SDF-1 alone and in co-operation with HGF regulates biology of human cervical carcinoma cells

Stromal Derived Factor-1 (SDF-1)-CXCR4 axis plays a pivotal role in biology and metastasis of several tumors. The aim of this study was to see if SDF-1 alone or in combination with Hepatocyte Growth Factor (HGF) affects biology of human cervical carcinoma (HCC) cells. We found that HCC cell lines investigated in our study highly express CXCR4 on their surface. CXCR4 was also expressed on tumor cells in tissue sections derived from cervical cancer patients. At the same time normal cervical epithelium was negative for CXCR4 expression what suggests a strong correlation between CXCR4 and malignant cell phenotype. Subsequently, we studied a potential role of the SDF-1-CXCR4 axis in HCC and noticed that SDF-1 (i) chemoattracted HCC cells, (ii) enhanced their scattering, (iii) stimulated nuclear localization of beta-catenins and upregulated their target gene cyclin D1 and (iv) at the molecular level induced calcium flux and activated RAS-MAPK, PI3-AKT and JAK-STAT pathways. SDF-1-mediated functions were additionally enhanced in the presence of HGF. Thus, our data show that the SDF-1-CXCR4 axis affects biology of HCC cells. Furthermore, we postulate that this axis might become a potential target to prevent progression of cervical cancer

SDF-1 alone and in co-operation with HGF regulates biology of human cervical carcinoma cells.

Stromal Derived Factor-1 (SDF-1)-CXCR4 axis plays a pivotal role in biology and metastasis of several tumors. The aim of this study was to see if SDF-1 alone or in combination with Hepatocyte Growth Factor (HGF) affects biology of human cervical carcinoma (HCC) cells. We found that HCC cell lines investigated in our study highly express CXCR4 on their surface. CXCR4 was also expressed on tumor cells in tissue sections derived from cervical cancer patients. At the same time normal cervical epithelium was negative for CXCR4 expression what suggests a strong correlation between CXCR4 and malignant cell phenotype. Subsequently, we studied a potential role of the SDF-1-CXCR4 axis in HCC and noticed that SDF-1 (i) chemoattracted HCC cells, (ii) enhanced their scattering, (iii) stimulated nuclear localization of beta-catenins and upregulated their target gene cyclin D1 and (iv) at the molecular level induced calcium flux and activated RAS-MAPK, PI3-AKT and JAK-STAT pathways. SDF-1-mediated functions were additionally enhanced in the presence of HGF. Thus, our data show that the SDF-1-CXCR4 axis affects biology of HCC cells. Furthermore, we postulate that this axis might become a potential target to prevent progression of cervical cancer

Enhanced Integrin α4β1-Mediated Adhesion Contributes to a Mobilization Defect of Endothelial Progenitor Cells in Diabetes.

Diabetes is associated with a deficit of circulating endothelial progenitor cells (EPCs), which has been attributed to their defective mobilization from the bone marrow. The basis for this mobilization defect is not completely understood, and we sought to determine if hyperglycemic conditions enhanced EPC adhesion. We found that culturing EPCs in high glucose media increased adhesion to bone marrow stromal cells. This enhanced adhesion was associated with decreased expression of protein kinase A regulatory subunit 1β (PRKAR1β), activation of protein kinase A (PKA), and phosphorylation of α4-integrin on serine 988. This potentiated adhesion was reversed by treatment with a PKA inhibitor, overexpression of PRKAR1β, or expression of a phosphorylation-defective α4-integrin variant (α4[S988A]). Using a model of type 1 diabetes, we showed that α4(S988A)-expressing mice have more circulating EPCs than their wild-type counterparts. Moreover, diabetic α4(S988A) mice demonstrate enhanced revascularization after hind limb ischemia. Thus, we have identified a novel signaling mechanism activating PKA in diabetes (downregulation of an inhibitory regulatory subunit) that leads to deficits of circulating EPCs and impaired vascular repair, which could be reversed by α4-integrin mutation

Rigor Me This: What Are the Basic Criteria for a Rigorous, Transparent, and Reproducible Scientific Study?

Scientific advancement is predicated upon the ability of a novel discovery to be independently reproduced and substantiated by others. Despite this inherent necessity, the research community is awash in published studies that cannot be replicated resulting in widespread confusion within the field and waning trust from the general public. In many cases, irreproducibility is the unavoidable consequence of a study that is conducted without the appropriate degree of rigor, typified by fundamental flaws in approach, design, execution, analysis, interpretation, and reporting. Combatting the irreproducibility pandemic in preclinical research is of urgent concern and is the primary responsibility of individual investigators, however there are important roles to be played by institutions, journals, government entities, and funding agencies as well. Herein, we provide an updated review of established rigor criteria pertaining to both in vitro and in vivo studies compiled from multiple sources across the research enterprise and present a practical checklist as a straightforward reference guide. It is our hope that this review may serve as an approachable resource for early career and experienced investigators alike, as they strive to improve all aspects of their scientific endeavors

Inducible Nitric Oxide Synthase (iNOS) Is a Novel Negative Regulator of Hematopoietic Stem/Progenitor Cell Trafficking

Nitric oxide (NO) is a gaseous free radical molecule involved in several biological processes related to inflammation, tissue damage, and infections. Based on reports that NO inhibits migration of granulocytes and monocytes, we became interested in the role of inducible NO synthetase (iNOS) in pharmacological mobilization of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM) into peripheral blood (PB). To address the role of NO in HSPC trafficking, we upregulated or downregulated iNOS expression in hematopoietic cell lines. Next, we performed mobilization studies in iNOS−/− mice and evaluated engraftment of iNOS−/− HSPCs in wild type (control) animals. Our results indicate that iNOS is a novel negative regulator of hematopoietic cell migration and prevents egress of HSPCs into PB during mobilization. At the molecular level, downregulation of iNOS resulted in downregulation of heme oxygenase 1 (HO-1), and, conversely, upregulation of iNOS enhanced HO-1 activity. Since HO-1 is a negative regulator of cell migration, the inhibitory effects of iNOS identified by us can be at least partially explained by its enhancing the HO-1 level in BM cells

Evidence for the Involvement of Sphingosine-1-Phosphate in the Homing and Engraftment of Hematopoietic Stem Cells to Bone Marrow

The α-chemokine stromal-derived factor 1 (SDF-1), which binds to the CXCR4 receptor, directs migration and homing of CXCR4+ hematopoietic stem/progenitor cells (HSPCs) to bone marrow (BM) stem cell niches. Nevertheless, it is also known that CXCR4-/- fetal liver-derived hematopoietic stem cells engraft into BM and that blockade of CXCR4 by its antagonist AMD3100 does not prevent engraftment of HSPCs. Because of this finding of SDF-1-CXCR4-independent BM homing, the unique role of SDF-1 in HSPC homing has recently been challenged. While SDF-1 is the only chemokine that chemoattracts HSPCs, other chemoattractants for these cells have recently been described, including the bioactive phosphosphingolipid sphingosine-1-phosphate (S1P). To address the potential role of S1P in homing of HSPCs to BM, we performed hematopoietic transplants into mice deficient in BM-expressed sphingosine kinase 1 (Sphk1-/-) using hematopoietic cells from normal control mice as well as cells from mice in which floxed CXCR4 (CXCR4fl/fl) was conditionally deleted. We observed the presence of a homing and engraftment defect in HSPCs of Sphk1-/- mice that was particularly profound after transplantation of CXCR4-/- BM cells. Thus, our results indicate that BM-microenvironment-expressed S1P plays a role in homing of HSPCs. They also support the concept that, in addition to the SDF-1-CXCR4 axis, other chemotactic axes are also involved in homing and engraftment of HSPCs

Collagen Type XIX Regulates Cardiac Extracellular Matrix Structure and Ventricular Function

The cardiac extracellular matrix plays essential roles in homeostasis and injury responses. Although the role of fibrillar collagens have been thoroughly documented, the functions of non-fibrillar collagen members remain underexplored. These include a distinct group of non-fibrillar collagens, termed, fibril-associated collagens with interrupted triple helices (FACITs). Recent reports of collagen type XIX (encoded by Col19a1) expression in adult heart and evidence of its enhanced expression in cardiac ischemia suggest important functions for this FACIT in cardiac ECM structure and function. Here, we examined the cellular source of collagen XIX in the adult murine heart and evaluated its involvement in ECM structure and ventricular function. Immunodetection of collagen XIX in fractionated cardiovascular cell lineages revealed fibroblasts and smooth muscle cells as the primary sources of collagen XIX in the heart. Based on echocardiographic and histologic analyses, Col19a1 null (Col19a1(N/N)) mice exhibited reduced systolic function, thinning of left ventricular walls, and increased cardiomyocyte cross-sectional areas—without gross changes in myocardial collagen content or basement membrane morphology. Col19a1(N/N) cardiac fibroblasts had augmented expression of several enzymes involved in the synthesis and stability of fibrillar collagens, including PLOD1 and LOX. Furthermore, second harmonic generation-imaged ECM derived from Col19a1(N/N) cardiac fibroblasts, and transmission electron micrographs of decellularized hearts from Col19a1(N/N) null animals, showed marked reductions in fibrillar collagen structural organization. Col19a1(N/N) mice also displayed enhanced phosphorylation of focal adhesion kinase (FAK), signifying de-repression of the FAK pathway—a critical mediator of cardiomyocyte hypertrophy. Collectively, we show that collagen XIX, which had a heretofore unknown role in the mammalian heart, participates in the regulation of cardiac structure and function—potentially through modulation of ECM fibrillar collagen structural organization. Further, these data suggest that this FACIT may modify ECM superstructure via acting at the level of the fibroblast to regulate their expression of collagen synthetic and stabilization enzymes

Macrophage Long Non-Coding RNAs in Pathogenesis of Cardiovascular Disease

Chronic inflammation is inextricably linked to cardiovascular disease (CVD). Macrophages themselves play important roles in atherosclerosis, as well as acute and chronic heart failure. Although the role of macrophages in CVD pathophysiology is well-recognized, little is known regarding the precise mechanisms influencing their function in these contexts. Long non-coding RNAs (lncRNAs) have emerged as significant regulators of macrophage function; as such, there is rising interest in understanding how these nucleic acids influence macrophage signaling, cell fate decisions, and activity in health and disease. In this review, we summarize current knowledge regarding lncRNAs in directing various aspects of macrophage function in CVD. These include foam cell formation, Toll-like receptor (TLR) and NF-kβ signaling, and macrophage phenotype switching. This review will provide a comprehensive understanding concerning previous, ongoing, and future studies of lncRNAs in macrophage functions and their importance in CVD