Local Expression Of TNF-α Research Articles

Kefir peptides attenuate atherosclerotic vascular calcification and osteoporosis in atherogenic diet-fed ApoE -/- knockout mice.

Aims: Vascular calcification (VC) and osteoporosis were previously considered two distinct diseases. However, current understanding indicates that they share common pathogenetic mechanisms. The available medicines for treating VC and osteoporosis are limited. We previously demonstrated that kefir peptides (KPs) alleviated atherosclerosis in high-fat diet (HFD)-induced apolipoprotein E knockout (ApoE -/- ) mice. The present study further addressed the preventive effects of KPs on VC and osteoporosis in ApoE -/- mice fed a high-cholesterol atherogenic diet (AD). Main methods: Seven-week-old ApoE -/- and wild-type C57BL/6 mice were randomly divided into five groups (n = 6). The development of VC and osteoporosis was evaluated after AD feeding for 13weeks in KP-treated ApoE -/- mice and compared to C57BL/6 and ApoE -/- mice fed a standard chow diet (CD). Key findings: The results indicated that KP-treated ApoE -/- mice exhibited lower serum total cholesterol, oxidized low-density lipoprotein (ox-LDL), malondialdehyde (MDA) levels, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatine kinase (CK) activities, which suggested that KPs prevented hyperlipidemia and possible damages to the liver and muscle in ApoE -/- mice. KPs reduced serum tumor necrosis factor-α (TNF-α) and the local expression of TNF-α, IL-1β, and macrophage-specific CD68 markers in aortic tissues, which suggested that KPs inhibited inflammatory responses in AD-fed ApoE -/- mice. KPs reduced the deposition of lipid, collagen, and calcium minerals in the aortic roots of AD-fed ApoE -/- mice, which suggested that KPs inhibited the calcific progression of atherosclerotic plaques. KPs exerted osteoprotective effects in AD-fed ApoE -/- mice, which was evidenced by lower levels of the bone resorption marker CTX-1 and higher levels of the bone formation marker P1NP. KPs improved cortical bone mineral density and bone volume and reduced trabecular bone loss in femurs. Significance: The present data suggested that KPs attenuated VC and osteoporosis by reducing oxidative stress and inflammatory responses in AD-fed ApoE -/- mice. Our findings contribute to the application of KPs as preventive medicines for the treatment of hyperlipidemia-induced vascular and bone degeneration.

Myocardial expression of somatotropic axis, adrenergic signalling, and calcium handling genes in heart failure with preserved ejection fraction and heart failure with reduced ejection fraction.

AimsLimited data are available regarding cardiac expression of molecules involved in heart failure (HF) pathophysiology. The majority of the studies have focused on end‐stage HF with reduced ejection fraction (HFrEF) without comparison with healthy subjects, while no data are available with regard to HF with preserved ejection fraction (HFpEF). HFpEF is a condition whose multiple pathophysiological mechanisms are still not fully defined, with many proposed hypotheses remaining speculative due to limited access to human heart tissue. This study aimed at evaluating cardiac expression levels of key genes of interest in human biopsy samples from patients affected with HFrEF and HFpEF in order to possibly point out distinct phenotypes.Methods and resultsTotal RNA was extracted from left ventricular cardiac biopsies collected from stable patients with HFrEF (n = 6) and HFpEF (n = 7) and healthy subjects (n = 9) undergoing elective cardiac surgery for valvular replacement, mitral valvuloplasty, aortic surgery, or coronary artery bypass. Real‐time PCR was performed to evaluate the mRNA expression levels of genes involved in somatotropic axis regulation [IGF‐1, IGF‐1 receptor (IGF‐1R), and GH receptor (GHR)], in adrenergic signalling (GRK2, GRK5, ADRB1, and ADRB2), in myocardial calcium handling (SERCA2), and in TNF‐α. Patients with HFrEF and HFpEF showed reduced serum IGF‐1 circulating levels when compared with controls (102 ± 35.6, 138 ± 11.5, and 160 ± 13.2 ng/mL, P < 0.001, respectively). At myocardial level, HFrEF showed significant decreased GHR and increased IGF‐1R expressions when compared with HFpEF and controls (0.54 ± 0.27, 0.94 ± 0.25, and 0.84 ± 0.2, P < 0.05 and 1.52 ± 0.9, 1.06 ± 0.21, and 0.72 ± 0.12, P < 0.05, respectively), while no differences in the local expression of IGF‐1 mRNA were detected among the groups (0.80 ± 0.45, 0.97 ± 0.18, and 0.63 ± 0.23, P = 0.09, respectively). With regard to calcium handling and adrenergic signalling, HFrEF displayed significant decreased levels of SERCA2 (0.19 ± 0.39, 0.82 ± 0.15, and 0.87 ± 0.32, P < 0.01) and increased levels of GRK2 (3.45 ± 2.94, 0.93 ± 0.12, and 0.80 ± 0.14, P < 0.01) and GRK5 (1.32 ± 0.70, 0.71 ± 0.14, and 0.77 ± 0.15, P < 0.05), while no significant difference was found in ADRB1 (0.66 ± 0.4, 0.83 ± 0.3, and 0.86 ± 0.4) and ADRB2 mRNA expression (0.65 ± 0.3, 0.66 ± 0.2, and 0.68 ± 0.1) when compared with HFpEF and controls. Finally, no changes in the local expression of TNF‐α were detected among groups.ConclusionsHeart failure with reduced ejection fraction and HFpEF patients with stable clinical condition display a distinct molecular milieu of genes involved in somatotropic axis regulation, calcium handling, and adrenergic derangement at a myocardial level. The unique opportunity to compare these results with a control group, as reference population, may contribute to better understand HF pathophysiology and to identify novel potential therapeutic targets that could be modulated to improve ventricular function in patients with HF.

Evaluation of the Correlation among the Expression of Inflammatory Cytokines, Degeneration of the Intervertebral Disc, and Prominent Symptoms in Degenerative Human Lumbar Intervertebral Discs

Introduction Low back pain (LBP) disease is reportedly associated with inflammatory cytokines such as tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), as well as with nerve growth factor (NGF) that is expressed in increased amounts within degenerative intervertebral discs (IVDs). In the present study, we aimed to assess the correlation between the local expression of TNF-α, IL-6, and NGF within degenerative human lumbar IVDs and the degree of degeneration, as well as the correlation between the expression of these mediators and the prominent symptoms. Materials and Methods In total, 58 IVD samples of patients who underwent surgery for various lumbar disorders were examined. The expression level of these mediators in each sample was determined using enzyme-linked immunosorbent assay. The samples were grouped according to the degree of IVD degeneration using Pfirrmann grading on magnetic resonance imaging, and the grades were correlated with the individual expression levels. The chief complaints of the patients were then recorded and assigned to the LBP group and the leg pain group, and were compared with the individual expression levels. Results A gradual increase in TNF-α (R: 0.391) and IL-6 (R: 0.388) expression levels were observed with a progression in the degree of degeneration, but NGF (R: − 0.164) exhibited a minimal decrease in the expression level. With regard to the chief complaints, the LBP group only exhibited a significant increase in the TNF-α expression level. Conclusion We noted a trend of increasing expression levels of TNF-α and IL-6 with the progression of IVD degeneration, which indicates that these cytokines may have an important role in the degenerative process of IVD at any stage. Moreover, NGF may have an important effect during the early stage of the progression of degeneration. With regard to the symptoms, TNF-α expression was significantly greater in the LBP group. Thus, we propose that TNF-α may be significantly involved in LBP. Disclosure of Interest None declared

Systemic TNFα Gene Therapy Synergizes With Liposomal Doxorubicine in the Treatment of Metastatic Cancer

Tumor necrosis factor alpha (TNFα) is a potent antitumoral cytokine, either killing tumor cells directly or affecting the tumor vasculature leading to enhanced accumulation of macromolecular drugs. Due to dose limiting side effects systemic administration of TNFα protein at therapeutically active doses is precluded. With gene vectors, tumor restricted TNFα expression can be achieved and in principle synergize with chemotherapy. Synthetic gene carriers based on polyamines were intravenously injected, which either passively accumulate within the tumor or specifically target the epidermal growth factor receptor. A single intravenous injection of TNFα gene vector promoted accumulation of liposomal doxorubicine (Doxil) in murine neuroblastoma and human hepatoma by enhancing tumor endothelium permeability. The expression of transgenic TNFα was restricted to tumor tissue. Three treatment cycles with TNFα gene vectors and Doxil significantly delayed tumor growth in subcutaneous murine Neuro2A neuroblastoma. Also tumors re-growing after initial treatment were successfully treated in a fourth cycle pointing at the absence of resistance mechanisms. Systemic Neuro2A metastases or human LS174T colon carcinoma metastases in liver were also successfully treated with this combined approach. In conclusion, this schedule opens the possibility for the efficient treatment of tumors metastases otherwise not accessible for macromolecular drug carriers.

Erythropoietin attenuates ischemia–reperfusion induced lung injury by inhibiting tumor necrosis factor-α and matrix metalloproteinase-9 expression

Erythropoietin (Epo) was recently defined as an endogenous agent with more than hematopoietic functions. Previously we explored the potential of this agent to ameliorate lung ischemia–reperfusion (I/R) injury. The present study aims to determine the optimal dose and timing of administration for improving lung injury, and to further investigate the mechanisms by which Epo ameliorates lung I/R injury. The left lungs of Sprague–Dawley rats underwent 90 min ischemia and 120 min reperfusion. Firstly, animals in different groups were intraperitoneally injected with various doses of recombined human erythropoietin (rhEpo) 24 h prior to operation, 2 h prior to operation, or after the onset of reperfusion. Pulmonary myeloperoxidase (MPO) activity and malondialdehyde (MDA) content were evaluated. Treatment with 3 KU/kg rhEpo 2 h prior to operation was optimal for attenuating pulmonary MPO activity and MDA content. With such treatment, ultrastructural changes of pneumocytes were observed, and the pneumocyte apoptosis index was also determined by terminal dUTP nick-end labeling method. The plasma concentrations of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-9 were evaluated by enzyme-linked immunosorbent assay, and pulmonary expression by immunohistochemistry. When pretreated with rhEpo, the pneumocyte ultrastructure was predominantly maintained and the pulmonary apoptosis index was markedly reduced. In comparison with untreated animals, in treated animals the plasma concentrations of TNF-α and MMP-9 were significantly decreased, and their expression in lung tissue was markedly reduced as well. The results indicated that Epo potently protected against lung I/R injury by inhibiting systemic and local expression of TNF-α and MMP-9.

Local Expression of Tumor Necrosis Factor-α and Interleukin-10 on Wound Healing of Intestinal Anastomosis During Endotoxemia in Mice

Background. This study aimed to evaluate the integrity of anastomotic wound healing after digestive surgery under septic conditions and define the participation of local expression of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) around the anastomotic segment. Materials and methods. Experimental animals were divided into lipopolysaccharide (LPS) and control groups, which had either LPS or normal saline solution injected into the peritoneal cavity 24 h before transection and anastomosis of the colon. Anastomotic bursting pressure (ABP) and tissue hydroxyproline concentration (HP) were measured as indicators of wound healing. Immunohistochemical staining for TNF-α and IL-10 on tissue samples obtained from the anastomotic segment were examined 1, 6, and 24 h after the operation. The reactive cells were counted under light microscopy. Results. ABP and HP were significantly lower in the LPS group than in the control group 7 days after surgery. In the LPS group, TNF-α expression increased about threefold over that in the control group 1 h after the operation. TNF-α-reactive cells were observed until 24 h after the operation in the LPS group, but not in the control group. On the other hand, IL-10 was not expressed in the control group during the observed period, whereas IL-10 was observed 24 h after the operation in the LPS group. Conclusions. It is suggested that anastomotic wound healing was impaired after the digestive surgery in animals treated with intraperitoneal LPS, and that local expression of TNF-α and IL-10 at the anastomotic site acts as an inhibitory factor in the wound healing process.

Impact of exercise and angiotensin converting enzyme inhibition on tumor necrosis factor-alpha and leptin in fructose-fed hypertensive rats.

The aim of this study was to evaluate the effects of moderate-intensity regular exercise and/or an angiotensin converting enzyme (ACE) inhibition on tumor necrosis factor-alpha (TNF-alpha) and glucose and lipid metabolism parameters. Spontaneously hypertensive rats (SHRs) were fed a fructose-rich diet during 16 weeks of either exercise training (Ex group: 20 m/min, 0% grade, 60 min/day, 5 days/week), administration of an ACE inhibitor (TM group: temocapril, 10 mg/kg/day), or a combination of both (TM+Ex group). The systolic blood pressure was reduced exclusively in the TM and TM+Ex group. Epididymal fat pads (EPI) weighed less in the TM+Ex group than in the single-treatment (TM) group. The serum leptin level was significantly and directly correlated with the EPI weight (p < 0.001). The TNF-alpha content per gram of EPI was the highest in the TM+Ex group. In addition, the EPI TNF-alpha level was negatively correlated with both the EPI weight and the serum leptin level (p < 0.001, respectively). In contrast, the TNF-alpha level of skeletal muscles was identical among the groups. The extensor digitorum longus had a significantly higher abundance of TNF-alpha protein than the soleus muscle. These data indicate that the local TNF-alpha expression is tissue-specific, and that upregulation of TNF-alpha in EPI by exercise training and/or ACE inhibition may have contributed to the reduction in fat cell volume via the induction of apoptosis and/or the regulation of metabolic homeostasis.

OVEREXPRESSION OF TUMOUR NECROSIS FACTOR α IN THE BRAIN OF TRANSGENIC MICE DIFFERENTIALLY ALTERS NERVE GROWTH FACTOR LEVELS AND CHOLINE ACETYLTRANSFERASE ACTIVITY

Tumour necrosis factor α (TNF-α) is a pleiotrophic cytokine synthesized primarily by macrophages and monocytes, which exerts a variety of biological activities during inflammatory responses, immune reactions, and wound healing. Within the central nervous system (CNS), the basal levels of TNF-α are almost undetectable, but increase after neurological insults. Using transgenic mice expressing high levels of TNF-α in the CNS, we investigated the effect of this cytokine on the levels of brain nerve growth factor (NGF), a neurotrophin playing a crucial role in the development, maintenance and regeneration of basal forebrain cholinergic neurons. The immunoenzymatic assay and in situ hybridization revealed that the constitutive expression of NGF decreased in the hippocampus, increased in the hypothalamus, while remained unchanged in the cortex. Moreover, septal cholinergic neurons which receive trophic support from NGF produced in the hippocampus display loss of choline acetyltransferase immunoreactivity, suggesting that the reduced availability of NGF may influence negatively the synthesis of brain cholinergic neurons. These observations indicate that the basal level of brain NGF can be influenced negatively or positively by local expression of TNF-α and that this cytokine, through dose-dependent regulation of NGF synthesis and release, may be involved in neurodegenerative events associated with aging.

Local Expression of TNFα in Neonatal NOD Mice Promotes Diabetes by Enhancing Presentation of Islet Antigens

The relationship of inflammation to autoimmunity has been long observed, but the underlying mechanisms are unclear. Here, we demonstrate that islet-specific expression of TNFα in neonatal nonobese diabetic mice accelerated diabetes. In neonatal transgenic mice, disease was preceded by apoptosis of some β cells, upregulation of MHC class I molecules on residual islet cells, and influx and activation of both antigen-presenting cells bearing MHC–islet peptide complexes and T cells. Infiltrating dendritic cells/macrophages, but not B cells, from neonatal islets activated islet-specific T cells in vitro. Thus, inflammation can trigger autoimmunity by recruiting and activating dendritic cells/macrophages to present self-antigens to autoreactive T cells.