Apelin-13 promotes late endothelial progenitor cells differentiation by regulating Krüppel-like factor 4.

OBJECTIVE: The endothelial progenitor cells (EPCs) differentiation plays an essential role in angiogenesis. The purpose of this study is to determine the potential mechanisms of apelin-13 in EPCs differentiation. MATERIALS AND METHODS: The rats EPCs were isolated from the bone marrow and identified by DIL-acLDL and FITC-UEA-1 staining. EPCs were divided into four groups: the negative control group, the Krüppel-like factor 4 (KLF4) upregulation group, the KLF4 downregulation group, and the apelin-13 group. The EPCs differentiation was evaluated by cell migration, proliferation, and the expressions of surface markers CD31, CD34, CD133, and VEGFR-2 on mRNA and the protein levels, as well as immunofluorescence. RESULTS: In the KLF4 up-regulation and apelin-13 groups, the EPCs number of G1, S, and G2/M phases decreased and suggested that KLF4 and apelin-13 were closely related to the EPCs proliferation. EPCs showed stronger migration ability with the elevation of KLF4 and apelin-13 while declined migration was detected in KLF4 siRNA transfected EPCs. The surface markers expressions on mRNA and the protein levels increased in the KLF4 upregulation group, and in the apelin-13 group there were similar results, as well as increased KLF4 expression. CONCLUSIONS: The upregulation of apelin-13 significantly increased the expressions of EPCs surface markers, which were involved in early EPCs differentiated into late EPCs and influenced the cells migration and proliferation. Taking the elevation of KLF4 which performed similar effects of apelin-13, we believe that apelin-13 activates or synergizes with KLF4 to promote this process.

Combination of cells-based therapy with apelin-13 and hyperbaric oxygen efficiently promote neovascularization in ischemic animal model.

OBJECTIVE: Critical lower-limb ischemia (CLLI) is characterized by high morbidity and mortality. The aim of this study was to explore the effectiveness of the combination of cell therapy with apelin-13 and hyperbaric oxygen in CLLI animal model. MATERIALS AND METHODS: The experimental ischemic rats were divided into five groups, including negative control, bone marrow derived mononuclear cells (BM-MNCs), apelin-13, hyperbaric oxygen treatment (HBOT) and apelin-13 with HBOT group. Each group was composed of 10 rats. Endothelial progenitor cells (EPCs) derived from bone marrow were transplanted into the ischemia rat model. After 3 weeks of transplantation, the formation of new vessels was evaluated by examining cluster of differentiation (CD)31, CD34 and vascular endothelial growth factor receptor 2 (VEGFR-2) expressions as well as a direct vision of vessels by hematoxylin and eosin (HE) staining and immunohistochemistry. RESULTS: Compared with the negative control group, both angiogenic factors expressions and the number of new vessels increased notably by the transplantation of BM-MNCs in the ischemic models. Apelin-13 or HBOT alone improved the efficacy within limit while the combination of the three elements remarkably promoted the neovascularization in ischemic limbs. CONCLUSIONS: BM-MNC induced angiogenesis in the ischemic limbs and was considered an effective resource for cell therapy. The preliminary data of this study showed that the combination of cell therapy with apelin-13 and HBOT improved the efficacy of angiogenesis.

[The clinical characteristics and pathologic mechanisms of acute macular neuroretinopathy].

Acute macular neuroretinopathy (AMN) is a rare macular disorder. The clinical diagnosis of AMN is difficult and complicated since the retinal symptoms of patients with AMN are usually unclear or untypical. Spectral domain optical coherence tomography (SD-OCT) is a reliable examination for imaging the retinal structure, which improved the insight of AMN in etiology and pathogenesis. This review summarizes and analyzes the recent clinical reports and research progress, in an effort to present a more accurate clinical recognition of AMN. (Chin J Ophthalmol, 2019, 55:311-315).

[Study on flavonoids in seeds of Hovenia dulcis].

Four flavanoids were isolated from the seed of Hovenia dulcis Thunb. On the basis of physicochemical properties and spectroscopic analysis, their structures were identified as dihydrokaempferol (I), quercetin (II), (+)-3,3',5',5,7-pentahydroflavanone (III) and (+)-dihydromyricetin (IV). Among them, III was a new compound; I and IV were first isolated from genus Hovenis.