Cloning and identification of a novel thyroid hormone receptor β isoform expressed in the pituitary gland.

We have previously identified a novel Trβ isoform (TrβΔ) in the rat, in which a novel exon N (108 bps) was found between exon 3 and exon 4 of TrβΔ, which represents the only difference between TrβΔ and Trβ1. In this study, we searched for an elongated Trβ2-like subtype with one additional exon N. We successfully isolated the entire mRNA/cDNA of a novel elongated Trβ2 isoform via PCR in the rat pituitary gland.

[The cloning, expression and the binding ability with TRβ1 of retinoid X receptor-α gene].

Retinoid X receptor-α (RXR-α), a member of nuclear receptor family, is capable of mediating retinoid signaling pathways and plays a critical role in regulating target gene transcription. To further study the function of RXR-α, abundant of recombinant RXR-α protein in hand is necessary. In this study an intact RXR-α coding sequence was amplified by RT-PCR and subsequently inserted into expression plasmid vector pQE-30Xa to form the recombinant construct of pQE-30Xa/RXR-α.

[Changes of nuclear factor-kappaB and intercellular adhesion molecule-1 in endothelial cells exposed to various intermittent hypoxia].

Objective: To construct a novel in vitro endothelial cell system to explore the changes of nuclear factor-kappaB (NF-kappaB) and intercellular adhesion molecule-1 (ICAM-1) levels after exposure to various intermittent hypoxia (IH) and re-oxygenation, an IH/reoxygenation (ROX) model.

Methods: We developed a gas control delivery system that permitted the exposure of ECV304 cell cultures, immortalized endothelial cell strain cultures of human umbilical vein endothelial cells (HUVEC), to IH/ROX cycles, simulating the pattern of hypoxic episodes seen in recurrent apnea. Cell samples were divided into the following groups according to IH duration/ROX duration.

[Interleukin-6 and tumor necrosis factor-alpha levels of endothelial cells in different hypoxia modes: in vitro experiment].

Objective: To investigate the damage of different patterns of intermittent hypoxia (IH) and continuous hypoxia (CH) on endothelial cells.

Methods: Human umbilical vein endothelial cells of the line ECV304 were cultured in a program-controlled gas delivery system newly developed and divided into 8 groups to undergo different IH/reoxygenation (ROX) cycles so as to simulate the patterns of hypoxic episode seen in recurrent apnea and chronic obstructive pulmonary disease: intermittent normoxia (IN) group (exposed to 21% O2 15 s/21% O2 225 s for 60 cycles), IH group (exposed to 1.5% O2 15 s/21% O2 225 s for 30 or 60 cycles), IH hypercapnia group (exposed to 1.

[Cloning and eukaryotic expression of wild type and truncated mouse ciliary neurotrophic factor gene].

Objective: To clone and eukaryotic express wild type and truncated mouse ciliary neurotrophic factor (CNTF) gene, and to observe the biological effect of two types of CNTF gene expressing in ARPE-19 cells.

Methods: RT-PCR was used to amplify the cDNA of CNTF gene, and truncated CNTF cDNA was obtained by site-directed mutagenesis. The two types of CNTF gene were cloned into plasmid pTracer-CMV and transfected to ARPE-19 cells.

Pre-deliver chitosanase to cells: a novel strategy to improve gene expression by endocellular degradation-induced vector unpacking.

A radio-labeled plasmid pTracer/Bsd/LacZ containing LacZ reporter gene was complexed with different molecular weights of chitosans (CS). Mouse myoblast cell line C2C12 was transfected by these chitosan-plasmid DNA complexes, and lipofectamine 2000 was used as control. Forty-eight hours after transfection, the activity of beta-galactosidase and radioactive count of cell lysis were determined.

[Cloning and expression of an Aspergillus fumigatus chitosanase gene].

According to published DNA sequence of Aspergillus fumigatus chitosanase(Csn) gene, 8 long single DNA strands each about 100bp and 4 DNA primers were designed and synthesised. By PCR, 8 DNA strands were connected into a complete chitosanase gene of 624bp. This chitosanase gene was not identical with its wild type, some point mutations were introduced into its DNA sequence by special design of those 8 DNA strands.

[Effects of various iodin-nutritional on activity of T4 5'-and 5-deiodinase in rat brain].

Objective: To investigate the changing of T4 5'-and 5-deiodinase within rat brain under various iodin-nutritional states.

Methods: Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition, and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T(4) 5'-and 5-deiodinase within brain was analyzed.

[The construction of yak liver cDNA library].

Yak is a very useful animal. The cDNA library of yak liver was constructed, which made a preparation for further cloning and expressing of wanted genes.mRNA from yak liver was extracted and purified, and cDNA was obtained by reverse transcription,and then cDNA library was constructed using plasmid pSPORT1 as the vector.

[The cloning and expression of rat insulin-like growth factor I gene].

In this study an exons-connecting technique was used to amplify the complete DNA sequence encoding the mature peptide of IGF-I. Two pairs of primers were synthesized, primer a (Pa) and primer b (Pb) were used to amplify exon 2 coding fragment while primer c (Pc) and primer d (Pd) for amplifying exon 3 coding fragment. Pb was 40 bp, 18 bp at its 5' end was same with the anti-sense of exon 3's 5' end.