Cell-surface translocation of annexin A2 contributes to bleomycin-induced pulmonary fibrosis by mediating inflammatory response in mice. Clin Sci (Lond). 2019;133:789-804. [PMID: 30902828 DOI: 10.1042/cs20180687]

Targeting AnxA2-EGFR signaling: hydroxychloroquine as a therapeutic strategy for bleomycin-induced pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease that causes progressive failure of lung function, and its molecular mechanism remains poorly understood. However, the AnnexinA2-epidermal growth factor receptor (EGFR) signaling pathway has been identified as playing a significant role in its development. Hydroxychloroquine, a common anti-malarial drug, has been found to inhibit this pathway and slow down the progression of IPF. To better understand the role of the AnxA2-EGFR signaling pathway in pulmonary fibrosis, an in vivo study was conducted. In this study, mice were induced with pulmonary fibrosis using bleomycin, and HCQ was administered intraperitoneally the next day of bleomycin induction. The study also employed nintedanib as a positive control. After the induction, the lungs showed increased levels of fibronectin and vimentin, along with enhanced expression of AnxA2, EGFR, and Gal-3, indicating pulmonary fibrosis. Additionally, the study also found that HCQ significantly inhibited these effects and showed antifibrotic properties similar to nintedanib. Overall, these findings suggest that HCQ can attenuate bleomycin-induced pulmonary fibrosis by inhibiting the AnxA2-EGFR signaling pathway. These results are promising for developing new treatments for IPF.

Human epididymis protein 4-annexin II binding promotes aberrant epithelial-fibroblast crosstalk in pulmonary fibrosis

Invasive lung myofibroblasts are the main cause of tissue remodeling in idiopathic pulmonary fibrosis (IPF). A key mechanism contributing to this important feature is aberrant crosstalk between the abnormal/injured lung epithelium and pulmonary fibroblasts. Here, we demonstrate that lungs from patients with IPF and from mice with bleomycin (BLM)-induced pulmonary fibrosis (PF) are characterized by the induction of human epididymis protein 4 (HE4) overexpression in epithelial cells. HE4 knockdown primarily in epithelial cells attenuates BLM-induced PF in mice, whereas the administration of recombinant mouse HE4 exacerbates fibrosis after BLM stimulation. Mechanistic analysis shows that HE4 and annexin II (ANXA2) specific binding enhances the profibrotic phenotype in epithelial cells, and directly promotes lung fibroblast activation, leading to aberrant epithelial-fibroblast crosstalk and the persistent myofibroblast phenotype. The HE4 and ANXA2 binding site is located after the 30th amino acid at the N terminus of the HE4 molecule. Finally, intratracheal administration of HE4 shRNA lentivirus protects mice against BLM-induced PF. These data suggest that HE4 can serve as a potential therapeutic target in the treatment of IPF.

Annexin A2: the feasibility of being a therapeutic target associated with cancer metastasis and drug resistance in cancer microenvironment

At present, there is still a lack of effective treatment strategies for cancer metastasis and drug resistance, so finding effective biomarkers is particularly important. AnnexinA2 (ANXA2), a vital membrane protein, critically influences cancer progression, tumor invasion, and tumor microenvironment modulation. To assess the possible application of ANXA2 as a therapeutic target against cancer cell metastasis and drug resistance to chemotherapeutic drugs in the tumor microenvironment, we elucidated the functionality of ANXA2 in stromal cells, angiogenic vascular cells, and infiltrated immune cells that mediate metastasis and drug resistance, as well as its potential as a therapeutic target. ANXA2 shows a high expression level in many tissues, and its expression level is even higher in several tumors and their microenvironments. ANXA2 is a crucial regulator of many factors and may serve as a target against drug-resistant cancers.

The novel insights of epithelial-derived exosomes in various fibrotic diseases

The characteristics of fibrosis include the abnormal accumulation of extracellular matrix proteins and abnormal tissue repair caused by injury, infection, and inflammation, leading to a significant increase in organ failure and mortality. Effective and precise treatments are urgently needed to halt and reverse the progression of fibrotic diseases. Exosomes are tiny vesicles derived from endosomes, spanning from 40 to 160 nanometers in diameter, which are expelled into the extracellular matrix environment by various cell types. They play a crucial role in facilitating cell-to-cell communication by transporting a variety of cargoes, including proteins, RNA, and DNA. Epithelial cells serve as the primary barrier against diverse external stimuli that precipitate fibrotic diseases. Numerous research suggests that exosomes from epithelial cells have a significant impact on several fibrotic diseases. An in-depth comprehension of the cellular and molecular mechanisms of epithelial cell-derived exosomes in fibrosis holds promise for advancing the exploration of novel diagnostic biomarkers and clinical drug targets. In this review, we expand upon the pathogenic mechanisms of epithelium-derived exosomes and highlight their role in the fibrotic process by inducing inflammation and activating fibroblasts. In addition, we are particularly interested in the bioactive molecules carried by epithelial-derived exosomes and their potential value in the diagnosis and treatment of fibrosis and delineate the clinical utility of exosomes as an emerging therapeutic modality, highlighting their potential application in addressing various medical conditions.

The intricate role of annexin A2 in kidney: a comprehensive review

Annexin A2 (Anxa2) is a calcium (Ca2+)-regulated phospholipid binding protein composed of a variable N-terminus and a conserved core domain. This protein has been widely found in many tissues and fluids, including tubule cells, glomerular epithelial cells, renal vessels, and urine. In acute kidney injury, the expression level of this protein is markedly elevated in response to acute stress. Moreover, Anxa2 is a novel biomarker and potential therapeutic target with prognostic value in chronic kidney disease. In addition, Anxa2 is associated not only with clear-cell renal cell carcinoma differentiation but also the formation of calcium-related nephrolithiasis. In this review, we discuss the characteristics and functions of Anxa2 and focus on recent reports on the role of Anxa2 in the kidney, which may be useful for future research.

Association Between IL-17 and Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by neutrophils airway infiltration. It is currently known that Interleukin-17 (IL-17) is an important pro-inflammatory factor. It can promote the accumulation of neutrophils and participate in the chronic inflammatory process of COPD. However, the value of IL-17 levels in the diagnosis and assessment of COPD remains controversial. In view of this, we conducted a systematic review and meta-analysis to assess its relevance.

Methods

We searched databases such as PubMed, Web of Science, Cochrane Library and Embase to extract original research.

Results

A total of 10 studies with 2268 participants were included in this meta-analysis. The results showed that the level of serum IL-17 in patients with stable COPD was significantly higher than that in healthy controls (standard mean difference SMD, 1.59, 95% CI 0.84-2.34; p<0.001). Compared with the stable COPD group, the serum IL-17 level in acute exacerbation (AECOPD) was significantly higher (SMD, 1.78, 95% CI 1.22-2.33; p<0.001). The level of IL-17 in sputum of COPD patients was also higher than that of healthy controls (SMD, 2.03, 95% CI 0.74-3.31; p<0.001).

Conclusion

Our results showed that IL-17 levels were elevated in serum and sputum in COPD patients compared with healthy controls, and IL-17 levels increased with disease progression. IL-17 serves as a potential biomarker to indicate the persistence of neutrophilic inflammation and exacerbation of COPD.

Chlorogenic Acid Inhibited Epithelial-Mesenchymal Transition to Treat Pulmonary Fibrosis through Modulating Autophagy

Chlorogenic acid (CGA), derived from dicotyledons and ferns, has been demonstrated with anti-inflammatory, anti-bacterial, and free radical-scavenging effects and can be used to treat pulmonary fibrosis (PF). However, the specific mechanism by which CGA treats PF needs to be further investigated. In this study, in vivo experiment was firstly performed to evaluate the effects of CGA on epithelial-mesenchymal transition (EMT) and autophagy in bleomycin (BLM)-induced PF mice. Then, the effects of CGA on EMT and autophagy was assessed using transforming growth factor beta (TGF-β) 1-induced EMT model in vitro. Furthermore, autophagy inhibitor (3-methyladenine) was used to verify that the inhibitory mechanism of CGA on EMT was associated with activating autophagy. Our results found that 60 mg/kg of CGA treatment significantly ameliorated lung inflammation and fibrosis in mice with BLM-induced PF. Besides, CGA inhibited EMT and promoted autophagy in mice with PF. In vitro studies also demonstrated that 50 µM of CGA treatment inhibited EMT and induced autophagy related factors in TGF-β1-induced EMT cell model. Moreover, the inhibitory effect of CGA on autophagy and EMT in vitro was abolished after using autophagy inhibitor. In conclusion, CGA could inhibit EMT to treat BLM-induced PF in mice through, activating autophagy.

Inhibition of ANXA2 regulated by SRF attenuates the development of severe acute pancreatitis by inhibiting the NF-κB signaling pathway

BACKGROUND

Acute pancreatitis (AP) is an inflammatory process of the pancreas resulting from biliary obstruction or alcohol consumption. Approximately, 10-20% of AP can evolve into severe AP (SAP). In this study, we sought to explore the physiological roles of the transcription factor serum response factor (SRF), annexin A2 (ANXA2), and nuclear factor-kappaB (NF-κB) in SAP.

METHODS

C57BL/6 mice and rat pancreatic acinar cells (AR42J) were used to establish an AP model in vivo and in vitro by cerulein with or without lipopolysaccharide (LPS). Production of pro-inflammatory cytokines (IL-1β and TNF-α) were examined by ELISA and immunoblotting analysis. Hematoxylin and eosin (HE) staining and TUNEL staining were performed to evaluate pathological changes in the course of AP. Apoptosis was examined by flow cytometric and immunoblotting analysis. Molecular interactions were tested by dual luciferase reporter, ChIP, and Co-IP assays.

RESULTS

ANXA2 was overexpressed in AP and correlated to the severity of AP. ANXA2 knockdown rescued pancreatic acinar cells against inflammation and apoptosis induced by cerulein with or without LPS. Mechanistic investigations revealed that SRF bound with the ANXA2 promoter region and repressed its expression. ANXA2 could activate the NF-κB signaling pathway by inducing the nuclear translocation of p50. SRF-mediated transcriptional repression of ANXA2-protected pancreatic acinar cells against AP-like injury through repressing the NF-κB signaling pathway.

CONCLUSION

Our study highlighted a regulatory network consisting of SRF, ANXA2, and NF-κB that was involved in AP progression, possibly providing some novel targets for treating SAP.

Animal models of drug-induced pulmonary fibrosis: an overview of molecular mechanisms and characteristics

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by progressive loss of pulmonary function. Drug-induced interstitial lung disease has been reported as a severe adverse effect of some drugs, such as bleomycin, amiodarone, and methotrexate. Based on good characteristics, drug-induced pulmonary fibrosis (PF) animal model has played a key role in our understanding of the molecular mechanisms of PF pathogenesis and recapitulates the specific pathology in patients and helps develop therapeutic strategies. Here, we summarize the mechanisms and characteristics of given fibrotic drug-induced animal models for PFs. Together with the key publications describing these models, this brief but detailed overview would be helpful for the pharmacological research with animal models of PFs. Potential mechanisms underlying drug induced lung toxicity.

Recombinant annexin A2 inhibits peripheral leukocyte activation and brain infiltration after traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of death and disability worldwide. The TLR4-NFκB signaling cascade is the critical pro-inflammatory activation pathway of leukocytes after TBI, and modulating this signaling cascade may be an effective therapeutic target for treating TBI. Previous studies indicate that recombinant annexin A2 (rA2) might be an interactive molecule modulating the TLR4-NFκB signaling; however, the role of rA2 in regulating this signaling pathway in leukocytes after TBI and its subsequent effects have not been investigated.

METHODS

C57BL/6 mice were subjected to TBI and randomly divided into groups that received intraperitoneal rA2 or vehicle at 2 h after TBI. The peripheral leukocyte activation and infiltrating immune cells were examined by flow cytometry, RT-qPCR, and immunostaining. The neutrophilic TLR4 expression on the cell membrane was examined by flow cytometry and confocal microscope, and the interaction of annexin A2 with TLR4 was assessed by co-immunoprecipitation coupled with Western blotting. Neuroinflammation was measured via cytokine proteome profiler array and RT-qPCR. Neurodegeneration was determined by Western blotting and immunostaining. Neurobehavioral assessments were used to monitor motor and cognitive function. Brain tissue loss was assessed via MAP2 staining.

RESULTS

rA2 administration given at 2 h after TBI significantly attenuates neutrophil activation and brain infiltration at 24 h of TBI. In vivo and in vitro data show that rA2 binds to and reduces TLR4 expression on the neutrophil surface and suppresses TLR4/NFκB signaling pathway in neutrophils at 12 h after TBI. Furthermore, rA2 administration also reduces pro-inflammation of brain tissues within 24 h and neurodegeneration at 48 h after TBI. Lastly, rA2 improves long-term sensorimotor ability and cognitive function, and reduces brain tissue loss at 28 days after TBI.

CONCLUSIONS

Systematic rA2 administration at 2 h after TBI significantly inhibits activation and brain infiltration of peripheral leukocytes, especially neutrophils at the acute phase. Consequently, rA2 reduces the detrimental brain pro-inflammation-associated neurodegeneration and ultimately ameliorates neurological deficits after TBI. The underlying molecular mechanism might be at least in part attributed to rA2 bindings to pro-inflammatory receptor TLR4 in peripheral leukocytes, thereby blocking NFκB signaling activation pathways following TBI.

Emerging Biological Functions of IL-17A: A New Target in Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease that causes high rates of disability and mortality worldwide because of severe progressive and irreversible symptoms. During the period of COPD initiation and progression, the immune system triggers the activation of various immune cells, including Regulatory T cells (Tregs), dendritic cells (DCs) and Th17 cells, and also the release of many different cytokines and chemokines, such as IL-17A and TGF-β. In recent years, studies have focused on the role of IL-17A in chronic inflammation process, which was found to play a highly critical role in facilitating COPD. Specially, IL-17A and its downstream regulators are potential therapeutic targets for COPD. We mainly focused on the possibility of IL-17A signaling pathways that involved in the progression of COPD; for instance, how IL-17A promotes airway remodeling in COPD? How IL-17A facilitates neutrophil inflammation in COPD? How IL-17A induces the expression of TSLP to promote the progression of COPD? Whether the mature DCs and Tregs participate in this process and how they cooperate with IL-17A to accelerate the development of COPD? And above associated studies could benefit clinical application of therapeutic targets of the disease. Moreover, four novel efficient therapies targeting IL-17A and other molecules for COPD are also concluded, such as Bufei Yishen formula (BYF), a Traditional Chinese Medicine (TCM), and curcumin, a natural polyphenol extracted from the root of Curcuma longa.

Chelerythrine Ameliorates Pulmonary Fibrosis via Activating the Nrf2/ARE Signaling Pathway

Chelerythrine (CHE) is a natural benzophenanthridine alkaloid, which has shown its anti-fibrosis activity in kidney and liver, while the impact of CHE in pulmonary fibrosis is still unclear. This study is developed to explore the impact and mechanism of CHE in pulmonary fibrosis. Pulmonary fibrosis mouse models were established through intratracheal injection of bleomycin (BLM), after which the mice were intraperitoneally injected with CHE (0.375 or 0.75 mg/kg/d) every other day. The mice were sacrificed at the 28th day to collect blood serum, bronchoalveolar lavage fluid (BALF), and pulmonary tissues. Then, the severity of pulmonary fibrosis and the expression of nuclear factor erythroid 2 [NF-E2]-related factor 2 (Nrf2) in the pulmonary tissues were detected. Western blot analysis quantified the expressions of fibronectin and alpha-smooth muscle actin (α-SMA). The levels of 4-hydroxynonenal (4-HNE), glutathione (GSH), superoxide dismutase (SOD), TGF-β and hydroxyproline (HP) in the BALF, and pulmonary tissues were measured. The expression levels of Nrf2 and its downstream genes, hemeoxygenase-1 (HO-1) and NAD (P) H: quinone oxidoreductase (NQO1) were examined. CHE at the concentration of 0.375 or 0.75 mg/kg/d could attenuate pulmonary fibrosis. CHE injection reduced the expression levels of fibronectin, α-SMA, and TGF-β, upregulated the levels of SOD and GSH and decreased the levels of 4-HNE and HP. Also, CHE increased the expressions of Nrf2, HO-1, and NQO1. Treatment of Nrf2/antioxidant response element (ARE) inhibitor could block the Nrf2/ARE signaling pathway, thus perturbing the inhibition of CHE on BLM-stimulated pulmonary fibrosis in mice. CHE alleviates BLM-induced pulmonary fibrosis in mice through activating the Nrf2/ARE pathway to increase the activity of antioxidant enzymes.

Annexin Animal Models-From Fundamental Principles to Translational Research

Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca²⁺)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.

Emodin attenuates silica-induced lung injury by inhibition of inflammation, apoptosis and epithelial-mesenchymal transition

Silicosis is a fatal pulmonary disease caused by the inhalation of silica dust, and characterized by inflammation and fibrosis of the lung, with no effective treatment to date. Here we investigate the effect of emodin, an anthraquinone derivative isolated from rhubarb using a mouse silicosis model and in vitro cultured human macrophages and alveolar epithelial cells. Results from histological examination indicated that emodin reduced the degree of alveolitis and fibrosis in the lungs of mice exposed to silica particles. We also demonstrated that emodin effectively inhibited the phosphorylation of Smad3 and NF-κB and reduced the levels of inflammatory factors in the lung tissue of mice treated with silica particles. In addition, we found that emodin inhibited apoptosis and demonstrated an anti-fibrotic effect by down-regulating the pro-apoptotic protein Bax and up-regulating the anti-apoptotic protein Bcl-2. Furthermore, emodin increased E-cadherin levels, reduced the expression of Vimentin, α-SMA and Col-I, as well as pro-inflammatory factors TGF-β1, TNF-α and IL-1β in vivo and in vitro. These results suggested that emodin can regulate epithelial-mesenchymal transition (EMT) through the inhibition of the TGF-β1/Smad3 signaling pathway and the NF-κB signaling pathway to prevent alveolar inflammation and apoptotic process. Overall, this study showed that emodin can alleviate pulmonary fibrosis in silicosis through regulating the inflammatory response and fibrotic process at multiple levels.

Establishment and validation of a drug-target microarray for SARS-CoV-2

COVID-19 has become one of the worst epidemic in the world, currently already more than four million people have been infected, which probably co-exist with human beings, and has a significant impact on the global economy and political order. In the process of fighting against the epidemic in China, the clinical value of a variety of herbal medicines has been recognized and written into the clinical application guide. However, their effective molecular mechanism and potential targets are still not clear. Pathology and pharmacology research will gradually attract attention in the post-epidemic outbreak term. Here, we constructed a COVID-19 protein microarray of potential therapy targets, which contains the main drug targets to the SARS-CoV-2 virus and the anti-virus, anti-inflammatory cellar targets of the host. Series of quality controls test has been carried out, which showed that it could be applied for drug target screening of bio-active natural products. The establishment of this microarray will provide a useful tool for the study of the molecular pharmacology of natural products.

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This study first proposed the idea of SARS-CoV-2 specific protein target microarray.

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The microarray was established and validated by practical test.

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Network pharmacology suggest this chip has a broad application in pharmacology.

Multiple Biological Roles of Extracellular Vesicles in Lung Injury and Inflammation Microenvironment

Lung injury and inflammation are complex pathological processes. The influence and crosstalk between various cells form a characteristic microenvironment. Extracellular vesicles from different cell sources in the microenvironment carry multiple cargo molecules, which affect the pathological process through different pathways. Here, we mainly discussed the mechanism of crosstalk between alveolar epithelial cells and different immune cells through extracellular vesicles in lung inflammation and reviewed the mechanism of extracellular vesicles released by blood and airways on lung inflammation. Finally, the role of extracellular vesicles in viral infection of the lung was also described.

Annexin A2 promotion of hepatocellular carcinoma tumorigenesis via the immune microenvironment

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a dismal prognosis, especially when diagnosed at advanced stages. Annexin A2 (ANXA2), is found to promote cancer progression and therapeutic resistance. However, the underlining mechanisms of ANXA2 in immune escape of HCC remain poorly understood up to now. Herein, we summarized the molecular function of ANXA2 in HCC and its relationship with prognosis. Furthermore, we tentatively elucidated the underlying mechanism of ANXA2 immune escape of HCC by upregulating the proportion of regulatory T cells and the expression of several inhibitory molecules, and by downregulating the proportion of natural killer cells and dendritic cells and the expression of several inhibitory molecules or effector molecules. We expect a lot of in-depth studies to further reveal the underlying mechanism of ANXA2 in immune escape of HCC in the future.

Rosmarinic acid exerts a neuroprotective effect on spinal cord injury by suppressing oxidative stress and inflammation via modulating the Nrf2/HO-1 and TLR4/NF-κB pathways

Spinal cord injury (SCI) is a severe central nervous system injury for which few efficacious drugs are available. Rosmarinic acid (RA), a water-soluble polyphenolic phytochemical, has antioxidant, anti-inflammatory, and anti-apoptotic properties. However, the effect of RA on SCI is unclear. We investigated the therapeutic effect and underlying mechanism of RA on SCI. Using a rat model of SCI, we showed that RA improved locomotor recovery after SCI and significantly mitigated neurological deficit, increased neuronal preservation, and reduced apoptosis. Also, RA inhibited activation of microglia and the release of TNF-α, IL-6, and IL-1β and MDA. Moreover, proteomics analyses identified the Nrf2 and NF-κB pathways as targets of RA. Pretreatment with RA increased levels of Nrf2 and HO-1 and reduced those of TLR4 and MyD88 as well as phosphorylation of IκB and subsequent nuclear translocation of NF-κB-p65. Using H2O2- and LPS-induced PC12 cells, we found that RA ameliorated the H2O2-induced decrease in viability and increase in apoptosis and oxidative injury by activating the Nrf2/HO-1 pathway. Also, LPS-induced cytotoxicity and increased apoptosis and inflammatory injury in PC-12 cells were mitigated by RA by inhibiting the TLR4/NF-κB pathway. The Nrf2 inhibitor ML385 weakened the effect of RA on oxidant stress, inflammation and apoptosis in SCI rats, and significantly increased the nuclear translocation of NF-κB. Therefore, the neuroprotective effect on SCI of RA may be due to its antioxidant and anti-inflammatory properties, which are mediated by modulation of the Nrf2/HO-1 and TLR4/NF-κB pathways. Moreover, RA activated Nrf2/HO-1, which amplified its inhibition of the NF-κB pathway.