. The contractions induced by the electric pulses increased glucose uptake and depleted glycogen in the C2C12 myotubes. C2C12 myotubes that differentiated after exogenous gene transfection by a lipofection or an electroporation method retained their normal contractile ability by electrical stimulation. These findings show that our C2C12 cell contraction system reproduces the muscle phenotypes that arise invivo (exercise), in situ (hindlimb muscles in an anesthetized animal), and invitro (dissected muscle tissues in incubation buffer) by acute muscle contraction, demonstrating that the system is applicable for the analysis of intracellular events evoked by acute muscle contraction.

Mediterranean diet supplemented with coenzyme Q10 modifies the expression of proinflammatory and endoplasmic reticulum stress-related genes in elderly men and women.

We have investigated whether the quality of dietary fat and supplementation with coenzyme Q(10) (CoQ) modifies expression of genes related with inflammatory response and endoplasmic reticulum stress in elderly persons. Twenty participants received three diets for 4 weeks each: Mediterranean diet + CoQ (Med + CoQ), Mediterranean diet (Med), and saturated fatty acid-rich diet (SFA). After 12-hour fast, volunteers consumed a breakfast with a fat composition similar to that consumed in each of the diets. Med and Med + CoQ diets produced a lower fasting calreticulin, IL-1b, and JNK-1 gene expression; a lower postprandial p65, IKK-b, MMP-9, IL-1b, JNK-1, sXBP-1, and BiP/Grp78 gene expression; and a higher postprandial IkB-a gene expression compared with the SFA diet. Med + CoQ diet produced a lower postprandial decrease p65 and IKK-b gene expression compared with the other diets. Our results support the anti-inflammatory effect of Med diet and that exogenous CoQ supplementation in synergy with a Med diet modulates the inflammatory response and endoplasmic reticulum stress.

Disturbed blood flow induces RelA expression via c-Jun N-terminal kinase 1: a novel mode of NF-κB regulation that promotes arterial inflammation.

RATIONALE: The nuclear factor (NF)-κB pathway is involved in arterial inflammation. Although the signaling pathways that regulate transcriptional activation of NF-κB are defined, the mechanisms that regulate the expression levels of NF-κB transcription factors are uncertain. OBJECTIVE: We studied the signaling mechanisms that regulate RelA NF-κB subunit expression in endothelial cells (ECs) and their role in arterial inflammation. METHODS AND RESULTS: Gene silencing and chromatin immunoprecipitation revealed that RelA expression was positively regulated by c-Jun N-terminal kinase (JNK) and the downstream transcription factor ATF2 in ECs. We concluded that this pathway promotes focal arterial inflammation as genetic deletion of JNK1 reduced NF-κB expression and macrophage accumulation at an atherosusceptible site. We hypothesized that JNK signaling to NF-κB may be controlled by mechanical forces because atherosusceptibility is associated with exposure to disturbed blood flow. This was assessed by positron emission tomography imaging of carotid arteries modified with a constrictive cuff, a method that was developed to study the effects of disturbed flow on vascular physiology in vivo. This approach coupled to en face staining revealed that disturbed flow elevates NF-κB expression and inflammation in murine carotid arteries via JNK1. CONCLUSIONS: We demonstrate that disturbed blood flow promotes arterial inflammation by inducing NF-κB expression in endothelial cells via JNK-ATF2 signaling. Thus, our findings illuminate a novel form of JNK-NF-κB crosstalk that may determine the focal nature of arterial inflammation and atherosclerosis.

Inhibition of JNK1 expression decreases migration and invasion of mouse hepatocellular carcinoma cell line in vitro.

c-Jun N-terminal kinase (JNK) is located in focal adhesion plaque (FAP). JNK is necessary to growth, morphogenesis, and differentiation of cells; especially JNK1 has a close relation with tumors. In this study, we silenced JNK1 by using short hairpin RNA (shRNA) and examined the effect on migration and invasion of mouse hepatocellular carcinoma (HCC) cell line Hca-F in vitro. Three shRNA expression vectors (JNK1shRNA-1, JNK1shRNA-2, and JNK1shRNA-3) were constructed and transfected to Hca-F cells stably. The most effective shRNA was selected by detecting the expression levels of mRNA and protein. Transwell assay was performed to detect the ability of migration and invasion of cells. A negative control sequence (JNK1shRNA control) and non-transfected normal Hca-F cells were treated as control groups. The "Results" showed that the expression vectors of pSilencer-JNK1shRNA were constructed and transfected to Hca-F cells successfully. The most effective shRNA was JNK1shRNA-2. The expressions of mRNA and protein of JNK1 in Hca-F cells after transfection of JNK1shRNA-2 were decreased significantly compared with the other groups (all, P<0.01; all, P<0.05). The ability of migration and invasion was decreased after down-regulation of JNK1 expression (all, P<0.05). These results suggest that the inhibition of JNK1 expression can decrease ability of migration and invasion of mouse hepatocellular carcinoma cell line in vitro. JNK1 plays an important role in lymphatic metastasis of HCC. It may be a new target for gene therapy of lymphatic metastasis of HCC.

Knockdown of the c-Jun-N-terminal kinase expression by siRNA inhibits MCF-7 breast carcinoma cell line growth.

We have examined the effect of two small interference RNA against Jnk-1 and Jnk-2 in the breast cancer cell line MCF-7. The expression of the JNK-1 and JNK-2 is frequently elevated in breast cancer and is a frequent genetic abnormality in this malignancy. For a better understanding of its role in maintaining the malignant phenotype, we used small RNA interference (siRNA) directed against Jnk-1 or Jnk-2. We made control and Jnk-1 and Jnk-2 siRNA using vector plasmid, which was then transfected to reduce its expression in MCF-7 cells. We assessed the effects of JNK-1 or JNK-2 silencing on cell growth by western blot analysis, soft agar assay, cell proliferation assay, cell viability by MTT assay and caspase assay in vitro. Our data showed that siRNA against Jnk-1 or Jnk-2 markedly and durably reduced its expression in MCF-7 cells by up to 70%, decreased the growth rate of MCF-7 cells, inhibited colony formation in soft agar and significantly reduced cell growth in MCF-7 carcinoma culture cell line. We also found that depletion of JNK-1/2 in this manner promoted apoptosis of MCF-7 cells upon serum withdrawal. In addition, we found that MCF-7 cells did not exhibit any caspase-3 activity. In conclusion, we observed that JNK-1 and JNK-2 have a pivotal function in the development of breast cancer. Our data show that decreasing the JNK-1 or JNK-2 protein level in MCF-7 cells by siRNA could significantly inhibit MCF-7 cell growth in in vitro assay, and imply the therapeutic potential of siRNA on the treatment of breast cancer by targeting overexpression kinases such as JNK-1/2 and might be a potential therapeutic target for human breast cancer.

MicroRNA-214 is aberrantly expressed in cervical cancers and inhibits the growth of HeLa cells.

MicroRNAs are a group of endogenously expressed, single-stranded, 18-24 nt RNAs that regulate diverse cellular pathways. Although documented evidence indicates that some microRNAs can function as oncogenes or tumor-suppressors, the role of miR-214 in regulating human cervical cancer cells remains unexplored. We determined the expression level of miR-214 and found it is downregulated in cervical cancer compared with normal tissue. Overexpression of miR-214 in HeLa cells, a human cervical cancer cell line, significantly inhibited cell proliferation according to the MTT and colony forming assays. HeLa cells that stably overexpress miR-214 downregulate the expression of MEK3 and JNK1 at both mRNA and protein levels. Further investigation revealed that miR-214 regulates the expression of MEK3 and JNK1 by targeting the 3'UTRs of these genes. Collectively, these results suggest that miR-214 negatively regulates HeLa cell proliferation by targeting the noncoding regions of MEK3 and JNK1 mRNAs.

Differential regulation of the antiapoptotic action of B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma extra long (Bcl-xL) by c-Jun N-terminal protein kinase (JNK) 1-involved pathway in neuroglioma cells.

Here, we confirmed that stable expression of B-cell lymphoma-xL (Bcl-xL) in N18TG neuroglioma cells could suppress c-Jun N-terminal protein kinase (JNK) activation, nuclear fragmentation, and cell death caused by etoposide treatment. Moreover, additional overexpression of JNK1 led to partially antagonize the antiapoptotic environment attained by Bcl-xL, implying that JNK1-involved pathway may play a role in down-regulation of the antiapoptotic effect of Bcl-xL. However, the antagonistic effect of JNK1 on the antiapoptotic action of Bcl-xL was significantly weaker than that on the action of Bcl-2. Interestingly, we found that overexpression of JNK1 led to increase of Bcl-xL expression. Thus, these results suggest that Bcl-xL and Bcl-2 may induce its antiapoptotic effect in a different mechanism, provoking the possibility of involvement of JNK1-involved pathway in Bcl-xL expression.

Reduction of JNK1 expression with antisense oligonucleotide improves adiposity in obese mice.

To investigate the role of JNK1 in metabolism, male ob/ob and diet-induced obese mice were treated with a JNK1-specific antisense oligonucleotide (ASO) or control ASO at 25 mg/kg or saline twice/wk for 6 and 7 wk, respectively. JNK1 ASO reduced JNK1 mRNA and activity by 65-95% in liver and fat tissues in both models. Compared with controls, treatment with JNK1 ASO did not change food intake but lowered body weight, fat pad weight, and whole body fat content. The treatment increased metabolic rate. In addition, the treatment markedly reduced plasma cholesterol levels and improved liver steatosis and insulin sensitivity. These positive observations were accompanied by the following changes: 1) increased mRNA levels of AR-beta(3) and UCP1 by >60% in BAT, 2) reduced mRNA levels of ACC1, ACC2, FAS, SCD1, DGAT1, DGAT2, and RBP4 by 30-60% in WAT, and 3) reduced mRNA levels of ACC1, FAS, G-6-Pase, and PKCepsilon by 40-70% and increased levels of UCP2 and PPARalpha by more than twofold in liver. JNK1 ASO-treated mice demonstrated reduced levels of pIRS-1 Ser(302) and pIRS-1 Ser(307) and increased levels of pAkt Ser(473) in liver and fat in response to insulin. JNK1 ASO-transfected mouse hepatocytes showed decreased rates of de novo sterol and fatty acid synthesis and an increased rate of fatty acid oxidation. These results indicate that inhibition of JNK1 expression in major peripheral tissues can improve adiposity via increasing fuel combustion and decreasing lipogenesis and could therefore provide clinical benefit for the treatment of obesity and related metabolic abnormalities.

Superior cervical ganglion-10 protein as a molecular effector of c-Jun N-terminal kinase 1: implications for the therapeutic targeting of Jun N-terminal kinase in nerve regeneration.

BACKGROUND: Cell stress and tissue injury lead to c-Jun N-terminal kinase (JNK) activation, which is known to contribute to cell death. Paradoxically, strong evidence supports an important role for JNK in the regeneration of neuronal processes, subsequent to injury. OBJECTIVE: Recent research revealed the growth cone-associated protein superior cervical ganglion-10 protein as a candidate effector for the regeneration pathway mediated by JNK1. This implies that neuroprotective strategies targeting JNK may have negative effects on neuronal regeneration, unless JNK1 function is spared, and that the mechanistic relationships between JNK1 and neuronal regeneration deserve increased attention. RESULTS: This review proposes a model reconciling the microtubule regulatory properties of superior cervical ganglion protein 10 with its role as a JNK effector of regeneration and highlight remaining issues to be resolved.