Granulocyte colony-stimulating factor reduces hyperoxia-induced alveolarization inhibition by increasing angiogenic factors

Protective Effect of CXCR4 Antagonist DBPR807 against Ischemia-Reperfusion Injury in a Rat and Porcine Model of Myocardial Infarction: Potential Adjunctive Therapy for Percutaneous Coronary Intervention

CXCR4 antagonists have been claimed to reduce mortality after myocardial infarction in myocardial infarction (MI) animals, presumably due to suppressing inflammatory responses caused by myocardial ischemia-reperfusion injury, thus, subsequently facilitating tissue repair and cardiac function recovery. This study aims to determine whether a newly designed CXCR4 antagonist DBPR807 could exert better vascular-protective effects than other clinical counterparts (e.g., AMD3100) to alleviate cardiac damage further exacerbated by reperfusion. Consequently, we find that instead of traditional continuous treatment or multiple-dose treatment at different intervals of time, a single-dose treatment of DBPR807 before reperfusion in MI animals could attenuate inflammation via protecting oxidative stress damage and preserve vascular/capillary density and integrity via mobilizing endothelial progenitor cells, leading to a desirable fibrosis reduction and recovery of cardiac function, as evaluated with the LVEF (left ventricular ejection fraction) in infarcted hearts in rats and mini-pigs, respectively. Thus, it is highly suggested that CXCR4 antagonists should be given at a single high dose prior to reperfusion to provide the maximal cardiac functional improvement. Based on its favorable efficacy and safety profiles indicated in tested animals, DBPR807 has a great potential to serve as an adjunctive medicine for percutaneous coronary intervention (PCI) therapies in acute MI patients.

Development of Stem-Cell-Mobilizing Agents Targeting CXCR4 Receptor for Peripheral Blood Stem Cell Transplantation and Beyond

The function of the CXCR4/CXCL12 axis accounts for many disease indications, including tissue/nerve regeneration, cancer metastasis, and inflammation. Blocking CXCR4 signaling with its antagonists may lead to moving out CXCR4⁺ cell types from bone marrow to peripheral circulation. We have discovered a novel series of pyrimidine-based CXCR4 antagonists, a representative (i.e., 16) of which was tolerated at a higher dose and showed better HSC-mobilizing ability at the maximal response dose relative to the approved drug 1 (AMD3100), and thus considered a potential drug candidate for PBSCT indication. Docking compound 16 into the X-ray crystal structure of CXCR4 receptor revealed that it adopted a spider-like conformation striding over both major and minor subpockets. This putative binding mode provides a new insight into CXCR4 receptor-ligand interactions for further structural modifications.

Mesenchymal stem cells in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a major cause of respiratory failure in critically ill patients and common outcome of various lung interstitial diseases. Its mortality remains high, and no effective pharmacotherapy, in addition to artificial ventilation and transplantation, exists. As such, the administration of mesenchymal stem or stromal cells (MSCs) is currently investigated as a new therapeutic method for pulmonary fibrosis. Clinical trials on MSC-based therapy as a potential treatment for lung injury and fibrosis are also performed. MSCs can migrate to injured sites and secrete multiple paracrine factors and then regulate endothelial and epithelial permeability, decrease inflammation, enhance tissue repair, and inhibit bacterial growth. In this review, recent studies on stem cells, particularly MSCs, involved in alleviating lung inflammation and fibrosis and their potential MSC-induced mechanisms, including migration and differentiation, soluble factor and extracellular vesicle secretion, and endogenous regulatory functions, were summarized.

Vascular and neural stem cells in the gut: do they need each other?

Enteric neurons and blood vessels form intricate networks throughout the gastrointestinal tract. To support the hypothesis of a possible interaction of both networks, we investigated whether primary mesenteric vascular cells (MVCs) and enteric nervous system (ENS)-derived cells (ENSc) depend on each other using two- and three-dimensional in vitro assays. In a confrontation assay, both cell types migrated in a target-oriented manner towards each other. The migration of MVCs was significantly increased when cultured in ENSc-conditioned medium. Co-cultures of ENSc with MVCs resulted in an improved ENSc proliferation and differentiation. Moreover, we analysed the formation of the vascular and nervous system in developing mice guts. It was found that the patterning of newly formed microvessels and neural stem cells, as confirmed by nestin and SOX2 stainings, is highly correlated in all parts of the developing gut. In particular in the distal colon, nestin/SOX2-positive cells were found in the tissues adjacent to the capillaries and in the capillaries themselves. Finally, in order to provide evidences for a mutual interaction between endothelial and neural cells, the vascular patterns of a RET((-/-)) knockout mouse model as well as human Hirschsprung's cases were analysed. In the distal colon of postnatal RET((-/-)) knockout mice, the vascular and neural networks were similarly disrupted. In aganglionic zones of Hirschsprung's patients, the microvascular density was significantly increased compared with the ganglionic zone within the submucosa. Taken together, these findings indicate a strong interaction between the enteric nervous and vascular system.