Research Progress of the UPR Mechanism and its Effect on Improving Foreign Protein Expression.

The unfolded protein response (UPR) is a protective mechanism against endoplasmic reticulum (ER) stress that induces a series of signal transduction pathways to eliminate misfolded proteins. The UPR mechanism is highly conserved in fungi, higher organisms, plants and mammals. The UPR pathway is activated to stabilize ER functions when there are too many unfolded proteins or misfolded proteins in the ER. However, stress continues when ER proteins are stimulated by toxic substances that affect the balance of the UPR pathway, which causes changes in the structure and function of the ER and other organelles. These ultimately disrupt homeostasis in the body and cause pathological reactions that can be fatal. The UPR mechanism has clear effects on stabilizing the protein-folding environment. Dysfunction or disruption of the UPR mechanism is associated with numerous disorders, including neurodegenerative diseases, loss of control of protein secretion, cerebral ischemia and epilepsy, neuropsychiatric diseases, eye diseases, skin diseases, metabolic and inflammatory diseases, atherosclerosis, and heart disease. Thus, characterization of UPR function and its dysfunction has significant importance and has broad application prospects, which make research into the UPR a research hotspot.

Progesterone regulation of Na/K-ATPase ß1 subunit expression in the mouse uterus during the peri-implantation period.

Luminal closure and embryo apposition are essential for blastocyst attachment during early pregnancy. In our preliminary microarray results (unpublished data), sodium-potassium adenosine triphosphatase (Na/K-ATPase) ß1 (Atp1b1) was highly expressed in mouse uterus on Days 3 and 4 of pregnancy. However, expression and regulation of Atp1b1 in the mammalian uterus during early pregnancy are unknown. Using in situ hybridization, a strong level of Atp1b1 mRNA was detected in luminal epithelial cells on Days 3 and 4 of pregnancy (Day 1 = day of vaginal plug). The expression pattern of FXYD domain-containing ion transport regulator 4 (Fxyd4) was similar to that of Atp1b1. Real-time reverse transcription polymerase chain reaction confirmed the high expression level of Atp1b1 mRNA. Compared with Day 1, the mRNA level of Atp1b1 on Days 3 and 4 increased by 3.5 ± 0.5 and 4.5 ± 0.5 fold, respectively. When the embryo invaded through epithelial cells into the maternal stromal compartment on day 5, Atp1b1 expression decreased to a basal level. Progesterone stimulated Atp1b1 expression by 2.8 ± 1 fold compared with oil in ovariectomized mice at 24 hours after treatment. Expression of Atp1b1 was further upregulated to 4 ± 0.4 fold by estrogen and progesterone. Based on time-course study, progesterone rapidly induced Atp1b1 expression at 6 and 12 hours (13.7 ± 0.5 and 16.6 ± 1.4, respectively); furthermore, this upregulation was blocked by RU486 (progesterone receptor antagonist). Transcription activity of the Atp1b1 promoter was (Day 1 = day of vaginal plug) stimulated by CCAAT/enhancer binding protein beta (Cebpb). In conclusion, Atp1b1 was highly expressed in luminal epithelium during peri-implantation and upregulated by progesterone.

[Analysis of human papillomavirus type 61, 83 and 84 MY fragments and preparation of standard samples].

OBJECTIVE: To investigate the mutations in nucleotide and amino acid level in HPV61, 83 and 84 Shanxi isolates. METHODS: Amplified fragments of HPV61, 83 and 84 from human papillomavirus (Human papillomavirus, HPV) molecular epidemiologic survey of Shanxi Province using HPV consensus primers MY09/11 were cloned in pMD18-T vector, and the plasmids were sequenced, then nucleotide sequences and amino acid sequences were analyzed. RESULTS: HPV61 and HPV83 isolates were consistent with reference strains U31793 and AF151983 in nucleotide sequences; four mutations of nucleotide (C6760T, T6931C, T6951C and C6987A) were found in HPV84 isolate compared with reference strain AF293960, among which C6987A resulted in D441E and the amplified sensitivity of standard sample of HPV61 using primers MY09/11 was higher than that of HPV83 and 84. CONCLUSION: HPV61 and HPV83 isolates were consistent with reference strains, four mutations of nucleotide and one mutation of amino acid were found in HPV84,the amplified sensitivity of standard sample of HPV61 using primers MY09/11 was the highest among those three isolates.