Thalidomide in Rat Liver Cirrhosis: Blockade of Tumor Necrosis Factor-α via Inhibition of Degradation of an Inhibitor of Nuclear Factor-κB

Experimental and Numerical Study of Non-Explosive Simulated Blast Loading on Reinforced Concrete Slabs

This study presents a non-explosive method for simulating blast loading on reinforced concrete (RC) slabs. The method involves using a newly developed blast simulator to apply a speedy impact load on the slab, which generates a pressure wave similar to that of an actual blast. Both experimental and numerical simulations were carried out to evaluate the effectiveness of the method. The experimental results showed that the non-explosive method can produce a pressure wave with a peak pressure and duration analogous to those of an actual blast. The numerical simulations also showed good agreement with the experimental results. Additionally, parameter studies were conducted to evaluate the effects of the rubber shape, the impact velocity, the bottom thickness, and the upper thickness on the impact loading. The results indicate that pyramidal rubber is more suitable as an impact cushion for simulating blast loading than planar rubber. The impact velocity has the widest range of regulation for peak pressure and impulse. As the velocity increases from 12.76 to 23.41 m/s, the corresponding range of values for peak pressure is 6.457 to 17.108 MPa, and for impulse, it is 8.573 to 14.151 MPa∙ms. The variation in the upper thickness of the pyramidal rubber has a more positive effect on the impact load than the bottom thickness. With the upper thickness increasing from 30 mm to 130 mm, the peak pressure decreased by 59.01%, and the impulse increased by 16.64%. Meanwhile, when the bottom part's thickness increased from 30 mm to 130 mm, the peak pressure decreased by 44.59%, and the impulse increased by 11.01%. The proposed method provides a safe and cost-effective alternative to traditional explosive methods for simulating blast loading on RC slabs.

Neuroinflammation as a Factor of Neurodegenerative Disease: Thalidomide Analogs as Treatments

Neuroinflammation is initiated when glial cells, mainly microglia, are activated by threats to the neural environment, such as pathogen infiltration or neuronal injury. Although neuroinflammation serves to combat these threats and reinstate brain homeostasis, chronic inflammation can result in excessive cytokine production and cell death if the cause of inflammation remains. Overexpression of tumor necrosis factor-α (TNF-α), a proinflammatory cytokine with a central role in microglial activation, has been associated with neuronal excitotoxicity, synapse loss, and propagation of the inflammatory state. Thalidomide and its derivatives, termed immunomodulatory imide drugs (IMiDs), are a class of drugs that target the 3'-untranslated region (3'-UTR) of TNF-α mRNA, inhibiting TNF-α production. Due to their multi-potent effects, several IMiDs, including thalidomide, lenalidomide, and pomalidomide, have been repurposed as drug treatments for diseases such as multiple myeloma and psoriatic arthritis. Preclinical studies of currently marketed IMiDs, as well as novel IMiDs such as 3,6'-dithiothalidomide and adamantyl thalidomide derivatives, support the development of IMiDs as therapeutics for neurological disease. IMiDs have a competitive edge compared to similar anti-inflammatory drugs due to their blood-brain barrier permeability and high bioavailability, with the potential to alleviate symptoms of neurodegenerative disease and slow disease progression. In this review, we evaluate the role of neuroinflammation in neurodegenerative diseases, focusing specifically on the role of TNF-α in neuroinflammation, as well as appraise current research on the potential of IMiDs as treatments for neurological disorders.

Modulation of Regulatory T Cell Activity by TNF Receptor Type II-Targeting Pharmacological Agents

There is now compelling evidence that tumor necrosis factor (TNF)-TNF receptor type II (TNFR2) interaction plays a decisive role in the activation, expansion, and phenotypical stability of suppressive CD4⁺Foxp3⁺ regulatory T cells (Tregs). In an effort to translate this basic research finding into a therapeutic benefit, a number of agonistic or antagonistic TNFR2-targeting biological agents with the capacity to activate or inhibit Treg activity have been developed and studied. Recent studies also show that thalidomide analogs, cyclophosphamide, and other small molecules are able to act on TNFR2, resulting in the elimination of TNFR2-expressing Tregs. In contrast, pharmacological agents, such as vitamin D3 and adalimumab, were reported to induce the expansion of Tregs by promoting the interaction of transmembrane TNF (tmTNF) with TNFR2. These studies clearly show that TNFR2-targeting pharmacological agents represent an effective approach to modulating the function of Tregs and thus may be useful in the treatment of major human diseases such as autoimmune disorders, graft-versus-host disease (GVHD), and cancer. In this review, we will summarize and discuss the latest progress in the study of TNFR2-targeting pharmacological agents and their therapeutic potential based on upregulation or downregulation of Treg activity.

Serum prealbumin is a predictive biomarker for stroke-associated infection after an ischemic stroke

BACKGROUND

Several prior studies have linked serum prealbumin (PA) as a predictor for perioperative infection. However, whether peripheral blood PA levels can be used as an indicator of stroke-associated infection (SAI) is still unclear. In this study, we attempt to find whether serum PA is a meaningful predictor in SAI after an ischemic stroke, so as to provide theoretical basis for clinical treatment.

METHODS

Consecutive patients with acute ischemic stroke who were admitted to our hospital were enrolled and serum PA was collected. A prospective study was conducted to observe the predictive value of PA in the SAI incident in ischemic stroke patients.

RESULTS

Of 104 patients, 29 (27.9%) developed an SAI after 7 d of follow-up. The stroke with SAI group had significantly lower PA levels than the stroke without SAI group (  p < 0.05). The optimal cutoff value for predicting SAI was PA ≤ 191 mg/L, with sensitivity and specificity of 58.62% and 81.33%, respectively. Kaplan-Meier survival analysis showed that stroke patients with low serum PA level (PA ≤ 191 mg/L) had a higher SAI rates (log-rank test, χ² = 16.870, p < 0.001). Cox regression analysis showed that PA ≤ 191 mg/L (hazard ratio = 3.207; 95% CI, 1.430-7.190, p = 0.005) was an independent risk factor for SAI.

CONCLUSIONS

Early detection of serum PA during the acute phase of ischemic stroke may help us to identify at-risk SAI patients, and hence rapidly guide the intervention to prevent SAI.

Protective effects of thalidomide on pulmonary injuries in a rat model of paraquat intoxication

Background

This study was designed to evaluate the protective effects of thalidomide on paraquat (PQ)-induced lung injuries in a rat model and to explore the underlying mechanisms.

Methods

Rats were exposed to 50 mg/kg PQ by oral gavage, and treated with thalidomide through oral administration at 60 mg/kg once a day, 6 days/week for 2 weeks. Serum levels of IL-6, TNF-alpha, TGFbeta1 and COL1A1 were detected at different time points after paraquat exposure. At the end of the study, lung tissues were collected for pathological inspection as well as analyses of water content and expression levels of IL-6, TNF-alpha, TGFbeta1 and COL1A1 mRNA.

Results

The results showed that thalidomide treatment could significantly alleviate PQ-induced pathological changes in lung tissue and severity of lung edema. Thalidomide treatment after PQ exposure resulted in significantly reduced serum levels of IL-6, TNF-alpha, TGF-beta1 and COL1A1, as compared to PQ group. PCR analysis demonstrated that expression levels of IL-6, TNF-alpha, TGF-beta1 and COL1A1 in lung tissue were significantly increased after PQ exposure but reduced by thalidomide, which were confirmed by immunohistochemistry staining.

Conclusions

Our results indicated that inflammatory factors played important roles in PQ-induced lung injuries and thalidomide could protect rats from PQ-induced lung injuries by inhibiting the upregulation of inflammatory factors.

Mechanism of immunomodulatory drugs' action in the treatment of multiple myeloma

Although immunomodulatory drugs (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, are widely used in the treatment of multiple myeloma (MM), the molecular mechanism of IMiDs' action is largely unknown. In this review, we will summarize recent advances in the application of IMiDs in MM cancer treatment as well as their effects on immunomodulatory activities, anti-angiogenic activities, intervention of cell surface adhesion molecules between myeloma cells and bone marrow stromal cells, anti-inflammatory activities, anti-proliferation, pro-apoptotic effects, cell cycle arrest, and inhibition of cell migration and metastasis. In addition, the potential IMiDs' target protein, IMiDs' target protein's functional role, and the potential molecular mechanisms of IMiDs resistance will be discussed. We wish, by presentation of our naive discussion, that this review article will facilitate further investigation in these fields.

Thalidomide prevents the progression of peritoneal fibrosis in mice

Thalidomide is clinically recognized as a therapeutic agent for multiple myeloma and has been known to exert anti-angiogenic actions. Recent studies have suggested the involvement of angiogenesis in the progression of peritoneal fibrosis. The present study investigated the effects of thalidomide on the development of peritoneal fibrosis induced by injection of chlorhexidine gluconate (CG) into the mouse peritoneal cavity every other day for 3 weeks. Thalidomide was given orally every day. Peritoneal tissues were dissected out 21 days after CG injection. Expression of CD31 (as a marker of endothelial cells), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), α-smooth muscle actin (as a marker of myofibroblasts), type III collagen and transforming growth factor (TGF)-β was examined using immunohistochemistry. CG group showed thickening of the submesothelial zone and increased numbers of vessels and myofibroblasts. Large numbers of VEGF-, PCNA-, and TGF-β-positive cells were observed in the submesothelial area. Thalidomide treatment significantly ameliorated submesothelial thickening and angiogenesis, and decreased numbers of PCNA- and VEGF-expressing cells, myofibroblasts, and TGF-β-positive cells. Moreover, thalidomide attenuated peritoneal permeability for creatinine, compared to the CG group. Our results indicate the potential utility of thalidomide for preventing peritoneal fibrosis.

Effects of immunomodulatory drugs on TNF-α and IL-12 production by purified epidermal langerhans cells and peritoneal macrophages

Background

Langerhans cells constitute a special subset of immature dendritic cells localized in the epidermis that play a key role in the skin's immune response. The production of cytokines is a key event in both the initiation and the regulation of immune responses, and different drugs can be used to remove or modify their production by DC and, therefore, alter immune responses in a broad spectrum of diseases, mainly in human inflammatory and autoimmune diseases. In the present study, we examined the effects of prednisone, thalidomide, cyclosporine A, and amitriptyline, drugs used in a variety of clinical conditions, on the production of TNF-α, IL-10, and IL-12 by purified epidermal Langerhans cells and peritoneal macrophages in BALB/c mice.

Findings

All drugs inhibited TNF-α production by Langerhans cells after 36 hours of treatment at two different concentrations, while prednisone and thalidomide decreased IL-12 secretion significantly, amitriptyline caused a less pronounced reduction and cyclosporine A had no effect. Additionally, TNF-α and IL-12 production by macrophages decreased, but IL-10 levels were unchanged after all treatments.

Conclusions

Our results demonstrate that these drugs modulate the immune response by regulating pro-inflammatory cytokine production by purified epidermal Langerhans cells and peritoneal macrophages, indicating that these cells are important targets for immunosuppression in various clinical settings.

Thalidomide inhibits lipopolysaccharide-induced tumor necrosis factor-α production via down-regulation of MyD88 expression

The effect of thalidomide on lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production was studied by using RAW 264.7 murine macrophage-like cells. Thalidomide significantly inhibited LPS-induced TNF-α production. Thalidomide prevented the activation of nuclear factor (NF)-KB by down-regulating phosphorylation of inhibitory KB factor (IKB), and IKB kinase (IKK)-α and IKK-β Moreover, thalidomide inhibited LPS-induced phosphorylation of AKT, p38 and stress-activated protein kinase (SAPK)/JNK. The expression of myeloid differentiation factor 88 (MyD88) protein and mRNA was markedly reduced in thalidomide-treated RAW 264.7 cells but there was no significant alteration in the expression of interleukin-1 receptor-associated kinase (IRAK) 1 and TNF receptor-associated factor (TRAF) 6 in the cells. Thalidomide did not affect the cell surface expression of Toll-like receptor (TLR) 4 and CD14, suggesting the impairment of intracellular LPS signalling in thalidomide-treated RAW 264.7 cells. Thalidomide significantly inhibited the TNF-α production in response to palmitoyl-Cys(RS)-2,3-di(palmitoyloxy) propyl)-Ala-Gly-OH (Pam3Cys) as a MyD88-dependent TLR2 ligand. Therefore, it is suggested that thalidomide might impair LPS signalling via down-regulation of MyD88 protein and mRNA and inhibit LPS-induced TNF-α production. The putative mechanism of thalidomide-induced MyD88 down-regulation is discussed.

Thalidomide decreases intrahepatic resistance in cirrhotic rats

Increased intrahepatic resistance (IHR) within cirrhotic liver is caused by increased endotoxemia, cytokines tumor necrosis factor-alpha (TNF-alpha), vasoconstrictor thromboxane A(2) (TXA(2)), and disrupted microvasculatures. We evaluated the effects of thalidomide-related inhibition of TNF-alpha upon the hepatic microcirculation of cirrhosis in rats. Portal venous pressure (PVP), hepatic TNF-alpha, expression of thromboxane synthase (TXS), and leukocyte common antigen (LCA) were measured in bile-duct-ligated (BDL) rats receiving 1 month of thalidomide (BDL-thalido rats). Portal perfusion pressure (PPP), IHR, and hepatic TXA(2) production were measured in the isolated liver perfusion system. Intravital microscopy was used to examine hepatic microvascular disruptions. In BDL-thalido rats, PVP, PPP, IHR, hepatic TXA(2) and TNF-alpha, hydroxyproline content, expression of TXS and LCA, and LPS-induced leukocyte recruitment were significantly decreased. Conversely, hepatic microvascular density and perfused sinusoids were significantly increased. Thalidomide decreased PVP and IHR by reducing hepatic TXA(2) and improving hepatic microvascular disruptions in rats with biliary cirrhosis.

Selective inactivation of NF-kappaB in the liver using NF-kappaB decoy suppresses CCl4-induced liver injury and fibrosis

Sustained hepatic inflammation induced by various causes can lead to liver fibrosis. Transcription factor NF-kappaB is important in regulating inflammatory responses, especially in macrophages. We presently investigated whether an NF-kappaB decoy, a synthetic oligodeoxynucleotide (ODN) imitating the NF-kappaB binding site, inhibited the inflammatory response after CCl(4) intoxication to prevent CCl(4)-induced hepatic injury and fibrosis. The NF-kappaB decoy was introduced into livers by injecting the spleens of mice, using a hemagglutinating virus of Japan (HVJ)-liposome method. ODN was transferred mainly to macrophages in normal or fibrotic livers. Increases in serum transaminases and production of inflammatory cytokines after a single challenge with CCl(4) were inhibited by the NF-kappaB decoy, which suppressed nuclear translocation of NF-kappaB in liver macrophages. Liver fibrosis induced by CCl(4) administration for 8 wk was suppressed by the NF-kappaB decoy, accompanied by diminished mRNA expression for transforming growth factor (TGF)-beta, procollagen type 1 alpha(1), and alpha-smooth muscle actin (SMA). In vitro, isolated liver macrophages showed increased DNA binding activity of NF-kappaB and inflammatory cytokine production after hydrogen peroxide treatment; both increases were inhibited significantly by the NF-kappaB decoy. In contrast, NF-kappaB decoy transferred to isolated hepatic stellate cells (HSC) had no effect on their morphological activation or alpha-SMA expression, although the decoy accelerated tumor necrosis factor (TNF)-alpha-induced apoptosis in activated HSC. The effect of NF-kappaB decoy suppressing fibrosis probably results mainly from anti-inflammatory effects on liver macrophages, with a possible minor contribution from its direct proapoptotic effect on activated HSC.