Effect of Melilotus extract on lung injury via the upregulation of tumor necrosis factor-α-induced protein-8-like 2 in septic mice

Sodium houttuyfonate effectively treats acute pulmonary infection of Pseudomonas aeruginosa by affecting immunity and intestinal flora in mice

Introduction

Pseudomonas aeruginosa is a major nosocomial pathogen that frequently causes ventilator-associated pneumonia in specific populations. Sodium houttuyfonate (SH) has shown mild antibacterial activity against P. aeruginosa in vitro, but the mechanism of potent antimicrobial activity of SH against P. aeruginosa infection in vivo remains unclear.

Methods

Here, using the mouse pneumonia model induced by P. aeruginosa nasal drip to explore the therapeutic effects of SH.

Results

We found that SH exhibits dose-dependent therapeutic effects of reducing P. aeruginosa burden and systemic inflammation in pneumonia mice. SH ameliorates inflammatory gene expression and production of inflammatory proteins, such as interleukin-6 (IL-6), nuclear factor kappa-B (NF-κB) and toll-like receptor 4 (TLR4), associated with the TLR4/NF-κB pathway in mice with P. aeruginosa pneumonia. Furthermore, we analyzed the intestinal flora of mice and found that compared with the model group, the abundance and diversity of beneficial bacterial flora of SH treatment groups increased significantly, suggesting that SH can improve the intestinal flora disorder caused by inflammation. In addition, SH improves alpha and beta diversity index and reduces species abundance differences of intestinal flora in pneumonia mice.

Discussion

Taken together, our presented results indicate that SH may effectively alleviate the acute pulmonary infection induced by P. aeruginosa by reducing the disturbance of regulating immunity and intestinal flora in mice.

TLR2/TLR4-Enhanced TIPE2 Expression Is Involved in Post-Hemorrhagic Shock Mesenteric Lymph-Induced Activation of CD4+T Cells

Purpose

Post hemorrhagic shock mesenteric lymph (PHSML) return contributes to CD4+ T cell dysfunction, which leads to immune dysfunction and uncontrolled inflammatory response. Tumor necrosis factor α induced protein 8 like-2 (TIPE2) is one of the essential proteins to maintain the immune homeostasis. This study investigated the role of TIPE2 in regulation of CD4+ T lymphocyte function in interaction of PHSML and TLR2/TLR4.

Methods

The splenic CD4+ T cells were isolated from various mice (WT, TLR2-/-, TLR4-/-) by immunomagnetic beads, and stimulated with PHSML, normal lymphatic fluid (NML), respectively. Application of TIPE2-carrying interfering fragments of lentivirus were transfected to WT, TLR4-/-, and TLR2-/- CD4+ T cells, respectively. After interference of TIPE2, they were stimulated with PHSML and NML for the examinations of TIPE2, TLR2, and TLR4 mRNA expressions, proliferation, activation molecules on surface, and cytokine secretion function.

Results

PHSML stimulation significantly upregulated TIPE2, TLR2, and TLR4 mRNA expressions, decreased proliferation, CD25 expression, and IFN-γ secretion, and increased the secretion ability of IL-4 in WT CD4+ T cells. TIPE2 silencing enhanced proliferative capacity, upregulated CD25 expression, and increased IFNγ secretion in CD4+ T cells. PHSML stimulated TLR2-/-CD4+ T or TLR4-/-CD4+ T cells of which TIPE2 were silenced. TLR2 or TLR4 knockout attenuated PHSML-induced CD4+ T cells dysfunction; PHSML stimulation of silent TIPE2-expressing TLR2-/-CD4+ T or TLR4-/-CD4+ T revealed that the coexistence of low TIPE2 expression with lack of TLR2 or TLR4 eliminated this beneficial effect.

Conclusion

TIPE2 improves the PHSML-mediated CD4+T cells dysfunction by regulating TLR2/TLR4 pathway, providing a new intervention target following hemorrhagic shock-induced immune dysfunction.

TIPE2 ameliorates lipopolysaccharide-induced apoptosis and inflammation in acute lung injury

Objective

Tumour necrosis factor-α-induced protein 8-like 2 (TIPE2) has strong anti-inflammatory properties. However, it is unknown whether increased TIPE2 is protective against lipopolysaccharide (LPS)-induced ALI. In the current study, we aimed to investigate whether increased TIPE2 can exert protective effects in a mouse model of ALI induced by LPS.

Methods

We administered TIPE2 adeno-associated virus (AAV-TIPE2) intratracheally into the lungs of mice. Three weeks later, ALI was induced by intratracheal injection of LPS into BALB/c mice. Twenty-four hours later, lung bronchoalveolar lavage fluid (BALF) was acquired to analyse cells and protein, arterial blood was collected for arterial blood gas analysis and the determination of pro-inflammatory factor levels, and lung issues were collected for histologic examination, transmission electron microscopy (TEM), TUNEL staining, wet/dry (W/D) weight ratio analysis, myeloperoxidase (MPO) activity analysis and blot analysis of protein expression.

Results

We found that TIPE2 overexpression markedly mitigated LPS-induced lung injury, which was evaluated by the deterioration of histopathology, histologic scores, the W/D weight ratio, and total protein expression in the BALF. Moreover, TIPE2 overexpression markedly attenuated lung inflammation, as evidenced by the downregulation of polymorphonuclear neutrophils (PMNs) in the BALF, lung MPO activity, and pro-inflammatory cytokine levels in the serum. Moreover, TIPE2 overexpression not only dramatically prevented LPS-induced pulmonary cell apoptosis in mice but also blocked LPS-activated JNK phosphorylation and NF-κB p65 nuclear translocation.

Conclusions

Our study shows that the increased expression of AAV-mediated TIPE2 in the lungs of mice inhibits acute inflammation and apoptosis and suppresses the activation of NF-κB and JNK in a murine model of ALI.

Protective Effects of Infliximab on Lung Injury Induced by Methotrexate

INTRODUCTION

Methotrexate (MTX) is used to treat cancers, several forms of arthritis and other rheumatic conditions, although MTX may cause pulmonary toxicity related to the production of free oxygen radicals, various cytokines. Infliximab (IB) with its potent effect on tumor necrosis factor-alpha (TNF-α) inhibition also inhibits the release of endothelin-1 (ET-1). We aimed to investigate whether IB reduces pulmonary damage induced by an overdose of MTX.

METHOD

The rats were divided into 3 groups of 8 animals. The control group was given only saline. One dose of 20mg/kg MTX intraperitoneal was administered in the MTX group. IB 7 mg/kg was given to the MTX+IB (MI) group. Three days after IB was administered, 20mg/kg MTX was given. Five days after MTX was administered, all rats were sacrificed.

RESULTS

The TNF-α, ET-1, malondialdehyde (MDA), myeloperoxidase (MPO) and caspase-3 levels in MTX group were significantly higher than in control groups of TNF-α (P=.001), ET-1 (P=.001), MDA (P=.001), MPO (P=.001) and caspase-3 levels (P=.001) and MI groups of TNF-α (P=.009), ET-1 (P=.001), MDA (P=.047), MPO (P=.007) and caspase-3 levels (P=.003). The MI group had less histopathological damage in lung tissue than the MTX group.

CONCLUSION

Overdose of MTX leads to cytokine release and the formation of reactive oxygen species in addition to increased ET-1 secretion release that causes lung damage. IB, as a potent proinflammatory agent, TNF-α blocker, can decrease ET-1 release and oxidative stress, it may show significant protective effects in lung tissue against damage caused by MTX overdose.

Protective Effects of Infliximab on Lung Injury Induced by Methotrexate

INTRODUCTION

Methotrexate (MTX) is used to treat cancers, several forms of arthritis and other rheumatic conditions, although MTX may cause pulmonary toxicity related to the production of free oxygen radicals, various cytokines. Infliximab (IB) with its potent effect on tumor necrosis factor-alpha (TNF-α) inhibition also inhibits the release of endothelin-1 (ET-1). We aimed to investigate whether IB reduces pulmonary damage induced by an overdose of MTX.

METHOD

The rats were divided into 3 groups of 8 animals. The control group was given only saline. One dose of 20mg/kg MTX intraperitoneal was administered in the MTX group. IB 7 mg/kg was given to the MTX+IB (MI) group. Three days after IB was administered, 20mg/kg MTX was given. Five days after MTX was administered, all rats were sacrificed.

RESULTS

The TNF-α, ET-1, malondialdehyde (MDA), myeloperoxidase (MPO) and caspase-3 levels in MTX group were significantly higher than in control groups of TNF-α (P=.001), ET-1 (P=.001), MDA (P=.001), MPO (P=.001) and caspase-3 levels (P=.001) and MI groups of TNF-α (P=.009), ET-1 (P=.001), MDA (P=.047), MPO (P=.007) and caspase-3 levels (P=.003). The MI group had less histopathological damage in lung tissue than the MTX group.

CONCLUSION

Overdose of MTX leads to cytokine release and the formation of reactive oxygen species in addition to increased ET-1 secretion release that causes lung damage. IB, as a potent proinflammatory agent, TNF-α blocker, can decrease ET-1 release and oxidative stress, it may show significant protective effects in lung tissue against damage caused by MTX overdose.

Rhodiola rosea suppresses thymus T-lymphocyte apoptosis by downregulating tumor necrosis factor-α-induced protein 8-like-2 in septic rats

In recent years, several studies have shown that Rhodiola rosea can enhance cellular immunity and humoral immune function in mice, and thus, it has become a research hotspot. However, its underlying mechanism of action has remained elusive. The present study investigated whether Rhodiola rosea was able to downregulate the expression of tumor necrosis factor-α-inducible protein 8-like 2 (TIPE2), thereby inhibiting the expression of apoptotic genes, attenuating T-lymphocyte apoptosis and improving immunity in septic mice. A mouse model of caecal ligation and puncture (CLP)-induced sepsis was established, and animals in the treatment group were pre-treated with an intraperitoneal injection of Rhodiola rosea extract, while animals in the control group and sham-operated group were injected with an equivalent amount of normal saline. TIPE2, B-cell lymphoma 2 (Bcl-2), Fas and Fas ligand (FasL) mRNA and protein levels in thymic T cells were determined using reverse transcription quantitative polymerase chain reaction and western blot analysis, respectively. Furthermore, the thymus T-lymphocyte apoptosis rate, thymus T-lymphocyte count and thymus T-lymphocyte sub-sets were assessed using flow cytometry. Levels of T-helper cell type 1 (Th1) cytokines [Interleukin (IL)-2, IL-12 and interferon (IFN)-γ] and Th2 cytokines (IL-4 and IL-10) were determined using ELISA. The results showed that, compared to that in the CLP group, the expression of TIPE2, Fas and FasL in the treatment group was significantly decreased, while the expression of Bcl-2 was increased (P<0.05). The thymus lymphocyte count in the CLP group was significantly higher compared with that in the treatment group (P<0.05). Furthermore, the apoptotic rate of thymus T-lymphocytes in the treatment group was significantly lower than that in the CLP group (P<0.05). In addition, treatment with Rhodiola rosea rescued decreased in the counts of the CD3⁺ T and CD4⁺ T sub-sets of thymus T lymphocytes in the CLP group (P<0.05), while not affecting the increased levels of Th2 cytokines (IL-4 and IL-10) in the CLP group compared with those in the control groups. In addition, the Th1 cytokines (IL-12, IL-2 and IFN-γ) were significantly increased (P<0.05) in the CLP group, and treatment with Rhodiola rosea led to further increases. The thymus index of septic mice treated with Rhodiola rosea as well as their survival rate were improved as compared with those in the CLP group. These findings suggested that Rhodiola rosea has protective effects against sepsis by decreasing apoptosis, increasing Th1 cytokines and enhancing the host’s immunity via the regulation of TIPE2 expression.