scholarly journals Oxygen-dependent expression of hypoxia-inducible factor-1α in renal medullary cells of rats

2001 ◽  
Vol 6 (3) ◽  
pp. 159-168 ◽  
Author(s):  
AI-PING ZOU ◽  
ZHI-ZHANG YANG ◽  
PIN-LAN LI ◽  
ALLEN W. COWLEY
Keyword(s):  
Transcription Factor ◽  
Renal Cortex ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Hypoxia Inducible Factor ◽  
Renal Medulla ◽  
Hypoxia Inducible Factor 1Α ◽  
Nuclear Extracts ◽  
Medullary Cells

Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that regulates the oxygen-dependent expression of a number of genes. This transcription factor may contribute to the abundant expression of many genes in renal medullary cells that function normally under hypoxic conditions. The present study was designed to determine the characteristics of HIF-1α cDNA cloned from the rat kidney and the expression profile of HIF-1α in different kidney regions and to explore the mechanism activating or regulating HIF-1α expression in renal medullary cells. A 3,718-bp HIF-1α cDNA from the rat kidney was first cloned and sequenced using RT-PCR and TA cloning technique. It was found that 823 amino acids deduced from this renal HIF-1α cDNA had 99%, 96%, and 90% identity with rat, mouse, or human HIF-1α deposited in GenBank, respectively. The 3′-untranslated region of HIF-1α mRNA from the rat kidney contained seven AUUUA instability elements, five of which were found to be conserved among rat, mouse, and human HIF-1α. Northern blot analyses demonstrated a corticomedullary gradient of HIF-1α mRNA expression in the kidney, with the greatest abundance in the renal inner medulla. Western blot analyses also detected a higher HIF-1α protein level in the nuclear extracts from the renal medulla than the renal cortex. A classic loop diuretic, furosemide (10 mg/kg ip), markedly increased renal medullary Po2 levels from 22.5 to 52.2 mmHg, which was accompanied by a significant reduction of HIF-1α transcripts in renal medullary tissue. In in vitro experiments, low Po2, but not elevated osmolarity, was found to significantly increase HIF-1α mRNA in renal medullary interstitial cells and inner medullary collecting duct cells. These results indicate that HIF-1α is more abundantly expressed in the renal medulla compared with the renal cortex. Increased abundance of HIF-1α mRNA in the renal medulla may represent an adaptive response of renal medullary cells to low Po2.

scholarly journals An immunohistochemical study of aspartate, glutamate, and taurine in rat kidney.

1994 ◽  
Vol 42 (5) ◽  
pp. 621-626 ◽  
Author(s):  
N Ma ◽  
E Aoki ◽  
R Semba
Keyword(s):  
Amino Acids ◽  
Renal Cortex ◽  
Rat Kidney ◽  
Renal Medulla ◽  
Loop Of Henle ◽  
Immunoperoxidase Method ◽  
Collecting Tubules ◽  
Convoluted Tubules ◽  
Thin Portion ◽  
Intrarenal Distribution

Biochemical studies have revealed considerable amounts of free amino acids in the kidney. We examined the intrarenal distribution of three amino acids (aspartate, glutamate, and taurine) in the rat kidney with an immunoperoxidase method. In the renal cortex, all three amino acids were concentrated in the renal corpuscles and in the epithelia of the collecting tubules. Immunostaining of the collecting tubules was more intense in the principal cells than in the intercalated cells. The distal convoluted tubules were also immunostained with aspartate- and glutamate- specific antibodies but not with the taurine-specific antibody. In the renal medulla, the immunoreactivity specific for aspartate and for glutamate was similar; it was weak in the thick portion of the loop of Henle and strong in the collecting tubules. Immunoreactivity specific for taurine was restricted to regions within the epithelia of the thin portion of the loop of Henle and the collecting tubules. The significance of the accumulated amino acids as osmoregulatory agents is discussed.

Hypoxic Stress Upregulates the Expression of Slc38a1 in Brown Adipocytes via Hypoxia-Inducible Factor-1α

Pharmacology ◽  
2017 ◽  
Vol 101 (1-2) ◽  
pp. 64-71 ◽  
Author(s):  
Tetsuhiro Horie ◽  
Kazuya Fukasawa ◽  
Takashi Iezaki ◽  
Gyujin Park ◽  
Yuki Onishi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Hypoxia Inducible Factor ◽  
Amino Acid Transporters ◽  
Hypoxic Stress ◽  
Gene Encoding ◽  
Brown Adipocytes ◽  
Hypoxia Inducible Factor 1Α ◽  
Brown Adipose

The availability of amino acid in the brown adipose tissue (BAT) has been shown to be altered under various conditions; however, little is known about the possible expression and pivotal role of amino acid transporters in BAT under physiological and pathological conditions. The present study comprehensively investigated whether amino acid transporters are regulated by obesogenic conditions in BAT in vivo. Moreover, we investigated the mechanism underlying the regulation of the expression of amino acid transporters by various stressors in brown adipocytes in vitro. The expression of solute carrier family 38 member 1 (Slc38a1; gene encoding sodium-coupled neutral amino acid transporter 1) was preferentially upregulated in the BAT of both genetic and acquired obesity mice in vivo. Moreover, the expression of Slc38a1 was induced by hypoxic stress through hypoxia-inducible factor-1α, which is a master transcription factor of the adaptive response to hypoxic stress, in brown adipocytes in vitro. These results indicate that Slc38a1 is an obesity-associated gene in BAT and a hypoxia-responsive gene in brown adipocytes.

scholarly journals Hypoxic Culture Promotes Dopaminergic-Neuronal Differentiation of Nasal Olfactory Mucosa Mesenchymal Stem Cells via Upregulation of Hypoxia-Inducible Factor-1α

2017 ◽  
Vol 26 (8) ◽  
pp. 1452-1461 ◽  
Author(s):  
Yi Zhuo ◽  
Lei Wang ◽  
Lite Ge ◽  
Xuan Li ◽  
Da Duan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Neuronal Differentiation ◽  
Hypoxia Inducible Factor ◽  
Cell Voltage ◽  
Ambient Air ◽  
Olfactory Mucosa ◽  
Hypoxia Inducible Factor 1Α ◽  
Downstream Target

Olfactory mucosa mesenchymal stem cells (OM-MSCs) display significant clonogenic activity and may be easily propagated for Parkinson’s disease therapies. Methods of inducing OM-MSCs to differentiate into dopaminergic (DAergic) neurons using olfactory ensheathing cells (OECs) are thus an attractive topic of research. We designed a hypoxic induction protocol to generate DAergic neurons from OM-MSCs using a physiological oxygen (O2) level of 3% and OEC-conditioned medium (OCM; HI group). The normal induction (NI) group was cultured in O2 at ambient air level (21%). The role of hypoxia-inducible factor-1α (HIF-1α) in the differentiation of OM-MSCs under hypoxia was investigated by treating cells with an HIF-1α inhibitor before induction (HIR group). The proportions of β-tubulin- and tyrosine hydroxylase (TH)-positive cells were significantly increased in the HI group compared with the NI and HIR groups, as shown by immunocytochemistry and Western blotting. Furthermore, the level of dopamine was significantly increased in the HI group. A slow outward potassium current was recorded in differentiated cells after 21 d of induction using whole-cell voltage-clamp tests. A hypoxic environment thus promotes OM-MSCs to differentiate into DAergic neurons by increasing the expression of HIF-1α and by activating downstream target gene TH. This study indicated that OCM under hypoxic conditions could significantly upregulate key transcriptional factors involved in the development of DAergic neurons from OM-MSCs, mediated by HIF-1α. Hypoxia promotes DAergic neuronal differentiation of OM-MSCs, and HIF-1α may play an important role in hypoxia-inducible pathways during DAergic lineage specification and differentiation in vitro.

scholarly journals Hypoxia-inducible factor 1α induces osteo/odontoblast differentiation of human dental pulp stem cells via Wnt/β-catenin transcriptional cofactor BCL9

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Shion Orikasa ◽  
Nobuyuki Kawashima ◽  
Kento Tazawa ◽  
Kentaro Hashimoto ◽  
Keisuke Sunada-Nara ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dental Pulp ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Dental Pulp Stem Cells ◽  
Pulp Tissue ◽  
Odontoblast Differentiation ◽  
Hypoxia Inducible Factor 1Α ◽  
Hypoxic Conditions

AbstractAccelerated dental pulp mineralization is a common complication in avulsed/luxated teeth, although the mechanisms underlying this remain unclear. We hypothesized that hypoxia due to vascular severance may induce osteo/odontoblast differentiation of dental pulp stem cells (DPSCs). This study examined the role of B-cell CLL/lymphoma 9 (BCL9), which is downstream of hypoxia-inducible factor 1α (HIF1α) and a Wnt/β-catenin transcriptional cofactor, in the osteo/odontoblastic differentiation of human DPSCs (hDPSCs) under hypoxic conditions. hDPSCs were isolated from extracted healthy wisdom teeth. Hypoxic conditions and HIF1α overexpression induced significant upregulation of mRNAs for osteo/odontoblast markers (RUNX2, ALP, OC), BCL9, and Wnt/β-catenin signaling target genes (AXIN2, TCF1) in hDPSCs. Overexpression and suppression of BCL9 in hDPSCs up- and downregulated, respectively, the mRNAs for AXIN2, TCF1, and the osteo/odontoblast markers. Hypoxic-cultured mouse pulp tissue explants showed the promotion of HIF1α, BCL9, and β-catenin expression and BCL9-β-catenin co-localization. In addition, BCL9 formed a complex with β-catenin in hDPSCs in vitro. This study demonstrated that hypoxia/HIF1α-induced osteo/odontoblast differentiation of hDPSCs was partially dependent on Wnt/β-catenin signaling, where BCL9 acted as a key mediator between HIF1α and Wnt/β-catenin signaling. These findings may reveal part of the mechanisms of dental pulp mineralization after traumatic dental injury.

scholarly journals Hypoxia-inducible factor-1α is a critical transcription factor for IL-10-producing B cells in autoimmune disease

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Xianyi Meng ◽  
Bettina Grötsch ◽  
Yubin Luo ◽  
Karl Xaver Knaup ◽  
Michael Sean Wiesener ◽  
...  
Keyword(s):  
Transcription Factor ◽  
B Cells ◽  
Autoimmune Disease ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1Α

Two transcriptional activators, CCAAT-box-binding transcription factor and heat shock transcription factor, interact with a human hsp70 gene promoter

1987 ◽  
Vol 7 (3) ◽  
pp. 1129-1138
Author(s):  
W D Morgan ◽  
G T Williams ◽  
R I Morimoto ◽  
J Greene ◽  
R E Kingston ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Heat Shock ◽  
Gene Promoter ◽  
Heat Shock Transcription Factor ◽  
Transcriptional Activators ◽  
Hsp70 Gene ◽  
Nuclear Extracts ◽  
Ccaat Box ◽  
Human Hsp70

We characterized the activity of a human hsp70 gene promoter by in vitro transcription. Analysis of 5' deletion and substitution mutants in HeLa nuclear extracts showed that the basal activity of the promoter depends primarily on a CCAAT-box sequence located at -65. A protein factor, CCAAT-box-binding transcription factor (CTF), was isolated from HeLa nuclear extracts and shown to be responsible for stimulation of transcription in a reconstituted in vitro system. DNase I footprinting revealed that CTF interacts with two CCAAT-box elements located at -65 and -147 of the human hsp70 promoter. An additional binding activity, heat shock transcription factor (HSTF), which interacted with the heat shock element, was also identified in HeLa extract fractions. This demonstrates that the promoter of this human hsp70 gene interacts with at least two positive transcriptional activators, CTF, which is required for CCAAT-box-dependent transcription as in other promoters such as those of globin and herpes simplex virus thymidine kinase genes, and HSTF, which is involved in heat inducibility.

Identification of promoter elements necessary for transcriptional regulation of a human histone H4 gene in vitro

1985 ◽  
Vol 5 (2) ◽  
pp. 380-389
Author(s):  
S M Hanly ◽  
G C Bleecker ◽  
N Heintz
Keyword(s):  
Transcription Factor ◽  
Transcription Initiation ◽  
Initiation Site ◽  
S Phase ◽  
Histone H4 ◽  
Promoter Elements ◽  
Nuclear Extracts ◽  
Distal Promoter ◽  
Histone H4 Gene

We have examined the nucleotide sequences necessary for transcription of a human histone H4 gene in vitro. Maximal transcription of the H4 promoter requires, in addition to the TATA box and cap site, promoter elements between 70 and 110 nucleotides upstream from the transcription initiation site. These distal promoter elements are recognized preferentially in extracts from synchronized S-phase HeLa cells. The inability of non-S-phase nuclear extracts to recognize the H4 upstream sequences reflects a specific lack of a transcription factor which interacts with those sequences. These results indicate that the cell cycle regulation of human histone gene expression involves both a specific transcription factor and distal transcription signals in the H4 promoter.

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