scholarly journals Activation of ubiquitin-proteasome pathway is involved in skeletal muscle wasting in a rat model with biliary cirrhosis: potential role of TNF-α

2005 ◽  
Vol 288 (3) ◽  
pp. E493-E501 ◽  
Author(s):  
Shih-Yi Lin ◽  
Wen-Yin Chen ◽  
Fa-Yauh Lee ◽  
Ching-Jang Huang ◽  
Wayne Huey-Herng Sheu
Keyword(s):  
Muscle Wasting ◽  
Ex Vivo ◽  
Muscle Protein ◽  
Biliary Cirrhosis ◽  
Mrna Levels ◽  
Male Adult ◽  
Protein Levels ◽  
Duct Ligation ◽  
Tnf Α ◽  
Ubiquitin Proteasome

Hepatic cirrhosis is associated with negative nitrogen balance and loss of lean body mass. This study aimed to identify the specific proteolytic pathways activated in skeletal muscles of cirrhotic rats. TNF-α can stimulate muscle proteolysis; therefore, a potential relationship between TNF-α and muscle wasting in liver cirrhosis was also evaluated. Cirrhosis was induced by bile duct ligation (BDL) in male adult Sprague-Dawley rats. mRNA and protein levels of various targets were determined by RT-PCR and Western blotting, respectively. The proteolytic rate was measured ex vivo using isolated muscles. Compared with sham-operated controls, BDL rats had an increased degradation rate of muscle proteins and enhanced gene expression of ubiquitin, 14-kDa ubiquitin carrier protein E2, and the proteasome subunits C2 and C8 ( P < 0.01). The muscle protein levels of free ubiquitin and conjugated ubiquitin levels were also elevated ( P < 0.01). However, there was no difference between the two groups with regard to cathepsin and calpain mRNA levels. Cirrhotic muscle TNF-α levels were increased and correlated positively with free and conjugated ubiquitin ( P < 0.01). We conclude that the ubiquitin-proteasome system is involved in muscle wasting of rats with BDL-induced cirrhosis. TNF-α might play a role in mediating activation of this proteolytic pathway, probably through a local mechanism.

scholarly journals Effect of the proinflammatory cytokine TNF-α on intestinal riboflavin uptake: inhibition mediated via transcriptional mechanism(s)

2018 ◽  
Vol 315 (5) ◽  
pp. C653-C663 ◽  
Author(s):  
Kasin Yadunandam Anandam ◽  
Omar A. Alwan ◽  
Veedamali S. Subramanian ◽  
Padmanabhan Srinivasan ◽  
Rubina Kapadia ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Significant Inhibition ◽  
Mrna Levels ◽  
In Vivo Models ◽  
Uptake Inhibition ◽  
Tnf Α ◽  
Vitro Model ◽  
Factor Α

Riboflavin (RF), is essential for normal cellular metabolism/function. Intestinal RF absorption occurs via a specific carrier-mediated process that involves the apical transporter RFVT-3 ( SLC52A3) and the basolateral RFVT-1 (SLC52A1). Previously, we characterized different cellular/molecular aspects of the intestinal RF uptake process, but nothing is known about the effect of proinflammatory cytokines on the uptake event. We addressed this issue using in vitro, ex vivo, and in vivo models. First, we determined the level of mRNA expression of the human (h)RFVT-3 and hRFVT-1 in intestinal tissue of patients with inflammatory bowel disease (IBD) and observed a markedly lower level compared with controls. In the in vitro model, exposing Caco-2 cells to tumor necrosis factor-α (TNF-α) led to a significant inhibition in RF uptake, an effect that was abrogated upon knocking down TNF receptor 1 (TNFR1). The inhibition in RF uptake was associated with a significant reduction in the expression of hRFVT-3 and -1 protein and mRNA levels, as well as in the activity of the SLC52A3 and SLC52A1 promoters. The latter effects appear to involve Sp1 and NF-κB sites in these promoters. Similarly, exposure of mouse small intestinal enteroids and wild-type mice to TNF-α led to a significant inhibition in physiological and molecular parameters of intestinal RF uptake. Collectively, these findings demonstrate that exposure of intestinal epithelial cells to TNF-α leads to inhibition in RF uptake and that this effect is mediated, at least in part, via transcriptional mechanism(s). These findings may explain the significantly low RF levels observed in patients with IBD.

ET-1 and TNF-α in HPS: analysis in prehepatic portal hypertension and biliary and nonbiliary cirrhosis in rats

2004 ◽  
Vol 286 (2) ◽  
pp. G294-G303 ◽  
Author(s):  
Bao Luo ◽  
Lichuan Liu ◽  
Liping Tang ◽  
Junlan Zhang ◽  
Yiqun Ling ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Portal Hypertension ◽  
Nitric Oxide Synthase ◽  
Receptor Expression ◽  
Heme Oxygenase 1 ◽  
Portal Vein Ligation ◽  
Biliary Cirrhosis ◽  
Duct Ligation ◽  
Tnf Α ◽  
Oxide Synthase

Common bile duct ligation (CBDL) triggers a molecular cascade resulting in the hepatopulmonary syndrome (HPS). Both increased hepatic endothelin-1 (ET-1) production and pulmonary vascular ETB receptor expression with stimulation of endothelial nitric oxide synthase and TNF-α mediated inducible nitric oxide synthase and heme oxygenase-1 expression in pulmonary intravascular macrophages occur. Whether biliary cirrhosis is unique in triggering ET-1 and TNF-α alterations and HPS is unknown. We evaluated for HPS in rat prehepatic portal hypertension [partial portal vein ligation (PVL)], biliary (CBDL) and nonbiliary [thioacetamide treatment (TAA)] cirrhosis, and assessed ET-1 infusion in normal and PVL animals. Control, PVL, CBDL, TAA-treated, and ET-1-infused PVL animals had ET-1 and TNF-α levels measured and underwent molecular and physiological evaluation for HPS. HPS developed only in biliary cirrhosis in association with increased plasma ET-1 and TNF-α levels and the development of established molecular changes in the pulmonary microvasculature. In contrast, PVL did not increase ET-1 or TNF-α levels and TAA treatment increased TNF-α levels alone, and neither resulted in the full development of molecular or physiological changes of HPS despite portal pressure increases similar to those after CBDL. Exogenous ET-1 increased TNF-α levels and triggered HPS after PVL. Combination of ET-1 and TNF-α overproduction is unique to biliary cirrhosis and associated with experimental HPS. ET-1 infusion increases TNF-α levels and triggers HPS in prehepatic portal hypertension. ET-1 and TNF-α interact to trigger pulmonary microvascular changes in experimental HPS.

scholarly journals Changes in Transporters and Metabolizing Enzymes in the Livers of Rats with Bile Duct Ligation

2019 ◽  
Vol 22 ◽  
pp. 457-465 ◽  
Author(s):  
Atsushi Kawase ◽  
Akira Kazaoka ◽  
Rei Yamamoto ◽  
Risa Minakata ◽  
Hiroaki Shimada ◽  
...  
Keyword(s):  
Bile Duct ◽  
Membrane Proteins ◽  
Nuclear Receptors ◽  
Bile Duct Ligation ◽  
Scaffold Proteins ◽  
Mrna Levels ◽  
Metabolizing Enzymes ◽  
Protein Levels ◽  
Duct Ligation ◽  
Liquid Chromatography Tandem Mass

Purpose: Bile duct ligation (BDL) in experimental animals is widely used as an animal model of liver cholestasis and fibrosis. The transcriptional process and plasma membrane localization of transporters are regulated by nuclear receptors and scaffold proteins, respectively. However, the detailed changes of these factors in the livers of BDL rats remain unclear. To clarify the effects of BDL on the levels of transporters and metabolizing enzymes, nuclear receptors, and scaffold proteins, we investigated changes in mRNA and protein levels of livers from BDL rats. Methods: Membrane proteins and microsomes were prepared from rats with BDL. The mRNA levels of transporters and nuclear receptors in livers of control and BDL rats were examined by real-time reverse transcription polymerase chain reaction. The protein levels of transporters, metabolizing enzymes and scaffold proteins in membrane proteins and microsomes were determined by liquid chromatography-tandem mass spectrometry-based targeted proteomics. Results: Mdr1a mRNA was significantly decreased at 1 and 2 weeks of BDL. The mRNA levels of MRP2 were significantly decreased. The mRNA levels of nuclear receptors were significantly decreased in livers of 1-week BDL rats. The protein levels of P-gp were significantly increased by BDL. Regarding scaffold proteins, the protein levels of ezrin, moesin and EBP50 were significantly decreased at 2 weeks of BDL. The protein levels of radixin were significantly increased at 1 week of BDL. In 1-week BDL rats, the protein levels of metabolizing enzymes such as CYP and UGT were significantly decreased. Conclusions: This study reports the comprehensive changes of transporters, metabolizing enzymes, nuclear receptors, and ezrin/radixin/moesin proteins in the livers of BDL rats. The expression levels of nuclear receptors and radixin that regulate the transcription and localization of CYP and/or transporters were decreased by BDL.

scholarly journals IL-33/ST2 axis promotes the inflammatory response of nasal mucosal epithelial cells through inducing the ERK1/2 pathway

2020 ◽  
Vol 26 (6) ◽  
pp. 505-513
Author(s):  
Yun-Qiu Li ◽  
Yu Zhong ◽  
Xu-Ping Xiao ◽  
Dan-Dan Li ◽  
Zheng Zhou ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ar Model ◽  
Inflammatory Factors ◽  
Mrna Levels ◽  
Model Group ◽  
Protein Levels ◽  
Tnf Α ◽  
Der P1 ◽  
The Relationship

Allergic rhinitis (AR) is a nasal mucosal inflammatory disease mediated by environmental allergens. At present, the relationship between the IL-33/ST2 axis, ERK1/2 pathway and AR progression needs further exploration. In our study, an AR model was constructed in vitro by treating HNEpC cells with Der p1. qRT-PCR was applied to assess the mRNA levels of IL-33, ST2, TNF-α, IL-6, and IL-8. Western blotting was used to measure the protein levels of IL-33, ST2, and the downstream proteins p-ERK1/2, ERK1/2, p-RSK, and RSK. IL-6, IL-8, IL-33, and TNF-α protein levels in cell supernatants were evaluated by ELISA. Flow cytometry was performed to check cell apoptosis of HNEpC in the presence or absence of Der p1. Our results indicate that the relative levels of IL-33, ST2, TNF-α, IL-6, and IL-8 were increased significantly in the AR model group. The above effects were notably reversed after transfection with shIL-33 or shST2. IL-33 stimulation further resulted in the increase in both ST2 and inflammation-associated cytokines, and these effects were restored after shST2 treatment. Also, the levels of inflammatory factors induced by IL-33 stimulation or ST2 overexpression were reversed after applying an ERK1/2 pathway blocker. In conclusion, IL-33/ST2 mediated inflammation of nasal mucosal epithelial cells by inducing the ERK1/2 pathway.

scholarly journals Differential regulation of lipid and protein metabolism in obese vs. lean subjects before and after a 72-h fast

2016 ◽  
Vol 311 (1) ◽  
pp. E224-E235 ◽  
Author(s):  
Ann Mosegaard Bak ◽  
Andreas Buch Møller ◽  
Mikkel Holm Vendelbo ◽  
Thomas Svava Nielsen ◽  
Rikke Viggers ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fat Mass ◽  
Muscle Protein ◽  
Whole Body ◽  
Mrna Levels ◽  
Mass Unit ◽  
Body Protein ◽  
Protein Levels ◽  
Tracer Techniques ◽  
Obese Subjects

Increased availability of lipids may conserve muscle protein during catabolic stress. Our study was designed to define 1) intracellular mechanisms leading to increased lipolysis and 2) whether this scenario is associated with decreased amino acid and urea fluxes, and decreased muscle amino acid release in obese subjects under basal and fasting conditions. We therefore studied nine lean and nine obese subjects twice, after 12 and 72 h of fasting, using measurements of mRNA and protein expression and phosphorylation of lipolytic and protein metabolic signaling molecules in fat and muscle together with whole body and forearm tracer techniques. Obese subjects displayed increased whole body lipolysis, decreased urea production rates, and decreased forearm muscle protein breakdown per 100 ml of forearm tissue, differences that persisted after 72 h of fasting. Lipolysis per fat mass unit was reduced in obese subjects and, correspondingly, adipose tissue hormone-sensitive lipase (HSL) phosphorylation and mRNA and protein levels of the adipose triglyceride lipase (ATGL) coactivator CGI58 were decreased. Fasting resulted in higher HSL phosphorylations and lower protein levels of the ATGL inhibitor G0S2. Muscle protein expressions of mammalian target of rapamycin (mTOR) and 4EBP1 were lower in obese subjects, and MuRf1 mRNA was higher with fasting in lean but not obese subjects. Phosphorylation and signaling of mTOR decreased with fasting in both groups, whereas ULK1 protein and mRNA levels increased. In summary, obese subjects exhibit increased lipolysis due to a large fat mass with blunted prolipolytic signaling, together with decreased urea and amino acid fluxes both in the basal and 72-h fasted state; this is compatible with preservation of muscle and whole body protein.

Diminished proteasomal degradation results in accumulation of Gfi1 protein in monocytes

Blood ◽  
2006 ◽  
Vol 109 (1) ◽  
pp. 100-108 ◽  
Author(s):  
Jurgen A. F. Marteijn ◽  
Laurens T. van der Meer ◽  
Liesbeth Van Emst ◽  
Theo de Witte ◽  
Joop H. Jansen ◽  
...  
Keyword(s):  
Ubiquitin Proteasome System ◽  
Proteasomal Degradation ◽  
Myeloid Differentiation ◽  
Mrna Levels ◽  
Monocytic Differentiation ◽  
Granulocytic Differentiation ◽  
Monocytic Cell ◽  
Protein Levels ◽  
Ubiquitin Proteasome ◽  
Monocytic Lineage

Abstract Gfi1 is a transcriptional repressor essential during myeloid differentiation. Gfi1−/− mice exhibit a block in myeloid differentiation resulting in the accumulation of an immature myelo-monocytic cell population and the complete absence of mature neutrophils. Even though mRNA levels of Gfi1 appear to be very low in monocytes, Gfi1 might play a role in the monocytic lineage as Gfi1−/− mice exhibit diminished monocyte-derived dendritic cells and disturbed cytokine production by macrophages in response to LPS. We show here that Gfi1 protein levels are mainly regulated by the ubiquitin-proteasome system. Upon forced monocytic differentiation of U937 cells, Gfi1 mRNA levels dropped but protein levels increased due to diminished proteasomal turnover. Similarly, Gfi1 mRNA levels are low in primary monocytes whereas the protein is clearly detectable. Conversely, Gfi1 mRNA levels are high in granulocytes but the protein is swiftly degraded by the proteasome in these cells. Chromatin immunoprecipitation experiments showed that Gfi1 binds to the promoter of several granulocyte-specific genes in primary monocytes, including C/EBPα, neutrophil elastase, and Gfi1 itself. The binding of the repressor Gfi1 to these promoters correlated with low expression of these genes in monocytes compared with granulocytes. Our data fit a model in which Gfi1 protein levels are induced in primary monocytes, due to diminished proteasomal degradation, to repress genes that play a role in granulocytic differentiation.

“Subclinical” gentamicin nephrotoxicity: a potential risk factor for exaggerated endotoxin-driven TNF-α production

2007 ◽  
Vol 293 (1) ◽  
pp. F43-F49 ◽  
Author(s):  
Richard A. Zager
Keyword(s):  
Antimicrobial Effect ◽  
Specific Response ◽  
Mrna Levels ◽  
Gram Negative ◽  
Protein Levels ◽  
Target Organs ◽  
Gentamicin Treatment ◽  
Tnf Α ◽  
Oxide Synthase ◽  
And Control

This study sought to determine whether gentamicin, a mainstay in treating Gram-negative sepsis, alters endotoxin (lipopolysaccharide; LPS)-driven TNF-α increases. CD-1 mice received 1 day of gentamicin treatment. Either 0, 24, or 72 h later, gentamicin-treated and control mice were injected with LPS. Renal cortical and plasma TNF-α, as well as MCP-1, protein levels were measured 2 or 24 h post-LPS injection. Renal cortical mRNAs for TNF-α, MCP-1, IL-10, and inducible nitric oxide synthase (iNOS) were also determined. Finally, gentamicin's potential impact(s) on TNF-α/MCP-1 mRNA levels in nontraditional “target” organs (liver, spleen) was assessed. Gentamicin, when administered alone, slightly increased renal cortical TNF-α and MCP-1 mRNAs, but without changing plasma or renal TNF-α/MCP-1 protein levels. The gentamicin protocol induced no overt renal damage (assessed by blood urea nitrogen, creatinine, and histology). Nevertheless, gentamicin augmented LPS responsiveness, as manifested, in part, by a doubling of LPS-induced plasma TNF-α increases (vs. LPS injection alone). Plasma and renal cortical MCP-1 protein levels were also selectively enhanced. Gentamicin augmented LPS-driven renal mRNA increases (TNF-α, MCP-1, IL-10, iNOS). However, this was not an entirely renal-specific response, since gentamicin also enhanced basal and LPS-stimulated hepatic TNF-α mRNA levels. Subclinical gentamicin toxicity can potentiate LPS-driven TNF-α increases. Alterations in multiple proinflammatory (TNF-α; MCP-1; iNOS) and anti-inflammatory (IL-10) genes in the kidney, and possibly in extrarenal organs, may be involved. Thus gentamicin's activity in Gram-negative sepsis may extend beyond its traditional antimicrobial effect.

scholarly journals Progestin increases the expression of gonadotropins in pituitaries of male zebrafish

2016 ◽  
Vol 230 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Cuili Wang ◽  
Dongteng Liu ◽  
Weiting Chen ◽  
Wei Ge ◽  
Wanshu Hong ◽  
...  
Keyword(s):  
Time Course ◽  
Ex Vivo ◽  
Mrna Levels ◽  
Adult Zebrafish ◽  
Male Adult ◽  
Positive Effects ◽  
Time Course Experiment ◽  
Nuclear Progesterone Receptor

Our previous study showed that the in vivo positive effects of 17α,20β-dihydroxy-4-pregnen-3-one (DHP), the major progestin in zebrafish, on early spermatogenesis was much stronger than the ex vivo ones, which may suggest an effect of DHP on the expression of gonadotropins. In our present study, we first observed that fshb and lhb mRNA levels in the pituitary of male adult zebrafish were greatly inhibited by 3 weeks exposure to 10nM estradiol (E2). However, an additional 24h 100nM DHP exposure not only reversed the E2-induced inhibition, but also significantly increased the expression of fshb and lhb mRNA. These stimulatory effects were also observed in male adult fish without E2 pretreatment, and a time course experiment showed that it took 24h for fshb and 12h for lhb to respond significantly. Because these stimulatory activities were partially antagonized by a nuclear progesterone receptor (Pgr) antagonist mifepristone, we generated a Pgr-knockout (pgr–/–) model using the TALEN technique. With and without DHP in vivo treatment, fshb and lhb mRNA levels of pgr–/– were significantly lower than those of pgr+/+. Furthermore, ex vivo treatment of pituitary fragments of pgr–/– with DHP stimulated lhb, but not fshb mRNA expression. Results from double-colored fluorescent in situ hybridization showed that pgr mRNA was expressed only in fshb-expressing cells. Taken together, our results indicated that DHP participated in the regulation of neuroendocrine control of reproduction in male zebrafish, and exerted a Pgr-mediated direct stimulatory effect on fshb mRNA at pituitary level.

scholarly journals TNF‑α treatment increases DKK1 protein levels in primary osteoblasts via upregulation of DKK1 mRNA levels and downregulation of miR‑335‑5p

2020 ◽  
Vol 22 (2) ◽  
pp. 1017-1025
Author(s):  
Shanshan Li ◽  
Yixin Yin ◽  
Liping Yao ◽  
Ziyi Lin ◽  
Shengjun Sun ◽  
...  
Keyword(s):  
Mrna Levels ◽  
Protein Levels ◽  
Tnf Α ◽  
Primary Osteoblasts

scholarly journals Restriction of HIV-1 Infection in Sickle Cell Trait

2021 ◽  
Author(s):  
Namita Kumari ◽  
Seyed Mehdi Nouraie ◽  
Asrar Ahmad ◽  
Hatajai Lassiter ◽  
Javed I Khan ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Mononuclear Cells ◽  
Sickle Cell Trait ◽  
Ex Vivo ◽  
Heme Oxygenase 1 ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Protein Levels ◽  
Living With Hiv ◽  
Hiv 1

Patients with Sickle cell disease (SCD) have lower risk for HIV-1 infection. We showed restriction of ex vivo HIV-1 infection in SCD peripheral blood mononuclear cells (PBMCs) that was due, in part, to the upregulation of antiviral, inflammatory and hemolytic factors including heme oxygenase-1 (HO-1). Here, we investigated whether individuals with sickle cell trait (SCT), who develop mild hemolysis, also restrict HIV-1 infection. Ex vivo infection of SCT PBMCs demonstrated ~2-fold reduction of HIV-1 replication and lower levels of HIV-1 reverse transcription products, 2-Long Terminal Repeats (LTR) circles, HIV-1 integration and gag RNA expression. SCT PBMCs had higher HO-1 mRNA and protein levels and reduced ribonucleotide reductase 2 (RNR2) protein levels. HO-1 inhibition by tin porphyrin eliminated ex vivo HIV-1 restriction. Among Howard University clinic recruits, higher levels of HO-1 and RNR2 mRNA and lower HIV-1 env mRNA levels were found in SCT individuals living with HIV-1. To determine the population level effect of SCT on HIV-1 prevalence, we assessed SCT trait among women living with HIV (WLH) in the Women Interagency HIV-1 Study (WIHS). Among WIHS African American participants, prevalence of SCT was lower among women with HIV compared with uninfected women (8.7% vs 14.2%; OR 0.57; 95%CI = 0.36-0.92, p=0.020). WIHS WLH with SCT had higher levels of CD4+/CD8+ ratios over 20 years of follow up (p=0.003) than matched WLH without SCT. Together, our findings suggest that HIV-1 restriction factors including HO-1 and RNR2 might restrict HIV-1 infection among individuals with SCT and limit the pathogenicity of HIV.

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