Renal Na+/H+ exchanger isoforms and their regulation by thyroid hormone

1996 ◽  
Vol 270 (2) ◽  
pp. C585-C592 ◽  
Author(s):  
K. K. Azuma ◽  
D. F. Balkovetz ◽  
C. E. Magyar ◽  
L. Lescale-Matys ◽  
Y. Zhang ◽  
...  

Na+ crosses the luminal membrane of the proximal tubule primarily via Na+/H+ exchange (NHE), and NHE activity is influenced by thyroid status. Pharmacological, immunological, and kinetic studies indicate multiple isoforms of NHE, and four full-length cDNAs have been cloned to date. The aims of this study were to determine which NHE mRNAs (NHE1, -2, -3, and -4) were expressed in the rat proximal tubule, the relative abundance of each in the renal cortex, and the effect of thyroid status on their expression. By blot hybridization of poly(A)+ RNA, all NHE isoform mRNAs were detected in the rat renal cortex; NHE1, -2, and -3 in the proximal tubule; and NHE1 and -3 in LLC-PK1 cells. NHE3 mRNA abundance was fourfold higher than the other three isoforms in renal cortex. The effect of thyroid status was assessed in renal cortex from euthyroid, hypothyroid, and hyperthyroid rats. Although none of the NHE mRNA levels was altered in the transition from euthyroid to hypothyroid states, both NHE2 and NHE3 mRNA levels increased 1.5-fold in the transition from hypo- to hyperthyroidism. NHE3 protein, measured by immunoblot with the use of an NHE3-specific antibody, was detected at 83-85 kDa in renal cortex and codistributed on sorbitol gradients with the brush-border marker alkaline phosphatase. No significant difference in NHE3 protein abundance was detected between hypothyroid and hyperthyroid rats. In conclusion, in the renal cortex, the NHE3 isoform predominates at the mRNA level, is expressed in apical membranes, and increases at the mRNA but not the protein levels in response to thyroid hormone treatment, suggesting parallel changes in synthesis and turnover of NHE3 by thyroid hormone.

1989 ◽  
Vol 121 (3) ◽  
pp. 383-388 ◽  
Author(s):  
J. A. Franklyn ◽  
S. King ◽  
J. A. Ahlquist ◽  
M. C. Sheppard

Abstract. We have examined the influence of hypothyroidism and thyroid hormone replacement on hepatic levels of Spot 14 and thyroxine binding prealbumin mRNAs determined by dot hybridization and by Northern blot hybridization to specific complementary DNA probes. A marked reduction in Spot 14 mRNA was demonstrated in hypothyroidism, compared with the euthyroid state. T3 replacement of hypothyroid rats, using a wide dose range of T3 (1–20 μg) and 6 and 72 h time points, demonstrated no sustained effect at 6 h, but a dose-dependent stimulation of Spot 14 mRNA at 72 h after daily treatment with T3 was commenced. In contrast, no effect of hypothyroidism or T3 replacement on hepatic levels of thyoxine binding prealbumin mRNA was demonstrated, indicating the specificity of thyroid hormone action. T3 treatment of euthyroid rats was also associated with a dose-related stimulation of Spot 14 mRNA levels. The effect of hypothyroidism and T3 treatment of the rat on hepatic Spot 14 mRNA contrasts with divergent regulatory influences of thyroid status in the anterior pituitary and ventricular myocardium demonstrated using identical animal models, indicating the tissue specific influences of thyroid status.


1995 ◽  
Vol 268 (4) ◽  
pp. F710-F717 ◽  
Author(s):  
E. N. Guillery ◽  
L. P. Karniski ◽  
M. S. Mathews ◽  
W. V. Page ◽  
J. Orlowski ◽  
...  

We have studied the role of glucocorticoids in inducing the maturation in activity of the proximal tubule Na+/H+ exchanger that follows birth. Renal cortical microvillus membrane vesicles were prepared from 132-day gestation sheep fetuses (n = 8) that had received intraperitoneal cortisol (13 micrograms.kg-1.h-1) for the previous 48 h. Membrane vesicles were also obtained from sham-operated twin controls (n = 8). Amiloride-sensitive uptake of 22Na+ by these vesicles was measured, and Woolf-Augustinsson-Hofstee plots were used to determine the Michaelis constant (Km) and maximal velocity (Vmax). There was no significant difference in Km; however, the Vmax was 61% higher in cortisol-treated fetuses. Posttreatment circulating cortisol levels were significantly higher in the treated fetuses. Total RNA was collected from renal cortex of the eight pairs of twins when killed. Renal cortex Na+/H+ exchanger 3 (NHE3) mRNA levels were approximately fourfold higher in cortisol-treated than in control fetuses. Although proximal tubule Na+/H+ exchanger activity and renal cortex NHE3 mRNA levels increased significantly in cortisol-treated fetuses, cortisol infusion did not stimulate renal sodium reabsorption in the fetus but rather produced a natriuresis. These results demonstrate that glucocorticoids can induce an increase in both Na+/H+ exchanger activity and NHE3 mRNA levels during the last trimester of gestation in sheep. However, these changes are not associated with an increased ability of the fetal kidney to reabsorb sodium.


2021 ◽  
Author(s):  
Xiuqin Wei ◽  
Chunbo Kang ◽  
Lei Gao ◽  
Mengqiao Zhang ◽  
Mei Xue ◽  
...  

Abstract Aim To determine whether oxidative stress and inflammation are associated with constipation by examining the expression of the main producers of reactive oxygen species, NADPH oxidases, and pro-inflammatory cytokines in the colon of patients with chronic functional constipation. Methods The colonic biopsies were collected from 32 patients with chronic functional constipation and 30 healthy subjects who underwent colonoscopy. Colonic mucosal histology was observed. IL-1β, IL-6, IL-8 mRNA, and four members of NADPH oxidase (NOX1, NOX2, DOUX2 and NOX4) protein and mRNA were assessed by immunohistochemistry, western blotting and RT-PCR. Results The tissues from both patients and healthy subjects showed normal histological structure without increase of inflammatory cells. NOX1 protein and mRNA levels were significantly increased compared to controls (P<0.05). DOUX2 protein, but not mRNA, was increased by twofold compared to controls (P<0.05). The levels of NOX2 and NOX4 protein and mRNA demonstrated no significant difference between patients and control subjects. The levels of IL-1β and IL-6 mRNA were significantly higher in constipation patients (P<0.05), while IL-8 mRNA level was no different between the two groups. Conclusion NADPH oxidase and pro-inflammatory cytokine might be involved in the pathogeneses of chronic functional constipation.


2005 ◽  
Vol 288 (1) ◽  
pp. E236-E245 ◽  
Author(s):  
Xiaoxiong Shen ◽  
Qiao-Ling Li ◽  
Gregory A. Brent ◽  
Theodore C. Friedman

The prohormone convertases (PCs) PC1 and PC2 are involved in the tissue-specific endoproteolytic processing of neuropeptide precursors within the secretory pathway. We previously showed that changes in thyroid status altered pituitary PC2 mRNA and that this regulation was due to triiodothyronine-dependent interaction of the thyroid hormone receptor (TR) with negative thyroid hormone response elements (nTREs) contained in a large proximal region of the human PC2 promoter. In the current study, we examined the in vivo regulation of brain PC2 mRNA by thyroid status and found that 6- n-propyl-2-thiouracil-induced hypothyroidism stimulated, whereas thyroxine-induced hyperthyroidism suppressed, PC2 mRNA levels in the rat hypothalamus and cerebral cortex. To address the mechanism of T3 regulation of the PC2 gene, we used human PC2 (hPC2) promoter constructs transiently transfected into GH3 cells and found that triiodothyronine negatively and 9- cis-retinoic acid positively regulated hPC2 promoter activity. EMSAs, using purified TRα1 and retinoid X receptor-β (RXRβ) proteins demonstrated that TRα bound the distal putative nTRE-containing oligonucleotide in the PC2 promoter, and RXR bound to both nTRE-containing oligonucleotides. EMSAs with oligonucleotides containing deletion mutations of the nTREs demonstrated that the binding to TR and RXR separately is reduced, but specific binding to TR and RXR together persists even with deletion of each putative nTRE. We conclude that there are two novel TRE-like sequences in the hPC2 promoter and that these regions act in concert in a unique manner to facilitate the effects of thyroid hormone and 9- cis-retinoic acid on PC2.


1997 ◽  
Vol 323 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Ulf ANDERSSON ◽  
Josef HOUŠTĚK ◽  
Barbara CANNON

Pre-translational regulation of subunit c has been suggested to control the biosynthesis of mitochondrial ATP synthase (ATPase) in brown adipose tissue (BAT). Subunit c is encoded by the genes P1 and P2, which encode identical mature proteins. We have determined here the levels of P1 and P2 mRNAs in different tissues, in response to cold acclimation in rats, during ontogenic development of BAT in hamsters, and following thyroid hormone treatment in rat BAT and liver. Quantitative ribonuclease protection analysis showed that both the P1 and P2 mRNAs were present in all rat tissues measured. Their total amount in each tissue corresponded well with the ATPase content of that tissue. While the P1/P2 mRNA ratio is high in ATPase-rich tissues, the P2 mRNA dominates in tissues with less ATPase. Cold acclimation affects P1 but not P2 gene expression in rat BAT. A rapid and transient increase in P1 mRNA is followed by sustained depression, which is accompanied by a decrease in ATPase content. Similarly, ontogenic suppression of ATPase content in hamster BAT was accompanied by suppression of the P1 mRNA levels, while P2 expression was virtually unchanged. Furthermore, when hypothyroid rats were treated with thyroid hormone, the steady-state level of P1 but not of P2 mRNA was significantly increased in liver. BAT was unaffected. We conclude that the P1 and P2 genes for subunit c are differentially regulated in vivo. While the P2 gene is expressed constitutively, the P1 gene responds to different physiological stimuli as a means of modulating the relative content of ATP synthase.


2021 ◽  
Author(s):  
Yu-E Yan ◽  
Xu-Rong Zhu ◽  
Fang He ◽  
Jing Xiong ◽  
Ye Tian ◽  
...  

Abstract Backgrouds: Stroke is the second most prevalent cause of death and the first cause of longterm disability worldwide. Inhibition of miR-155 was found playing a protective role in ischemic stroke, one possible mechanism was regulating Ras-homolog enriched in brain (Rheb)/mammalian target of rapamycin (mTOR) pathway. For possible specific intervention strategy, further exploring the expression characteristics of miR-155 and mRNAs of the Rheb/mTOR pathway in ischemic stroke is neccesary. Results: Our results demonstrated that the infarction volume decreased with the prolongation of the reperfusion in the MCAO/R model rats (P < 0.05). Meanwhile, the miR155 expression obviously increased in both the ischemic core and the ischemic penumbra (IP) area of the model rats, but this trend weakened as the reperfusion time increased. Besides, the expression of mRNAs of Rheb, mTOR, S6kb1, and 4Ebp1 seemed to increase in both the ischemic core and the IP area of the model rats.Interestingly, the mRNA level of S6kb1 obviously increased of all model groups in both the ischemic core and the IP area (P < 0.05),while the mRNA levels of Rheb, mTOR, and 4Ebp1 increased in the first 24 h and rapidly decreased after 48 h and as a result, a statistically significant difference was found only in the 48-h group (P < 0.05). Conclusion: Along with the shrinked infarct volume, the levels of miR-155 decreased and the S6kb1 mRNA level increased as the leghtening of re-perfusion, as to the mRNA levels of Rheb, mTOR, and 4Ebp1,statistical significance was found only in the 48-h group. Unexpectedly, there was no difference between the ischemic core and the IP area for all the above molecules.Indicating that intervention measures targeting to miR155 should be taken systemicly as early as possible after stroke onset,especially within the early 48 hours.


2022 ◽  
Vol 20 ◽  
pp. 205873922110529
Author(s):  
Kota Takemoto ◽  
Sachio Takeno ◽  
Takashi Ishino ◽  
Tsutomu Ueda ◽  
Takao Hamamoto ◽  
...  

Introduction Nitric oxide (NO) is synthesized through NO synthase (NOS). The proximal NOS2 gene promoter contains the pentanucleotide CCTTT repeat polymorphism. We examined whether CCTTT repeats are associated with NOS2 expression in the sinonasal tissues and clinical manifestations in patients with chronic rhinosinusitis. Methods Mucosal specimens were obtained from the ethmoid sinus and inferior turbinate of 30 eosinophilic chronic rhinosinusitis (ECRS) and 28 non-ECRS patients. CCTTT repeats were classified into short alleles (S), with less than or equal to 14, and long alleles (L), with more than 14. The subjects were classified into the L/S + L/L and S/S groups. Results In ECRS, the NOS2 mRNA levels of the ethmoid sinus mucosa were significantly higher in the L/S + L/L group than in the S/S group (median, 1.66 and 0.77, respectively). On the ther hand, ECRS patients showed no significant difference in the NOS2 mRNA level of the inferior turbinate between the L/S + L/L group and the S/S group (median, 0.63 and 0.88, respectively). In ECRS, preoperative SNOT-22 were significantly higher in the L/S + L/L group than in the S/S group, whereas the former group showed a lower postoperative recurrence risk. Conclusion CCTTT repeat polymorphism in the NOS2 promotor gene may be a useful indicator to evaluate ECRS severity and prognosis.


2020 ◽  
Vol 20 (6) ◽  
pp. 878-886
Author(s):  
Sobhan Helbi ◽  
Behnam Ravanbakhsh ◽  
Mohammad Karimi ◽  
Wesam Kooti ◽  
Nahid Jivad

Objective: Multiple sclerosis (MS) is a chronic neurodegenerative disease of the central nervous system. The most common disease phenotype is Relapsing-Remitting MS (RRMS). Beta interferons are the first line of RRMS patients’ treatment. Interferon-inducible protein 16 (IFI16) as a DNA sensing molecule and its downstream complex stimulator of interferon genes (STING) play a critical role in the activation of type I interferons. Hence we aimed to evaluate the expression rate of IFI16 and STING in RRMS patients’ blood under a different type of IFNβ treatment. Methods: In the present study, 99 individuals participated. The participants were divided into 4 groups: 28 control subjects, 25 new cases of RRMS patients, 25 RRMS patients treated with IFNβ-1a (B1a), 21 RRMS patients treated with IFNβ-1b (B1b). The EDTA-treated blood samples were taken and transferred at standard conditions to the Cellular and Molecular Research Center of Shahrekord University of Medical Sciences, RNA was extracted and converted into cDNA. To evaluate the expression of IFI16 and STING, the Real-Time PCR method using SYBR Green/ROX qPCR master mix was performed done. The level of genes expression was measured using 2–ΔΔCt method. The obtained data were analyzed using SPSS v22 software. Results: Comparison of the IFI and STING mRNA expression in blood samples in association with gender and age showed no significant differences (p>0.05). Also, the evaluation of IFI16 mRNA level revealed that the IFI16 genes’ expressions were remarkably higher in the new case group compared to the control group, however, STING expression did not show any significant difference. The mRNA levels of IFI16 and STING in IFNβ-treated groups were significantly lower than the new case group (p<0.001). Also, the genes’ expressions in both the IFNβ-treated groups were significantly lower compared to the control group (p<0.001). In the assessment of the correlation of IFI16 and STING expressions with age and sex in different research groups, no statistically significant differences were seen (p>0.05). Conclusion: Perhaps the IFNβ therapy decreases the IFI16 and STING expression in a STINGdependent pathway as a negative feedback mechanism for regulation of the immune system and suppression of pro-inflammatory cytokines production. The important role of DNA sensing molecules and STING-dependent pathway in MS gives a new insight into future treatment based on STING-direct therapies.


2000 ◽  
Vol 165 (2) ◽  
pp. 223-229 ◽  
Author(s):  
J Arola ◽  
J Liu ◽  
P Heikkila ◽  
V Ilvesmaki ◽  
K Salmenkivi ◽  
...  

Inhibins are gonadal glycoprotein hormones whose main endocrine function is to inhibit pituitary FSH secretion. In addition to testes and ovaries, other steroid-producing organs are sites of inhibin alpha subunit expression. To study the role of inhibins in human adrenal gland, we screened a panel of 150 adrenals (10 normal adrenals, 25 adrenocortical hyperplasias, 65 adrenocortical adenomas, 30 adrenocortical carcinomas and 20 phaeochromocytomas) for inhibin alpha expression. mRNA levels of inhibin alpha subunit were studied in 57 samples and all tissues were stained immunohistochemically with an inhibin alpha subunit-specific antibody. Inhibin alpha mRNA was detected in all adrenocortical tissues. Virilizing adenomas possessed a 10-fold higher median inhibin alpha mRNA expression than did normal adrenals. Bilaterally and nodularly hyperplastic adrenals and other than virilizing adrenocortical tumours had their median inhibin alpha mRNA levels close to those of normal adrenals. Immunohistochemically, inhibin alpha subunit was detectable in all normal and hyperplastic adrenals, as well as in 73% of the adrenocortical tumours. However, the percentage of inhibin alpha-positive cells varied greatly in different tumour types. The median percentage of positive cells was 10 in non-functional and Conn's adenomas, 30 in Cushing's adenomas and 75 in virilizing adenomas. In malignant adrenocortical tumours the median percentage of inhibin alpha-immunopositive cells was 20 in non-functional carcinomas, 30 in Conn's carcinomas, 65 in Cushing's carcinomas and 75 in virilizing carcinomas. All phaeochromocytomas were negative for inhibin alpha subunit both at the mRNA level and immunohistochemically. Our data show that inhibin alpha subunit is highly expressed in both normal and neoplastic androgen-producing adrenocortical cells, with less expression in cortisol-producing and hardly any in aldosterone-producing cells. This suggests a specific role for inhibins in the regulation of adrenal androgen production. We did not find any significant difference in inhibin alpha expression between benign and malignant adrenocortical tumours. Thus inhibin alpha gene does not seem to have a tumour suppressor role in human adrenal cortex.


2019 ◽  
Vol 64 (No. 2) ◽  
pp. 89-97
Author(s):  
A. Kubešová ◽  
K. Šťastný ◽  
M. Faldyna ◽  
Z. Sládek ◽  
I. Steinhauserová ◽  
...  

This study aimed to obtain a comprehensive look at the influence of castration on mRNA expression of the genes CYP2E1, CYP1A2, CYP2A19, HSD3B, SULT2A1 and SULT1A1 and their correlation with boar taint compounds (androstenone, skatole and indole) and Improvac-specific antibodies in a Czech commercial hybrid (Large White × Landrace (sow) × Duroc (boar)). Pigs were divided into groups of entire male pigs (NC), pigs castrated surgically (SC), pigs immunologically castrated and slaughtered 8 weeks (IM8) or 15 weeks (IM15) after the second dose of Improvac, and gilts (GI). Hepatic mRNA expression, measured by quantitative real-time polymerase chain reaction, differed significantly between the control group (entire male pigs) and all groups of interest for CYP2E1, CYP1A2 and CYP2A19. The mRNA level of the HSD3B gene differed significantly between the control group and the IM8, IM15 and GI groups. SULT1A1 gene expression was significantly different between the control group and the SC, IM8 and GI. In the case of SULT2A1, a significant difference was observed only between the control group and IM8 pigs. For all genes and treatment groups described above, expression was increased relative to the control. Significant differences for Improvac-specific antibodies between IM8 and IM15 groups were observed, indicating decrease of antibodies over time. Moreover, negative correlations between androstenone and mRNA levels of CYP2A19, CYP2E1 and SULT1A1 suggest that gene expression is suppressed.


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