The MAPK MEK1/2-ERK1/2 Pathway and Its Implication in Hepatocyte Cell Cycle Control

Primary cultures of hepatocytes are powerful models in studying the sequence of events that are necessary for cell progression from a G0-like state to S phase. The models mimic the physiological process of hepatic regeneration after liver injury or partial hepatectomy. Many reports suggest that the mitogen-activated protein kinase (MAPK) ERK1/2 can support hepatocyte proliferationin vitroandin vivoand the MEK/ERK cascade acts as an essential element in hepatocyte responses induced by the EGF. Moreover, its disregulation has been associated with the promotion of tumor cell growth of a variety of tumors, including hepatocellular carcinoma. Whereas the strict specificity of action of ERK1 and ERK2 is still debated, the MAPKs may have specific biological functions under certain contexts and according to the differentiation status of the cells, notably hepatocytes. In this paper, we will focus on MEK1/2-ERK1/2 activations and roles in normal rodent hepatocytesin vitroand in vivo after partial hepatectomy and in human hepatocarcinoma cells. The possible specificity of ERK1 and ERK2 in normal and transformed hepatocyte will be discussed in regard to other differentiated and undifferentiated cellular models.

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Partial Inhibition of HO-1 Attenuates HMP-Induced Hepatic Regeneration against Liver Injury in Rats

Oxidative Medicine and Cellular Longevity ◽

10.1155/2018/9108483 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Ning He ◽

Jun-Jun Jia ◽

Hai-Yang Xie ◽

Jian-Hui Li ◽

Yong He ◽

...

Keyword(s):

Protein Level ◽

Liver Graft ◽

Hepatocyte Proliferation ◽

Hepatic Regeneration ◽

Significant Elevation ◽

Hypothermic Machine Perfusion ◽

Underlying Mechanisms ◽

First Time

We found better liver graft regeneration with hypothermic machine perfusion (HMP) compared with static cold storage (SCS) for the first time in our pilot study, but the underlying mechanisms are unknown. Upregulated heme oxygenase- (HO-) 1 expression has been reported to play a pivotal role in promoting hepatocyte proliferation. Here, we evaluated the novel role of HO-1 in liver graft protection by HMP. Rats with a heterozygous knockout of HO-1 (HO-1+/−) were generated and subjected to 3 h of SCS or HMP pre-half-size liver transplantation (HSLT) in vivo or 6 h of SCS or HMP in vitro; control rats were subjected to the same conditions (HO-1+/+). We found that HSLT induced significant elevation of the HO-1 protein level in the regenerated liver and that HO-1 haplodeficiency resulted in decreased proliferation post-HSLT. Compared with SCS, HMP induced significant elevation of the HO-1 protein level along with better liver recovery, both of which were reduced by HO-1 haplodeficiency. HO-1 haplodeficiency-induced decreased proliferation was responsible for the attenuated regenerative ability of HMP. Mechanistically, HO-1 haploinsufficiency resulted in suppression of hepatocyte growth factor (HGF)/Akt activity. Our results suggest that inhibition of HO-1 mitigates HMP-induced liver recovery effects related to proliferation, in part, by downregulating the HGF-Akt axis.

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Sigma 1 Receptor is Overexpressed in Hepatocellular Adenoma: Involvement of ERα and HNF1α

Cancers ◽

10.3390/cancers12082213 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2213

Author(s):

Laure Villemain ◽

Sylvie Prigent ◽

Aurélie Abou-Lovergne ◽

Laura Pelletier ◽

Magali Chiral ◽

...

Keyword(s):

Knockout Mice ◽

Hepatocellular Adenoma ◽

Integral Membrane Protein ◽

Hepatocyte Proliferation ◽

Sigma 1 Receptor ◽

Cellular Models ◽

Huh7 Cells ◽

The Impact

Sigma receptor 1 (SigR1) is an endoplasmic reticulum resident integral membrane protein whose functions remain unclear. Although the liver shows the highest expression of SigR1, its role in this organ is unknown. SigR1 is overexpressed in many cancers and its expression is correlated to hormonal status in hormone-dependent cancers. To better understand the role of SigR1 in hepatocytes we focused our work on the regulation of its expression in tumoral liver. In this context, hepatocellular adenomas, benign hepatic tumors associated with estrogen intake are of particular interest. The expression of SigR1 mRNA was assessed in hepatocellular adenoma (HCA) patients using qPCR. The impact of estrogen on the expression of SigR1 was studied in vivo (mice) and in vitro (HepG2 and Huh7 cells). The effect of HNF1α on the expression of SigR1 was studied in vivo by comparing wild type mice to HNF1 knockout mice. Estrogen enhanced SigR1 expression through its nuclear receptor ERα. HNF1α mutated HCA (H-HCA) significantly overexpressed SigR1 compared to all other HCA subtypes. HNF1 knockout mice showed an increase in SigR1 expression. Overexpressing SigR1 in cellular models increases proliferation rate and storage of lipid droplets, which phenocopies the H-HCA phenotype. SigR1 is involved in hepatocyte proliferation and steatosis and may play an important role in the control of the H-HCA phenotype.

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Exosomal circ-RBM23 sponging miR-139-5p to promote liver regeneration through RRM2/AKT/mTOR pathway

10.21203/rs.3.rs-783482/v1 ◽

2021 ◽

Author(s):

Guolin He ◽

Yu Fu ◽

Zeyi Guo ◽

Honglei Zhu ◽

Lei Feng ◽

...

Keyword(s):

Stem Cells ◽

Liver Regeneration ◽

Partial Hepatectomy ◽

Membrane Vesicles ◽

Hepatocyte Proliferation ◽

Intercellular Interaction ◽

Proliferative Effect ◽

Proliferation In Vitro

Abstract BackgroundExosomes are small nano-size membrane vesicles and are involved in intercellular interaction. Here, we examined if exosomes obtained from human placental stem cells promote liver regeneration after partial hepatectomy. MethodsExosomes generated from primary human placental stem cells were isolated and characterized. Cell co-culture model was used to clarify whether exosomes can induce hepatocytes proliferation in vitro . Partial hepatectomy mouse model was used to evaluate whether exosomes can promote hepatocytes proliferation in vivo . ResultsIt is found that human placental-derived stem cells exosomes (hPDSCs-exo) can induce hepatocyte proliferation in vitro and in vivo . Mechanistically, exosomal circ-RBM23 served as a ceRNA for miR-139-5p, regulated RRM2 and accelerated proliferation through AKT/mTOR pathways. Ablation of exosomal circ-RBM23 suppressed the proliferative effect of exosomes. ConclusionsThe hPMSCs exosomal circ-RBM23 stimulated cell proliferation and liver regeneration after 70% partial hepatectomy by regulated RRM2. Our findings highlight a potential novel therapeutic avenue for liver regeneration after hepatectomy.

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Partial Hepatectomy-Induced Upregulation of miR-1907 Accelerates Liver Regeneration by Activation Autophagy

BioMed Research International ◽

10.1155/2018/3817057 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9

Author(s):

Tianfei Lu ◽

Jun Hao ◽

Chuan Shen ◽

Guangxiang Gu ◽

Jianjun Zhang ◽

...

Keyword(s):

Body Weight ◽

Liver Regeneration ◽

Partial Hepatectomy ◽

Weight Ratio ◽

Underlying Mechanism ◽

Hepatocyte Proliferation ◽

Pharmacological Intervention ◽

Body Weight Ratio

Liver regeneration after partial hepatectomy (PH) is a highly orchestrated biological process in which synchronized hepatocyte proliferation is induced after massive liver mass loss. Hepatocyte proliferation could be regulated by multiple signals, such as miRNAs and autophagy, but underlying mechanism remains unclear. Here a functional miRNA during liver regeneration was identified and its underlying mechanism was delineated in vitro and in vivo. We found that miR-1907 was highly upregulated during liver regeneration after 2/3 PH at various timepoints. The level of miR-1907 was also increased in normal liver cell line treated with HGF at different concentrations. Functionally, miR-1907 enhanced hepatocyte proliferation in vitro and in vivo, and the liver/body weight ratio in miR-1907-overexpressed mice was significantly higher in comparison to the control mice after 2/3 PH. Forced expression of miR-1907 promoted autophagy activation of hepatocyte. Importantly, autophagy inhibition significantly attenuated miR-1907-induced hepatocyte proliferation and the liver/body weight ratio. Finally, GSK3β, a suppressor of autophagy signaling, was identified as the direct target gene of miR-1907. Taken together, miR-1907 accelerates hepatocyte proliferation during liver regeneration by activating autophagy; thus pharmacological intervention regulating miR-1907/autophagy axis may be therapeutically beneficial in liver transplantation and liver failure by inducing liver regeneration.

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MKK3 sustains cell proliferation and survival through p38DELTA MAPK activation in colorectal cancer

Cell Death and Disease ◽

10.1038/s41419-019-2083-2 ◽

2019 ◽

Vol 10 (11) ◽

Cited By ~ 5

Author(s):

Lorenzo Stramucci ◽

Angelina Pranteda ◽

Arianna Stravato ◽

Carla Azzurra Amoreo ◽

Annarita Pennetti ◽

...

Keyword(s):

Colorectal Cancer ◽

Map Kinases ◽

Molecular Mechanisms ◽

Malignant Tumors ◽

Mapk Pathway ◽

Primary Cultures ◽

Mitogen Activated Protein Kinase ◽

Antitumor Effects

Abstract Colorectal cancer (CRC) is one of the most common malignant tumors worldwide and understanding its underlying molecular mechanisms is crucial for the development of therapeutic strategies. The mitogen-activated protein kinase-kinase 3 (MKK3) is a specific activator of p38 MAP kinases (p38 MAPKs), which contributes to the regulation of several cellular functions, such as proliferation, differentiation, apoptosis as well as response to drugs. At present, the exact MKK3/p38 MAPK pathway contribution in cancer is heavily debated because of its pleiotropic function. In this work, we retrospectively explored the prognostic and pathobiologic relevance of MKK3 in a cohort of CRC patients and assessed MKK3 molecular functions in a panel of CRC lines and colonocytes primary cultures. We found increased MKK3 levels in late-stage CRC patients which correlated with shorter overall survival. Herein, we report that the MKK3 targeting by inducible RNA interference univocally exerts antitumor effects in CRC lines but not in primary colonocytes. While MKK3 depletion per se affects growth and survival by induction of sustained autophagy and death in some CRC lines, it potentiates response to chemotherapeutic drug 5-fluorouracil (5-FU) in all of the tested CRC lines in vitro. Here, we demonstrate for the first time that in CRC the MKK3 specifically activates p38delta MAPK isoform to sustain prosurvival signaling and that such effect is exacerbated upon 5-FU challenge. Indeed, p38delta MAPK silencing recapitulates MKK3 depletion effects in CRC cells in vitro and in vivo. Overall, our data identified a molecular mechanism through which MKK3 supports proliferation and survival signaling in CRC, further supporting MKK3 as a novel and extremely attractive therapeutic target for the development of promising strategies for the management of CRC patients.

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The Mitogen-Activated Protein Kinase Kinase/Extracellular Signal-Regulated Kinase Cascade Activation Is a Key Signalling Pathway Involved in the Regulation of G1 Phase Progression in Proliferating Hepatocytes

Molecular and Cellular Biology ◽

10.1128/mcb.19.9.6003 ◽

1999 ◽

Vol 19 (9) ◽

pp. 6003-6011 ◽

Cited By ~ 197

Author(s):

Hélène Talarmin ◽

Claude Rescan ◽

Sandrine Cariou ◽

Denise Glaise ◽

Giuliana Zanninelli ◽

...

Keyword(s):

Cyclin D1 ◽

Partial Hepatectomy ◽

Mek Inhibitor ◽

Signalling Pathway ◽

Mitogen Activated Protein Kinase ◽

Mrna Accumulation ◽

Erk Activation ◽

Mitogen Activated Protein

ABSTRACT In this study, activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signalling pathway was analyzed in proliferating rat hepatocytes both in vivo after partial hepatectomy and in vitro following epidermal growth factor (EGF)-pyruvate stimulation. First, a biphasic MEK/ERK activation was evidenced in G1 phase of hepatocytes from regenerating liver but not from sham-operated control animals. One occurred in early G1 (30 min to 4 h), and the other occurred in mid-late G1, peaking at around 10.5 h. Interestingly, the mid-late G1 activation peak was located just before cyclin D1 induction in both in vivo and in vitro models. Second, the biological role of the MEK/ERK cascade activation in hepatocyte progression through the G1/S transition was assessed by adding a MEK inhibitor (PD 98059) to EGF-pyruvate-stimulated hepatocytes in primary culture. In the presence of MEK inhibitor, cyclin D1 mRNA accumulation was inhibited, DNA replication was totally abolished, and the MEK1 isoform was preferentially targeted by this inhibition. This effect was dose dependent and completely reversed by removing the MEK inhibitor. Furthermore, transient transfection of hepatocytes with activated MEK1 construct resulted in increased cyclin D1 mRNA accumulation. Third, a correlation between the mid-late G1 MEK/ERK activation in hepatocytes in vivo after partial hepatectomy and the mitogen-independent proliferation capacity of these cells in vitro was established. Among hepatocytes isolated either 5, 7, 9, 12 or 15 h after partial hepatectomy, only those isolated from 12- and 15-h regenerating livers were able to replicate DNA without additional growth stimulation in vitro. In addition, PD 98059 intravenous administration in vivo, before MEK activation, was able to inhibit DNA replication in hepatocytes from regenerating livers. Taken together, these results show that (i) early induction of the MEK/ERK cascade is restricted to hepatocytes from hepatectomized animals, allowing an early distinction of primed hepatocytes from those returning to quiescence, and (ii) mid-late G1 MEK/ERK activation is mainly associated with cyclin D1 accumulation which leads to mitogen-independent progression of hepatocytes to S phase. These results allow us to point to a growth factor dependency in mid-late G1 phase of proliferating hepatocytes in vivo as observed in vitro in proliferating hepatocytes and argue for a crucial role of the MEK/ERK cascade signalling pathway.

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Mechanism of CK2.3, a Novel Mimetic Peptide of Bone Morphogenetic Protein Receptor Type IA, Mediated Osteogenesis

International Journal of Molecular Sciences ◽

10.3390/ijms20102500 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2500 ◽

Cited By ~ 3

Author(s):

Vrathasha Vrathasha ◽

Hilary Weidner ◽

Anja Nohe

Keyword(s):

Signaling Pathways ◽

Treatment Options ◽

Time Frame ◽

Bmp Signaling ◽

C2c12 Cells ◽

Molecular Sequence ◽

Sequence Of Events ◽

Protein Receptor

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.

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The Revolutionary Roads to Study Cell–Cell Interactions in 3D In Vitro Pancreatic Cancer Models

Cancers ◽

10.3390/cancers13040930 ◽

2021 ◽

Vol 13 (4) ◽

pp. 930

Author(s):

Donatella Delle Cave ◽

Riccardo Rizzo ◽

Bruno Sainz ◽

Giuseppe Gigli ◽

Loretta L. del Mercato ◽

...

Keyword(s):

Pancreatic Cancer ◽

Therapeutic Response ◽

Three Dimensional ◽

Cellular Models ◽

Common Cancer ◽

Cancer Models ◽

Anti Cancer ◽

Tumor Environment

Pancreatic cancer, the fourth most common cancer worldwide, shows a highly unsuccessful therapeutic response. In the last 10 years, neither important advancements nor new therapeutic strategies have significantly impacted patient survival, highlighting the need to pursue new avenues for drug development discovery and design. Advanced cellular models, resembling as much as possible the original in vivo tumor environment, may be more successful in predicting the efficacy of future anti-cancer candidates in clinical trials. In this review, we discuss novel bioengineered platforms for anticancer drug discovery in pancreatic cancer, from traditional two-dimensional models to innovative three-dimensional ones.

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In Vitro Culture of Human Thyroid Cells: Preliminary Findings on the Role of the Pathological Condition of the Donors

Alternatives to Laboratory Animals ◽

10.1177/026119299702500208 ◽

1997 ◽

Vol 25 (2) ◽

pp. 153-160

Author(s):

Francesca Mattioli ◽

Marianna Angiola ◽

Laura Fazzuoli ◽

Francesco Razzetta ◽

Antonietta Martelli

Keyword(s):

Pathological Condition ◽

Primary Cultures ◽

S Phase ◽

Human Thyroid ◽

Thyroid Cells ◽

Toxicological Studies ◽

Predictive Indicator

Although primary cultures of human thyroid cells are used for endocrinological and toxicological studies, until now no attention has been paid toward verifying whether the hormonal conditions to which the gland was exposed in vivo prior to surgery could influence in vitro responses. Our findings suggest that the hormonal situation in vivo cannot be used as a predictive indicator of triiodothyronine and thyroxine release and/or S-phase frequency in vitro, either with or without the addition of bovine thyrotropin.

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Thymoquinone, a Dietary Bioactive Compound, Exerts Anti-Inflammatory Effects in Colitis by Stimulating Expression of the Colonic Epithelial PPAR-γ Transcription Factor

Nutrients ◽

10.3390/nu13041343 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1343

Author(s):

Balaji Venkataraman ◽

Saeeda Almarzooqi ◽

Vishnu Raj ◽

Abdullah T. Alhassani ◽

Ahmad S. Alhassani ◽

...

Keyword(s):

Transcription Factor ◽

Activity Index ◽

Nigella Sativa ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Ppar Γ ◽

Anti Inflammatory ◽

Ht 29

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders with increasing incidence and prevalence worldwide. Here, we investigated thymoquinone (TQ), a naturally occurring phytochemical present in Nigella sativa, for anti-inflammatory effects in colonic inflammation. To address this, we used in vivo (mice) and in vitro (HT-29 cells) models in this investigation. Our results showed that TQ treatment significantly reduced the disease activity index (DAI), myeloperoxidase (MPO) activity, and protected colon microscopic architecture. In addition, TQ also reduced the expression of proinflammatory cytokines and mediators at both the mRNA and protein levels. Further, TQ decreased phosphorylation of the activated mitogen-activated protein kinase (MAPK) signaling pathway and nuclear factor kappa B (NF-κB) proteins and enhanced colon epithelial PPAR-γ transcription factor expression. TQ significantly decreased proinflammatory chemokines (CXCL-1 and IL-8), and mediator (COX-2) mRNA expression in HT-29 cells treated with TNF-α. TQ also increased HT-29 PPAR-γ mRNA, PPAR-γ protein expression, and PPAR-γ promoter activity. These results indicate that TQ inhibits MAPK and NF-κB signaling pathways and transcriptionally regulates PPAR-γ expression to induce potent anti-inflammatory activity in vivo and in vitro models of colon inflammation.

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