scholarly journals Investigating the Role of Farnesoid X Receptor in Heme Biosynthesis and Ductular Reaction

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A810-A811
Author(s):  
Angela E Dean ◽  
Emilian Jungwirth ◽  
Katrin Panzitt ◽  
Martin Wagner ◽  
Sayeepriyadarshini Anakk

Abstract Bile acids (BAs) have gained traction not just as emulsifiers of fat, but also as hormones. Nuclear receptor Farnesoid X receptor (FXR) is the master regulator of BAs and can also control glucose and lipid metabolism. We examined if FXR contributed towards heme biosynthesis and induction of a ductular reaction. Male and female whole body Fxr knockout (FxrKO) mice, as well as liver- and intestine-specific knockouts (LFxrKO and IFxrKO, respectively) were treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC, a ferrochelatase inhibitor) for two weeks. At the end of the two weeks, mice were fasted for four hours and euthanized. All groups of mice had lost a similar percentage of body weight when fed the DDC diet. However, female FxrKO mice had significantly increased liver to body weight ratio, while male FxrKO mice had significantly decreased liver to body weight ratio when fed the DDC diet compared with their wild type counterparts. Serum liver injury markers were analyzed and liver histology and changes in genes involved in the heme biosynthesis pathway were examined. Both male and female whole body FxrKO livers had decreased ductular reaction with minimal bile plugs (porphyrin accumulation) compared with their wild type counterparts. LFxrKO mice mimicked diminished ductular reaction, while IFxrKO mice exhibited severe ductular reaction similar to that of wild type mice, indicating that the ductular reaction is dependent on hepatic FXR. ChIP-Seq for FXR revealed binding peaks in the heme biosynthesis genes, Alas1, Alad, Uros, and Fech, suggesting that FXR may act as a transcription factor for these genes. Further investigation revealed that Pbgd gene expression was increased, while Fech gene expression was decreased in female FxrKO mice compared to wild type mice. In male mice, Pbgd, Uros, Urod, and Cpox gene expression was increased in the absence of Fxr. In conclusion, Fxr is necessary to mount a ductular reaction and plays a key role in heme biosynthesis in the liver.

1995 ◽  
Vol 269 (3) ◽  
pp. H1003-H1008 ◽  
Author(s):  
A. Younes ◽  
M. O. Boluyt ◽  
L. O'Neill ◽  
A. L. Meredith ◽  
M. T. Crow ◽  
...  

Atrial natriuretic peptide (ANP), a cardiac-specific hormone, is stored in the atria and released in response to atrial stretch. During cardiac hypertrophy, ANP gene expression is markedly upregulated in the left ventricle (LV). Because the hearts of normotensive senescent rats exhibit left atrial (LA) and left ventricular (LV) hypertrophy and dilatation, we examined ANP mRNA levels by Northern blot analysis and ANP peptide concentrations by radioimmunoassay in atria, LVs, and plasma of rats at 2, 6, 18, and 22-24 mo of age. Compared with LVs of 6-mo-old rats, the LV-to-body weight ratio was elevated 30% by 18 mo of age, whereas levels of ANP mRNA were elevated twofold (not significant) and sevenfold (P < 0.05) in the LV of 18- and 22- to 24-mo-old rats, respectively. The concentration of immunoreactive ANP (ir-ANP) exhibited a four- to fivefold increase in LVs of 18- and 22- to 24-mo-old rats compared with values for 6-mo-old rats (43 +/- 4 pmol/g wet wt; means +/- SE). Among 18-and 22- to 24-mo-old rats a significant correlation was observed between ANP peptide concentration and LV hypertrophy (r 2 = 0.64). Levels of ANP mRNA and ir-ANP in the atria exhibited only modest changes with aging.(ABSTRACT TRUNCATED AT 250 WORDS)


Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 41
Author(s):  
Nouf Aljobaily ◽  
Michael J. Viereckl ◽  
David S. Hydock ◽  
Hend Aljobaily ◽  
Tsung-Yen Wu ◽  
...  

Background: Treatment with the chemotherapy drug doxorubicin (DOX) may lead to toxicities that affect non-cancer cells including the liver. Supplementing the diet with creatine (Cr) has been suggested as a potential intervention to minimize DOX-induced side effects, but its effect in alleviating DOX-induced hepatoxicity is currently unknown. Therefore, we aimed to examine the effects of Cr supplementation on DOX-induced liver damage. Methods: Male Sprague-Dawley rats were fed a diet supplemented with 2% Cr for four weeks, 4% Cr for one week followed by 2% Cr for three more weeks, or control diet for four weeks. Animals then received either a bolus i.p. injection of DOX (15 mg/kg) or saline as a placebo. Animals were then sacrificed five days-post injection and markers of hepatoxicity were analyzed using the liver-to-body weight ratio, aspartate transaminase (AST)-to- alanine aminotransferase (ALT) ratio, alkaline phosphatase (ALP), lipemia, and T-Bilirubin. In addition, hematoxylin and eosin (H&E) staining, Picro-Sirius Red staining, and immunofluorescence staining for CD45, 8-OHdG, and β-galactosidase were performed to evaluate liver morphology, fibrosis, inflammation, oxidative stress, and cellular senescence, respectively. The mRNA levels for biomarkers of liver fibrosis, inflammation, oxidative stress, and senescence-related genes were measured in liver tissues. Chromosomal stability was evaluated using global DNA methylation ELISA. Results: The ALT/AST ratio and liver to body weight ratio tended to increase in the DOX group, and Cr supplementation tended to attenuate this increase. Furthermore, elevated levels of liver fibrosis, inflammation, oxidative stress, and senescence were observed with DOX treatment, and Cr supplementation prior to DOX treatment ameliorated this hepatoxicity. Moreover, DOX treatment resulted in chromosomal instability (i.e., altered DNA methylation profile), and Cr supplementation showed a tendency to restore chromosomal stability with DOX treatment. Conclusion: The data suggest that Cr protected against DOX-induced hepatotoxicity by attenuating fibrosis, inflammation, oxidative stress, and senescence.


1996 ◽  
Vol 80 (3) ◽  
pp. 734-741 ◽  
Author(s):  
E. E. Dupont-Versteegden

The effects of exercise and the combination of exercise and clenbuterol on progression of muscular dystrophy were studied in mdx mice. At 3 wk of age, mdx mice were randomly assigned to sedentary (MS), exercise (ME), or combined exercise and clenbuterol (MEC) groups. Clenbuterol was given in the drinking water (1.0-1.5 mg . kg body weight-1 . day-1), and exercise consisted of spontaneous running activity on exercise wheels. At 3 mo or 1 yr of age, ventilatory function, contractile properties, and morphological characteristics of the soleus (Sol) and diaphragm (Dia) muscles were measured. The mdx mice receiving clenbuterol ran less than the mice without clenbuterol. The combination of clenbuterol and exercise was associated with an increase in Sol muscle weight and a muscle weight-to-body weight ratio of 30-35% compared with the sedentary group and approximately 20% compared to exercise alone. Myosin and total protein concentrations of the Sol and Dia increased in the MEC group at 1 yr of age only. Normalized active tension was increased in the Dia at 1 yr of age in both the ME and MEC groups by approximately 30%. Absolute tetanic tension of the Sol was increased at both 3 mo and 1 yr of age in the MEC compared with the MS group. At 1 yr of age, there was an additional 23% increase compared with the ME group. Fatigability increased in the MEC group by approximately 25% in the Sol and Dia muscles at both ages compared with the MS and ME groups. Results indicate that exercise and exercise plus clenbuterol decrease the progression of muscular dystrophy. However, different mechanisms may be involved because the combination of clenbuterol and exercise resulted in increased fatigability and the development of deformities, whereas exercise alone did not. Therefore, clenbuterol may not be suitable for use in patients with muscular dystrophy.


2016 ◽  
Vol 36 (9) ◽  
pp. 901-909 ◽  
Author(s):  
D Sheela ◽  
R Vijayaraghavan ◽  
S Senthilkumar

Buprenorphine drug cartridge was made for autoinjector device for use in emergency and critical situations to reduce the morbidity and mortality. Water-filled cartridges were prepared and buprenorphine was injected aseptically in the cartridge, to make 0.05 and 0.10 mg/mL. Rats were injected intraperitoneally, buprenorphine (0.3 and 0.6 mg/kg), repeatedly with the autoinjector and compared with manual injection (7 days and 14 days) using various haematological and biochemical parameters. No significant change was observed in the body weight, organ to body weight ratio and haematological variables in any of the experimental groups compared with the control group. Except serum urea and aspartate aminotransferase, no significant change was observed in glucose, cholesterol, triglycerides, bilirubin, protein, albumin, creatinine, uric acid, alanine aminotransferase, gamma glutamyltransferase and alkaline phosphatase. The autoinjectors deliver the drugs with spray effect and force for faster absorption. In the present study, the autoinjector meant for intramuscular injection was injected intraperitoneally in rats, and the drug was delivered with force on the vital organs. No significant difference was observed in the autoinjector group compared to the manual group showing tolerability and safety of the buphrenorphine autoinjector. This study shows that buprenorphine autoinjector can be considered for further research work.


2018 ◽  
Vol 75 (6) ◽  
pp. 1042-1049
Author(s):  
Seongjoon Park ◽  
Erkhembayar Nayantai ◽  
Toshimitsu Komatsu ◽  
Hiroko Hayashi ◽  
Ryoichi Mori ◽  
...  

Abstract The orexigenic hormone neuropeptide Y (NPY) plays a pivotal role in the peripheral regulation of fat metabolism. However, the mechanisms underlying the effects of sex on NPY function have not been extensively analyzed. In this study, we examined the effects of NPY deficiency on fat metabolism in male and female mice. Body weight was slightly decreased, whereas white adipose tissue (WAT) mass was significantly decreased as the thermogenic program was upregulated in NPY-/- female mice compared with that in wild-type mice; these factors were not altered in response to NPY deficiency in male mice. Moreover, lack of NPY resulted in an increase in luteinizing hormone (LH) expression in the pituitary gland, with concomitant activation of the estradiol-mediated thermogenic program in inguinal WAT, and alleviated age-related modification of adiposity in female mice. Taken together, these data revealed a novel intracellular mechanism of NPY in the regulation of fat metabolism and highlighted the sexual dimorphism of NPY as a promising target for drug development to reduce postmenopausal adiposity.


2014 ◽  
Vol 38 (1) ◽  
pp. 74-82
Author(s):  
Wassan M. Hussen

The aim of the present study is to prepare ethanol extract of Pomegranate peel and the effects of this extract on testicular weight to body weight ratio, Serum cholesterol, testosterone concentration and histopathological changes of testes in rabbits treated with carbon tetrachloride (CCl4). Twenty four adult male rabbits were used. They were divided randomly into four equal groups. Animals were treated for 56 days as following: Rabbits of the 1st group were received 1 ml distal water orally once a day and olive oil 0.5 ml /kg B.W. I.P twice a week as control group. The second group were treated I.P with 500mg / kg B.W. of CCl4 mixing with equal volume of olive oil (0.5 ml/kg B.W.) twice a week (group T1). The third group was received pomegranate peel extract orally (100 mg/kg B.W) once a day and olive oil 0.5 ml /kg B.W. I.P twice a week (group T2). The fourth group were received pomegranate peel extract (100 mg/kg B.W) once a day oral I.P with 500 mg / kg B.W. of CCl4 mixing with equal volume of olive oil (o.5 ml/kg B.W.) twice a week (group T3). Blood samples were collected at (0, 14, 28, 42 and 56) days for measuring testosterone concentration, Serum cholesterol after treatments. Animals weighed and scarified and testis were removed and weighed, Samples of testis were taken for histopathological study. The results of the present study showed that treatment with pomegranate peel extract causes a significant (P>0.05) increase in testicular weight to body weight ratio. Also a significant (P>0.05) decreased of serum cholesterol and a significantly (P>0.05) elevation of testosterone concentration were observed. Histopathological examination of the testis was revealed that the extract of Pomegranate peel protect the testis against lesions caused by CCl4. In conclusion, Pomegranate peel extract could protect the tissue of testicles from CCl4 perhaps, by its anti-oxidative effect of pomegranate peel extract, hence eliminating the deleterious effects or toxic effect of CCl4.


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