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Purpose Recent studies have demonstrated that macrophage migration inhibitory factor (MIF) is of importance in asthmatic inflammation. The role of MIF in modulating airway remodeling has not yet been thoroughly elucidated to date. In the present study, we hypothesized that MIF promoted airway remodeling by intensifying airway smooth muscle cell (ASMC) autophagy and explored the specific mechanisms. Methods MIF knockdown in the lung tissues of C57BL/6 mice was conducted by instilling intratracheally adeno-associated virus (AAV) vectors (MIF-mutant AAV9) into mouse lung tissues. Mice genetically deficient in the autophagy marker ATG5 (ATG5 +/− ) was used to detect the role of autophagy in ovalbumin (OVA)-asthmatic murine models. Moreover, to block the expression of MIF and CD74 in vitro models, inhibitors, antibodies and lentivirus transfection techniques were employed. Results First, MIF knockdown in the lung tissues of mice showed markedly reduced airway remodeling in OVA murine mice models. Secondly, ASMC autophagy was increased in the OVA-challenged models. Mice genetically deficient in the autophagy marker ATG5 (ATG5 +/− ) that were primed and challenged with OVA showed lower airway remodeling than genetically wild-type asthmatic mice. Thirdly, MIF can induce ASMC autophagy in vitro . Moreover, the cellular source of MIF which promoted ASMC autophagy was macrophages. Finally, MIF promoted ASMC autophagy in a CD74-dependent manner. Conclusions MIF can increase asthmatic airway remodeling by enhancing ASMC autophagy. Macrophage-derived MIF can promote ASMC autophagy by targeting CD74.

Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. However, a large fraction of genetic cause remains unexplained, especially in sporadic IPF (∼80% IPF). By systemically reviewing related literature and potential pathogenic pathways, 92 potentially IPF-related genes were selected and sequenced in genomic DNAs from 253 sporadic IPF patients and 125 matched health controls using targeted massively parallel next-generation sequencing. The identified risk variants were confirmed by Sanger sequencing. We identified two pathogenic and 10 loss-of-function (LOF) candidate variants, accounting for 4.74% (12 out of 253) of all the IPF cases. In burden tests, rare missense variants in three genes (CSF3R, DSP, and LAMA3) were identified that have a statistically significant relationship with IPF. Four common SNPs (rs3737002, rs2296160, rs1800470, and rs35705950) were observed to be statistically associated with increased risk of IPF. In the cumulative risk model, high risk subjects had 3.47-fold (95%CI: 2.07-5.81, P = 2.34 × 10 ) risk of developing IPF compared with low risk subjects. We drafted a comprehensive map of genetic risks (including both rare and common candidate variants) in patients with IPF, which could provide insights to help in understanding mechanisms, providing genetic diagnosis, and predicting risk for IPF.

BackgroundPrevious reports have suggested that malignant transformations originate from adult stem cells, and may thus express the stem-cell-associated markers. The purpose of this study is to investigate the differential expression and clinical significance of seven stem-cell-associated markers (Bmi1, CD133, CD44, Sox2, Nanog, OCT4 and Msi2) in lung cancer, providing new targets for the diagnosis and treatment of lung cancer.MethodsIn this study, we evaluated the differential expression of mRNA levels seven stem-cell-associated markers by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) from 112 human lung cancer and 18 non-cancer tissues obtained by bronchoscopy. We further verified the differential expression of these markers by immunohistochemistry in 50 lung cancer specimens, 30 benign inflammatory lesion tissues and 20 non-tumor adjacent lung tissues.ResultsWith the exception of OCT4, other markers Bmi1, CD133, CD44, Sox2, Nanog and Msi2 mRNA and protein were abundantly expressed in lung cancer. Additionally, Nanog expression was highly upregulated in lung cancer tissues and rarely presented in non-cancerous lung tissues, the sensitivity and specificity of Nanog mRNA reached 63.4% and 66.7%, respectively. Nanog therefore possessed high diagnostic value, however, CD44, Bmi1 and CD133 showed poor diagnostic value in lung cancer.ConclusionNanog may serve as a promising diagnostic marker of lung cancer and potential therapeutic target in lung cancer.

Abstract. Lung cancer is the most frequent cancer worldwide, in terms of incidence and mortality. Due to challenges in the diagnosis of the disease, the 5-year overall survival rate is only ~16%. Previous studies have suggested that malignant transformations originate from adult stem cells, and malignant lesions may therefore express stem-cell-associated markers. The purpose of the present study is to investigate the expression and clinical significance of the stem cell-associated markers Sal-like protein 4 (SALL4) and leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) in lung cancer, and to provide novel diagnostic markers and targets for the treatment of lung cancer. The expression of the stem cell-associated markers SALL4 and LGR5 was analyzed by immunohistochemistry performed on 135 human lung cancer tissue specimens and 10 non-cancer lung tissue specimens. The clinical significance of the expression of these markers and correlation between their expression and clinical parameters was also assessed. SALL4 expression was highly upregulated in lung cancer tissues, but was not present in non-cancerous lung tissues, and the sensitivity and specificity of SALL4 reached 88% and 100%, respectively. By contrast, LGR5 demonstrated 97% sensitivity, but the specificity was poor. Therefore, SALL4 may be an extremely useful diagnostic marker for lung cancer, but LGR5 is not as useful. IntroductionLung cancer is the most common cancer worldwide, in terms of incidence and mortality, as it comprises 17% of total novel cancer cases and 23% of the total global cancer mortalities (1). In order to improve the survival rate, it is important to diagnose and surgically excise lung cancer at an early stage of disease (2). Therefore, it is necessary to identify biomarkers with the potential to facilitate tumor diagnosis, particularly in the early stages of the disease. The cancer stem cell (CSC) theory proposes that tumors contain a small subpopulation of CSCs, which are responsible for tumor growth, invasion and metastasis (2). CSCs and normal tissue stem cells share important characteristics, including self-renewal, multipotency and unlimited proliferation, and potentially possess overlapping molecular mechanisms (3,4). Currently, a considerable number of stem cell-associated markers have been identified (2,3). Numerous studies have revealed that Sal-like protein 4 (SALL4) and leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) are also involved in the tumorigenesis, development and metastasis of various tumors (5-7), and these proteins are expected to become potential diagnostic markers and therapeutic targets in cancer.SALL4, a homolog of the Drosophila homeotic gene spalt, is a zinc-finger transcription factor that is required for the proliferation and maintenance of pluripotency through interaction with OCT3/4, sex determining region Y-box 2 and NANOG (8,9). SALL4 is also highly expressed in embryonic stem cells (8)(9)(10)(11)(12). Notably, SALL4 is also overexpressed in various types of human he...