MiR-140-3p Ameliorates the Progression of Osteoarthritis via Targeting CXCR4

Osteoarthritis is a common disease character with progressive destruction of cartilage. MicroRNA (miR)-140-3p was validated as a biomarker for osteoarthritis. However, the mechanism by which miRNA-140-3p regulates osteoarthritis remains unclear. Thus, this study aims to evaluate the potential function of miRNA-140-3p during the pathogenesis of osteoarthritis. MiRNA-140-3p expression in tissue and CHON-001 chondrocyte cells was determined with quantitative real time (qRT)-PCR. In vitro osteoarthritis model was established by treatment of the chondrocyte cells CHON-001 with interleukin (IL)-1β. Cell proliferation and apoptosis were measured with cell counting kit-8 (CCK8) and Annexin V/propidium iodide (PI) apoptosis assay, respectively. Protein expressions were evaluated using Western blot. The target gene of miR-140-3p was predicted using Targetscan and miRDB. MiR-140-3p was downregulated in knee tissue from patients with osteoarthritis. IL-1β inhibited the proliferation of CHON-001 cells via inducing apoptosis. In addition, IL-1β significantly inhibited the expressions of collagen II and aggrecan and increased the level of matrix metalloproteinase (MMP)13. However, the effects of IL-1β could be ameliorated by the addition of miR-140-3p mimics. Moreover, luciferase reporter assay demonstrated CXCR4 as a target gene of miR-140-3p. IL-1β-induced upregulation of CXCR4 could be blocked by miR-140-3p mimics. Our study indicated that miR-140-3p could suppress the progression of osteoarthritis by directly targeting CXCR4. Therefore, miR-140-3p might serve as a potential therapeutic target for the treatment of osteoarthritis.

Chemokine receptor Cxcr4 contributes to kidney fibrosis via multiple effectors

Kidney fibrosis is the final common pathway for virtually every type of chronic kidney disease and is a consequence of a prolonged healing response that follows tissue inflammation. Chronic kidney inflammation ultimately leads to progressive tissue injury and scarring/fibrosis. Several pathways have been implicated in the progression of kidney fibrosis. In the present study, we demonstrate that G protein-coupled chemokine (C-X-C motif) receptor (CXCR)4 was significantly upregulated after renal injury and that sustained activation of Cxcr4 expression augmented the fibrotic response. We demonstrate that after unilateral ureteral obstruction (UUO), both gene and protein expression of Cxcr4 were highly upregulated in tubular cells of the nephron. The increased Cxcr4 expression in tubules correlated with their increased dedifferentiated state, leading to increased mRNA expression of platelet-derived growth factor (PDGF)-α, transforming growth factor (TGF)-β1, and concurrent loss of bone morphogenetic protein 7 (Bmp7). Ablation of tubular Cxcr4 attenuated UUO-mediated fibrotic responses, which correlated with a significant reduction in PDGF-α and TGF-β1 levels and preservation of Bmp7 expression after UUO. Furthermore, Cxcr4(+) immune cells infiltrated the obstructed kidney and further upregulate their Cxcr4 expression. Genetic ablation of Cxcr4 from macrophages was protective against UUO-induced fibrosis. There was also reduced total kidney TGF-β1, which correlated with reduced Smad activation and α-smooth muscle actin levels. We conclude that chronic high Cxcr4 expression in multiple effector cell types can contribute to the pathogenesis of renal fibrosis by altering their biological profile. This study uncovered a novel cross-talk between Cxcr4-TGF-β1 and Bmp7 pathways and may provide novel targets for interrupting the progression of fibrosis.

Alterations in the profile of blood neutrophil membrane receptors caused by in vivo adrenocorticotrophic hormone actions

Elevated levels of adrenocorticotrophic hormone (ACTH) mobilize granulocytes from bone marrow into the blood, although these neutrophils are refractory to a full migratory response into inflamed tissues. Here, we investigated the dependence of glucocorticoid receptor activation and glucocorticoid-regulated protein annexin A1 (ANXA1) on ACTH-induced neutrophilia and the phenotype of blood neutrophil after ACTH injection, focusing on adhesion molecule expressions and locomotion properties. ACTH injection (5 μg ip, 4 h) induced neutrophilia in wild-type (WT) mice and did not alter the elevated numbers of neutrophils in RU-38486 (RU)-pretreated or ANXA1(-/-) mice injected with ACTH. Neutrophils from WT ACTH-treated mice presented higher expression of Ly6G⁺ANXA1(high), CD18(high), CD62L(high), CD49(high), CXCR4(high), and formyl-peptide receptor 1 (FPR1(low)) than those observed in RU-pretreated or ANXA1(-/-) mice. The membrane phenotype of neutrophils collected from WT ACTH-treated mice was paralleled by elevated fractions of rolling and adherent leukocytes to the cremaster postcapillary venules together with impaired neutrophil migration into inflamed air pouches in vivo and in vitro reduced formyl-methionyl-leucyl-phenylalanine (fMLP) or stromal-derived factor-1 (SDF-1α)-induced chemotaxis. In an 18-h senescence protocol, neutrophils from WT ACTH-treated mice had a higher proportion of ANXAV(low)/CXCR4(low), and they were less phagocytosed by peritoneal macrophages. We conclude that alterations on HPA axis affect the pattern of membrane receptors in circulating neutrophils, which may lead to different neutrophil phenotypes in the blood. Moreover, ACTH actions render circulating neutrophils to a phenotype with early reactivity, such as in vivo leukocyte-endothelial interactions, but with impaired locomotion and clearance.

Chemokine (C-X-C motif) receptor 4 RNA interference inhibits bone metastasis in breast cancer

Chemokine (C-X-C motif) receptor 4 (CXCR4) has been found to closely correlate with the incidence, development, treatment and prognosis of breast cancer. The aim of the present study was to investigate the effects of CXCR4 on bone metastasis in breast cancer and to explore the mechanisms of this process. CXCR4 small interfering RNA was transfected into the breast cancer cell line, MDA-MB-231BA-rfp, and the cell proliferation and invasion abilities of the cells were measured using cell counting kit-8 cell proliferation and Transwell assays. A mouse model of breast cancer with bone metastasis was prepared and the bone metastasis was confirmed using micro-positron emission tomography. The associated proteins were detected by western blot analysis and the results showed that CXCR4 RNAi inhibited the cell proliferation and invasion ability of the MDA-MB-231BA-rfp cells. In addition, CXCR4 RNAi inhibited the duration and extent of bone metastasis in the MDA-MB-231BA-rfp cells in the mouse model, while the inhibition of CXCR4 RNAi blocked the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (AKT)/matrix metalloproteinase (MMP)-9 pathway. In conclusion, the present study demonstrated that CXCR4 RNAi inhibits bone metastasis and the cell proliferation and invasion abilities of breast cancer cells. Furthermore, the CXCR4/PI3K/AKT/MMP-9 pathway may be important in the bone metastasis of breast cancer.

Pathogenesis, diagnosis, and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are hepatobiliary cancers with features of cholangiocyte differentiation; they can be classified anatomically as intrahepatic CCA (iCCA), perihilar CCA (pCCA), or distal CCA. These subtypes differ not only in their anatomic location, but in epidemiology, origin, etiology, pathogenesis, and treatment. The incidence and mortality of iCCA has been increasing over the past 3 decades, and only a low percentage of patients survive until 5 years after diagnosis. Geographic variations in the incidence of CCA are related to variations in risk factors. Changes in oncogene and inflammatory signaling pathways, as well as genetic and epigenetic alterations and chromosome aberrations, have been shown to contribute to the development of CCA. Furthermore, CCAs are surrounded by a dense stroma that contains many cancer-associated fibroblasts, which promotes their progression. We have gained a better understanding of the imaging characteristics of iCCAs and have developed advanced cytologic techniques to detect pCCAs. Patients with iCCAs usually are treated surgically, whereas liver transplantation after neoadjuvant chemoradiation is an option for a subset of patients with pCCAs. We review recent developments in our understanding of the epidemiology and pathogenesis of CCA, along with advances in classification, diagnosis, and treatment.

Vitamin D deficiency and severe asthma

Vitamin D has received tremendous amount of attention recently due to the ever-increasing reports of association between vitamin D deficiency and a wide range of conditions, from cancer to fertility to longevity. The fascination of disease association with vitamin D deficiency comes from the relatively easy solution to overcome such a risk factor, that is, either by increase in sun exposure and/or diet supplementation. Many reviews have been written on a protective role of vitamin D in asthma and related morbidities; here, we will summarize the epidemiological evidence supporting a role of vitamin D against hallmark features of severe asthma, such as airway remodeling and asthma exacerbations. Furthermore, we discuss data from in vitro and in vivo studies which provide insights on the potential mechanisms of how vitamin D may protect against severe asthma pathogenesis and how vitamin D deficiency may lead to the development of severe asthma. Approximately 5-15% of asthmatic individuals suffer from the more severe forms of disease in spite of aggressive therapies and they are more likely to have irreversible airflow obstruction associated with airway remodeling. At present drugs commonly used to control asthma symptoms, such as corticosteroids, do not significantly reverse or reduce remodeling in the airways. Hence, if vitamin D plays a protective role against the development of severe asthma, then the most effective therapy may simply be a healthy dose of sunshine.