Hypoxia downregulates the angiogenesis in human placenta via Notch1 signaling pathway.

Placentation, which is critical for maternal-fetal exchange of nutrients and gases, is a complicated process comprising stepwise vasculogenesis and angiogenesis. Hypoxia caused by impaired trophoblast invasion may cause various angiogenic abnormalities in human placenta. The Notch1 signaling pathway plays an important role in the regulation of angiogenesis. The angiogenesis of human umbilical vein endothelial cells (HUVECs) under normal/hypoxic conditions and the mRNA/protein level of Notch1/Dell4/Jagged1 were investigated in this study. The effects of DAPT/JAG-1 on the migration of HUVECs were also assessed by cell wound healing assay, so as to discover the possible role of notch1 signaling pathway in the angiogenesis of human placenta. The results showed that angiogenic ability of HUVECs was seriously reduced under hypoxic conditions. The mRNA and protein levels of Notch1/Dell4/Jagged1 were decreased in the hypoxic group compared to the control one. In addition, the migration capability of HUVECs was significantly obstructed when treated with DAPT and under hopoxic condition, but promoted when treated with JAG-1. The above results demonstrate that hypoxia downregulates the angiogenesis in human placenta via Notch1 signaling pathway.

Hypoxia Downregulates the Angiogenesis in Human Placenta via Notch1Signaling Pathway / 华中科技大学学报（医学）（英德文版）

Placentation,which is critical for maternal-fetal exchange of nutrients and gases,is a complicated process comprising stepwise vasculogenesis and angiogenesis.Hypoxia caused by impairedtrophoblast invasion may cause various angiogenic abnormalities in human placenta.The Notchl signaling pathway plays an important role in the regulation of angiogenesis.The angiogenesis of human umbilical vein endothelial cells (HUVECs) under normal/hypoxic conditions and the mRNA/protein level of Notchl/Dell4/Jaggedl were investigated in this study.The effects of DAPT/JAG-1 on the migration of HUVECs were also assessed by cell wound healing assay,so as to discover the possible role of notchl signaling pathway in the angiogenesis of human placenta.The results showed that angiogenic ability of HUVECs was seriously reduced under hypoxic conditions.The mRNA and protein levels of Notchl/Dell4/Jaggedl were decreased in the hypoxic group compared to the control one.In addition,the migration capability of HUVECs was significantly obstructed when treated with DAPT and under hopoxic condition,but promoted when treated with JAG-1.The above results demonstrate that hypoxia downregulates the angiogenesis in human placenta via Notch 1 signaling pathway.

Saccharopolyspora qijiaojingensis sp. nov., a halophilic actinomycete isolated from a salt lake.

A halophilic actinomycete strain, designated YIM 91168T, was isolated from a salt lake in Xinjiang province, north-west China. The isolate grew at 20-40 degrees C, pH 5-8 and 6-22% (w/v) NaCl; there was no growth in the absence of NaCl. The whole-cell hydrolysate contained meso-diaminopimelic acid, galactose and arabinose. The major fatty acids were iso-C15:0, iso-C16:0 and iso-C17:0. MK-9(H4) was the predominant menaquinone and the genomic DNA G+C content was 70.1 mol%. These chemotaxonomic data, together with its morphological properties, were consistent with the assignment of strain YIM 91168T to the genus Saccharopolyspora. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 91168T had highest sequence similarity (95.4%) with Saccharopolyspora gregorii NCIB 12823T, and showed lower 16S rRNA gene sequence similarity (93.0-95.1%) with the other species of the genus Saccharopolyspora. On the basis of evidence from this polyphasic study, the novel species Saccharopolyspora qijiaojingensis sp. nov. is proposed. The type strain is YIM 91168T (=DSM 45088T=KCTC 19235T).

Zhihengliuella alba sp. nov., and emended description of the genus Zhihengliuella.

A Gram-positive, non-motile, white-pigmented, short rod actinobacterium, designated YIM 90734T, was isolated from a saline soil sample collected from Ganjiahu Suosuo Forest National Nature Reserve in Xinjiang province, north-west China, and its taxonomic position was investigated by using a polyphasic approach. Strain YIM 90734T grew optimally at 28-37 degrees C and pH 6.0-8.0 and in 5% (w/v) NaCl. The peptidoglycan type was A4alpha, L-Lys-L-Ala-L-Glu and tyvelose and mannose were the major cell-wall sugars. The predominant menaquinones were MK-10 and MK-9. Major cellular fatty acids (>10% of total) were anteiso-C15:0 and anteiso-C17:0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phospholipid and two unknown glycolipids. The DNA G+C content was 70.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 90734T belonged to the genus Zhihengliuella. The 16S rRNA gene sequence similarity between strain YIM 90734T and the type strain of the only recognized Zhihengliuella species, Zhihengliuella halotolerans, was 97.7%. However, the level of DNA-DNA relatedness of the two strains was 41.4%. The DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain YIM 90734T could be differentiated from Z. halotolerans. On the basis of the data presented, strain YIM 90734T is considered to represent a novel species of the genus Zhihengliuella, for which the name Zhihengliuella alba sp. nov. is proposed. The type strain is YIM 90734T (=KCTC 19375T=DSM 21143T). The description of the genus Zhihengliuella has also been emended.

Marinococcus luteus sp. nov., a halotolerant bacterium isolated from a salt lake, and emended description of the genus Marinococcus.

A Gram-positive, aerobic, motile, coccoid, orange-pigmented bacterium, designated strain YIM 91094(T), was isolated from a salt lake sample collected from Barkol Lake in Xinjiang Province, north-west China. The strain was able to grow at pH 6.0-8.0 (optimal growth at pH 7.0), at 10-37 degrees C (optimal growth at 28 degrees C) and in the presence of 0-25 % (w/v) NaCl [optimal growth in the presence of 10-15 % (w/v) NaCl]. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain YIM 91094(T) was affiliated with the genus Marinococcus and exhibited levels of sequence similarity of 99.2 % to Marinococcus halotolerans YIM 70157(T) and 99.7 % to Marinococcus halophilus DSM 20408(T). However, it showed moderately low levels of DNA-DNA relatedness with the above type strains (56.0 and 57.5 %, respectively). The peptidoglycan type of strain YIM 91094(T) was A1gamma, with meso-diaminopimelic acid as the diagnostic diamino acid. MK-7 was the predominant menaquinone and anteiso-C(15 : 0) (49.9 % of the total) and anteiso-C(17 : 0) (29.6 %) were the major cellular fatty acids. The DNA G+C content was 48.7 mol%. Strain YIM 91094(T) possessed chemotaxonomic markers that were consistent with its classification in the genus Marinococcus. On the basis of the data presented, strain YIM 91094(T) is considered to represent a novel species of the genus Marinococcus, for which the name Marinococcus luteus sp. nov. is proposed. The type strain is YIM 91094(T) (=KCTC 13214(T)=CCTCC AA 208014(T)). An emended description of the genus Marinococcus is provided.