Transcription factor specificity protein 1 modulates TGFβ1/Smad signaling to negatively regulate SIGIRR expression by human M1 macrophages stimulated with substance P

Aprepitant exerts anti-fibrotic effect via inhibition of TGF-β/Smad3 pathway in bleomycin-induced pulmonary fibrosis in rats

Bleomycin is a well-recognized antineoplastic drug. However, pulmonary fibrosis (PF) is considered to be the principal drawback that greatly limits its use. Here, we sought to investigate ability of the neurokinin receptor 1 blocker, aprepitant, to prevent PF caused by bleomycin. Male adult Wistar rat groups were given a single intratracheal injection of bleomycin, either alone or in combination with aprepitant therapy for 3 or 14 days. Collagen deposition and a rise in transforming growth factor beta (TGF-β) immunoreactivity in lung tissue serve as evidence of bleomycin-induced PF. The serum levels of lactate dehydrogenase, alkaline phosphatase, and total antioxidant improved after aprepitant therapy.Additionally, it reduced the protein expressions of interferon alpha, tumor necrosis factor alpha, and lung lipid peroxidation. Moreover, aprepitant treatment led to an increase in the antioxidant indices glutathione, glutathione peroxidase, and catalase. Aprepitant is postulated to protect against bleomycin-induced PF by decreasing TGF-β, phosphorylating Smad3, and increasing interleukin 37, an anti-fibrotic cytokine, and G Protein-coupled Receptor Kinase 2. Aprepitant for 14 days considerably exceeded aprepitant for 3 days in terms of improving lung damage and having an anti-fibrotic impact. In conclusion, aprepitant treatment for 14 days may be used as an adjuvant to bleomycin therapy to prevent PF, mostly through inhibiting the TGF-/p-Smad3 fibrotic pathway.

IL-23 production in human macrophages is regulated negatively by tumor necrosis factor α-induced protein 3 and positively by specificity protein 1 after stimulation of the toll-like receptor 7/8 signaling pathway

The IL-23/IL-17 axis plays an important role in the development of autoimmune diseases, but the mechanism regulating IL-23 production is mainly unknown. We investigated how TNFAIP3 and Sp1 affect IL-23 production by human macrophages after exposure to resiquimod, a TLR7/8 agonist.

IL-23 production was significantly upregulated by resiquimod but only slightly by LPS (a TLR4 agonist). Interestingly, IL-23 levels were significantly attenuated after sequential stimulation with LPS and resiquimod, but IL-12p40 and IL-18 levels were not. TLR4-related factors induced by LPS may regulate IL-23 expression via TLR7/8 signaling. LPS significantly enhanced TNFAIP3 and IRAK-M levels but reduced Sp1 levels. After exposure to resiquimod, RNA interference of TNFAIP3 upregulated IL-23 significantly more than siRNA transfection of IRAK-M did. In contrast, knockdown of Sp1 by RNA interference significantly attenuated IL-23 production. Transfection with siRNA for TNFAIP3 enhanced IL-23 expression significantly. After stimulation with resiquimod, GW7647—an agonist for PPARα (an inducer of NADHP oxidase)—and siRNA for UCP2 (a negative regulator of mitochondrial ROS generation) enhanced TNFAIP3 and reduced IL-23. siRNA for p22phox and gp91phox slightly increased Sp1 levels. However, after exposure to resiquimod siRNA-mediated knockout of DUOX1/2 significantly enhanced Sp1 and IL-23 levels, and decreased TNFα-dependent COX-2 expression. Concomitantly, TNFAIP3 levels was attenuated by DUOX1/2 siRNA. TNFAIP3 and Sp1 levels are reciprocally regulated through ROS generation.

In conclusion, after stimulation of the TLR7/8 signaling pathway IL-23 production in human macrophages is regulated negatively by TNFAIP3.

4-hexylresorcinol-induced protein expression changes in human umbilical cord vein endothelial cells as determined by immunoprecipitation high-performance liquid chromatography

4-Hexylresorcinol (4HR) is used as a food preservative and an ingredient of toothpaste and cosmetics. The present study was performed using 233 antisera to determine the changes in protein expression induced by 4HR in human umbilical cord vein endothelial cells (HUVECs), and evaluated the 4HR-induced effects in comparison with previous results (Kim et al., 2019). Similar to RAW 264.7 cells, 4HR-treated HUVECs showed decreases in the expression of the proliferation-related proteins, cMyc/MAX/MAD network proteins, p53/RB and Wnt/β-catenin signaling, and they showed inactivation of DNA transcription and protein translation compared to the untreated controls. 4HR upregulated growth factors (TGF-β1, β2, β3, SMAD2/3, SMAD4, HGF-α, Met, IGF-1) and RAS signaling proteins (RAF-B, p38, p-p38, p-ERK-1, and Rab-1), and induced stronger expression of the cellular protection-, survival-, and differentiation-related proteins in HUVECs than in RAW 264.7 cells. 4HR suppressed NFkB signaling in a manner that suggests potential anti-inflammatory and wound healing effects by reducing M1 macrophage polarization and increasing M2 macrophage polarization in both cells. 4HR-treated HUVECs tended to increase the ER stress mediators by upregulating eIF2AK3, ATF4, ATF6, lysozyme, and LC3 and downregulating eIF2α and GADD153 (CHOP), resulting in PARP-1/AIF-mediated apoptosis. These results indicate that 4HR has similar effects on the protein expression of HUVECs and RAW 264.7 cells, but their protein expression levels differ according to cell types. The 4HR-treated cells showed global protein expression characteristic of anticancer and wound healing effects, which could be alleviated simultaneously by other proteins exerting opposite functions. These results suggest that although 4HR has similar effects on the global protein expression of HUVECs and RAW 264.7 cells, the 4HR-induced molecular interferences in those cells are complex enough to produce variable protein expression, leading different cell functions. Moreover, HUVECs have stronger wound healing potential to overcome the impact induced by 4HR than RAW 264.7 cells.

Identification of atypical mitogen-activated protein kinase MAPK4 as a novel regulator in acute lung injury

Background

Acute lung injury (ALI) is a serious disease with highly morbidity and mortality that causes serious health problems worldwide. Atypical mitogen activated protein kinases (MAPKs) play critical roles in the development of tissues and have been proposed as promising therapeutic targets for various diseases. However, the potential role of atypical MAPKs in ALI remains elusive. In this study, we investigated the role of atypical MAPKs family member MAPK4 in ALI using LPS-induced murine ALI model.

Results

We found that MAPK4 deficiency mice exhibited prolonged survival time after LPS challenge, accompanied by alleviated pathology in lung tissues, decreased levels of pro-inflammatory cytokines and altered composition of immune cells in BALF. Furthermore, the transduction of related signaling pathways, including MK5, AKT, JNK, and p38 MAPK pathways, was reduced obviously in LPS-treated MAPK4^−/− mice. Notably, the expression of MAPK4 was up-regulated in lung tissues of ALI model, which was not related with MAPK4 promoter methylation, but negatively orchestrated by transcriptional factors NFKB1 and NR3C1. Further studies have shown that the expression of MAPK4 was also increased in LPS-treated macrophages. Meanwhile, MAPK4 deficiency reduced the expression of related pro-inflammatory cytokines in macrophage in response to LPS treatment. Finally, MAPK4 knockdown using shRNA pre-treatment could ameliorate the pathology of lung tissues and prolong the survival time of mice after LPS challenge.

Conclusions

Collectively, these findings reveal an important biological function of atypical MAPK in mediating the pathology of ALI, indicating that MAPK4 might be a novel potential therapeutic target for ALI treatment.

Blocking CXCR1/2 contributes to amelioration of lipopolysaccharide-induced sepsis by downregulating substance P

OBJECTIVES

C-X-C chemokine receptor types 1/2 (CXCR1/2) is known to be activated in liver damage in acute-on-chronic liver failure; however, the role in lipopolysaccharide (LPS)-induced sepsis is unknown. The current study was designed to determine whether or not CXCR1/2 blockade with reparixin ameliorates acute lung injury (ALI) by affecting neuropeptides in a LPS-induced sepsis mouse model.

MATERIALS AND METHODS

Male C57BL/6 mice (10 to 14-week old) were divided into sham, LPS, sham-R, and LPS-R groups. Bronchoalveolar lavage fluid (BALF) was collected and evaluated. The lung histopathology was assessed by immunocytochemistry staining. Western blot analysis was used to measure myeloperoxidase, substance P (SP), and vasoactive intestinal peptide.

RESULTS

LPS-induced animal models were ameliorated by cotreatment with a CXCR1/2 antagonist. Moreover, the protective effects of CXCR1/2 antagonists were attributed to the increased secretion of pro-opiomelanocortin and decreased the secretion of SP. Reparixin decreased the expression of necroptosis cell death markers induced by LPS.

CONCLUSION

The results of this study indicate that blockade of CXCR1/2 may represent a promising therapeutic strategy for the treatment of sepsis-associated ALI through regulation of neuropeptides and necroptosis.