scholarly journals Molecular cloning of a novel secreted peptide, INM02, and regulation of its expression by glucose

2009 ◽  
Vol 202 (3) ◽  
pp. 355-364 ◽  
Author(s):  
Xuanchun Wang ◽  
Wei Gong ◽  
Yu Liu ◽  
Zhihong Yang ◽  
Wenbai Zhou ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
High Glucose ◽  
Northern Blot Analysis ◽  
Polyclonal Antibodies ◽  
Rat Tissues ◽  
Mrna Levels ◽  
Bladder Tissue ◽  
Reading Frame ◽  
Low Glucose

We report the identification of a novel secreted peptide, INM02. The mRNA transcript of human INM02 gene is about 3.0 kb. Its open-reading frame contains 762 bps and encodes a protein of 254 amino acids. Northern blot analysis demonstrates that INM02 mRNA is widely expressed in rat tissues, especially with abundant quantities in pancreatic islets, testis, and bladder tissue. We have expressed recombinant INM02 protein and generated rabbit anti-INM02 polyclonal antibodies. We show here that INM02 could be detectable in human serum by ELISA. We also present evidence that INM02 mRNA expression could be regulated by glucose. Experiments on both MIN6 cells and intact isolated islets demonstrate that INM02 mRNA levels are increased more than threefold by high glucose (25 mM) when compared with low glucose (5.5 mM). ELISA analysis shows that secretion of INM02 is significantly augmented by high glucose in vitro. It is speculated that as a novel secreted protein, INM02 is associated with functions of pancreatic islets, especially of β-cells.

Identification and characterization of a novel Neospora caninum immune mapped protein 1

Parasitology ◽  
2012 ◽  
Vol 139 (8) ◽  
pp. 998-1004 ◽  
Author(s):  
X. CUI ◽  
T. LEI ◽  
D. Y. YANG ◽  
P. HAO ◽  
Q. LIU
Keyword(s):  
Neospora Caninum ◽  
Polyclonal Antibodies ◽  
Functional Protein ◽  
Reading Frame ◽  
Protein Motifs ◽  
Apicomplexan Parasites ◽  
Potential Vaccine ◽  
Palmitoylation Site

SUMMARYImmune mapped protein 1 (IMP1) is a newly discovered protein in Eimeria maxima. It is recognized as a potential vaccine candidate against E. maxima and a highly conserved protein in apicomplexan parasites. Although the Neospora caninum IMP1 (NcIMP1) orthologue of E. maxima IMP1 was predicted in the N. caninum genome, it was still not identified and characterized. In this study, cDNA sequence encoding NcIMP1 was cloned by RT-PCR from RNA isolated from Nc1 tachyzoites. NcIMP1 was encoded by an open reading frame of 1182 bp, which encoded a protein of 393 amino acids with a predicted molecular weight of 42·9 kDa. Sequence analysis showed that there was neither a signal peptide nor a transmembrane region present in the NcIMP1 amino acid sequence. However, several kinds of functional protein motifs, including an N-myristoylation site and a palmitoylation site were predicted. Recombinant NcIMP1 (rNcIMP1) was expressed in Escherichia coli and then purified rNcIMP1 was used to prepare specific antisera in mice. Mouse polyclonal antibodies raised against the rNcIMP1 recognized an approximate 43 kDa native IMP1 protein. Immunofluorescence analysis showed that NcIMP1 was localized on the membrane of N. caninum tachyzoites. The N-myristoylation site and the palmitoylation site were found to contribute to the localization of NcIMP1. Furthermore, the rNcIMP1-specific antibodies could inhibit cell invasion by N. caninum tachyzoites in vitro. All the results indicate that NcIMP1 is likely to be a membrane protein of N. caninum and may be involved in parasite invasion.

scholarly journals Murine protein tyrosine phosphatase-PEST, a stable cytosolic protein tyrosine phosphatase

1995 ◽  
Vol 308 (2) ◽  
pp. 425-432 ◽  
Author(s):  
A Charest ◽  
J Wagner ◽  
S H Shen ◽  
M L Tremblay
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Northern Blot Analysis ◽  
Catalytic Domain ◽  
Tyrosine Phosphatase ◽  
Glutathione S Transferase ◽  
Epitope Tag ◽  
Reading Frame ◽  
Protein Tyrosine ◽  
Cytosolic Protein

We have isolated the murine cDNA homologue of the human protein tyrosine phosphatase PTP-PEST (MPTP-PEST) from an 18.5-day mouse embryonic kidney library. The cDNA isolated has a single open reading frame predicting a protein of 775 amino acids. When expressed in vitro as a glutathione S-transferase fusion protein, the catalytic domain (residues 1-453) shows intrinsic phosphatase activity. Reverse transcriptase PCR and Northern-blot analysis show that MPTP-PEST mRNA is expressed throughout murine development. Indirect immunofluorescence in COS-1 cells against a heterologous epitope tag attached to the N-terminus of MPTP-PEST, together with cellular fractionation and Western-blot experiments from different murine cell lines, indicate that MPTP-PEST is a free cytosolic protein of 112 kDa. Finally, sequence analysis indicates that the C-terminal portion of the protein contains four regions rich in proline, glutamate, serine and threonine, otherwise known as PEST sequences. These are characteristic of proteins that display very short intracellular half-lives. Despite the presence of these motifs, pulse-chase labelling experiments demonstrate that MPTP-PEST has a half-life of more than 4 h.

A preprogalanin cDNA from the turtle pituitary and regulation of its gene expression

2007 ◽  
Vol 292 (4) ◽  
pp. R1649-R1656 ◽  
Author(s):  
John Yuh-Lin Yu ◽  
Chin-Hon Pon ◽  
Hui-Chen Ku ◽  
Chih-Ting Wang ◽  
Yung-Hsi Kao
Keyword(s):  
Mrna Expression ◽  
Untranslated Region ◽  
Signal Sequence ◽  
Biological Effects ◽  
In Vitro Study ◽  
The Body ◽  
Mrna Levels ◽  
Coding Region ◽  
Reading Frame

Galanin is a hormone 29 or 30 amino acids (aa) long that is widely distributed within the body and exerts numerous biological effects in vertebrates. To fully understand its physiological roles in reptiles, we analyzed preprogalanin cDNA structure and expression in the turtle pituitary. Using the Chinese soft-shell turtle ( Pelodiscus sinensis order Testudines), we obtained a 672-base pair (bp) cDNA containing a 99-bp 5′-untranslated region, a 324-bp preprogalanin coding region, and a 249-bp 3′-untranslated region. The open-reading frame encoded a 108-aa preprogalanin protein with a putative 23-aa signal sequence at the NH2 terminus. Based on the location of putative Lys-Arg dibasic cleavage sites and an amidation signal of Gly-Lys-Arg, we propose that turtle preprogalanin is processed to yield a 29-aa galanin peptide with Gly1 and Thr29 substitutions and a COOH-terminal amidation. Sequence comparison revealed that turtle preprogalanin and galanin-29 had 48–81% and 76–96% aa identities with those of other vertebrates, respectively, suggesting their conservative nature. Expression of the turtle galanin gene was detected in the pituitary, brain, hypothalamus, stomach, liver, pancreas, testes, ovaries, and intestines, but not in the adipose or muscle tissues, suggesting tissue-dependent differences. An in vitro study that used pituitary tissue culture indicated that treatment with 17β-estradiol, testosterone, or gonadotropin-releasing hormone resulted in increased galanin mRNA expression with dose- or time-dependent differences, whereas leptin and neuropeptide Y reduced galanin mRNA levels. These results suggest a hormone-dependent effect on hypophyseal galanin mRNA expression.

scholarly journals Glucose stimulates and insulin inhibits release of pancreatic TRH in vitro

2000 ◽  
pp. 60-65 ◽  
Author(s):  
J Benicky ◽  
V Strbak
Keyword(s):  
B Cells ◽  
Pancreatic Islets ◽  
High Glucose ◽  
Adenosine Monophosphate ◽  
Isolated Pancreatic Islets ◽  
Glucose Addition ◽  
Adult Rat ◽  
Camp Stimulation ◽  
Stimulation Of

OBJECTIVE: Pancreatic TRH is present in insulin-producing B-cells of the islets of Langerhans. There is fragmentary evidence that it may be involved in glucoregulation. The aim of our present study was to analyze how glucose and insulin affect TRH secretion by the pancreatic islets. DESIGN: Isolated pancreatic islets were incubated with different concentrations of glucose, insulin and glucagon, and TRH release was measured. RESULTS: In the present study, 6 and 12mmol/l d-glucose caused significant TRH release from isolated adult rat pancreatic islets when compared with that in the presence of the same concentrations of biologically ineffective l-glucose. Thirtymmol/l d-glucose was also ineffective, but this was not due to depression of secretion by hyperosmolarity since isosmotic compensation for the high glucose addition did not restore its stimulatory effect. Five micromol/l dibutyryl cyclic 3',5'-adenosine monophosphate (db-cAMP) increased both basal and glucose-stimulated TRH release, but this effect was not seen with 50micromol/l db-cAMP. Stimulation of phosphodiesterase by imidazole resulted in decreased basal but not glucose-stimulated release of TRH. Glucagon (10(-7)mol/l) did not affect either basal or glucose-stimulated release of TRH, while insulin (10(-7) and 10(-6)mol/l) inhibited both. CONCLUSION: Our present data showing that glucose stimulates and insulin inhibits pancreatic TRH release are compatible with the possibility that this substance may play a role in glucoregulation.

scholarly journals Pancreatic islets of bank vole show signs of dysfunction after prolonged exposure to high glucose concentrations in vitro

2010 ◽  
Vol 206 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Martin Blixt ◽  
Bo Niklasson ◽  
Stellan Sandler
Keyword(s):  
Gender Difference ◽  
Pancreatic Islets ◽  
High Glucose ◽  
Prolonged Exposure ◽  
Cell Function ◽  
Insulin Biosynthesis ◽  
Bank Voles ◽  
Glucose Tolerant ◽  
Β Cell Function

Bank voles develop glucose intolerance/diabetes mellitus when kept in captivity. We have characterized β-cell function of glucose intolerant/diabetic animals, and found that this animal model has features of both human type 1 and type 2 diabetes. The aim of this study was to study the functional alterations of islets isolated from glucose tolerant bank voles after a prolonged exposure to various glucose concentrations in vitro. For this purpose, pancreatic islets from normal (glucose tolerant) male and female bank voles were cultured at different glucose concentrations (5.6, 11.1 (control), or 28 mM) whereupon islet functions were examined. Overall, islet insulin output was lowered at 5.6 mM glucose, and similar to control, or enhanced after culture in 28 mM glucose. High glucose culture led to decreased insulin contents, but there was no change in islet DNA content and in morphological assessments of cell death, with the latter findings suggesting that the so-called glucotoxicity had not evolved. A slight gender difference was observed in that islets isolated from females exhibited a glucose-regulated (pro)insulin biosynthesis rate and insulin gene expression. In conclusion, we have found that islets isolated from female and male bank voles are affected by glucose concentrations in vitro in that some signs of dysfunction were observed upon high glucose exposure. A minor gender difference was observed suggesting that the islets of the females may more readily adapt to the elevated glucose concentration than islets of the male bank voles. It could be that these in vitro gender differences observed may represent a mechanism underlying the gender difference in diabetes development observed among bank voles.

scholarly journals MicroRNA-27a targets Sfrp1 to induce renal fibrosis in diabetic nephropathy by activating Wnt/β-Catenin signalling

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
MingJun Shi ◽  
PingPing Tian ◽  
ZhongQiang Liu ◽  
Fan Zhang ◽  
YingYing Zhang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Renal Fibrosis ◽  
Negative Control ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Expression Levels ◽  
Stage Renal Disease

Abstract Diabetic nephropathy (DN) commonly causes end-stage renal disease (ESRD). Increasing evidence indicates that abnormal miRNA expression is tightly associated with chronic kidney disease (CKD). This work aimed to investigate whether miR-27a can promote the occurrence of renal fibrosis in DN by suppressing the expression of secreted frizzled-related protein 1 (Sfrp1) to activate Wnt/β-catenin signalling. Therefore, we assessed the expression levels of miR-27a, Sfrp1, Wnt signalling components, and extracellular matrix (ECM)-related molecules in vitro and in vivo. Sfrp1 was significantly down-regulated in a high-glucose environment, while miR-27a levels were markedly increased. A luciferase reporter assay confirmed that miR-27a down-regulated Sfrp1 by binding to the 3′ untranslated region directly. Further, NRK-52E cells under high-glucose conditions underwent transfection with miR-27a mimic or the corresponding negative control, miR-27a inhibitor or the corresponding negative control, si-Sfrp1, or combined miR-27a inhibitor and si-Sfrp1. Immunoblotting and immunofluorescence were performed to assess the relative expression levels of Wnt/β-catenin signalling and ECM components. The mRNA levels of Sfrp1, miR-27a, and ECM-related molecules were also detected by quantitative real-time PCR (qPCR). We found that miR-27a inhibitor inactivated Wnt/β-catenin signalling and reduced ECM deposition. Conversely, Wnt/β-catenin signalling was activated, while ECM deposition was increased after transfection with si-Sfrp1. Interestingly, miR-27a inhibitor attenuated the effects of si-Sfrp1. We concluded that miR-27a down-regulated Sfrp1 and activated Wnt/β-catenin signalling to promote renal fibrosis.

Sustained exposure of toxically damaged mouse pancreatic islets to high glucose does not increase β-cell dysfunction

1989 ◽  
Vol 123 (1) ◽  
pp. 47-51 ◽  
Author(s):  
D. L. Eizirik ◽  
S. Sandler
Keyword(s):  
Pancreatic Islets ◽  
Insulin Release ◽  
High Glucose ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Stimulation ◽  
Cell Dysfunction ◽  
Mouse Pancreatic Islets ◽  
Insulin Secretory Response

ABSTRACT The aim of this study was to clarify whether prolonged in-vitro exposure of either normal or damaged β cells to a high glucose environment can be toxic to these cells. For this purpose NMRI mice were injected intravenously with a diabetogenic dose of streptozotocin (SZ; 160 mg/kg) or vehicle alone (controls). Their islets were isolated 15 min after the injection and subsequently maintained in culture for 21 days in the presence of 11·1 or 28 mmol glucose/l. After this period, during acute glucose stimulation, the control islets showed a marked increase in their insulin release in response to a high glucose stimulus. In the SZ-exposed islets there was a decrease in DNA and insulin contents, and a deficient insulin secretory response to glucose. However, in the SZ-damaged islets as well as in the control islets, culture with 28 mmol glucose/l compared with 11·1 mmol glucose/l did not impair islet retrieval after culture, islet DNA content or glucose-induced insulin release. Thus, the degree of damage was similar in the SZ-treated islets cultured at the two concentrations of glucose. These results suggest that glucose is not toxic to normal or damaged mouse pancreatic islets over a prolonged period in tissue culture. Journal of Endocrinology (1989) 123, 47–51

scholarly journals Tenidap sodium inhibits secretory non-pancreatic phospholipase A2synthesis by foetal rat calvarial osteoblasts

1995 ◽  
Vol 4 (1) ◽  
pp. 67-70 ◽  
Author(s):  
W. Pruzanski ◽  
B. P. Kennedy ◽  
H. van den Bosch ◽  
E. Stefanski ◽  
M. Wloch ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Northern Blot Analysis ◽  
Phospholipase A ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Dual Inhibitor ◽  
Pancreatic Phospholipase ◽  
Foetal Rat ◽  
Dose Dependent

Tenidap (TD) was initially defined as a dual inhibitor of cyclooxygenase and lipoxygenase. This study was designed to assess its inhibitory activity against proinflammatory phospholipase A2. This study shows that TD inhibits the synthesis of pro-inflammatory secretory non-pancreatic phospholipase A2(sPLA2). Concentrations as low as 0.25 μg/ml (0.725 μM) reduced the release of sPLA2by 40% from foetal rat calvarial osteoblasts stimulated with IL-1β and TNFα, whereas a concentration of 2.5 μg/ml (7.25 μM) reduced the release by over 80%. TD also markedly reduced the release of sPLA2from unstimulated cells. There was no direct inhibition of sPLA2enzymatic activity by TDin vitro. Northern blot analysis showed that TD did not affect the sPLA2mRNA levels; however, immunoblotting showed a dose-dependent reduction in sPLA2enzyme. These results, together with a marked reduction in sPLA2enzymatic activity, suggest that TD inhibits sPLA2synthesis at the post-transcriptional level. Therefore TD seems to inhibit the arachidonic acid cascade proximally to cyclooxygenase and lipoxygenase and its anti-inflammatory activity may be related at least in part to the inhibition of sPLA2synthesis.

Expression and Regulation of Glycosyltransferases for N-Glycosyl Oligosaccharides in Fresh Human Surgical and Murine Tissues and Cultured Cell Lines

1995 ◽  
Vol 89 (4) ◽  
pp. 397-404 ◽  
Author(s):  
M. Li ◽  
V. Andersen ◽  
P. Lance
Keyword(s):  
Cell Lines ◽  
Serum Proteins ◽  
Human Colon ◽  
Rat Tissues ◽  
Mrna Levels ◽  
Human Tissues ◽  
Bacterial Fermentation ◽  
Fold Induction ◽  
Size Heterogeneity

1. Mammalian membrane and serum proteins are glycosylated by the addition of heterogeneous N-linked oligosaccharides. It has been widely speculated that oligosaccharide diversity is achieved by corresponding heterogeneity of expression of the glycosyltransferases that are responsible for oligosaccharide synthesis. 2. We surveyed mRNA levels of three sequentially acting glycosyltransferases, N-acetylglucosaminyltransferase I, β1,4-galactosyltransferase and α2,6-sialyltransferase, in 11 human tissues and confirmed the expected variations. 3. The size heterogeneity of α2,6-sialyltransferase transcripts reported in rat tissues was evident neither in the human tissue survey nor in a panel of murine RNAs. Tissue distributions of alternative terminal sialyltransferases, α2,6-sialyltransferase and α2,3-sialyltransferase, were distinct. 4. Relative glycosyltransferase mRNA levels in four transformed human cell lines cultured in vitro did not fully reflect levels in the corresponding human tissues. 5. Expression of α2,6-sialyltransferase mRNA was approximately 2.6-fold greater in adenocarcinomatous than in normal human colon, and β1,4-galactosyltransferase expression was approximately 1.8-fold greater in normal than in adenocarcinomatous colon. 6. n-Butyrate (0.003–0.005 mol/l), a short-chain fatty acid that is produced by colonic bacterial fermentation, caused approximately 80% inhibition of α2,6-sialyltransferase, approximately 2.5-fold induction of β1,4-galactosyltransferase and approximately 6-fold induction of N-acetylglucosaminyltransferase mRNAs in T84 (colonic) cells. The effects on α2,6-sialyltransferase and β1,4-galactosyltransferase were near maximal by 6 h, but induction of N-acetylglucosaminyltransferase was fully apparent only after exposure for 24 h.

scholarly journals Influence of high glucose in the expression of miRNAs and IGF1R signaling pathway in human myometrial explants

2021 ◽  
Author(s):  
Rodolfo R. Favaro ◽  
Diana M. Morales-Prieto ◽  
Jörg Herrmann ◽  
Jürgen Sonnemann ◽  
Ekkehard Schleussner ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Signaling Pathway ◽  
High Glucose ◽  
Human Myometrium ◽  
Mrna Levels ◽  
Group Data ◽  
Short Term Exposure ◽  
Low Glucose ◽  
Biochemical Analyses ◽  
Igf1r Signaling

Abstract Purpose Several roles are attributed to the myometrium including sperm and embryo transport, menstrual discharge, control of uterine blood flow, and labor. Although being a target of diabetes complications, the influence of high glucose on this compartment has been poorly investigated. Both miRNAs and IGF1R are associated with diabetic complications in different tissues. Herein, we examined the effects of high glucose on the expression of miRNAs and IGF1R signaling pathway in the human myometrium. Methods Human myometrial explants were cultivated for 48 h under either high or low glucose conditions. Thereafter, the conditioned medium was collected for biochemical analyses and the myometrial samples were processed for histological examination as well as miRNA and mRNA expression profiling by qPCR. Results Myometrial structure and morphology were well preserved after 48 h of cultivation in both high and low glucose conditions. Levels of lactate, creatinine, LDH and estrogen in the supernatant were similar between groups. An explorative screening by qPCR arrays revealed that 6 out of 754 investigated miRNAs were differentially expressed in the high glucose group. Data validation by single qPCR assays confirmed diminished expression of miR-215-5p and miR-296-5p, and also revealed reduced miR-497-3p levels. Accordingly, mRNA levels of IGF1R and its downstream mediators FOXO3 and PDCD4, which are potentially targeted by miR-497-3p, were elevated under high glucose conditions. In contrast, mRNA expression of IGF1, PTEN, and GLUT1 was unchanged. Conclusions The human myometrium responds to short-term exposure (48 h) to high glucose concentrations by regulating the expression of miRNAs, IGF1R and its downstream targets.

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