Inhibition of tumor necrosis factor-α enhances apoptosis induced by nuclear factor-κB inhibition in leukemia cells

Inhibition of nuclear factor-κB (NF-κB) results in antitumor activity in leukemia cells, and may be a potential therapeutic strategy for the treatment of leukemia. However, a significant limitation of NF-κB inhibition in the treatment of leukemia is the low efficiency of this technique. NF-κB inhibitor treatment induces apoptosis in leukemia cells; however, it additionally causes inflammatory molecules to induce increased sensitivity of healthy hematopoietic cells to cell death signals, therefore limiting its clinical applications. Tumor necrosis factor-α (TNF-α) is a key regulator of inflammation, and induces a variety of actions in leukemic and healthy hematopoietic cells. TNF-α induces NF-κB-dependent and -independent survival signals, promoting the proliferation of leukemia cells. However, in healthy hematopoietic cells, TNF-α induces death signaling, an effect which is enhanced by the inhibition of NF-κB. Based on these observations, the present study hypothesized that inhibition of TNF-α signaling may be able to protect healthy hematopoietic cells and other tissue cells, while increasing the anti-leukemia effects of NF-κB inhibition on leukemia cells. The role and underlying molecular mechanisms of TNF-α inhibition in the regulation of NF-κB inhibition-induced apoptosis in leukemia cells was therefore investigated in the present study. The results indicated that inhibition of TNF-α enhanced NF-κB inhibition-induced apoptosis in leukemia cells. It was also revealed that protein kinase B was significant in the regulation of TNF-α and NF-κB inhibition-induced apoptosis. During this process, intrinsic apoptotic pathways were activated. A combination of NF-κB and TNF-α inhibition may be a potential specific and effective novel therapeutic strategy for the treatment of leukemia.

Modulation of TNF-α mRNA stability by human antigen R and miR181s in sepsis-induced immunoparalysis

Immunoparalysis is an important pathological mechanism in sepsis. However, an effective small molecule therapy is lacking. Here, we show that ouabain, a Na⁺,K⁺-ATPase ligand, can reverse immunoparalysis in vitro, in vivo, and in clinical samples. Notably, the effect of ouabain was critically dependent on TNF-α expression. However, ouabain had opposing effects on the stability of TNF-α mRNA: Ouabain triggered miR-181 transcription, which promoted TNF-α mRNA degradation and induced immunoparalysis, and ouabain triggered the nuclear export of human antigen R (HuR), which stabilized TNF-α mRNA and suppressed immuno-paralysis. Interestingly, because the miR-181 binding site is located within the HuR binding site in the 3′-untranslated region of TNF-α, in ouabain-treated cells, HuR competed with miR-181 for binding to TNF-α mRNA and recruited TNF-α mRNA to stress granules, thereby stabilizing TNF-α mRNA and reversing immunoparalysis. Ouabain also induced GM-CSF and interferon-γ expression in a HuR-dependent manner. Hence, the fine-tuning of TNF-α mRNA stability by HuR and miR181 plays a crucial role in immunoparalysis, and Na⁺,K⁺-ATPase ligands are promising agents for immunoparalysis therapy.

Effects on the tumor specific growth factor and tumor necrosis factor α in rats' precancerous lesion of primary hepatocellular carcinoma by direct moxibustion at Ganshu (BL 18) acupoint

OBJECTIVE

To investigate the effect of direct moxibustion at Ganshu (BL18) on the serum concentrations of tumor specific growth factor (TSGF) and tumor necrosis factor α (TNF-α) in a rat model with precancerous lesion of primary hepatocellular carcinoma (HCC), so as to explore the mechanism of moxibustion underlying improvement of HCC.

METHODS

Sixty male Wistar rats were randomly divided into control group (n=10), model group (n=20), prevention group 1 (n=15) and prevention group 2 (n=15). The normal rats were injected with physiological saline as blank control. At the same time, the rats of other three groups were injected with diethylnitrosamine to establish the HCC model. Direct moxibustion with grain-sized moxa was applied to bilateral Ganshu acupoint of the rats in the prevention group 1 (1 treatment course, 20 days) and prevention group 2 (2 treatment courses, 40 days), 5 doses for each acupoint, 0.5 mg/dose, once every other day. At each time point (before model establishment, the end of 1st course prevention, the end of 2nd course prevention and the end of model establishment), serum levels of TSGF and TNF-α were detected using enzyme-linked immunosorbent assay.

RESULTS

Compared with the control group, there was a remarkably increase of serum TSGF and TNF-α contents in the model group at the end of the experiment (P<0.05). At the end of the 1st course of direct moxibustion, the contents of serum TSGF and TNF-α of rats in the prevention group 1 were significantly increased compared with that of the model group (P<0.05). At the end of the 2nd course of direct moxibustion, serum TSGF and TNF-α levels of rats in the model group were higher than the normal group with significantly difference (P<0.05), and the levels of TSGF and TNF-α in the prevention group 2 were significantly reduced in comparison with the model group (P<0.05).

CONCLUSION

It was possible that direct moxibustion could inhibit precancerous lesion and postpone hepatocarcinogenesis, and the therapeutic effect of two courses were better than one course.

Scanning for Therapeutic Targets within the Cytokine Network of Idiopathic Inflammatory Myopathies

The idiopathic inflammatory myopathies (IIM) constitute a heterogeneous group of chronic disorders that include dermatomyositis (DM), polymyositis (PM), sporadic inclusion body myositis (IBM) and necrotizing autoimmune myopathy (NAM). They represent distinct pathological entities that, most often, share predominant inflammation in muscle tissue. Many of the immunopathogenic processes behind the IIM remain poorly understood, but the crucial role of cytokines as essential regulators of the intramuscular build-up of inflammation is undisputed. This review describes the extensive cytokine network within IIM muscle, characterized by strong expression of Tumor Necrosis Factors (TNFα, LTβ, BAFF), Interferons (IFNα/β/γ), Interleukins (IL-1/6/12/15/18/23) and Chemokines (CXCL9/10/11/13, CCL2/3/4/8/19/21). Current therapeutic strategies and the exploration of potential disease modifying agents based on manipulation of the cytokine network are provided. Reported responses to anti-TNFα treatment in IIM are conflicting and new onset DM/PM has been described after administration of anti-TNFα agents to treat other diseases, pointing to the complex effects of TNFα neutralization. Treatment with anti-IFNα has been shown to suppress the IFN type 1 gene signature in DM/PM patients and improve muscle strength. Beneficial effects of anti-IL-1 and anti-IL-6 therapy have also been reported. Cytokine profiling in IIM aids the development of therapeutic strategies and provides approaches to subtype patients for treatment outcome prediction.

17β-estradiol contributes to the accumulation of myeloid-derived suppressor cells in blood by promoting TNF-α secretion

Estrogens are strongly implicated in gender differences in immune responses by influencing the development and activation of immune cells. Recent studies have shown that myeloid-derived suppressor cells (MDSCs), derived from CD11b(+)Gr-1(+) myeloid cells under pathological conditions, play vital roles in modulating immune responses. However, it is still unknown the effects of estrogens on MDSCs. In the present study, we investigated the effects and mechanisms of estrogens on regulating the accumulation of MDSCs. It was found that, compared with male patients with systemic lupus erythematosus (SLE), female patients with SLE showed a higher frequency of MDSCs in peripheral blood mononuclear cells and a higher level of tumor necrosis factor α (TNF-α) in serum. Notably, estradiol level in the serum of female patients with SLE was positively correlated with the frequency of MDSCs. Moreover, 17β-estradiol could promote TNF-α-induced accumulation of MDSCs in vivo by increasing the fundamental frequency of CD11b(+)Gr-1(+) cells. Furthermore, 17β-estradiol promoted the secretion of TNF-α in vivo, which contributed to the increase of the frequency of CD11b(+)Gr-1(+) cells. In addition, it was also found that female mice showed a higher frequency of CD11b(+)Gr-1(+) cells and a higher TNF-α level in blood than the age-matched male mice. These data indicate that 17β-estradiol contributes to the accumulation of MDSCs in blood by promoting TNF-α secretion, which increases the fundamental frequency of CD11b(+)Gr-1(+) cells. Our findings provide a new insight into the mechanism of gender difference in the prevalence of inflammation and autoimmune diseases.

Modulation expression of tumor necrosis factor α in the radiation-induced lung injury by glycyrrhizic acid

To evaluate the ability of glycyrrhizic acid (GLA) to reduce the tumor necrosis factor α (TNF-α), release on messenger ribonucleic acid (mRNA) and protein production in the lungs using GLA in response to irradiation were studied. The animals were divided into four groups: No treatment (NT group), GLA treatment only (GLA group), irradiation only (XRT group), and GLA treatment plus irradiation (GLA/XRT group). Rats were killed at different time points. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expression of TNF-α in the lungs (compared with non-irradiated lungs). An enzyme-linked immunosorbant assay (ELISA) assay was used to measure the TNF-α protein level. The TNF-α mRNA expression in the lungs of the XRT rats was clearly higher at all-time points compared to the NT rats. The TNF-α mRNA expression in the lungs of the GLA/XRT rats was lower at all-time points compared to the XRT rats. Release of the TNF-α on protein level in the lungs of the XRT rats increased at all-time points compared to the NT rats. In contrast to the XRT rats, the lungs of the GLA/XRT rats revealed a reduction on TNF-α protein level at 6 h after irradiation. This study has clearly showed the immediate down-regulation of the TNF-α mRNA and protein production in the lungs using GLA in response to irradiation.

-308 G/A TNF-α gene polymorphism influences the course of basal cell carcinoma in a Polish population

INTRODUCTION

The etiopathogenesis of basal cell carcinoma (BCC) is multifactorial. The TNF-α gene seems to be an interesting gene candidate for BCC susceptibility because of the proinflammatory and immunosuppressive properties of its product. The aim of the study was to assess the frequency of -308 G/A and -238 G/A gene polymorphisms in the TNF-α gene and serum levels of cytokine in patients with BCC.

MATERIAL AND METHODS

The study included 176 (94 women, 82 men) patients with BCC and 261 healthy volunteers. -308 G/A and -238 G/A TNF-α polymorphisms were analyzed using the amplification refractory mutation system-polymerase chain reaction method (ARMS-PCR). Serum concentrations of TNF-α were measured using ELISA.

RESULTS

There was no statistically significant association between allele, genotype and haplotype frequencies in BCC patients in comparison with controls. Occurrence of the -308 TNF-α A allele or GA genotype in the group of patients with BCC increases risk of recurrence of tumor recurrence (OR = 4.8, 95% CI: 1.6-13.9, p = 0.004 and OR = 4.97, 95% CI: 1.7-14.5, p = 0.004). Moreover, -308 TNF-α GG genotype decreased risk of recurrence (OR = 0.2, 95% CI: 0.07-0.6, p = 0.004). The -238/-308 GA haplotype was connected with increased risk of recurrence (OR = 4.36, 95% CI: 1.49-12.7, p = 0.007). We also found significantly higher TNF-α levels among BCC patients in comparison with controls (p = 0.004).

CONCLUSIONS

The obtained results did not confirm the role of the -308 G/A and -238 G/A TNF-α gene polymorphisms in BCC development, but the presence of the A allele or GA genotype in -308 G/A TNF-α gene polymorphism may have an impact on the course of the disease.

Lack of TNF-alpha receptor type 2 protects motor neurons in a cellular model of amyotrophic lateral sclerosis and in mutant SOD1 mice but does not affect disease progression

Changes in the homeostasis of tumor necrosis factor α (TNFα) have been demonstrated in patients and experimental models of amyotrophic lateral sclerosis (ALS). However, the contribution of TNFα to the development of ALS is still debated. TNFα is expressed by glia and neurons and acts through the membrane receptors TNFR1 and TNFR2, which may have opposite effects in neurodegeneration. We investigated the role of TNFα and its receptors in the selective motor neuron death in ALS in vitro and in vivo. TNFR2 expressed by astrocytes and neurons, but not TNFR1, was implicated in motor neuron loss in primary SOD1-G93A co-cultures. Deleting TNFR2 from SOD1-G93A mice, there was partial but significant protection of spinal motor neurons, sciatic nerves, and tibialis muscles. However, no improvement of motor impairment or survival was observed. Since the sciatic nerves of SOD1-G93A/TNFR2-/- mice showed high phospho-TAR DNA-binding protein 43 (TDP-43) accumulation and low levels of acetyl-tubulin, two indices of axonal dysfunction, the lack of symptom improvement in these mice might be due to impaired function of rescued motor neurons. These results indicate the interaction between TNFR2 and membrane-bound TNFα as an innovative pathway involved in motor neuron death. Nevertheless, its inhibition is not sufficient to stop disease progression in ALS mice, underlining the complexity of this pathology. We show evidence of the involvement of neuronal and astroglial TNFR2 in the motor neuron degeneration in ALS. Both concur to cause motor neuron death in primary astrocyte/spinal neuron co-cultures. TNFR2 deletion partially protects motor neurons and sciatic nerves in SOD1-G93A mice but does not improve their symptoms and survival. However, TNFR2 could be a new target for multi-intervention therapies.

Inhibition of inflammatory cytokines after early decompression may mediate recovery of neurological function in rats with spinal cord injury

A variety of inflammatory cytokines are involved in spinal cord injury and influence the recovery of neuronal function. In the present study, we established a rat model of acute spinal cord injury by cerclage. The cerclage suture was released 8 or 72 hours later, to simulate decompression surgery. Neurological function was evaluated behaviorally for 3 weeks after surgery, and tumor necrosis factor α immunoreactivity and apoptosis were quantified in the region of injury. Rats that underwent decompression surgery had significantly weaker immunoreactivity of tumor necrosis factor α and significantly fewer apoptotic cells, and showed faster improvement of locomotor function than animals in which decompression surgery was not performed. Decompression at 8 hours resulted in significantly faster recovery than that at 72 hours. These data indicate that early decompression may improve neurological function after spinal cord injury by inhibiting the expression of tumor necrosis factor α.

PGC-1α regulates the expression and activity of IRF-1

Interferon regulatory transcription factor 1 (IRF-1) regulates downstream signals of tumor necrosis factor α (TNF-α). The activity of IRF-1 is mediated by Jak/Stat signaling pathway. In this study, we found that PPAR γ coactivator-1α (PGC-1α) is able to suppress the induction of IRF-1. Treatment with TNF-α in MC3T3 cells leads to a sustainable increase in the expression of IRF-1 and its target gene cyclooxygenase 2 (COX-2). In contrast, TNF-α treatment led to a sustainable reduction in expression of PGC-1α. Interestingly, we found that overexpression of PGC-1α attenuated the induction of IRF-1 and COX-2. However, silence of PGC-1α exacerbated the induction of IRF-1 and COX-2. Importantly, we found that the effect of PGC-1α on repressing IRF-1 expression and activity is facilitated by the reduction in phosphorylation of STAT1 at position 727 (S727P), an essential transcriptional activator of IRF-1. Finally, we found that calyculin A, a pharmacological inhibitor of protein phosphatase 2A (PP2A) and PP1 abolishes the repression of STAT1 phosphorylation mediated by PGC-1α, suggesting a new mechanism of PGC-1α in regulating STAT1/IRF-1 pathway.

Short-Wave Diathermy Pretreatment and Inflammatory Myokine Response After High-Intensity Eccentric Exercise

CONTEXT

Various modalities have been used to pretreat skeletal muscle to attenuate inflammation.

OBJECTIVE

To determine the effects of short-wave diathermy (SWD) preheating treatment on inflammation and stress markers after eccentric exercise.

DESIGN

Controlled laboratory study.

SETTING

University laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Fifteen male (age = 22 ± 4.9 years, height = 179.75 ± 9.56 cm, mass = 82.22 ± 12.67 kg) college-aged students.

INTERVENTION(S)

Seven participants were selected randomly to receive 40 minutes of SWD heat treatment (HT), and 8 participants served as the control (CON) group and rested without SWD. Both groups completed 7 sets of 10 repetitions of a high-intensity eccentric exercise protocol (EEP) at 120% of the 1-repetition maximum (1-RM) leg extension.

MAIN OUTCOME MEASURE(S)

We biopsied muscles on days 1, 3 (24 hours post-EEP), and 4 (48 hours post-EEP) and collected blood samples on days 1, 2 (4 hours post-EEP), 3, and 4. We determined 1-RM on day 2 (24 hours post-SWD) and measured 1-RM on days 3 and 4. We analyzed the muscle samples for interleukin 6 (IL-6), tumor necrosis factor α, and heat shock protein 70 and the blood for serum creatine kinase.

RESULTS

We found a group × time interaction for intramuscular IL-6 levels after SWD (F2,26 = 7.13, P = .003). The IL-6 decreased in HT (F1,6 = 17.8, P = .006), whereas CON showed no change (P > .05). We found a group × time interaction for tumor necrosis factor α levels (F2,26 = 3.71, P = .04), which increased in CON (F2,14 = 7.16, P = .007), but saw no changes for HT (P > .05). No group × time interactions were noted for 1-RM, heat shock protein 70, or creatine kinase (P > .05).

CONCLUSIONS

The SWD preheating treatment provided a treatment effect for intramuscular inflammatory myokines induced through high-intensity eccentric exercise but did not affect other factors associated with intense exercise and inflammation.

Collagen matrix as a tool in studying fibroblastic cell behavior

Type I collagen is a fibrillar protein, a member of a large family of collagen proteins. It is present in most body tissues, usually in combination with other collagens and other components of extracellular matrix. Its synthesis is increased in various pathological situations, in healing wounds, in fibrotic tissues and in many tumors. After extraction from collagen-rich tissues it is widely used in studies of cell behavior, especially those of fibroblasts and myofibroblasts. Cells cultured in a classical way, on planar plastic dishes, lack the third dimension that is characteristic of body tissues. Collagen I forms gel at neutral pH and may become a basis of a 3D matrix that better mimics conditions in tissue than plastic dishes.

Extracellular signal-regulated kinase-5: Novel mediator of insulin and tumor necrosis factor α-stimulated vascular cell adhesion molecule-1 expression in vascular cells

BACKGROUND

Atherosclerosis may be stimulated by the increased presence of insulin and tumor necrosis-factor-α (TNFα) with subsequent expression of vascular cell adhesion molecule-1 (VCAM-1). We hypothesized that extracellular signal-regulated kinase-5 (ERK5) plays an important role in insulin and TNFα-stimulated total and cell surface VCAM-1 expression.

METHODS

Rat aorta vascular endothelial cells were first transfected with either no inhibitory RNA, inactive (scrambled) inhibitory ERK5 RNA (scERK5) or active inhibitory ERK5 RNA (siERK5) and then treated with either (i) no analog; (ii) insulin (1 nM), or TNFα (1 ng/mL) alone, or (iii) insulin plus TNFα for 6 h. Thereafter either total VCAM-1 protein or surface VCAM-1 protein was determined.

RESULTS

Genetic inhibition of ERK5 decreased TNFα-stimulated total VCAM-1 expression by 57% and surface expression by 27%. In contrast, genetic inhibition of ERK5 did not significantly decrease insulin-stimulated total or surface VCAM-1 expression. Interestingly, genetic inhibition of ERK5 did not significantly decrease insulin plus TNFα-stimulated total VCAM-1 expression, but significantly (P < 0.05) decreased insulin plus TNFα-stimulated surface VCAM-1 expression 41%.

CONCLUSIONS

We report here that ERK5 plays a minor role in insulin-stimulation of VCAM-1, but plays a significant role in TNFα-stimulation of both total and cell surface VCAM-1 protein expression. Taken together, these results demonstrate that not only does ERK5 have differential mediation of insulin and TNFα-stimulated VCAM-1 expression, but also has differential regulation of insulin plus TNFα-stimulated total and surface VCAM-1 expression, suggesting that other intermediates of the insulin and TNFα intracellular pathways are contributing to atherogenesis.

Effects of berberine and red yeast on proinflammatory cytokines IL-6 and TNF-α in peripheral blood mononuclear cells (PBMCs) of human subjects

BACKGROUND AND AIMS

Obesity is a condition associated with chronic or acute inflammatory response characterized by an increase of proinflammatory cytokine levels. Peripheral blood mononuclear cells (PBMCs) migrate in adipose tissue inducing synthesis and secretion of adipocytokines as IL-6 and TNF-α. The aim of this study was to investigate the effect of berberine (a natural alkaloid) and red yeast (a natural antioxidant) on IL-6 and TNF-α cytokines release and gene expression, in circulating lipopolisaccarides (LPS) stimulated PBMCs.

METHODS AND RESULTS

PBMCs isolated from whole blood of healthy donors were stimulated with LPS to induce cytokines production; simultaneously cells were treated with increasing doses of berberine and red yeast. The substances were administered alone or in association. IL-6 and TNF-α protein levels in the culture medium and their mRNA levels were assessed by ELISA and real time PCR, respectively. Berberine and red yeast treatment prevented the LPS induction of IL-6 release in the culture medium of PBMCs. In addition, berberine plus red yeast treatment showed a synergic inhibitory effect on IL-6 release at low concentration. Berberine and red yeast showed an inhibitory effect also on LPS induction of TNF-α release exerting a synergic effect mainly at high concentrations. On the contrary, berberine and red yeast did not significantly affect IL-6 and TNF-α mRNA levels induced by LPS. In this case, only concomitant treatment of PBMCs with high doses of berberine and red yeast inhibits LPS induced IL-6 or TNF-α mRNA levels.

CONCLUSIONS

The results of our study show that both berberine and red yeast were able to carry out anti-inflammatory action through an inhibition of proinflammatory IL-6 and TNF-α protein release. Moreover, when given in combination these substances were able to inhibit IL-6 and TNF-α gene expression in PBMCs activated by LPS. Therefore, these substances could represent a useful pharmacological treatment to reduce the proinflammatory status accompanied with obesity.

Regulation of CD163 mRNA and soluble CD163 protein in human adipose tissue in vitro

CD163-positive macrophages are highly expressed in the human adipose tissue (AT) particularly from obese individuals. However, little is known about the regulation of CD163 mRNA and the protein level of sCD163 in human AT. We aimed to examine the regulation of CD163 and sCD163 in AT. Human s.c. AT samples (n=5) were stimulated with dexamethasone (DEX; 200  nmol/l), lipopolysaccharide (LPS; 100  ng/ml), or DEX+LPS for various time periods up to 24  h. Gene expressions of CD163, ADAM17, IL10, and TNFA (TNF) were measured by RT-PCR. Protein levels of sCD163, IL10, and TNFα (TNF) were measured by ELISA. Furthermore, AT was separated into stromal and adipocyte fraction. We found that CD163 mRNA was strongly expressed in the stromal vascular fraction but hardly detectable in the isolated adipocytes. Incubating whole AT with DEX significantly up-regulated CD163 (P<0.001), whereas incubation with LPS had no effects on CD163 (P>0.05). By contrast, the protein level of sCD163 was not affected by DEX (P>0.05), but LPS significantly increased the level of sCD163 and TNFα (P<0.05). This might be due to the concomitant LPS stimulation of ADAM17, which is known to mediate shedding of the extracellular domains of sCD163 and TNFα. Finally, DEX significantly reduced the LPS-induced TNFα release to the incubation medium but had no effects on sCD163. We conclude that the expression of CD163 and the release of sCD163 are differentially regulated in human AT. Moreover, similar to studies on differentiated blood monocytes, TNFα and sCD163 are concomitantly released in human AT by LPS, which also up-regulate ADAM17.

TNF-α enhances the effect of TGF-β on Gli2 expression in the KG-1 leukemic cell line

The Hedgehog (Hh) signaling pathway regulates a variety of tumor-related diseases, including leukemia. The present study aimed to determine whether there was an interaction between the Hh signaling pathway and transforming growth factor (TGF)-β in the KG-1 cell line. KG-1 cells were treated with TGF-β, tumor necrosis factor (TNF)-α and specific inhibitor of smad3 (SIS3). The expression level of Gli family zinc finger 2 (Gli2) was detected by quantitative polymerase chain reaction (qPCR) and western blot analyses. The results revealed that TGF-β significantly decreased the expression level of Gli2 in KG-1 cells, and that TNF-α and TGF-β together further reduced Gli2 expression in KG-1 cells. SIS3 inhibited the effect of TGF-β. These results suggest that Gli2 expression in KG-1 cells is suppressed by TGF-β in a Smad3-dependent manner, TNF-α can enhance the effect of TGF-β on Gli2 expression and that this occurs independently of Hh receptor signaling.

Aortic cholesterol accumulation correlates with systemic inflammation but not hepatic and gonadal adipose tissue inflammation in low-density lipoprotein receptor null mice

Inflammation is a major contributor to the development of atherosclerotic plaque, yet the involvement of liver and visceral adipose tissue inflammatory status in atherosclerotic lesion development has yet to be fully elucidated. We hypothesized that an atherogenic diet would increase inflammatory response and lipid accumulation in the liver and gonadal adipose tissue (GAT) and would correlate with systemic inflammation and aortic lesion formation in low-density lipoprotein (LDL) receptor null (LDLr-/-) mice. For 32 weeks, LDLr-/- mice (n = 10/group) were fed either an atherogenic (high saturated fat and cholesterol) or control (low fat and cholesterol) diet. Hepatic and GAT lipid content and expression of inflammatory factors were measured using standard procedures. Compared with the control diet, the atherogenic diet significantly increased hepatic triglyceride and total cholesterol (TC), primarily esterified cholesterol, and GAT triglyceride content. These changes were accompanied by increased expression of acyl-CoA synthetase long-chain family member 5, CD36, ATP-binding cassette, subfamily A, member 1 and scavenger receptor B class 1, and they decreased the expression of cytochrome P450, family 7 and subfamily a, polypeptide 1 in GAT. Aortic TC content was positively associated with hepatic TC, triglyceride, and GAT triglyceride contents as well as plasma interleukin 6 and monocyte chemoattractant protein-1 concentrations. Although when compared with the control diet, the atherogenic diet increased hepatic tumor necrosis factor α production, they were not associated with aortic TC content. These data suggest that the LDLr-/- mice responded to the atherogenic diet by increasing lipid accumulation in the liver and GAT, which may have increased inflammatory response. Aortic TC content was positively associated with systemic inflammation but not hepatic and GAT inflammatory status.

Update on the therapy of Behçet disease

Behçet disease is a chronic inflammatory systemic disorder, characterized by a relapsing and remitting course. It manifests with oral and genital ulcerations, skin lesions, uveitis, and vascular, central nervous system and gastrointestinal involvement. The main histopathological finding is a widespread vasculitis of the arteries and veins of any size. The cause of this disease is presumed to be multifactorial involving infectious triggers, genetic predisposition, and dysregulation of the immune system. As the clinical expression of Behçet disease is heterogeneous, pharmacological therapy is variable and depends largely on the severity of the disease and organ involvement. Treatment of Behçet disease continues to be based largely on anecdotal case reports, case series, and a few randomized clinical trials.

PTPRO plays a dual role in hepatic ischemia reperfusion injury through feedback activation of NF-κB

BACKGROUND & AIMS

Nuclear factor-κB (NF-κB) activation in hepatocytes and macrophages appeared as a double-edged-sword in hepatic ischemia reperfusion (IR) injury. Protein tyrosine phosphatase receptor type O (PTPRO) was recently identified as a potential activator of c-Src, which can in turn activate the NF-κB pathway. In this study, we aimed to determine the change and function of PTPRO in hepatocytes and macrophages during IR.

METHODS

Clinical patients with benign liver condition undergoing liver surgery were recruited in our study. Wild type (WT) and ptpro(-/-) C57BL/6 mice were processed to construct hepatic IR models. Isolated mouse hepatocytes and macrophages were treated with peroxide or TNFα in vitro.

RESULTS

In human and mouse IR models, PTPRO level was decreased in the early phase but reversed in the late phase. In vitro studies demonstrated that NF-κB up-regulated PTPRO transcription. Using ptpro(-/-) mice and primary cells, we found that PTPRO deficiency resulted in reduction of NF-κB activation in both hepatocytes and macrophages and was correlated to c-Src phosphorylation; PTPRO in hepatocytes alleviated, but PTPROt in macrophages exacerbated IR injury.

CONCLUSIONS

PTPRO activates NF-κB in a positive feedback manner, and plays a dual role in hepatic IR injury.

Atopic disorders and depression: findings from a large, population-based study

BACKGROUND

Atopy, a common disorder characterized by a sensitivity to allergic reactions, affects a large proportion of the adult population and, as with depression, is associated with immune-inflammatory pathway changes. We sought to determine the role of atopic disorders in depression using data from a randomly-selected, population-based study of men and women.

METHODS

Cross-sectional data derived from the Geelong Osteoporosis Study for 942 males and 1085 females were analyzed. Depression [major depressive disorder (MDD), minor depression and dysthymia] was assessed using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition. Data on medical conditions, including atopic disorders (asthma, hay fever and eczema), smoking status, alcohol consumption, socioeconomic status, and physical activity were documented by self-report. Logistic regression modeling was used to explore the associations between atopic disorders and depression.

RESULTS

Atopic disorders were associated with a 59% increased likelihood of depression [gender and smoking-adjusted odds ratio (OR) 1:50, 95% CI 1.20-1.97]. Sub-group analyses revealed a similar pattern for those with MDD [gender and smoking-adjusted OR 1:54, 95% CI 1.22-1.94]. These associations were independent of socio-demographic characteristics, clinical and lifestyle factors.

LIMITATIONS

Reliance on self-report for allergic symptoms and cross-sectional nature of study.

CONCLUSION

This population-based study provides evidence of the potential contribution of allergic disorders to depression. Further research is required to elucidate the direction of this association and to further explicate its underlying physiology, including immune-inflammation markers.

The cellular inhibitor of apoptosis protein-2 is a possible target of novel treatment for endometriosis

PROBLEM

How is the tumor necrosis factor (TNF) α-induced inhibitor of apoptosis (IAP) protein expression in endometriotic stromal cells (ESCs) involved in cell viability and signaling pathways?

METHOD OF STUDY

Endometriotic stromal cells were isolated from ovarian chocolate cysts in 20 patients who underwent laparoscopic surgery. IAP protein expression and IκB phosphorylation were evaluated by Western blot analysis. Interleukin (IL)-8 protein expression and cell proliferation were assessed by ELISA.

RESULTS

Cellular IAP (cIAP)-2 protein expression in endometriotic tissue was higher than that of endometrium. TNFα markedly enhanced cIAP-2 protein expression in ESCs. Pretreatment with a nuclear factor (NF)-κB inhibitor attenuated TNFα-induced cIAP-2 expression. An antagonist of IAPs abrogated TNFα-induced cIAP-2 protein expression and showed a decrease in TNFα-induced IL-8 protein expression and BrdU incorporation in ESCs.

CONCLUSIONS

TNFα and its downstream NFκB pathway have proven to be critical regulators of highly expressed cIAP-2 in ESCs. cIAP-2 may be a novel therapeutic target for endometriosis.

Turbo methanol extract inhibits bone resorption through regulation of T cell function

Marine organisms have bioactive potential which has tremendous pharmaceutical promise. Emerging evidence highlights the importance of the interplay between bone and the immune system of which T lymphocytes and their product act as key regulators of bone resorption. In the present investigation we have analyzed the anti-osteoporotic effect of turbo methanol extract (TME) in the reversal of bone resoprtion. Forty-two female Swiss albino mice were used and randomly assigned into sham-operated group (sham) and six ovariectomized (OVX) subgroups, i.e. OVX with vehicle (OVX) that received daily oral administration of water ad libitum; OVX with estradiol (2mg/kg/day); and OVX with different doses of TME i.e. TME 100mg/kg, TME 50mg/kg, TME 25mg/kg and TME 12.5mg/kg. Oral administration of TME or estradiol started on the second week after ovariectomy for a period of 4weeks. We observed that the administration of TME increased the trabeculation in tibia and reduced the atrophy in the uterus. TME significantly decreased the serum alkaline phosphatase (ALP) and acid phosphatase (ACP) activity in OVX mice. Micro CT analysis revealed that the TME administration preserved the bone volume, connectivity density, trabecular number, trabecular thickness and trabecular separation in OVX mice. Bone mineralization was measured in different groups of mice by Raman spectroscopy. Reversal of bone resorption was observed in TME treated group of mice. To further investigate the mechanism of action of TME, we analyzed the T lymphocyte proliferation and profiles of cytokine TNFα and sRANKL in TME treated ovariectomized mice. Decrease in the elevation of T cell subsets was observed after the supplementation with TME. The extract significantly lowered the T cell proliferation responses to mitogens, phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) and phytohemagglutinin (PHA). A marked reduction in TNFα and sRANKL secretion in serum and TNFα in cell free supernatants of activated T lymphocytes was observed upon TME administration. TME could significantly inhibit the in vitro osteoclastogenesis and the bone resorption observed using artificial calcium coated slides. Collectively, these results indicate that TME has the potential to inhibit bone resorption and may prove to be a potential candidate for the development of an anti-osteoporosis drug.

Melatonin: the watchdog of villous trophoblast homeostasis against hypoxia/reoxygenation-induced oxidative stress and apoptosis

Human placenta produces melatonin and expresses its receptors. We propose that melatonin, an antioxidant, protects the human placenta against hypoxia/reoxygenation (H/R)-induced damage. Primary term villous cytotrophoblasts were cultured under normoxia (8% O2) with or without 1mM melatonin for 72h to induce differentiation into the syncytiotrophoblast. The cells were then cultured for an additional 22h under normoxia or subjected to hypoxia (0.5% O2) for 4h followed by 18h reoxygenation (8% O2) with or without melatonin. H/R induced oxidative stress, which activated the Bax/Bcl-2 mitochondrial apoptosis pathway and the downstream fragmentation of DNA. Villous trophoblast treatment with melatonin reversed all the negative effects induced by H/R to normoxic levels. This study shows that melatonin protects the villous trophoblast against H/R-induced oxidative stress and apoptosis and suggests a potential preventive and therapeutic use of this indolamine in pregnancy complications characterized by syncytiotrophoblast survival alteration.

Peroxiredoxin V selectively regulates IL-6 production by modulating the Jak2-Stat5 pathway

Mammalian peroxiredoxin V (PrdxV) is a multifunctional protein that protects cells from DNA damage and inhibits stress-induced apoptosis. However, PrdxV is also known to be involved in modulating lipopolysaccharide (LPS)-induced host cell signaling, but its precise role is not fully understood. In this study, we used stably transfected RAW264.7 cells and transiently transfected 293-mTLR4-MD2-CD14 cells expressing wild-type (WT) or mutant (C48S) PrdxV to characterize the function and mechanism of action of PrdxV in LPS-induced immune responses. We found that PrdxV selectively reduces production of interleukin 6 (IL-6) by inhibiting activation of signal transducer and activator of transcription 5 (Stat5) through interaction with Jak2. Notably, this activity of PrdxV was dependent on its catalytic Cys48 residue, but not its peroxidase activity. The binding of to Jak2 effectively inhibited Jak2 phosphorylation, but PrdxV did not act as efficiently as SOCS1 (suppressor of cytokine signaling 1). Our results suggest that PrdxV is a key mediator contributing to the regulation of LPS/TLR4-induced immune responses.

Endo-PDI is required for TNFα-induced angiogenesis

Protein disulfide isomerase (PDI) and its homologs are oxidoreductases facilitating protein folding in the ER. Endo-PDI (also termed ERp46) is highly expressed in endothelial cells. It belongs to the PDI family but its physiological function is largely unknown. We studied the role of Endo-PDI in endothelial angiogenic responses. Stimulation of human umbilical vein endothelial cells (with TNFα (10ng/ml) increased ERK1/2 phosphorylation. This effect was largely attenuated by Endo-PDI siRNA, whereas JNK and p38 MAP kinase phosphorylation was Endo-PDI independent. Similarly, TNFα-stimulated NF-κB signaling determined by IκBα degradation as well as TNFα-induced ICAM expression was unaffected by Endo-PDI siRNA. The action of Endo-PDI was not mediated by extracellular thiol exchange or cell surface PDI as demonstrated by nonpermeative inhibitors and PDI-neutralizing antibody. Moreover, exogenously added PDI failed to restore ERK1/2 activation after Endo-PDI knockdown. This suggests that Endo-PDI acts intracellularly potentially by maintaining the Ras/Raf/MEK/ERK pathway. Indeed, knockdown of Endo-PDI attenuated Ras activation measured by G-LISA and Raf phosphorylation. ERK activation influences gene expression by the transcriptional factor AP-1, which controls MMP-9 and cathepsin B, two proteases required for angiogenesis. TNFα-stimulated MMP-9 and cathepsin B induction was reduced by silencing of Endo-PDI. Accordingly, inhibition of cathepsin B or Endo-PDI siRNA blocked the TNFα-stimulated angiogenic response in the spheroid outgrowth assays. Moreover ex vivo tube formation and in vivo Matrigel angiogenesis in response to TNFα were attenuated by Endo-PDI siRNA. In conclusion, our study establishes Endo-PDI as a novel, important mediator of AP-1-driven gene expression and endothelial angiogenic function.