scholarly journals A disintegrin and metalloproteinase 17 regulates TNF and TNFR1 levels in inflammation and liver regeneration in mice

2013 ◽  
Vol 305 (1) ◽  
pp. G25-G34 ◽  
Author(s):  
Ryan S. McMahan ◽  
Kimberly J. Riehle ◽  
Nelson Fausto ◽  
Jean S. Campbell

A disintegrin and metalloproteinase 17 (ADAM17), or tumor necrosis factor (TNF)-α-converting enzyme, is a key metalloproteinase and physiological convertase for a number of putative targets that play critical roles in cytokine and growth factor signaling. These interdependent pathways are essential components of the signaling network that links liver function with the compensatory growth that occurs during liver regeneration following 2/3 partial hepatectomy (PH) or chemically induced hepatotoxicity. Despite identification of many soluble factors needed for efficient liver regeneration, very little is known about how such ligands are regulated in the liver. To directly study the role of ADAM17 in the liver, we employed two cell-specific ADAM17 knockout (KO) mouse models. Using lipopolysaccharide (LPS) as a robust stimulus for TNF release, we found attenuated levels of circulating TNF in myeloid-specific ADAM17 KO mice (ADAM17 m-KO) and, unexpectedly, in mice with hepatocyte-specific ADAM17 deletion (ADAM17 h-KO), indicating that ADAM17 expression in both cell types plays a role in TNF shedding. After 2/3 PH, induction of TNF, TNFR1, and amphiregulin (AR) was significantly attenuated in ADAM17 h-KO mice, implicating ADAM17 as the primary sheddase for these factors in the liver. Surprisingly, the extent and timing of hepatocyte proliferation were not affected after PH or carbon tetrachloride injection in ADAM17 h-KO or ADAM17 m-KO mice. We conclude that ADAM17 regulates TNF, TNFR1, and AR in the liver, and its expression in both hepatocytes and myeloid cells is important for TNF regulation after LPS injury or 2/3 PH, but is not required for liver regeneration.

RSC Advances ◽  
2019 ◽  
Vol 9 (25) ◽  
pp. 14321-14330 ◽  
Author(s):  
Hainiang Liu ◽  
Haoren Wang ◽  
Dong Cheng ◽  
Qinfu Wang ◽  
Zuowei Pei ◽  
...  

Excessive tumor necrosis factor-α (TNF-α) could enhance cell death and aggravate left ventricular remodeling and myocardial dysfunction.


2010 ◽  
Vol 298 (1) ◽  
pp. G74-G80 ◽  
Author(s):  
Xiaodan Ren ◽  
Bin Hu ◽  
Lisa M. Colletti

Hepatocyte proliferation following partial hepatectomy is an important component of liver regeneration, and recent in vitro studies have shown that IL-22 is involved in cellular proliferation in a variety of cell types, including hepatocytes. IL-22 functions through IL-10Rβ and IL-22Rα. The goal of this study was to investigate the potential role of IL-22 in liver regeneration after 70% hepatectomy. Following 70% hepatectomy, done under general anesthesia in mice, serum IL-22 and hepatic IL-22Rα mRNA were significantly increased. Although administration of exogenous IL-22 prior to hepatectomy did not increase hepatocyte proliferation, administration of anti-IL-22 antibody before hepatectomy did significantly decrease hepatocyte proliferation. Furthermore, IL-22 treatment prior to 70% hepatectomy induced stat-3 activation; no significant changes were seen in ERK1/2 activation, stat-1 activation, or stat-5 activation. IL-22 pretreatment also significantly increased hepatic and serum IL-6 levels. In addition, animals treated with anti-IL-22 antibody also expressed less TGF-α. In conclusion, these data suggest that IL-22 is involved in liver regeneration and this may be due to interaction with IL-6 and TGF-α cascades.


2006 ◽  
Vol 290 (4) ◽  
pp. G583-G589 ◽  
Author(s):  
Robert F. Schwabe ◽  
David A. Brenner

TNF-α activates several intracellular pathways to regulate inflammation, cell death, and proliferation. In the liver, TNF-α is not only a mediator of hepatotoxicity but also contributes to the restoration of functional liver mass by driving hepatocyte proliferation and liver regeneration. This review summarizes recent advances in TNF-α signaling mechanisms that demonstrate how the IKK, ROS, and JNK pathways interact with each other to regulate hepatocyte apoptosis and proliferation. Activation of these pathways is causatively linked to liver injury induced by concanavalin A, TNF-α, and ischemia-reperfusion and to liver regeneration and hepatocarcinogenesis. In light of recent findings, pharmacological inhibitors of JNK and IKK and antioxidants may be promising new tools for the treatment of hepatitis, ischemia-reperfusion injury, and hepatocellular carcinoma.


Author(s):  
Sridhar Muthusami ◽  
R. Ileng Kumaran ◽  
Kokelavani Nampalli Babu ◽  
Sneha Krishnamoorthy ◽  
Akash Guruswamy ◽  
...  

: Chronic inflammation can lead to the development of many diseases including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohn's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation together with genetic and epigenetic changes has been shown to lead to the development and progression of CRC. Various cell types present in the colon such as enterocytes, Paneth cells, goblet cells and macrophages express receptors for inflammatory cytokines and respond to tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6 and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key proinflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of proinflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy), to alleviate the symptoms or treat inflammationassociated CRC by using monoclonal antibodies or aptamers to block proinflammatory molecules, inhibitors of tyrosine kinases in inflammatory signaling cascade, competitive inhibitors of proinflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/proinflammatory cytokine gene expression.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2231
Author(s):  
Qingjun Lu ◽  
Hao Shen ◽  
Han Yu ◽  
Jing Fu ◽  
Hui Dong ◽  
...  

The role of Kupffer cells (KCs) in liver regeneration is complicated and controversial. To investigate the distinct role of F4/80+ KCs at the different stages of the regeneration process, two-thirds partial hepatectomy (PHx) was performed in mice to induce physiological liver regeneration. In pre- or post-PHx, the clearance of KCs by intraperitoneal injection of the anti-F4/80 antibody (α-F4/80) was performed to study the distinct role of F4/80+ KCs during the regenerative process. In RNA sequencing of isolated F4/80+ KCs, the initiation phase was compared with the progression phase. Immunohistochemistry and immunofluorescence staining of Ki67, HNF-4α, CD-31, and F4/80 and Western blot of the TGF-β2 pathway were performed. Depletion of F4/80+ KCs in pre-PHx delayed the peak of hepatocyte proliferation from 48 h to 120 h, whereas depletion in post-PHx unexpectedly led to persistent inhibition of hepatocyte proliferation, indicating the distinct role of F4/80+ KCs in the initiation and progression phases of liver regeneration. F4/80+ KC depletion in post-PHx could significantly increase TGF-β2 serum levels, while TGF-βRI partially rescued the impaired proliferation of hepatocytes. Additionally, F4/80+ KC depletion in post-PHx significantly lowered the expression of oncostatin M (OSM), a key downstream mediator of interleukin-6, which is required for hepatocyte proliferation during liver regeneration. In vivo, recombinant OSM (r-OSM) treatment alleviated the inhibitory effect of α-F4/80 on the regenerative progression. Collectively, F4/80+ KCs release OSM to inhibit TGF-β2 activation, sustaining hepatocyte proliferation by releasing a proliferative brake.


2021 ◽  
Vol 22 (5) ◽  
pp. 2388
Author(s):  
Masaru Yamaguchi ◽  
Shinichi Fukasawa

The aim of this paper is to provide a review on the role of inflammation in orthodontically induced inflammatory root resorption (OIIRR) and accelerating orthodontic tooth movement (AOTM) in orthodontic treatment. Orthodontic tooth movement (OTM) is stimulated by remodeling of the periodontal ligament (PDL) and alveolar bone. These remodeling activities and tooth displacement are involved in the occurrence of an inflammatory process in the periodontium, in response to orthodontic forces. Inflammatory mediators such as prostaglandins (PGs), interleukins (Ils; IL-1, -6, -17), the tumor necrosis factor (TNF)-α superfamily, and receptor activator of nuclear factor (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) are increased in the PDL during OTM. OIIRR is one of the accidental symptoms, and inflammatory mediators have been detected in resorbed roots, PDL, and alveolar bone exposed to heavy orthodontic force. Therefore, these inflammatory mediators are involved with the occurrence of OIIRR during orthodontic tooth movement. On the contrary, regional accelerating phenomenon (RAP) occurs after fractures and surgery such as osteotomies or bone grafting, and bone healing is accelerated by increasing osteoclasts and osteoblasts. Recently, tooth movement after surgical procedures such as corticotomy, corticision, piezocision, and micro-osteoperforation might be accelerated by RAP, which increases the bone metabolism. Therefore, inflammation may be involved in accelerated OTM (AOTM). The knowledge of inflammation during orthodontic treatment could be used in preventing OIIRR and AOTM.


2021 ◽  
pp. 14-17
Author(s):  
Mukherjee.J. R ◽  
Mukherjee. B ◽  
Roy. S ◽  
Jana. D ◽  
Bandopadhyay. S ◽  
...  

Background: Pancreatic acinar cell injury triggers the synthesis and release of pro-inammatory cytokines and chemokines. The involvement of several pro-inammatory and anti-inammatory cytokines, such as in interleukin (IL)-1, IL-1β, IL-6, IL-8, IL-10, IL-18, IL-33 and tumor necrosis factor-α is involved in the pathogenesis of pancreatitis. Aim: This study aims to validate the role of activation of TNF-alpha and IL-10 as a biomaker marker in patients with Pancreatitis in Indian subcontinent.Material and methods: 50 Patients of Pancreatitis attending general surgery OPD and admitted to General Surgery department of SSKM Hospital, Kolkata, West Bengal, India were taken. Result: It was found that in alcoholic, the mean TNF - α (mean±s.d.) of the patients was 19.4027 ± 8.3275 pg/ml. In ascites, the mean TNF - α (mean±s.d.) of the patients was 19.9767 ± 2804 pg/ml. In chronic, the mean TNF - α (mean±s.d.) of the patients was 18.8533 ± 8.4674 pg/ml. In gall stone, the mean TNF - α (mean±s.d.) of the patients was 16.3421 ± 9.9499 pg/ml. In osteoarthritis, the mean TNF - α (mean±s.d.) of the patients was 12.4750 ± 8.3085 pg/ml. Distribution of mean TNF - α vs. association was not statistically signicant (p=0.7309).Conclusion: It was found that IL10 was higher in Ascites patients though it was not statistically signicant. TNF alpha was higher in Ascites patients. TNF alpha was higher in normal Pancreatitis.


Author(s):  
Maryam Gholamalizadeh ◽  
Samaneh Mirzaei Dahka ◽  
Hadi Sedigh Ebrahim-Saraie ◽  
Mohammad Esmail Akbari ◽  
Azam Pourtaheri ◽  
...  

1999 ◽  
Vol 73 (2) ◽  
pp. 1672-1681 ◽  
Author(s):  
Li-Ru You ◽  
Chun-Ming Chen ◽  
Yan-Hwa Wu Lee

ABSTRACT Our previous study indicated that the core protein of hepatitis C virus (HCV) can associate with tumor necrosis factor receptor (TNFR)-related lymphotoxin-β receptor (LT-βR) and that this protein-protein interaction plays a modulatory effect on the cytolytic activity of recombinant form LT-βR ligand (LT-α1β2) but not tumor necrosis factor alpha (TNF-α) in certain cell types. Since both TNF-α/TNFR and LT-α1β2/LT-βR are also engaged in transcriptional activator NF-κB activation or c-Jun N-terminal kinase (JNK) activation, the biological effects of the HCV core protein on these regards were elucidated in this study. As demonstrated by the electrophoretic mobility shift assay, the expression of HCV core protein prolonged or enhanced the TNF-α or LT-α1β2-induced NF-κB DNA-binding activity in HuH-7 and HeLa cells. The presence of HCV core protein in HeLa or HuH-7 cells with or without cytokine treatment also enhanced the NF-κB-dependent reporter plasmid activity, and this effect was more strongly seen with HuH-7 cells than with HeLa cells. Western blot analysis suggested that this modulation of the NF-κB activity by the HCV core protein was in part due to elevated or prolonged nuclear retention of p50 or p65 species of NF-κB in core protein-producing cells with or without cytokine treatment. Furthermore, the HCV core protein enhanced or prolonged the IκB-β degradation triggering by TNF-α or LT-α1β2 both in HeLa and HuH-7 cells. In contrast to that of IκB-β, the increased degradation of IκB-α occurred only in LT-α1β2-treated core-producing HeLa cells and not in TNF-α-treated cells. Therefore, the HCV core protein plays a modulatory effect on NF-κB activation triggering by both cytokines, though the mechanism of NF-κB activation, in particular the regulation of IκB degradation, is rather cell line and cytokine specific. Studies also suggested that the HCV core protein had no effect on TNF-α-stimulated JNK activity in both HeLa and HuH-7 cells. These findings, together with our previous study, strongly suggest that among three signaling pathways triggered by the TNF-α-related cytokines, the HCV core protein potentiates NF-κB activation in most cell types, which in turn may contribute to the chronically activated, persistent state of HCV-infected cells.


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