scholarly journals New Evidence of Gut Microbiota Involvement in the Neuropathogenesis of Bipolar Depression by TRANK1 Modulation: Joint Clinical and Animal Data

2021 ◽  
Vol 12 ◽  
Author(s):  
Jianbo Lai ◽  
Peifen Zhang ◽  
Jiajun Jiang ◽  
Tingting Mou ◽  
Yifan Li ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Depressive Episode ◽  
Cortical Neurons ◽  
Fecal Microbiota Transplantation ◽  
Bipolar Depression ◽  
Inflammatory Factors ◽  
Mrna Levels ◽  
New Evidence ◽  
Lps Treatment

Tetratricopeptide repeat and ankyrin repeat containing 1 (TRANK1) is a robust risk gene of bipolar disorder (BD). However, little is known on the role of TRANK1 in the pathogenesis of BD and whether the gut microbiota is capable of regulating TRANK1 expression. In this study, we first investigated the serum mRNA level of TRANK1 in medication-free patients with a depressive episode of BD, then a mice model was constructed by fecal microbiota transplantation (FMT) to explore the effects of gut microbiota on brain TRANK1 expression and neuroinflammation, which was further verified by in vitro Lipopolysaccharide (LPS) treatment in BV-2 microglial cells and neurons. 22 patients with a depressive episode and 28 healthy individuals were recruited. Serum level of TRANK1 mRNA was higher in depressed patients than that of healthy controls. Mice harboring ‘BD microbiota’ following FMT presented depression-like phenotype. mRNA levels of inflammatory cytokines and TRANK1 were elevated in mice hippocampus and prefrontal cortex. In vitro, LPS treatment activated the secretion of pro-inflammatory factors in BV-2 cells, which was capable of upregulating the neuronal expression of TRANK1 mRNA. Moreover, primary cortical neurons transfected with plasmid Cytomegalovirus DNA (pcDNA3.1(+)) vector encoding human TRANK1 showed decreased dendritic spine density. Together, these findings add new evidence to the microbiota-gut-brain regulation in BD, indicating that microbiota is possibly involved in the neuropathogenesis of BD by modulating the expression of TRANK1.

scholarly journals Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Jintao Gao ◽  
Fangru Chen ◽  
Huanan Fang ◽  
Jing Mi ◽  
Qi Qi ◽  
...  
Keyword(s):  
Skin Lesion ◽  
Inflammatory Response ◽  
Mouse Model ◽  
Nuclear Translocation ◽  
Marker Gene ◽  
Inflammatory Factors ◽  
Mrna Levels ◽  
Hacat Keratinocytes ◽  
Tnf Α

Abstract Background Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms. Methods HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR. Results Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice. Conclusions Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

scholarly journals A118 GUT MICROBIOTA TRANSPLANTATION FROM A PATIENT WITH SEVERE CONSTIPATION INDUCED CHANGES IN COLONIC FUNCTION AND STRUCTUR OF GNOTOBIOTIC MICE

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 137-138
Author(s):  
X Bai ◽  
G De Palma ◽  
J Lu ◽  
S M Collins ◽  
P Bercik
Keyword(s):  
Gut Microbiota ◽  
Fecal Microbiota Transplantation ◽  
Fecal Microbiota ◽  
Colonic Transit ◽  
Slow Transit Constipation ◽  
Antibiotic Exposure ◽  
Ach Release ◽  
Germ Free ◽  
Gi Transit

Abstract Background Increasing evidence suggests that gut microbiota play a key role in gastrointestinal (GI) tract function. We have previously shown that fecal microbiota transplantation diarrhea predominant IBS patients into germ-free mice induces faster GI transit, increased permeability and innate immune activation. However, it is unknown whether gut dysfunction is induced by microbiota from patients with chronic constipation. Aims Here, we investigated the role of the intestinal microbiota in the expression of severe slow transit constipation in a patient with previous C difficile infection and extensive antibiotic exposure. Methods Germ-free (GF) mice (14 weeks old) were gavaged with diluted fecal content from the patient with constipation (PA) or a sex and age-matched healthy control (HC). 12 weeks later, we assessed gut motility and GI transit using videofluoroscopy and a bead expulsion test.. We then investigated intestinal and colonic smooth muscle isometric contraction in vitro using electric field stimulation (EFS), and acetylcholine (Ach) release was assessed by superfusion using [3H] choline. Histological changes were evaluated by H&E and immunohistochemistry. Results Mice with PA microbiota had faster whole GI transit (score 18.9 ± 0.9 (N=9) than mice with HC microbiota (15.4 ± 1.0, N=10, p=0.032), with markers located mainly in the distal small bowel and cecum. However, bead expulsion from the colon was significantly longer in PA mice (420.8 s ± 124.6 s, N=9) than in HC mice (82.6 s ± 20.0 s, N=10, p=0.026). This delayed colonic transit was likely due to colonic retroperistalsis visualized videofluoroscopically by retrograde flow of barium in the right colon of PA mice. There was no difference between the two groups in small intestinal or colonic tissues in Ach release or contractility induced by carbachol or KCl,. EFS caused transient biphasic relaxation and contraction in small intestine and colon, with the colonic contraction being stronger in the PA group. Microscopic tissue analysis showed disruption of the interstitial cells of Cajal (ICC) network and increased lymphocyte infiltration in colonic mucosa and submucosa in PA mice. Conclusions These results indicate that the microbiota is a driver of delayed colonic transit in a patient whose constipation started following extensive antibiotic exposure for C. difficile infection. The observed dysmotility pattern was not due to lower muscle contractility but likely caused by immune mediated changes in the ICC network. Funding Agencies CIHR

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 Cross-Talk Between Butyric Acid and Gut Microbiota in Ulcerative Colitis Following Fecal Microbiota Transplantation

2021 ◽  
Vol 12 ◽  
Author(s):  
Hao-Ming Xu ◽  
Hong-Li Huang ◽  
Jing Xu ◽  
Jie He ◽  
Chong Zhao ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Gut Microbiota ◽  
Butyric Acid ◽  
Fecal Microbiota Transplantation ◽  
Short Chain Fatty Acids ◽  
Fecal Microbiota ◽  
16S Sequencing ◽  
Α Diversity ◽  
The Impact

Fecal microbiota transplantation (FMT) can inhibit the progression of ulcerative colitis (UC). However, how FMT modulates the gut microbiota and which biomarker is valuable for evaluating the efficacy of FMT have not been clarified. This study aimed to determine the changes in the gut microbiota and their relationship with butyric acid following FMT for UC. Fecal microbiota (FM) was isolated from healthy individuals or mice and transplanted into 12 UC patients or colitis mice induced by dextran sulfate sodium (DSS). Their clinical colitis severities were monitored. Their gut microbiota were analyzed by 16S sequencing and bioinformatics. The levels of fecal short-chain fatty acids (SCFAs) from five UC patients with recurrent symptoms after FMT and individual mice were quantified by liquid chromatography–mass spectrometry (LC–MS). The impact of butyric acid on the abundance and diversity of the gut microbiota was tested in vitro. The effect of the combination of butyric acid-producing bacterium and FMT on the clinical responses of 45 UC patients was retrospectively analyzed. Compared with that in the controls, the FMT significantly increased the abundance of butyric acid-producing bacteria and fecal butyric acid levels in UC patients. The FMT significantly increased the α-diversity, changed gut microbial structure, and elevated fecal butyric acid levels in colitis mice. Anaerobic culture with butyrate significantly increased the α-diversity of the gut microbiota from colitis mice and changed their structure. FMT combination with Clostridium butyricum-containing probiotics significantly prolonged the UC remission in the clinic. Therefore, fecal butyric acid level may be a biomarker for evaluating the efficacy of FMT for UC, and addition of butyrate-producing bacteria may prolong the therapeutic effect of FMT on UC by changing the gut microbiota.

scholarly journals Protective Effect of Uric Acid on ox-LDL-Induced HUVECs Injury via Keap1-Nrf2-ARE Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yajuan Lin ◽  
Yunpeng Xie ◽  
Zhujing Hao ◽  
Hailian Bi ◽  
Yang Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Nuclear Translocation ◽  
Density Lipoprotein ◽  
Endothelial Damage ◽  
The Body ◽  
Inflammatory Factors ◽  
Cell Phenotype ◽  
Mrna Levels

Uric acid is an effective antioxidant. Oxidized low-density lipoprotein (ox-LDL) is derived from circulating LDL and promotes atherosclerosis. The Keap1-Nrf2-ARE pathway is a key body pathway involved in protection against internal and external oxidative damages. The role of uric acid on vascular endothelial function damaged by ox-LDL, and its effect on the Keap1-Nrf2-ARE pathway has not been fully explored. HUVECs were treated with different concentrations of uric acid and ox-LDL to explore the effect of uric acid in vitro. Cell phenotype was determined by cytometry and Western blot. Nuclear translocation of Nrf2 was determined by immunofluorescence. Coimmunoprecipitation was used to determine the level of Nrf2 ubiquitination. A microfluidic device was used to mimic the vascular environment in the body, and the level of mRNA levels of inflammatory factors was determined by RT-PCR. The findings of this study show that suitable uric acid can significantly reduce endothelial damage caused by ox-LDL, such as oxidative stress, inflammation, and increased adhesion. In addition, uric acid reduced Nrf2 ubiquitination and increased nuclear translocation of Nrf2 protein, thus activating the Keap1-Nrf2-ARE pathway and playing a protective role. Interestingly, the effects of UA were significantly inhibited by administration of Brusatol, an inhibitor of Nrf2. In summary, suitable concentrations of uric acid can alleviate the oxidative stress level of endothelial cells through Nrf2 nuclear translocation and further protect cells from damage.

scholarly journals Aquaporin-1 attenuates macrophage-mediated inflammatory responses by inhibiting p38 mitogen-activated protein kinase activation in lipopolysaccharide-induced acute kidney injury

2019 ◽  
Vol 68 (12) ◽  
pp. 1035-1047 ◽  
Author(s):  
Bohui Li ◽  
Chunmei Liu ◽  
Kaihong Tang ◽  
Xuening Dong ◽  
Longge Xue ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Inflammatory Responses ◽  
Kidney Injury ◽  
Protective Role ◽  
Mitogen Activated Protein Kinase ◽  
Regulatory Mechanisms ◽  
Detection Methods ◽  
Inflammatory Factors ◽  
Mrna Levels

Abstract Objective This study was designed to investigate the role of AQP1 in the development of LPS-induced AKI and its potential regulatory mechanisms in the inflammatory responses of macrophages. Methods Male Wistar rats were injected intraperitoneally with LPS, and biochemical and histological renal damage was assessed. The levels of inflammatory mediators, macrophage markers and AQP1 in blood and kidney tissues were assessed by ELISA. RTPCR was used to assess changes in the relative levels of AQP1 mRNA induced by LPS. Western blot and immunofluorescence analyses were performed to assay the activation of the p38 MAPK and NF-κB pathways, respectively. The same detection methods were used in vitro to determine the regulatory mechanisms underlying AQP1 function. Results AQP1 mRNA levels were dramatically decreased in AKI rats following the increased expression of inflammatory factors. In vitro experiments demonstrated that silencing the AQP1 gene increased inflammatory mediator secretion, altered the classical activation of macrophages, greatly enhanced the phosphorylation of p38 and accelerated the translocation of NF-κB. Furthermore, these results were blocked by doramapimod, a p38 inhibitor. Therefore, these effects were mediated by the increased phosphorylation of p38 MAPK. Conclusion Our results suggest that altered AQP1 expression may be associated with the development of inflammation in AKI. AQP1 plays a protective role in modulating acute renal injury and can attenuate macrophage-mediated inflammatory responses by downregulating p38 MAPK activity in LPS-induced RAW264.7 cells. The pharmacological targeting of AQP1-mediated p38 MAPK signalling may provide a novel treatment approach for AKI.

scholarly journals Gut microbiota-mediated lysophosphatidylcholine generation promotes colitis in intestinal epithelium-specific Fut2 deficiency

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Xuelian Tang ◽  
Weijun Wang ◽  
Gaichao Hong ◽  
Caihan Duan ◽  
Siran Zhu ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Intestinal Epithelium ◽  
Intestinal Inflammation ◽  
Fecal Microbiota Transplantation ◽  
Fecal Microbiota ◽  
Epithelial Barrier ◽  
16S Rrna Analysis ◽  
New Strategy

Abstract Background and aims Previous study disclosed Fucosyltransferase 2 (Fut2) gene as a IBD risk locus. This study aimed to explore the mechanism of Fut2 in IBD susceptibility and to propose a new strategy for the treatment of IBD. Methods Intestinal epithelium-specific Fut2 knockout (Fut2△IEC) mice was used. Colitis was induced by dextran sulfate sodium (DSS). The composition and diversity of gut microbiota were assessed via 16S rRNA analysis and the metabolomic findings was obtained from mice feces via metabolite profiling. The fecal microbiota transplantation (FMT) experiment was performed to confirm the association of gut microbiota and LPC. WT mice were treated with Lysophosphatidylcholine (LPC) to verify its impact on colitis. Results The expression of Fut2 and α-1,2-fucosylation in colonic tissues were decreased in patients with UC (UC vs. control, P = 0.036) and CD (CD vs. control, P = 0.031). When treated with DSS, in comparison to WT mice, more severe intestinal inflammation and destructive barrier functions in Fut2△IEC mice was noted. Lower gut microbiota diversity was observed in Fut2△IEC mice compared with WT mice (p < 0.001). When exposed to DSS, gut bacterial diversity and composition altered obviously in Fut2△IEC mice and the fecal concentration of LPC was increased. FMT experiment revealed that mice received the fecal microbiota from Fut2△IEC mice exhibited more severe colitis and higher fecal LPC concentration. Correlation analysis showed that the concentration of LPC was positively correlated with four bacteria—Escherichia, Bilophila, Enterorhabdus and Gordonibacter. Furthermore, LPC was proved to promote the release of pro-inflammatory cytokines and damage epithelial barrier in vitro and in vivo. Conclusion Fut2 and α-1,2-fucosylation in colon were decreased not only in CD but also in UC patients. Gut microbiota in Fut2△IEC mice is altered structurally and functionally, promoting generation of LPC which was proved to promote inflammation and damage epithelial barrier.

scholarly journals Effects of Antibiotic Pretreatment of an Ulcerative Colitis-Derived Fecal Microbial Community on the Integration of Therapeutic Bacteria In Vitro

mSystems ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Kaitlyn Oliphant ◽  
Kyla Cochrane ◽  
Kathleen Schroeter ◽  
Michelle C. Daigneault ◽  
Sandi Yen ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Microbial Community ◽  
Side Effects ◽  
Antimicrobial Resistance ◽  
Gut Microbiota ◽  
Fecal Microbiota Transplantation ◽  
Clinical Success ◽  
Distinct Species ◽  
Fecal Microbiota

ABSTRACT Fecal microbiota transplantation (FMT) is a proposedly useful strategy for the treatment of gastrointestinal (GI) disorders through remediation of the patient gut microbiota. However, its therapeutic success has been variable, necessitating research to uncover mechanisms that improve patient response. Antibiotic pretreatment has been proposed as one method to enhance the success rate by increasing niche availability for introduced species. Several limitations hinder exploring this hypothesis in clinical studies, such as deleterious side effects and the development of antimicrobial resistance in patients. Thus, the purpose of this study was to evaluate the use of an in vitro, bioreactor-based, colonic ecosystem model as a form of preclinical testing by determining how pretreatment with the antibiotic rifaximin influenced engraftment of bacterial strains sourced from a healthy donor into an ulcerative colitis-derived defined microbial community. Distinct species integrated under the pretreated and untreated conditions, with the relative rifaximin resistance of the microbial strains being an important influencer. However, both conditions resulted in the integration of taxa from Clostridium clusters IV and XIVa, a concomitant reduction of Proteobacteria, and similar decreases in metabolites associated with poor health status. Our results agree with the findings of similar research in the clinic by others, which observed no difference in primary patient outcomes whether or not patients were given rifaximin prior to FMT. We therefore conclude that our model is useful for screening for antibiotics that could improve efficacy of FMT when used as a pretreatment. IMPORTANCE Patients with gastrointestinal disorders often exhibit derangements in their gut microbiota, which can exacerbate their symptoms. Replenishing these ecosystems with beneficial bacteria through fecal microbiota transplantation is thus a proposedly useful therapeutic; however, clinical success has varied, necessitating research into strategies to improve outcomes. Antibiotic pretreatment has been suggested as one such approach, but concerns over harmful side effects have hindered testing this hypothesis clinically. Here, we evaluate the use of bioreactors supporting defined microbial communities derived from human fecal samples as models of the colonic microbiota in determining the effectiveness of antibiotic pretreatment. We found that relative antimicrobial resistance was a key determinant of successful microbial engraftment with rifaximin (broad-spectrum antibiotic) pretreatment, despite careful timing of the application of the therapeutic agents, resulting in distinct species profiles from those of the control but with similar overall outcomes. Our model had results comparable to the clinical findings and thus can be used to screen for useful antibiotics.

scholarly journals Dysbacteriosis-Derived Lipopolysaccharide Causes Embryonic Osteopenia through Retinoic-Acid-Regulated DLX5 Expression

2020 ◽  
Vol 21 (7) ◽  
pp. 2518
Author(s):  
Lingsen You ◽  
Liwei Zhu ◽  
Pei-zhi Li ◽  
Guang Wang ◽  
Hongmei Cai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Gut Microbiota ◽  
Retinoic Acid Receptor ◽  
Immunofluorescent Staining ◽  
Inflammatory Factors ◽  
Mineral Density ◽  
Alizarin Red ◽  
Gut Microbiota Dysbiosis ◽  
Lps Treatment

Growing evidence suggests an adverse impact of gut microbiota dysbiosis on human health. However, it remains unclear whether embryonic osteogenesis is affected by maternal gut dysbacteriosis. In this study, we observed that elevated lipopolysaccharide (LPS) levels led to skeletal developmental retardation in an established mouse model of gut microbiota dysbiosis. Using chick embryos exposed to dysbacteriosis-derived LPS, we found restriction in the development of long bones as demonstrated by Alcian blue and alizarin red staining. Micro-CT and histological analysis exhibited decreased trabecular volume, bone mineral density, and collagen production, as well as suppressed osteoblastic gene expression (Ocn, Runx2, Osx, and Dlx5) in chick embryonic phalanges following LPS treatment. Atomic force microscopy manifested decreased roughness of MC3T3-E1 cells and poorly developed matrix vesicles (MVs) in presence of LPS. The expression of the aforementioned osteoblastic genes was suppressed in MC3T3-E1 cells as well. High-throughput RNA sequencing indicated that retinoic acid (RA) may play an important role in LPS-induced osteopenia. The addition of RA suppressed Dlx5 expression in MC3T3-E1 cells, as was also seen when exposed to LPS. Quantitative PCR, Western blot, and immunofluorescent staining showed that retinoic acid receptor α (RARα) was upregulated by LPS or RA treatment, while the expression of DLX5 was downregulated. CYP1B1 expression was increased by LPS treatment in MC3T3-E1 cells, which might be attributed to the increased inflammatory factors and subsequently activated NF-κB signaling. Eventually, blocking RA signals with AGN193109 successfully restored LPS-inhibited osteoblastic gene expression. Taken together, our data reveals that maternal gut microbiota dysbiosis can interfere with bone ossification, in which Dlx5 expression regulated by RA signaling plays an important role.

scholarly journals Expression of CD14 by Hepatocytes: Upregulation by Cytokines during Endotoxemia

1998 ◽  
Vol 66 (11) ◽  
pp. 5089-5098 ◽  
Author(s):  
Shubing Liu ◽  
Lajwanti S. Khemlani ◽  
Richard A. Shapiro ◽  
Mark L. Johnson ◽  
Kaihong Liu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Hepatocytes ◽  
Amino Acid Sequences ◽  
Mrna Levels ◽  
Soluble Cd14 ◽  
Protein Levels ◽  
Cd14 Mrna ◽  
Lps Treatment

ABSTRACT Studies were undertaken to examine hepatocyte CD14 expression during endotoxemia. Our results show that lipopolysaccharide (LPS) treatment in vivo caused a marked upregulation in CD14 mRNA and protein levels in rat hepatocytes. Detectable increases in mRNA were seen as early as 1.5 h after LPS treatment; these increases peaked at 20-fold by 3 h and returned to baseline levels by 24 h. In situ hybridization localized the CD14 mRNA expression to hepatocytes both in vitro and in vivo. Increases in hepatic CD14 protein levels were detectable by 3 h and peaked at 12 h. Hepatocytes from LPS-treated animals expressed greater amounts of cell-associated CD14 protein, and more of the soluble CD14 was released by hepatocytes from LPS-treated rats in vitro. The increases in hepatocyte CD14 expression during endotoxemia occurred in parallel to increases of CD14 levels in plasma. To provide molecular identification of the hepatocyte CD14, we cloned the rat liver CD14 cDNA. The longest clone consists of a 1,591-bp insert containing a 1,116-bp open reading frame. The deduced amino acid sequence is 372 amino acids long, has 81.8 and 62.8% homology to the amino acid sequences of mouse and human CD14, respectively, and is identical to the rat macrophage CD14. The expressed CD14 protein from this clone was functional, as indicated by NF-κB activation in response to LPS and fluorescein isothiocyanate-LPS binding in CHO cells stably transfected with rat CD14. A nuclear run-on assay showed that CD14 transcription rates were significantly increased in hepatocytes from LPS-treated animals, indicating that the upregulation in CD14 mRNA levels observed in rat hepatocytes after LPS treatment is dependent, in part, on increased transcription. In vitro and in vivo experiments indicated that interleukin-1β and/or tumor necrosis factor α participate in the upregulation of CD14 mRNA levels in hepatocytes. Our data indicate that hepatocytes express CD14 and that hepatocyte CD14 mRNA and protein levels increase rapidly during endotoxemia. Our observations also support the idea that soluble CD14 is an acute-phase protein and that hepatocytes could be a source for soluble CD14 production.

Sign in / Sign up

Export Citation Format

Share Document