A Far-Upstream Oct-1 Motif Regulates Cytokine-Induced Transcription of the Human Inducible Nitric Oxide Synthase Gene

Park, Kyong Soo; Guo, Zhong; Shao, Lei; Du, Qiang; Geller, David A.

doi:10.1016/j.jmb.2009.05.036

Cited by 12 publications

(13 citation statements)

References 53 publications

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“…It has been classified as a proximal activator that usually functions from a position close to the TATA box, typically activating transcription in response to a remote enhancer [27]. However, active Oct sites in upstream enhancers have also been described, such as the one recently identified [12] in the far upstream hiNOS promoter (10 kb).…”

Section: Discussionmentioning

confidence: 99%

“…Table 1. Total mRNA was extracted and RT-PCR performed with primers to the proximal region of the hiNOS gene (5 0 ) corresponding to exon 1 and distal region (3 0 ) corresponding to exons [11][12][13][14][15][16][17] Oct-1 cooperates with the TATA binding initiation complex 2617…”

Section: Discussionmentioning

confidence: 99%

“…These were used to perform RT-PCR on nuclear RNA of control and CMtreated cells. Figure 6a shows amplification of probe 1 (corresponding to exon 1) in resting cells, whereas no signal is detected from probes 2 (exons 2-5) and 3 (exons [11][12][13][14]. Upon CM stimulation, all fragments are amplified within 1 h, indicating active elongation and processivity.…”

Section: Oct-1 Binding To P-oct Primes Hinos For Transcriptionmentioning

confidence: 99%

“…Oct-1 was shown to contribute to a DNA-protein complex with the p50 subunit of NFjB to modulate iNOS transcription [11]. However, the only report of Oct participation in the regulation of human iNOS describes an Oct site in the far upstream promoter (10 kb) that is bound by Oct-1 and plays a role in modulating transcriptional activation by NFjB [12].…”

Section: Introductionmentioning

confidence: 99%

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Oct-1 cooperates with the TATA binding initiation complex to control rapid transcription of human iNOS

Reveneau

Petrakis

Goldring

et al. 2012

Cell. Mol. Life Sci.

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Expression of the human inducible nitric oxide synthase (hiNOS) is generally undetectable in resting cells, but stimulation by a variety of signals including cytokines induces transcription in most cell types. The tight transcriptional regulation of the enzyme is a complex mechanism many aspects of which remain unknown. Here, we describe an octamer (Oct) element in hiNOS proximal promoter, located close to the TATA box. This site constitutively binds Oct-1 and its deletion abrogates cytokine-induced transcription, showing that it is indispensable though not sufficient for transcription. Increasing the distance between Oct and the TATA box by inserting inert DNA sequence inhibits transcription, and footprinting of this region shows no other protein binding in resting cells, suggesting an interaction between the two complexes. Chromatin immunoprecipitation assays detect the presence of Oct-1, RNA polymerase II and trimethyl K4 histone H3 on the proximal promoter in resting cells, confirming that the gene is primed for transcription before stimulation. RT-PCR of various fragments along the hiNOS gene shows that transcription is initiated in resting cells and this is inhibited by interference with Oct-1 binding to the proximal site of the promoter. We propose that, through interaction with the initiation complex, Oct-1 regulates hiNOS transcription by priming the gene for the rapid response required in an immune response.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Oct-1 Binding To P-oct Primes Hinos For Transcriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oct-1 cooperates with the TATA binding initiation complex to control rapid transcription of human iNOS

Reveneau

Petrakis

Goldring

et al. 2012

Cell. Mol. Life Sci.

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“…Lipopolysaccharide (LPS), deprived from Gram-negative bacteria, is one of the major causes of septic shock and it can result in the apoptosis of human alveolar epithelial A549 cells [10]. It has been demonstrated that NO is produced at high levels by iNOS during septic and inflammatory conditions [11] and can modulate cell death through S-nitrosylation [1].…”

Section: Introductionmentioning

confidence: 99%

Effects of Ghrelin on iNOS-Derived NO Promoted LPS-Induced Pulmonary Alveolar Epithelial A549 Cells Apoptosis

Zeng

Huang

Zheng

et al. 2018

Cell Physiol Biochem

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Background/Aims: In the process of abnormal apoptosis of pulmonary alveolar type II epithelial A549 cells in acute respiratory distress syndrome (ARDS), inducible nitric oxide synthase (iNOS) activity in the lung, nitric oxide (NO) production, and the level of protein S-nitrosylation were increased. However, the role of excessive NO production in sepsis-induced ARDS is controversial. Additionally, ghrelin is a growth hormone that exerts an inhibitory role in cell apoptosis. We examined the effect of NO and S-nitrosylation on apoptosis of A549 cells induced by Lipopolysaccharide (LPS) and molecular mechanism underlying the anti-apoptotic effect of ghrelin in this process. Methods: Flow cytometry and qPCR were used to detect lentiviral infection efficiency and iNOS gene level, respectively. Extracellular and intracellular NO levels were observed by Griess assay kit and DAF-FM DA. Mitochondrial transmembrane potential, apoptosis rate and SNO levels were determined by flow cytometry, Biotin-Switch method and immunofluoresence staining. The expression of iNOS, apoptotic proteins and JNK were assessed by immunoblot analysis. Results: The results showed about two times increase in iNOS expression and intracellular NO levels response to LPS exposure at 24 hours (P< 0.05), while not in extracellular NO levels. NO donors, S-nitroso-N-acetylpenicillamine (SNAP) significantly raised (36.7%, P< 0.05; 38.4%, P< 0.05; 41.8%, P< 0.05) extracellular NO levels without influencing the intracellular NO levels. LPS increased the apoptosis rate (42.4%±2.6% vs 2.8%±1%, P< 0.05) of A549 accompanied by increased Bax levels and decreased Bcl-2 levels through activating JNK signaling, which was reversed when we diminished the iNOS expression in A549 cells using lentiviral vectors encoding iNOS shRNA in the presence of LPS (24.8%±3.8% vs 42.4%±2.6%, P< 0.05). However, the apoptosis rate was increased when SNAP was added (38.8%±1.3% vs 24.8%±3.8%, P< 0.05). Furthermore, we investigated whether ghrelin exert a protective role against LPS-induced apoptosis and the potential mechanism involved in. Ghrelin alone appeared to decrease iNOS expression (32.3%, P< 0.05; 42.3%, P< 0.05), which showed no signifiant difference between LPS+ghrelin group and LPS group. However, this study showed that ghrelin decreased the intracellular NO production (38.9%, P< 0.05), protein S-nitrosylation levels (33.5%, P< 0.05), Bax protein expression (70.2%, P< 0.05), whereas increasing Bcl-2 protein expression (14.1%, P< 0.05) and mitochondrial transmembrane potential (∆ΨM) (20.7%, P< 0.05) in the presence of LPS. Conclusion: The data suggested that NO derived from iNOS induced by LPS stimulation exerts an important role in promoting apoptosis of A549 cells, and ghrelin abolished intracellular NO production and protein S-nitrosylation levels, abrogating the apoptosis of A549 cells partly through inhibiting mitochondrial-dependent pathways.

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Up‐regulation of inflammatory reactions by MPT32, a secreted protein of Mycobacterium tuberculosis in RAW264.7 macrophages

Kim,

Choi,

Abekura

et al. 2023

J of Cellular Biochemistry

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Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) and is still one of the global health burdens. The occurrence of various cases and multidrug resistance confirm that TB has not been completely conquered. For these reasons, the present research has been conducted to explore TB vaccine and drug candidate possibility using Mtb‐secreted proteins. Among these proteins, MPT32 is known to have antigenicity and immunogenicity. There has not been a report on the host immune responses and regulation in macrophage cells. The present study was conducted with MPT32 in RAW 264.7 murine macrophage cells that control immune responses by sensing pathogen invasion and environmental change. We have found that MPT32 could activate lipopolysaccharide (LPS)‐induced gene expression of metalloproteinase‐9 (MMP‐9) and inflammation in RAW 264.7 cells. After treating cells with MPT32, the increase in pro‐inflammatory cytokines, such as tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐1β (IL‐1β) and IL‐6, was observed. In addition, activated macrophages expressed inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) to generate various inflammatory mediator molecules, such as nitric oxide (NO). The increase in iNOS and COX‐2 levels, which are up‐regulators of MMP‐9 expression, was also confirmed. The biochemical events are involved in the downstream of activated MAPK signaling and translocation of NF‐κB transcription factor. The present results prove the immunomodulatory effect of MPT32 in the RAW 264.7 murine macrophage cells. it claims the possibility of a TB vaccination and drug candidate using MPT32, contributing to the prevention of TB.

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A Far-Upstream Oct-1 Motif Regulates Cytokine-Induced Transcription of the Human Inducible Nitric Oxide Synthase Gene

Cited by 12 publications

References 53 publications

Oct-1 cooperates with the TATA binding initiation complex to control rapid transcription of human iNOS

Oct-1 cooperates with the TATA binding initiation complex to control rapid transcription of human iNOS

Effects of Ghrelin on iNOS-Derived NO Promoted LPS-Induced Pulmonary Alveolar Epithelial A549 Cells Apoptosis

Up‐regulation of inflammatory reactions by MPT32, a secreted protein of Mycobacterium tuberculosis in RAW264.7 macrophages

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