5'-upstream region of the phospholipase C-beta2 gene, 810 bp, was cloned and characterized. S1 nuclease mapping and primer extension analyses revealed that a single transcriptional start site locates at 284 nucleotides upstream from the beginning of translation. The 5-upstream region lacks both TATA motif and typical initiator sequence, but retains GC-rich segment. Two putative regulatory regions, a negative region (-636/-588) and a positive region (-98/ -13) were identified in the upstream region of PLC-beta2 gene. We suggest that the transcription of PLC-beta2 may be regulated by binding of regulatory proteins to the negative and/or positive regulatory regions located in the upstream of the gene.
Aspergillus Nuclease S1/metabolism ; Base Sequence ; Cells, Cultured ; Chloramphenicol O-Acetyltransferase/metabolism ; Cloning, Molecular ; Conserved Sequence ; Gene Deletion ; Isoenzymes/*chemistry/*genetics ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Phospholipase C/*chemistry/*genetics ; Promoter Regions (Genetics) ; Protein Binding ; Support, Non-U.S. Gov't ; Transcription, Genetic ; Transfection

Objectives To investigate the value of oral glucose tolerance (OGTT)-insulin/C peptide release test in early diagnosis of chronic pancreatitis (CP)-associated abnormal glucose tolerance.Methods Sixty patients with CP who were admitted to the Department of Gastroenterology,Changhai Hospital from June 2017 to February 2018 were divided into CP with normal glucose tolerance (CP-NGT),CP with impaired glucose tolerance (CP-IGT),CP with newly diagnosed diabetes(CP-new-DM) and CP with the previous history of diabetes (CP-history-DM) according to previous medical records and data from OGTT-insulin/C peptide release test.The characteristics of glucose metabolism,the changes of blood glucose,insulin and C peptide released among the four groups were compared.Results In 43 cases of patients with CP without diabetes,the abnormal glucose metabolism was detected in 6 cases (14.0％) by fasting blood glucose or glycosylated hemoglobin,and in 30 cases (69.8％) by OGTT-insulin/C-peptide release test.The detection rate of abnormal glucose metabolism was increased by 55.8％.In the group of CP-history-DM,the peak secretion of blood glucose,insulin,C peptide was all at 120 min,and the multiplication of increased release of C peptide (peak/baseline) [4.1 (3.4,4.4) vs (6.1 ± 2.2) 、(6.4 ± 2.5)、(6.8 ± 3.8)],the C peptide area under curve (C-PAUC) [(3.6 ± 1.4)]μg · h-1 · L-1 vs 8.6(7.1,9.7),(8.1 ±3.1),(6.9 ±2.7) μg · h-1 L-1] and the homeostasis model of assessment for β cell (HOMA-β) [24.4 (11.4,37.4) vs 52.4 (44.6,92.1),(89.8 ± 57.2),(72.4 ± 57.0)] were all significantly lower,and the difference was statistically significant(all P＜0.05).In the group of CP-new-DM,the peak of blood glucose was at 60 min,while the peak of insulin,C peptide was at 1 20 min,the early insulin secretion index (/ I30/A G30) [2.2 (0.8,4.2)vs (11.4 ± 9.4)] and insulin secretion sensitivity index-2 (ISSI-2) [256.1 (160.1,340.7) vs (548.5 ± 173.2)] in group of CP-new-DM were significantly lower than those in the group of CP-NGT,and the difference was statistically significant (all P ＜0.05).Conclusions The insulin /C peptide secretion was insufficient in the early stage of CP-related diabetes mellitus.Routine OGTT-insulin / C peptide release test for patients with CP can increase the detection rate of abnormal glucose metabolism.

NHERF1/EBP50 (Na⁺/H⁺ exchanger regulating factor 1; Ezrin-binding phosphoprotein of 50 kDa) organizes stable protein complexes beneath the apical membrane of polar epithelial cells. By contrast, in cancer cells without any fixed polarity, NHERF1 often localizes in the cytoplasm. The regulation of cytoplasmic NHERF1 and its role in cancer progression remain unclear. In this study, we found that, upon lysophosphatidic acid (LPA) stimulation, cytoplasmic NHERF1 rapidly translocated to the plasma membrane, and subsequently to cortical protrusion structures, of ovarian cancer cells. This movement depended on direct binding of NHERF1 to C-terminally phosphorylated ERM proteins (cpERMs). Moreover, NHERF1 depletion downregulated cpERMs and further impaired cpERM-dependent remodeling of the cell cortex, suggesting reciprocal regulation between these proteins. The LPA-induced protein complex was highly enriched in migratory pseudopodia, whose formation was impaired by overexpression of NHERF1 truncation mutants. Consistent with this, NHERF1 depletion in various types of cancer cells abolished chemotactic cell migration toward a LPA gradient. Taken together, our findings suggest that the high dynamics of cytosolic NHERF1 provide cancer cells with a means of controlling chemotactic migration. This capacity is likely to be essential for ovarian cancer progression in tumor microenvironments containing LPA.
Cell Membrane ; Cell Movement ; Cytoplasm ; Cytosol ; Epithelial Cells ; Membranes ; Ovarian Neoplasms* ; Pseudopodia ; Tumor Microenvironment