MicroRNA-26b-5p promotes development of neonatal respiratory distress syndrome by inhibiting differentiation of mesenchymal stem cells to type II of alveolar epithelial cells via regulating Wnt5a.

OBJECTIVE: The aim was to investigate the role of microRNA-26b-5p in regulating mesenchymal stem cells (MSCs) differentiation to type II of alveolar epithelial cells (AECII) in the disease course of neonatal respiratory distress syndrome (NRDS). MATERIALS AND METHODS: MSCs were first derived from rat bone marrow. In vitro induction of MSCs differentiation to AECII was conducted by SAGM. The mRNA levels of microRNA-26b-5p, Wnt5a, and AECII-related genes (Occludin, KGF, CK18, SpA, SpB, and SpC) during the process of cell differentiation were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Enzyme-linked immunosorbent assay (ELISA) was conducted for detecting levels of inflammatory factors tumor necrosis factor-α (TNF-α), interferon-α (INF-α), and interleukin-1 (IL-1) in cell supernatant. Dual-luciferase reporter gene assay was then carried out to verify the regulatory effect of microRNA-26b-5p on Wnt5a. MicroRNA-26b-5p expression in serum samples of NRDS neonates and healthy neonates was detected by qRT-PCR as well. RESULTS: MicroRNA-26b-5p was overexpressed in NRDS neonates than those of healthy neonates. Besides, microRNA-26b-5p was highly expressed in the process of MSCs differentiation to AECII. MicroRNA-26b-5p overexpression remarkably inhibited AECII differentiation and Wnt5a expression. Levels of TNF-α, INF-α, and IL-1 in cell supernatant during differentiation induction were elevated. The regulatory effects of microRNA-26b-5p on AECII differentiation, Wnt5a expression, and inflammatory response were reversed by Wnt5a overexpression. CONCLUSIONS: MicroRNA-26b-5p inhibits MSCs differentiation to AECII via inhibiting Wnt5a expression through the Wnt pathway.

A mutation in FBN1 disrupts profibrillin processing and results in isolated skeletal features of the Marfan syndrome.

Dermal fibroblasts from a 13-yr-old boy with isolated skeletal features of the Marfan syndrome were used to study fibrillin synthesis and processing. Only one half of the secreted profibrillin was proteolytically processed to fibrillin outside the cell and deposited into the extracellular matrix. Electron microscopic examination of rotary shadowed microfibrils made by the proband's fibroblasts were indistinguishable from control cells. Sequencing of the FBN1 gene revealed a heterozygous C to T transition at nucleotide 8176 resulting in the substitution of a tryptophan for an arginine (R2726W), at a site immediately adjacent to a consensus sequence recognized by a cellular protease. Six other individuals in the proband's family had the FBN1 mutation that segregated with tall stature. None of the affected individuals have cardiac or ocular manifestations of the Marfan syndrome. This mutation identifies a putative site for profibrillin to fibrillin processing, and is associated with isolated skeletal features of the Marfan syndrome, indicating that the FBN1 gene is one of the genes that determines height in the general population. The cellular effect of the mutation may be equivalent to a "null" FBN1 allele and may define the phenotype associated with FBN1 "null" alleles.

Molecular Detection of Theileria species in Cattle from Jilin Province, China.

Bovine theileriosis is a tick-borne disease that is hampering the development of the domestic cattle industry in northern China. This study involved a molecular survey of bovine Theileria species in 137 blood samples from cattle in the Jilin province of China. The DNA samples were screened by species-specific 18S rRNA PCR. Results revealed that 19.7% (27/137), 17.5% (24/137) and 10.9% (15/137) were found to be infected with Theileria sinensis, Theileria orientalis, respectively. Mixed infection was found in 8.8% (12/137). The overall detection rates of Baishan, Yanji, Jilin and Liaoyuan districts was 60.0%, 17.5%, 5.3% and 0%, respectively. There is little information on the detection and distribution of bovine Theileria species in northern China. Therefore, this study provides important data for understanding the epidemiology of Theileria species and designing appropriate approaches for the diagnosis and control of bovine theileriosis in northern China.

Molecular detection and genotyping of Anaplasma spp. and Theileria spp. infections in sheep and cattle from the northeast region of China.

Anaplasmosis and theileriosis are significant tick-borne diseases threatening the livestock industry worldwide. In the present study, we screened 127 cattle and 115 sheep blood DNA samples from northeastern China for Theileria and Anaplasma pathogens by polymerase chain reaction (PCR) using species-specific primers. The result showed that only Theileria orientalis and Anaplasma ovis were detected, with a prevalence of 2.9% for T. orientalis in cattle and 57.4% for A. ovis in sheep. Fragments of Anaplasma ovis major surface protein 4 (AoMSP4) and Theileria orientalis major piroplasm surface protein (ToMPSP) genes were sequenced for phylogenetic analysis. Sequence analysis showed that the AoMSP4 gene was conserved, with 100% sequence identity value among sheep samples. However, the ToMPSP gene was relatively diverse, with sequence identity ranging from 87.6%-99l.0% among cattle samples. Phylogenetic analysis showed that the ToMPSP gene sequences isolated from 4 cattle samples were classified into type 1, type 2 and type 7, while the AoMSP4 gene sequences obtained from 66 sheep were classified into genotype I, according to the neighbour-joining distance method. This study provides important data for understanding the epidemiology of tick-borne diseases and genetic diversity of these pathogens in the northeast region of China.

Aortic dissection, patent ductus arteriosus, iris hypoplasia and brachytelephalangy in a male adolescent.

We describe a 14-year-old male with dissection of the descending aorta, bilateral iris hypoplasia, striae distensae and brachytelephalangy, the latter being most marked in the thumbs. Inguinal herniae and a patent ductus arteriosus were surgically repaired in infancy. The pattern of abnormalities may constitute a previously undescribed syndrome. The proband died suddenly at the age of 17 years.

Antibody response to rubella virus antigen and structural proteins in retinitis pigmentosa.

Elevated serum ELISA IgG antibodies to rubella virus (RV) were found by three independent determinations in 41 (72%) of 57 adults with the retinal degeneration retinitis pigmentosa, while antibody responses to five other common neurotropic viruses were normal. However, these patients lacked clinical signs of active RV infection or known recent RV exposure, and 56 lacked IgM anti-RV antibody. Unusual relative percentages of IgG antibody to RV structural proteins compared with those of controls were found in patients' sera by radioimmunoprecipitation assay. For retinitis pigmentosa patients, percentage of RV envelope glycoprotein E1 antibody was similar to, of RV envelope glycoprotein E2 antibody was greater than, and of antibody to RV nucleocapsid C protein was lower than control percentages. Abnormal immunity to RV was also suggested by a lack of increased proliferation of lymphocytes to RV antigen despite elevated anti-RV antibody in patients with retinitis pigmentosa. Not associated with age or particular genetic pattern, these divergences from normal immunity suggest an unusual association between RV proteins and retinitis pigmentosa.

Monoclonal antibody-defined epitope map of expressed rubella virus protein domains.

An expanded library of murine monoclonal antibodies (MAbs) was generated by infecting BALB/C mice with the Therien strain of rubella virus (RV) and selecting secreting hybrids by enzyme-linked immunosorbent assay (ELISA) using purified virion targets. A panel of plasmids containing specified RV cDNA fragments was also constructed by using a variety of strategies with pGE374- and pGE374-derived expression vectors. Hybrid RecA-RV-beta-galactosidase (LacZ)- or RecA-RV-truncated LacZ-containing proteins collectively representing the entire open reading frame of the structural proteins of RV were overexpressed in Escherichia coli. Bacterial lysates were then probed by ELISA with selected MAbs and by immunoblot following separation by electrophoresis under denaturing conditions. With this approach, MAbs that appeared to react with linear determinants defined epitopes localized within the following domains: MAbs C-1, C-2, and C-8 bind epitopes within the predicted amino-terminal 21 amino acids of the capsid region C9 to C29; MAb C-9 binds to a domain bounded by C64 and C97; MAbs E2-1 through E2-6 bind to the E2 glycoprotein backbone region from E2(1) to E2(115); MAbs E1-18 and E1-20 bind to the E1 glycoprotein region from E1(202) to E1(283). MAb E1-18 neutralizes RV infectivity; MAb E1-20 neutralizes infectivity and modestly inhibits hemagglutination. Analyses with selected synthetic peptides have confirmed several of the molecular domains deduced with the expressed proteins. These plasmid constructions and peptides have proven useful in beginning to unravel the molecular organization of several antigenic sites of this human pathogen.