Grape Seed Proanthocyanidin Ameliorates LPS-induced Acute Lung Injury By Modulating M2a Macrophage Polarization Via the TREM2/PI3K/Akt Pathway.

Acute lung injury (ALI) is an acute and progressive pulmonary inflammatory disease that is difficult to cure and has a poor prognosis. Macrophages, which have various phenotypes and diverse functions, play an essential role in the pathogenesis of ALI. Grape seed proanthocyanidin (GSP) has received much attention over several decades, and many biological activities such as anti-apoptotic, antioxidant, and anti-inflammatory have been identified. This study aimed to determine the effect of GSP on lipopolysaccharide (LPS)-induced ALI. In this study, we established an ALI mouse model by tracheal instillation of LPS, and by pre-injection of GSP into mice to examine the effect of GSP on the ALI mouse model. Using H&E staining, flow cytometry, and ELISA, we found that GSP attenuated LPS-induced lung pathological changes and decreased inflammatory cytokine expression in ALI mice. In addition, GSP reduced the recruitment of monocyte-derived macrophages to the lung and significantly promoted the polarization of primary mouse lung macrophages from M1 to M2a induced by LPS. In vitro, GSP also decreased the expression levels of inflammatory cytokines such as TNF-α, IL-6, IL-1ß, and M1 macrophage marker iNOS induced by LPS in MH-S cells, while increasing the expression levels of M2a macrophage marker CD206. Bioinformatics analysis identified TREM2 and the PI3K/Akt pathway as candidate targets and signaling pathways that regulate M1/M2a macrophage polarization in ALI, respectively. Furthermore, GSP activated PI3K/Akt and increased TREM2 expression in vivo and in vitro. Meanwhile, GSP's impact on M2a polarization and inflammation suppression was attenuated by the PI3K inhibitor LY294002 or siRNA knockdown TREM2. In addition, GSP-enhanced PI3K/Akt activity was prevented by TREM2 siRNA. In conclusion, this study demonstrated that GSP could ameliorate LPS-induced ALI by modulating macrophage polarization from M1 to M2a via the TREM2/PI3K/Akt pathway.

The Novel Regulatory Role of the lncRNA-miRNA-mRNA Axis in Chronic Inflammatory Airway Diseases.

Chronic inflammatory airway diseases, characterized by airway inflammation and airway remodelling, are increasing as a cause of morbidity and mortality for all age groups and races across the world. The underlying molecular mechanisms involved in chronic inflammatory airway diseases have not been fully explored. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) have recently attracted much attention for their roles in the regulation of a variety of biological processes. A number of studies have confirmed that both lncRNAs and miRNAs can regulate the initiation and progression of chronic airway diseases by targeting mRNAs and regulating different cellular processes, such as proliferation, apoptosis, inflammation, migration, and epithelial-mesenchymal transition (EMT). Recently, accumulative evidence has shown that the novel regulatory mechanism underlying the interaction among lncRNAs, miRNAs and messenger RNAs (mRNAs) plays a critical role in the pathophysiological processes of chronic inflammatory airway diseases. In this review, we comprehensively summarized the regulatory roles of the lncRNA-miRNA-mRNA network in different cell types and their potential roles as biomarkers, indicators of comorbidities or therapeutic targets for chronic inflammatory airway diseases, particularly chronic obstructive pulmonary disease (COPD) and asthma.

Cigarette smoke extracts induce apoptosis in Raw264.7 cells via endoplasmic reticulum stress and the intracellular Ca2+/P38/STAT1 pathway.

Cigarette smoke (CS) exposure is a risk factor for chronic obstructive pulmonary disease (COPD). CS exposure impairs the ability of killing pathogens in macrophages, which might be due to the abnormal apoptosis induced by CS. This study explored the effects and mechanisms of cigarette smoke extract (CSE) on the apoptosis of macrophages in vitro. Raw264.7 cells were treated with CSE at different concentrations, and viability and apoptosis of cells was accessed. The protein expression was detected by western blot. The intracellular Ca2+ level was evaluated by Fluo-4 AM probe assay. CSE induced the apoptosis and increased the expression of cleaved caspase 3, which were attenuated by a caspase inhibitor. CSE increased the expression of CHOP, BiP and P-eif2α, and the inhibitor of endoplasmic reticulum stress (ERS) decreased the apoptosis induced by CSE. Phosphorylation levels of P38, JNK and ERK1/2 were increased following incubation with CSE. Only P38 inhibitor significantly reduced apoptosis induced by CSE, while ERK1/2 inhibitor promoted apoptosis. Phosphorylation of STAT1 at Ser727 was activated by CSE and attenuated by the P38 inhibitor. Finally, CSE increased the level of intracellular Ca2+, and calcium chelator partly attenuated the apoptosis and phosphorylation of P38 and STAT1 induced by CSE. CSE induced a caspase 3-dependent apoptosis in Raw264.7 cells via ERS and intracellular Ca2+/P38/STAT1 pathway.

Multisystemic Sarcoidosis Presenting With Leg Ulcers, Pancytopenia, and Polyserositis Was Successfully Treated With Glucocorticoids: A Case Report and Literature Review.

INTRODUCTION: Sarcoidosis is a chronic granulomatous disease of unknown etiology. A variety of studies have pointed out that almost every part of the body can be affected, but it most often affected the lungs and intrathoracic lymph nodes. However, cases of sarcoidosis involving multiple organs in one patient are rarely reported. We describe a unique case of sarcoidosis, which was characterized by multiorgan involvement, including leg ulcers, splenomegaly, pancytopenia, and polyserositis. Glucocorticoids were effective during the treatment of the above lesions. This case highlights the diversity of clinical manifestations of sarcoidosis and emphasizes the importance of its differential diagnosis and the periodical follow-up. These are crucial to physicians in the diagnosis and treatment of sarcoidosis. MAIN SYMPTOMS AND IMPORTANT CLINICAL FINDINGS: A 30-year-old male complained about intermittent fever 3 years ago. A computed tomographic scan of the chest showed lymphadenopathy in the mediastinum and hilar regions. Routine blood tests showed leukopenia and mild anemia. The pathologic result of mediastinal lymph node biopsy was granulomatous lesions; thus, the patient was diagnosed with type II sarcoidosis without glucocorticoid therapy. In the following 2 years, the patient suffered from intermittent fever accompanied by dyspnea, fatigue, occasional cough, less sputum, and apparent weight loss. Abnormal physical examinations included leg ulcers and splenomegaly. Laboratory and physical tests revealed pancytopenia, polyserositis, and enlargement of lymph nodes. The pathological findings of leg ulceration, pleura, and left supraclavicular lymph node all suggested granulomas. DIAGNOSIS INTERVENTIONS AND OUTCOMES: It strongly suggested sarcoidosis since tuberculosis, lymphoma, and connective tissue disease were all excluded. Due to severe conditions and multiorgan involvement, we tried to provide methylprednisolone for this patient. After 9 months of oral glucocorticoids therapy, his subjective symptoms as well as hematological and radiological findings were all improved. His leg skin ulceration and scab were also completely disappeared. CONCLUSION: Sarcoidosis has diverse clinical presentations, and many patients present with atypical symptoms. It needs to be timely identified by the clinician and carefully differentiated from other diseases with similar findings so as to make an accurate diagnosis. In this case, the patient had a poor clinical response to glucocorticoids in the early stage of treatment due to the severe condition and multi-organ involvement. It is worth noting that the patient had improved significantly after 9 months of treatment of corticosteroids, which suggested that follow-up is critical.