scholarly journals Tissue-specific regulation of dipeptidyl peptidase IV expression during development

1991 ◽  
Vol 277 (2) ◽  
pp. 331-334 ◽  
Author(s):  
M Hildebrandt ◽  
W Reutter ◽  
J D Gitlin

The patterns of dipeptidyl peptidase (DPP) IV activity and protein amount in different rat organs during development were compared. In order to elucidate the molecular basis for these patterns, total RNA was isolated from lung and kidney at different stages of development and analysed by Northern-blot hybridization using an oligonucleotide derived from the DPP IV cDNA sequence. This oligonucleotide hybridized to two distinct mRNAs of approx. 3.2 and 4.8 kb respectively. During kidney development, the pattern for DPP IV mRNA paralleled that of DPP IV activity and protein amount, suggesting that, in kidney, the expression of DPP IV is primarily controlled at the transcriptional level. In contrast, the magnitude of DPP IV activity during lung development compared with that of DPP IV mRNA in lung suggests that post-transcriptional mechanisms are involved in regulating the expression of DPP IV in lung. Organ-specific regulation of DPP IV expression may provide a useful model for further comparative studies of transcriptional and post-transcriptional mechanisms of DPP IV expression within the same organism.

2001 ◽  
Vol 69 (4) ◽  
pp. 2493-2501 ◽  
Author(s):  
Jean-San Chia ◽  
Ya-Yu Lee ◽  
Peng-Tu Huang ◽  
Jen-Yang Chen

ABSTRACT Streptococcus mutans, which causes dental caries in the human oral cavity and occasionally causes infective endocarditis in the heart, withstands adverse environmental stress through diverse alterations in protein synthesis. Differential gene expression in response to environmental stress was analyzed by RNA fingerprinting using arbitrarily primed PCR with a panel of 11mer primers designed for differential display in Enterobacteriaceae. Dot and Northern blot hybridization confirmed that the transcription of several genes was up- or down-regulated following exposure to acid shock from pH 7.5 to 5.5. RNA of a gene designated AP-185 (acid-stress protein) was induced specifically by acid treatment, while RNA of GSP-781 (general-stress protein) was up-regulated significantly when bacteria were exposed to high osmolarity and temperature, as well as low pH. The deduced amino acid sequence of AP-185 shares homology (78% identity) with branched-chain amino acid aminotransferase. Cloning and sequence analysis of GSP-781 revealed a potential secreted protein of a molecular mass of about 43 kDa and with a pI predicted to be 5.5. Transcriptional levels of another gene, designated AR-186 (acid-repressed protein), which encodes putative aconitase, were repressed by acid treatment but were enhanced by plasma or serum components. Analogous results were identified in icd andcitZ genes, and repression of these genes, along with AR-186, was also observed when they were exposed to high osmolarity and temperature. These results indicate that differential regulation of specific genes at the transcriptional level is triggered by different stress and that genes responsible for glutamate biosynthesis in the citrate pathway are coordinately regulated during the stress response of S. mutans.


1994 ◽  
Vol 140 (1) ◽  
pp. 63-72 ◽  
Author(s):  
H Ungefroren ◽  
M Davidoff ◽  
R Ivell

Abstract Northern blot hybridization showed that bovine and sheep testis, unlike testes from other mammals, contain moderate levels of an apparently normal oxytocin gene transcript. In situ hybridization localized this mRNA to within the seminiferous tubules, possibly in the Sertoli cells. Conflicting with this result, immunohistochemistry showed that both oxytocin and the syngeneic neurophysin I epitopes are both clearly restricted to the Leydig cells, being expressed here at a low level. Since illegitimate transcription from spurious start sites can lead to a lack of translation product, the integrity of the major ruminant testicular transcripts of the oxytocin gene was checked using differential hybridization, RNase protection and multiple polymerase chain reaction assays. All tests showed the transcripts to have a normal, translatable composition and to be transcribed from the conventional 5' initiation site. Therefore, the block in oxytocin gene expression within the tubules is probably due to a lesion at the post-transcriptional level. The low level peptide expression in the Leydig cells can probably be attributed to the presence of functional transcripts in these cells, which are below the level of significant detection for the in situ hybridization assay. Journal of Endocrinology (1994) 140, 63–72


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1078C-1078
Author(s):  
Hany M. El-Naggar ◽  
Paul E. Read ◽  
Ayed Al-Abdallat

Phenylalanine ammonia-lyase (PAL) enzyme is the most extensively studied enzyme in the phenylpropanoid pathway. Studies on the biosynthesis of rosmarinic acid (RA) showed that the PAL enzyme catalyzes the initial step of the phenylpropanoid pathway. The increase in RA content in plant tissues in vitro coincided with the increase in PAL activity. The aim of this study was to investigate the activity of the gene responsible for the production of the PAL enzyme in the five rosemary genotypes; this will give more understanding about the accumulation of rosmarinic acid in the five rosemary genotypes. The genotypes were Majorca, Rosmarinus officinalis, Pine Scented, Madeline Hill and APR. Northern blot hybridization between the PAL gene primer and the five genotypes' cDNA showed bands at 300 bp in all the five genotypes for the PAL gene. The expression of the PAL gene was high in genotypes Majorca, Rosmarinus officinalis, and Madeline Hill, while the expression was low in genotypes Pine Scented and APR. It was expected that the genotypes having the highest PAL gene expression will produce the highest amount of RA, but the highest genotype in PAL gene expression Madeline Hill had the lowest RA production in their leaves. This could occur due to the tissue specific regulation inside plant tissues. Inside the callus tissues, where the specific tissue regulation no longer exists, the RA was produced in repetitively large amounts in genotypes with high PAL gene expression.


2005 ◽  
Vol 53 (S 01) ◽  
Author(s):  
C Skrabal ◽  
L Thompson ◽  
E Potapov ◽  
R Southard ◽  
D Joyce ◽  
...  

1999 ◽  
Vol 45 (12) ◽  
pp. 1008-1016 ◽  
Author(s):  
Jane A Colmer ◽  
Abdul N Hamood

The expression of the toxA and regA genes in Pseudomonas aeruginosa is negatively regulated by iron at the transcriptional level. We have previously described ptxR, an exotoxin A regulatory gene which appears to enhance toxA expression through regA. In this study, we have tried to determine if ptxR expression correlates with its effect on toxA and regA expression throughout the growth cycle of P. aeruginosa strain PAO1. This was done using Northern blot hybridization experiments (with toxA, regA, and ptxR probes), and ptxR transcriptional fusion studies. To avoid problems related to the presence of multiple copies of ptxR in PAO1, we have constructed a PAO1 strain (PAO1-XR) that carries only two ptxR genes in its chromosome. Our results showed that when PAO1-XR was grown in iron-limited conditions, the increase in exotoxin A activity and the accumulation of toxA mRNA appeared at about mid- to late-exponential phase. A similar increase in the accumulation of regA mRNA was detected. Both regA transcripts, T1 and T2, were enhanced in PAO1-XR. In iron-sufficient medium, neither toxA nor regA mRNA was detected at any time point in the growth cycle of PAO1-XR. In contrast, the accumulation of ptxR mRNA was detected throughout the growth cycle of PAO1-XR under both iron-deficient and iron-sufficient conditions. The presence of iron in the growth medium also had no effect on the level of β-galactosidase activity produced by a ptxR-lacZ fusion in PAO1. These results suggest that (i) the enhancement in toxA expression by ptxR correlates with the enhancement in regA expression; (ii) ptxR affects the expression of the regA P1 and P2 promoters; (iii) ptxR expression precedes its effect on toxA and regA expression; and (iv) unlike toxA and regA, the overall expression of ptxR throughout the growth cycle of PAO1 is not negatively regulated by iron.Key words: ptxR, differential expression, transcriptional regulation, regA, toxA.


2005 ◽  
Vol 123 (1) ◽  
pp. 118-125 ◽  
Author(s):  
Christian A. Skrabal ◽  
Larry O. Thompson ◽  
Evgenji V. Potapov ◽  
Robert E. Southard ◽  
David L. Joyce ◽  
...  

2020 ◽  
Vol 16 ◽  
Author(s):  
Lucas Ribeiro dos Santos ◽  
Marcio Luis Duarte ◽  
Maria Stella Peccin ◽  
Antônio Ricardo de Toledo Gagliardi ◽  
Tamara Melnik

Introduction:: Hepatic steatosis is a frequent condition, that afflicts, especially, obese and insulin resistant patients; diagnosis is made, usually, through imaging tests. Despite the high prevalence and risk of complications, there is no specific treatment approved, though a vast number of medications have been tested. Objective:: To determine the efficacy of dipeptidyl peptidase IV inhibitors (i DPP-IV) in the treatment of NAFLD. Methods:: We searched the electronic databases of the Cochrane Library, MEDLINE, EMBASE and LILACS, as well as reference lists of the included studies and grey literature; 9 studies were selected for inclusion. Results:: 7 studies were used for metanalysis, for 3 outcomes. i DPP-IV showed an ALT-reducing power of MD -10.83 [95% CI 35.23 to 13.57] at 3 months and MD -9.27 [95% CI 10.92 to -7.62] at 6 months of intervention, as well as reduction of hepatic steatosis via MRI of SMD 0.10 [95% CI 0.31 to 0.50]; the overall incidence of adverse events was very low. The studies were considered of low and very low quality by the GRADE evaluation. Conclusion:: Because of the poor overall quality of the studies and heterogeneity of the population analyzed, i DPP-IV did not show efficacy on inflammatory markers or fibrosis in patients with NAFLD.


2017 ◽  
Vol 8 (6) ◽  
pp. 2249-2257 ◽  
Author(s):  
A. B. Nongonierma ◽  
M. Hennemann ◽  
S. Paolella ◽  
R. J. FitzGerald

Wheat gluten hydrolysates contain known/potential DPP-IV inhibitory peptides.


1983 ◽  
Vol 3 (8) ◽  
pp. 1501-1510 ◽  
Author(s):  
L H Bowman ◽  
W E Goldman ◽  
G I Goldberg ◽  
M B Hebert ◽  
D Schlessinger

The locations of three cleavages that can occur in mouse 45S pre-rRNA were determined by Northern blot hybridization and S1 nuclease mapping techniques. These experiments indicate that an initial cleavage of 45S pre-rRNA can directly generate the mature 5' terminus of 18S rRNA. Initial cleavage of 45S pre-rRNA can also generate the mature 5' terminus of 5.8S rRNA, but in this case cleavage can occur at two different locations, one at the known 5' terminus of 5.8S rRNA and another 6 or 7 nucleotides upstream. This pattern of cleavage results in the formation of cytoplasmic 5.8S rRNA with heterogeneous 5' termini. Further, our results indicate that one pathway for the formation of the mature 5' terminus of 28S rRNA involves initial cleavages within spacer sequences followed by cleavages which generate the mature 5' terminus of 28S rRNA. Comparison of these different patterns of cleavage for mouse pre-rRNA with that for Escherichia coli pre-rRNA implies that there are fundamental differences in the two processing mechanisms. Further, several possible cleavage signals have been identified by comparing the cleavage sites with the primary and secondary structure of mouse rRNA (see W. E. Goldman, G. Goldberg, L. H. Bowman, D. Steinmetz, and D. Schlessinger, Mol. Cell. Biol. 3:1488-1500, 1983).


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