Regulation of Monoamine Oxidase B Gene Expression: Key Roles for Transcription Factors Sp1, Egr1 and CREB, and microRNAs miR-300 and miR-1224

Zhu

et al. 2021

Basic Clin. Androl.

Background Occludin protein is the primary assembling protein of TJs and the structural basis for tight junction formation between Sertoli cells in the spermatogenic epithelium. The expression of miR-122-5p and occludin are negatively correlated. In order to investigate the regulation mechanism of miR-122-5p on occludin and TJ, the present study isolated primary Sertoli cells from C57BL/6 mice, identified a transcription factor of miR-122-5p in testicle, studied the modulating loci of miR-122-5p on occludin using a dual-luciferase reporter assay, analyzed the regulate of miR-122-5p on the expression of occludin with real-time RT-PCR and Western blot, and studied the effect of miR-122-5p on the tight junction using a Millicell Electrical Resistance System. Results The relative luciferase activity in the pcDNA-Sp1 + pGL3-miR-122-5p promoter group was significantly higher than that in the pcDNA-Sp1 + pGL3-basic group, which suggests that transcript factor Sp1 promotes the transcription of miR-122-5p. The relative luciferase activity in the occludin 3′-UTR (wt) + miR-122-5p mimic group was significantly lower than that in the other groups (p < 0.01), which indicates that miR-122-5p modulates the expression of occludin via the ACACTCCA sequence of the occludin-3’UTR. The levels of occludin mRNA and protein in the miR-122-5p mimic group were significantly lower than that in the other groups (p < 0.05), which indicates that miR-122-5p reduces the expression of occludin. The trans-epithelial resistance of the miR-122-5p mimic group was significantly lower than that of the blank control group after day 4 (p < 0.05), which indicates that miR-122-5p inhibited the assembly of the inter-Sertoli TJ permeability barrier in vitro. Conclusion These results displayed that miR-122-5p could regulate tight junctions via the Sp1-miR-122-5p-occludin-TJ axis.

Section: Discussionmentioning

confidence: 99%

miR-122-5p regulates the tight junction of the blood-testis barrier of mice via occludin

Zhu

et al. 2021

Basic Clin. Androl.

“…It is expressed mainly in liver and other tissues in a minor extent [55]. In regulation of its transcription, the complex Sp1/Egr1/CREB, as well as microRNAs miR-1224 and miR-300, seem to be involved [56]. In other tissues, such as the gastrointestinal tract, histamine is oxidized by DAO, a cytosolic membrane-associated protein that produces imidazole acetaldehyde and oxygen peroxide [49].…”

Section: Histamine Metabolism and Its Connections To Other Metabolic Modulesmentioning

confidence: 99%

Histamine, Metabolic Remodelling and Angiogenesis: A Systems Level Approach

et al. 2021

Histamine is a highly pleiotropic biogenic amine involved in key physiological processes including neurotransmission, immune response, nutrition, and cell growth and differentiation. Its effects, sometimes contradictory, are mediated by at least four different G-protein coupled receptors, which expression and signalling pathways are tissue-specific. Histamine metabolism conforms a very complex network that connect many metabolic processes important for homeostasis, including nitrogen and energy metabolism. This review brings together and analyses the current information on the relationships of the “histamine system” with other important metabolic modules in human physiology, aiming to bridge current information gaps. In this regard, the molecular characterization of the role of histamine in the modulation of angiogenesis-mediated processes, such as cancer, makes a promising research field for future biomedical advances.

“…Authenticated Normal Rat Kidney epithelial cells (NRK 52e) were obtained from the Indian national cell-line and hybridoma repository at the National Center for Cell Sciences, Pune, India. Dulbecco's modified Eagle's medium with high glucose and glutamine (HyClone, USA) supplemented with 10% fetal bovine serum, streptomycin (100 mg/mL) and penicillin G (100 U/ml) (Invitrogen, USA) was used for culturing cells in 25-cm 2 tissue culture flasks, 60 mm or 100 mm dishes as described previously 29 . The cells were periodically tested for mycoplasma contamination through a PCR-based method.…”

Section: Cell Culture and Transfectionmentioning

confidence: 99%

“…The incubation under hypoxia was for two hours, ensuing which they were lysed for downstream assays. Luciferase assays were carried out using a luciferase assay buffer (100 mM Tris-acetate, pH 7.8, 10 mM magnesium acetate, 1 mM EDTA, pH 8.0, 3 mM ATP and 100 µM beetle luciferin potassium salt) as described previously 29 . The values obtained as relative luciferase units per second (RLU/s) were normalized with β-galactosidase activity and total protein estimated by Bradford assay.…”

Section: Acute Hypoxic Exposure and Luciferase Assaymentioning

confidence: 99%

“…Subsequently, cDNA was synthesised using cDNA synthesis kit (Takara, USA) according to manufacturer's instructions. 20-40 ng of cDNA was used in each qPCR reaction and the fold change of expression with respect to the control (WKY normotensive rats or cells grown under normoxic condition) was calculated using the ΔΔCt method as described previously 29 .…”

Section: Rna Isolation and Quantitative Real-time Pcr In Nrk52e Cellsmentioning

confidence: 99%

See 1 more Smart Citation

Hypoxia-mediated regulation of mitochondrial transcription factors: Implications for hypertensive renal physiology

Natarajan

Arige

et al. 2019

Preprint

Self Cite

Abbreviations mtTFs, mitochondrial transcription factors; OXPHOS, oxidative phosphorylation; ATP, adenosine triphosphate; ETC, electron transport chain, TiH, tubulointerstitial hypoxia; PGC-1αperoxisome proliferator activated receptor gamma coactivator 1-alpha; SHR, spontaneously hypertensive rats; WKY, Wistar Kyoto rat; HIF-1α, Hypoxia Inducible factor 1α; HREs, hypoxia response elements; mtDNA, mitochondrial DNA; ChIP, chromatin immunoprecipitation; bp, base pair. AbstractIntroduction: Kidneys are organs with high resting metabolic rate and low tissue pO 2 due to enhanced mitochondrial oxygen consumption and ATP production for active solute transport.Such enhanced mitochondrial activity leads to progressive hypoxia from the renal cortex to medulla. Renal tubulointerstitial hypoxia (TiH) is severe in hypertensive rats due to increased sodium reabsorption within their nephrons. However, expression of mitochondrial transcription factors (mtTFs) (viz. Tfam, Tfb1m and Tfb2m) and mitochondrial biogenesis is not reported during hypoxic conditions. Materials and Methods:Transcriptional regulation of Tfam, Tfb1m and Tfb2m under acute hypoxia was studied using promoter-driven luciferase assays, qPCR, western blotting and Chromatin Immunoprecipitation. Results:The expression of HIF-1α, PGC-1α, Tfam, Tfb1m, Tfb2m and OXPHOS proteins were higher in hypertensive rats as compared to the normotensive ones. Additionally, studies on NRK52e cells show that acute hypoxia increases the expression of these genes. We also observed a positive correlation between HIF-1α and mtTFs in human tissues. Furthermore, we report for the first time, that HIF-1α binds to promoters of Tfam, Tfb1m and Tfb2m genes and augments their promoter activity.Conclusion: Hypertensive rats, with increased TiH show enhanced expression of mitochondrial proteins. HIF-1α directly binds to and increases promoter activity of mtTFs.Acute hypoxia induces the expression of mtTFs and probably promotes mitochondrial biogenesis in NRK52e cells.