Characterization of the Roles of Vimentin in Regulating the Proliferation and Migration of HSCs during Hepatic Fibrogenesis

TRIM47 promotes hypopharyngeal and laryngeal cancers progression through promoting K63-linked ubiquitination of vimentin

Hypopharyngeal and laryngeal cancers which belong to head and neck squamous cell carcinoma (HNSCC) are the two most malignant types of head and neck cancer, characterized by a low 5-year survival rate, high recurrence and metastasis rate. It is vital to explore strategies to suppress metastasis and improve prognosis for patients with these cancers. In this research, we analyzed the clinical data and found that E3 ubiquitin ligase TRIM47 was upregulated in cancer tissues of hypopharyngeal cancer and was closely associated with poor survival outcomes. In terms of mechanism, we performed tandem affinity chromatography and denatured Ni-NTA Agarose pulldown. As a result, TRIM47 was found to interact with vimentin and control vimentin stabilization through ubiquitination, specifically in the form of K63 chains. Importantly, through experiments of cancer cell viability and migration, we found that TRIM47 could enhance the proliferation and metastasis abilities of cancer cells in a vimentin-dependent manner, thus promoting the advancement of hypopharyngeal and laryngeal cancers. TRIM47 was verified to regulate cancer cells metastasis in vivo using metastasis models. All these results imply that TRIM47 emerges as a potential biomarker for early diagnosis and metastasis prediction of hypopharyngeal and laryngeal cancers and represents a promising therapeutic target.

miR-106b-5p protects against drug-induced liver injury by targeting vimentin to stimulate liver regeneration

Understanding the endogenous mechanism of adaptive response to drug-induced liver injury (arDILI) may discover innovative strategies to manage DILI. To gain mechanistic insight into arDILI, we investigated exosomal miRNAs in the adaptive response to toosendanin-induced liver injury (TILI) of mice. Exosomal miR-106b-5p was identified as a specific regulator of arDILI by comprehensive miRNA profiling. Outstandingly, miR-106b-5p agomir treatment alleviated TILI and other DILI by inhibiting apoptosis and promoting hepatocyte proliferation. Conversely, antagomir treatments had opposite effects, indicating that miR-106b-5p protects mice from liver injury. Injured hepatocytes released miR-106b-5p-enriched exosomes taken up by surrounding hepatocytes. Vim (encodes vimentin) was identified as an important target of miR-106b-5p by dual luciferase reporter and siRNA assays. Furthermore, single-cell RNA-sequencing analysis of toosendanin-injured mouse liver revealed a cluster of Vim + hepatocytes; nonetheless declined following miR-106b-5p cotreatment. More importantly, Vim knockout protected mice from acetaminophen poisoning and TILI. In the clinic, serum miR-106b-5p expression levels correlated with the severity of DILI. Indeed, liver biopsies of clinical cases exposed to different DILI causing drugs revealed marked vimentin expression among harmed hepatocytes, confirming clinical relevance. Together, we report mechanisms of arDILI whereby miR-106b-5p safeguards restorative tissue repair by targeting vimentin.

Distinctive protein expression in elderly livers in a Sprague-Dawley rat model of normothermic ex vivo liver machine perfusion

BACKGROUND

Liver grafts are frequently declined due to high donor age or age mismatch with the recipient. To improve the outcome of marginal grafts, we aimed to characterize the performance of elderly vs. young liver grafts in a standardized rat model of normothermic ex vivo liver machine perfusion (NMP).

METHODS

Livers from Sprague-Dawley rats aged 3 or 12 months were procured and perfused for 6 h using a rat NMP system or collected as a reference group (n = 6/group). Tissue, bile, and perfusate samples were used for biochemical, and proteomic analyses.

RESULTS

All livers cleared lactate during perfusion and continued to produce bile after 6 h of perfusion (614 mg/h). Peak urea levels in 12-month-old animals were higher than in younger animals. Arterial and portal venous pressure, bile production and pH did not differ between groups. Proteomic analysis identified a total of 1477 proteins with oxidoreductase and catalytic activity dominating the gene ontology analysis. Proteins such as aldehyde dehydrogenase 1A1 and 2-Hydroxyacid oxidase 2 were significantly more present in livers of older age.

CONCLUSIONS

Young and elderly liver grafts exhibited similar viability during NMP, though proteomic analyses indicated that older grafts are less resilient to oxidative stress. Our study is limited by the elderly animal age, which corresponds to mature but not elderly human age typically seen in marginal human livers. Nevertheless, reducing oxidative stress could be a promising therapeutic target in the future.

Mechanobiology in Metabolic Dysfunction-Associated Steatotic Liver Disease and Obesity

With the ongoing obesity epidemic, the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is expected to rise and necessitates a greater understanding of how the disease proceeds from benign excess lipid in hepatocytes to liver fibrosis and eventually to liver cancer. MASLD is caused, at least in part, by hepatocytes' storage of free fatty acids (FAs) that dysfunctional adipocytes are no longer able to store, and therefore, MASLD is a disease that involves both the liver and adipose tissues. The disease progression is not only facilitated by biochemical signals, but also by mechanical cues such as the increase in stiffness often seen with fibrotic fatty livers. The change in stiffness and accumulation of excess lipid droplets impact the ability of a cell to mechanosense and mechanotranduce, which perpetuates the disease. A mechanosensitive protein that is largely unexplored and could serve as a potential therapeutic target is the intermediate filament vimentin. In this review, we briefly summarize the recent research on hepatocyte and adipocyte mechanobiology and provide a synopsis of studies on the varied, and sometimes contradictory, roles of vimentin. This review is intended to benefit and encourage future studies on hepatocyte and adipocyte mechanobiology in the context of MASLD and obesity.

Vimentin at the core of wound healing

As a member of the large family of intermediate filaments (IFs), vimentin has emerged as a highly dynamic and versatile cytoskeletal protein involved in many key processes of wound healing. It is well established that vimentin is involved in epithelial-mesenchymal transition (EMT) during wound healing and metastasis, during which epithelial cells acquire more dynamic and motile characteristics. Moreover, vimentin participates in multiple cellular activities supporting growth, proliferation, migration, cell survival, and stress resilience. Here, we explore the role of vimentin at each phase of wound healing, with focus on how it integrates different signaling pathways and protects cells in the fluctuating and challenging environments that characterize a healing tissue.

Phosphorylated vimentin at Ser72 is associated with epithelial-mesenchymal transition in lupus nephritis

OBJECTIVES

To measure the expression of vimentin and its phosphorylated forms in lupus nephritis (LN) and explore their potential role in LN development.

METHODS

Lupus renal biopsies from LN patients and normal renal biopsies from kidney transplant donors were collected. The expression of vimentin and its phosphorylated forms (p-vimentin (Ser39, Ser56, Ser72, Ser83, and Tyr117)) were measured by Western blots and immunohistochemistry. To construct stable cell line that overexpress vimentin and its phosphorylated forms, an immortalized proximal tubule epithelial cell line (HK-2 cells) was utilized. The roles of vimentin and its phosphorylated forms on the migration of HK-2 cells were examined by transwell migration assay and wound healing analysis.

RESULTS

We first observed a significant upregulation of vimentin protein in TGFβ1-induced HK-2 cells. This finding was further confirmed in renal tissues obtained from LN patients and animal model. Interestingly, among the five phosphorylated forms of vimentin, only vimentin phosphorylated at Ser72 was upregulated in LN. Through the establishment of stable vimentin and its phosphorylated forms overexpression in HK-2 cells, we found that the overexpression of vimentin and its phosphorylated forms at Ser72 significantly enhances the cell migration.

CONCLUSIONS

Vimentin phosphorylated on Ser72 is important for renal epithelial cell migration, which would enhance the progression of vimentin-induced epithelial-mesenchymal transition during LN development.

FRMD3 inhibits the growth and metastasis of breast cancer through the ubiquitination-mediated degradation of vimentin and subsequent impairment of focal adhesion

Recurrence and metastasis are the main causes of breast cancer (BRCA)-related death and remain a challenge for treatment. In-depth research on the molecular mechanisms underlying BRCA progression has been an important basis for developing precise biomarkers and therapy targets for early prediction and treatment of progressed BRCA. Herein, we identified FERM domain-containing protein 3 (FRMD3) as a novel potent BRCA tumor suppressor which is significantly downregulated in BRCA clinical tissue and cell lines, and low FRMD3 expression has been closely associated with progressive BRCA and shortened survival time in BRCA patients. Overexpression and knockdown experiments have revealed that FRMD3 significantly inhibits BRCA cell proliferation, migration, and invasion in vitro and suppresses BRCA xenograft growth and metastasis in vivo as well. Mechanistically, FRMD3 can interact with vimentin and ubiquitin protein ligase E3A(UBE3A) to induce the polyubiquitin-mediated proteasomal degradation of vimentin, which subsequently downregulates focal adhesion complex proteins and pro-cancerous signaling activation, thereby resulting in cytoskeletal rearrangement and defects in cell morphology and focal adhesion. Further evidence has confirmed that FRMD3-mediated vimentin degradation accounts for the anti-proliferation and anti-metastasis effects of FRMD3 on BRCA. Moreover, the N-terminal ubiquitin-like domain of FRMD3 has been identified as responsible for FRMD3-vimentin interaction through binding the head domain of vimentin and the truncated FRMD3 with the deletion of ubiquitin-like domain almost completely loses the anti-BRCA effects. Taken together, our study indicates significant potential for the use of FRMD3 as a novel prognosis biomarker and a therapeutic target of BRCA and provides an additional mechanism underlying the degradation of vimentin and BRCA progression.

Transcriptome Analysis Reveals Vimentin-Induced Disruption of Cell-Cell Associations Augments Breast Cancer Cell Migration

In advanced metastatic cancers with reduced patient survival and poor prognosis, expression of vimentin, a type III intermediate filament protein is frequently observed. Vimentin appears to suppress epithelial characteristics and augments cell migration but the molecular basis for these changes is not well understood. Here, we have ectopically expressed vimentin in MCF-7 and investigated its genomic and functional implications. Vimentin changed the cell shape by decreasing major axis, major axis angle and increased cell migration, without affecting proliferation. Vimentin downregulated major keratin genes KRT8, KRT18 and KRT19. Transcriptome-coupled GO and KEGG analyses revealed that vimentin-affected genes were linked to either cell-cell/cell-ECM or cell cycle/proliferation specific pathways. Using shRNA mediated knockdown of vimentin in two cell types; MCF-7FV (ectopically expressing) and MDA-MB-231 (endogenously expressing), we identified a vimentin-specific signature consisting of 13 protein encoding genes (CDH5, AXL, PTPRM, TGFBI, CDH10, NES, E2F1, FOXM1, CDC45, FSD1, BCL2, KIF26A and WISP2) and two long non-coding RNAs, LINC00052 and C15ORF9-AS1. CDH5, an endothelial cadherin, which mediates cell-cell junctions, was the most downregulated protein encoding gene. Interestingly, downregulation of CDH5 by shRNA significantly increased cell migration confirming our RNA-Seq data. Furthermore, presence of vimentin altered the lamin expression in MCF-7. Collectively, we demonstrate, for the first time, that vimentin in breast cancer cells could change nuclear architecture by affecting lamin expression, which downregulates genes maintaining cell-cell junctions resulting in increased cell migration.

Signaling Pathways and Protein-Protein Interaction of Vimentin in Invasive and Migration Cells: A Review

The vimentin (encoded by VIM) is one of the 70 human intermediate filaments (IFs), building highly dynamic and cell-type-specific web networks in the cytoplasm. Vim^-/- mice exhibit process defects associated with cell differentiation, which can have implications for understanding cancer and disease. This review showed recent reports from studies that unveiled vimentin intermediate filaments (VIFs) as an essential component of the cytoskeleton, followed by a description of vimentin's physiological functions and process reports in VIF signaling pathway and gene network studies. The main focus of the discussion is on vital signaling pathways associated with how VIF coordinates invasion cells and migration. The current research will open up multiple processes to research the function of VIF and other IF proteins in cellular and molecular biology, and they will lead to essential insights into different VIF levels for the invasive metastatic cancer cells. Enrich GO databases used Gene Ontology and Pathway Enrichment Analysis. Estimation with STRING online was to predict the functional and molecular interactions of proteins-protein with Cytoscape analysis to search and select the master genes. Using Cytoscape and STRING analysis, we presented eight genes, RhoA, Smad3, Akt1, Cdk2, Rock1, Rock2, Mapk1, and Mapk8, as the essential protein-protein interaction with vimentin involved in the invasion.

Liver pathology and biochemistry in patients with mutations in TRIM37 gene (Mulibrey nanism)

BACKGROUND AND AIMS

Mulibrey nanism (MUL) is a multiorgan disease caused by recessive mutations in the TRIM37 gene. Chronic heart failure and hepatopathy are major determinants of prognosis in MUL patients, which prompted us to study liver biochemistry and pathology in a national cohort of MUL patients.

METHODS

Clinical, laboratory and imaging data were collected in a cross-sectional survey and retrospectively from hospital records. Liver histology and immunohistochemistry for 10 biomarkers were assessed.

RESULTS

Twenty-one MUL patients (age 1-51 years) with tumour suspicion showed moderate congestion, steatosis and fibrosis in liver biopsies and marginally elevated levels of serum GGT, AST, ALT and AST to platelet ratio index (APRI) in 20%-66%. Similarly, GGT, AST, ALT and APRI levels were moderately elevated in 12%-69% of 17 MUL patients prior to pericardiectomy. In a cross-sectional evaluation of 36 MUL outpatients, GGT, total bilirubin and galactose half-life (Gal½) correlated with age (r = 0.45, p = .017; r = 0.512, p = .007; r = 0.44, p = .03 respectively). The frequency of clearly abnormal serum values of 15 parameters analysed, however, was low even in patients with signs of restrictive cardiomyopathy. Transient elastography (TE) of the liver revealed elevated levels in 50% of patients with signs of heart failure and TE levels correlated with several biochemistry parameters. Biomarkers of fibrosis, sinusoidal capillarization and hepatocyte metaplasia showed increased expression in autopsy liver samples from 15 MUL patients.

CONCLUSION

Liver disease in MUL patients was characterized by sinusoidal dilatation, steatosis and fibrosis with individual progression to cirrhosis and moderate association of histology with cardiac function, liver biochemistry and elastography.

In vitro and in vivo study: Ethanolic extract leaves of Azadirachta indica Juss. variant of Indonesia and Philippines suppresses tumor growth of hepatocellular carcinoma by inhibiting IL-6/STAT3 signaling

Background: Azadirachta indica Juss. has been shown to suppress cancer progression through a variety of mechanisms. In order to treat cancer progression, cancer immunotherapy is used to stimulate the immune system where immunosuppression is present in tumor microenvironments. Many cancer cells produce a lot of interleukin-6 (IL-6) and signal transducer activator of transcription 3 (STAT3). STAT3 plays a key role in suppressing the expression of critical immune activation regulators. IL-6-mediated STAT3 activation is common in the tumor microenvironment. Inhibiting the IL-6/STAT3 signaling pathway has become a therapeutic option for cancer progression. As vimentin is also expressed in hepatic stellate cells boosting cancer survival. We focused on the precise effect of extract from leaves of Azadirachta indica Juss, on inhibiting the IL-6/STAT3 signaling cascade on hepatocellular carcinoma by in vitro and in vivo study. Methods: In the in vitro study, the effect of Azadirachta indica Juss. variant Indonesia and Philippines against the expression of IL-6 and STAT3 was examined in liver cancer cell line. In the in vivo study, 24 male rats ( Rattus norvegicus) strain Wistar were induced by diethylnitrosamine and carbon tetrachloride (CCl 4). Based on the therapy given, the groups were divided into negative control, positive control, Indonesia extract, and Philippine extract. Expression of IL-6, STAT3, and vimentin were tested using immunohistochemistry staining. The data were analyzed using analysis of variance, which was then followed by the Tukey test. Results: Statistically significant difference in IL-6 and STAT3 was observed between the treatment groups and positive control group by in vitro study and in vivo study. Generally, there is no significant difference between treatment using Indonesian and Philippine leaves. Conclusion: Both therapy doses of Azadirachta indica variant in Indonesia and Philippines were able to reduce IL-6, STAT3 and vimentin expression of hepatocellular carcinoma cell by in vitro and in vivo experiment.

Impact of Vimentin on Regulation of Cell Signaling and Matrix Remodeling

Vimentin expression contributes to cellular mechanoprotection and is a widely recognized marker of fibroblasts and of epithelial-mesenchymal transition. But it is not understood how vimentin affects signaling that controls cell migration and extracellular matrix (ECM) remodeling. Recent data indicate that vimentin controls collagen deposition and ECM structure by regulating contractile force application to the ECM and through post-transcriptional regulation of ECM related genes. Binding of cells to the ECM promotes the association of vimentin with cytoplasmic domains of adhesion receptors such as integrins. After initial adhesion, cell-generated, myosin-dependent forces and signals that impact vimentin structure can affect cell migration. Post-translational modifications of vimentin determine its adaptor functions, including binding to cell adhesion proteins like paxillin and talin. Accordingly, vimentin regulates the growth, maturation and adhesive strength of integrin-dependent adhesions, which enables cells to tune their attachment to collagen, regulate the formation of cell extensions and control cell migration through connective tissues. Thus, vimentin tunes signaling cascades that regulate cell migration and ECM remodeling. Here we consider how specific properties of vimentin serve to control cell attachment to the underlying ECM and to regulate mesenchymal cell migration and remodeling of the ECM by resident fibroblasts.

Cytoskeleton alterations in non-alcoholic fatty liver disease

BACKGROUND

Due to its extremely high prevalence and severity, non-alcoholic fatty liver disease (NALFD) is a serious health and economic concern worldwide. Developing effective methods of diagnosis and therapy demands a deeper understanding of its molecular basis. One of the strategies in such an endeavor is the analysis of alterations in the morphology of liver cells. Such alterations, widely reported in NAFLD patients and disease models, are related to the cytoskeleton. Therefore, the fate of the cytoskeleton components is useful to uncover the molecular basis of NAFLD, to further design innovative approaches for its diagnosis and therapy.

MAIN FINDINGS

Several cytoskeleton proteins are up-regulated in liver cells of NAFLD patients. Under pathological conditions, keratin 18 is released from hepatocytes and its detection in the blood emerges as a non-invasive diagnosis tool. α-Smooth muscle actin is up-regulated in hepatic stellate cells and its down-regulation has been widely tested as a potential NALFD therapeutic approach. Other cytoskeleton proteins, such as vimentin, are also up-regulated.

CONCLUSIONS

NAFLD progression involves alterations in expression levels of proteins that build the liver cytoskeleton or associate with it. These findings provide a timely opportunity of developing novel approaches for NAFLD diagnosis and therapy.

Hepatic inflammation and liver fibrogenesis: A potential target for the treatment of cystic echinococcosis-associated hepatic injury

To investigate the effect of cystic echinococcosis (CE) on liver damage, we developed a secondary experimental echinococcosis in Swiss mice by intraperitoneal inoculation of viable protoscoleces. Mice were randomly allocated into three groups: Ctrl group, PBS group, and CE group. Mice were euthanized and associated indications were investigated to evaluate inflammatory and fibrotic responses in liver. Hepatic damage and fibrotic reaction were histologically analyzed. The hepatic expression of iNOS, TNF-α, NF-κβ, vimentin, Bcl-2 and CD68 was evaluated by Immunohistochemical examinations. Interestingly, a significant iNOS, TNF-α, NF-κβ, vimentin, Bcl-2 and CD68 increase levels was observed in liver tissue and pericystic layer of hepatic hydatid cyst and correlate with the abundance of collagen and reticulin fibers. These observations could promote a potential target for the treatment of CE-associated hepatic injury.

Resolvin D1 attenuates CCl4 Induced Liver Fibrosis by Inhibiting Autophagy-Mediated HSC activation via AKT/mTOR Pathway

Resolvin D1 (RvD1) was previously reported to relieve inflammation and liver damage in several liver diseases, but its potential role in liver fibrosis remains elusive. The aim of our study was to investigate the effects and underlying mechanisms of RvD1 in hepatic autophagy in liver fibrosis. In vivo, male C57BL/6 mice were intraperitoneally injected with 20% carbon tetrachloride (CCl4, 5 ml/kg) twice weekly for 6 weeks to establish liver fibrosis model. RvD1 (100 ng or 300 ng/mouse) was added daily in the last 2 weeks of the modeling period. In vitro, lipopolysaccharide (LPS)-activated LX-2 cells were co-treated with increasing concentrations (2.5-10 nM) of RvD1. The degree of liver injury was measured by detecting serum AST and ALT contents and H&E staining. Hepatic fibrosis was assessed by masson's trichrome staining and metavir scoring. The qRT-PCR, western blot, immunohistochemistry, and immunofluorescence were applied to liver tissues or LPS-activated LX-2 cells to explore the protective effects of RvD1 in liver fibrosis. Our findings reported that RvD1 significantly attenuated CCl4 induced liver injury and fibrosis by decreasing plasma AST and ALT levels, reducing collagen I and α-SMA accumulation and other pro-fibrotic genes (CTGF, TIMP-1 and Vimentin) expressions in mouse liver, restoring damaged histological architecture and improving hepatic fibrosis scores. In vitro, RvD1 also repressed the LPS induced LX-2 cells activation and proliferation. These significant improvements mainly attributed to the inhibiting effect of RvD1 on autophagy in the process of hepatic stellate cell (HSC) activation, as demonstrated by decreased ratio of LC3-II/I and elevated p62 after RvD1 treatment. In addition, using AZD5363 (an AKT inhibitor that activates autophagy) and AZD8055 (an mTOR inhibitor, another autophagy activator), we further verified that RvD1 suppressed autophagy-mediated HSC activation and alleviated CCl4 induced liver fibrosis partly through AKT/mTOR pathway. Overall, these results demonstrate that RvD1 treatment is expected to become a novel therapeutic strategy against liver fibrosis.

Antioxidant properties of red raspberry extract alleviate hepatic fibrosis via inducing apoptosis and transdifferentiation of activated hepatic stellate cells

Hepatic fibrosis is a wound-healing process caused by prolonged liver damage and often occurs due to hepatic stellate cell activation in response to reactive oxygen species (ROS). Red raspberry has been found to attenuate oxidative stress, mainly because it is rich in bioactive components. In the current study, we investigated the inhibitory effects and associated molecular mechanisms of red raspberry extract (RBE) upon activated hepatic stellate cell (aHSC) in cellular and rat models. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased in the dimethylnitrosamine (DMN)-applied samples, whereas treatment of RBE significantly suppressed the activities of these enzymes. In addition, a histopathological analysis demonstrated that RBE could substantially diminish the hepatic collagen content and alpha-smooth muscle actin (α-SMA) expression induced by DMN. Administration of 250 μg/mL RBE could also arrest the growth and enhance the apoptosis of activated HSC-T6 cells, which was accompanied with elevated levels of activated caspases and poly (ADP-ribose) polymerase (PARP) cleavage. Particularly, RBE application remarkably abolished oxidative damage within the cells and reduced the carbonylation of proteins, which was attributed to the upregulation of catalase, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). Moreover, the knockdown of Nrf2 together with the RBE treatment synergistically abrogated the expression of α-SMA and promoted the level of peroxisome proliferator-activated receptor gamma (PPAR-γ), suggesting that RBE could mitigate the transdifferentiation of HSC in a Nrf2-independent manner. These findings implied that the application of RBE could effectively remove oxidative stress and relieve the activation of HSC via modulating the caspase/PARP, Nrf2/HO-1 and PPAR-γ pathways, which may allow the development of novel therapeutic strategies against chemical-caused liver fibrogenesis.

Comparative Analysis of Dental Pulp and Periodontal Stem Cells: Differences in Morphology, Functionality, Osteogenic Differentiation and Proteome

Dental stem cells are heterogeneous in their properties. Despite their common origin from neural crest stem cells, they have different functional capacities and biological functions due to niche influence. In this study, we assessed the differences between dental pulp stem cells (DPSC) and periodontal ligament stem cells (PDLSC) in their pluripotency and neuroepithelial markers transcription, morphological and functional features, osteoblast/odontoblast differentiation and proteomic profile during osteogenic differentiation. The data were collected in paired observations: two cell cultures, DPSC and PDLSC, were obtained from each donor. Both populations had the mesenchymal stem cells surface marker set exposed on their membranes but differed in Nestin (a marker of neuroectodermal origin) expression, morphology, and proliferation rate. OCT4 mRNA was revealed in DPSC and PDLSC, while OCT4 protein was present in the nuclei of DPSC only. However, transcription of OCT4 mRNA was 1000-10,000-fold lower in dental stem cells than in blastocysts. DPSC proliferated at a slower rate and have a shape closer to polygonal but they responded better to osteogenic stimuli as compared to PDLSC. RUNX2 mRNA was detected by qPCR in both types of dental stem cells but RUNX2 protein was detected by LC-MS/MS shotgun proteomics only in PDLSC suggesting the posttranscriptional regulation. DSPP and DMP1, marker genes of odontoblastic type of osteogenic differentiation, were transcribed in DPSC but not in PDLSC samples. Our results prove that DPSC and PDLSC are different in their biology and therapeutic potential: DPSC are a good candidate for osteogenic or odontogenic bone-replacement cell-seeded medicines, while fast proliferating PDLSC are a prospective candidate for other cell products.

Molecular characterization and cell type composition deconvolution of fibrosis in NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide. In adults with NAFLD, fibrosis can develop and progress to liver cirrhosis and liver failure. However, the underlying molecular mechanisms of fibrosis progression are not fully understood. Using total RNA-Seq, we investigated the molecular mechanisms of NAFLD and fibrosis. We sequenced liver tissue from 143 adults across the full spectrum of fibrosis stage including those with stage 4 fibrosis (cirrhosis). We identified gene expression clusters that strongly correlate with fibrosis stage including four genes that have been found consistently across previously published transcriptomic studies on NASH i.e. COL1A2, EFEMP2, FBLN5 and THBS2. Using cell type deconvolution, we estimated the loss of hepatocytes versus gain of hepatic stellate cells, macrophages and cholangiocytes with advancing fibrosis stage. Hepatocyte-specific functional analysis indicated increase of pro-apoptotic pathways and markers of bipotent hepatocyte/cholangiocyte precursors. Regression modelling was used to derive predictors of fibrosis stage. This study elucidated molecular and cell composition changes associated with increasing fibrosis stage in NAFLD and defined informative gene signatures for the disease.

Vimentin loss promotes cancer proliferation through up-regulating Rictor/AKT/β-catenin signaling pathway

Vimentin protein is one of the main cytoskeleton and plays an important role in cell motility and metastasis. Nowadays, vimentin is widely studied as an epithelial-mesenchymal transition (EMT) marker of cancer cells while its involvement in cancer proliferation is poorly understood. In this study, we investigated the participation of vimentin in regulating cancer proliferation by silencing VIM gene in four cancer cell lines. Our results demonstrated that vimentin loss significantly induced cancer cell proliferation both in vitro and in vivo, which has not been reported so far. Mechanistically, knockdown of vimentin expression activated AKT phosphorylation and its downstream β-catenin signaling. Nuclear translocation and transcriptional activity of β-catenin was enhanced after silencing vimentin expression. Furthermore, vimentin loss could prevent Rictor from autophagy-dependent degradation via reducing AMPK-mediated autophagy signaling. AICAR, an AMPK activator, down-regulated Rictor and p-AKT levels while vimentin knockdown could rescue the effects. In vivo, it was also found that Ki67 expression and p-AKT/β-catenin signaling pathway were obviously up-regulated in the tumor tissues in which vimentin was silenced compared to control groups. Taken together, these data showed the novel function of vimentin in regulating cancer proliferation via Rictor/AKT/β-catenin signaling pathway, which suggested that it need more careful consideration before inhibiting metastatic cancers through targeting vimentin.

Chemical conversion of aged hepatocytes into bipotent liver progenitor cells

AIM

In the aging society, understanding the influence of hepatocyte age on hepatocyte donation may inform efforts to expand alternative cell sources to mitigate liver donor shortage. A combination of the molecules Y27632, A-83-01, and CHIR99021 has been used to reprogram rodent young hepatocytes into chemically induced liver progenitor (CLiP) cells; however, whether it could also reprogram aged hepatocytes has not yet been elucidated.

METHODS

Primary hepatocytes were isolated from aged and young donor rats, respectively. Hepatic histological changes were evaluated. Differences in gene expression in hepatocytes were identified. The in vitro reprogramming plasticity of hepatocytes as evidenced by CLiP conversion and the hepatocyte and cholangiocyte maturation capacity of reprogrammed CLIPs were analyzed. The effect of hepatocyte growth factor (HGF) on cell propagation was also investigated.

RESULTS

The histological findings revealed ongoing liver damage with inflammation, fibrosis, senescence, and ductular reaction in aged livers. Microarray analysis showed altered gene expression profiles in hepatocytes from aged donors, especially with regard to metabolic pathways. Aged hepatocytes could be converted into CLiPs (Aged-CLiPs) expressing progenitor cell markers, but with a relatively low proliferative rate compared with young hepatocytes. Aged-CLiPs possessed both hepatocyte and cholangiocyte maturation capacity. HGF facilitated CLiP conversion in aged hepatocytes, which was partly related to the activation of Erk1 and Akt1 signaling.

CONCLUSIONS

Aged rat hepatocytes have retained reprogramming plasticity as evidenced by CLiP conversion in culture. HGF promoted proliferation and CLiP conversion in aged hepatocytes. Hepatocytes from aged donors may be used as an alternative cell source to mitigate donor shortage.

Characterizing the Relapse Potential in Different Luminal Subtypes of Breast Cancers with Functional Proteomics

Poor prognosis due to the high relapse and metastasis rates of breast cancer has been particularly linked to the luminal B subtype. The current study utilized MCF-7 and ZR-75-1 to investigate various luminal subtypes of breast cancers that have discrepant expressions in the estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). Understanding of the differential protein profiles and the associated pathways could help alleviate the malignance and promote the long-term survival rate of breast cancer patients. Functional proteome tools were applied to comprehensively delineate the global protein alterations that reflect the varieties of biological features between the two subtypes. In this study, a total of 11 proteins with significant and meaningful changes were identified. These protein targets including PRX2, CK19, nucleophosmin and cathepsin D were mostly involved in cell differentiation or proliferation. Particularly, cathepsin D was highly expressed in the luminal B subtype. Moreover, the level of cathepsin-D was also upregulated in the clinical metastatic tissues. Accordingly, the RNA interference-mediated silencing of cathepsin D stimulated ER expression but suppressed the level of HER2. The knockdown of cathepsin D enhanced the level of ZO-1 and a remarkable decrease in N-cadherin was also detected. Again, the matrix metalloproteinases (MMP) activity was impaired under the cathepsin D abolishment. Collectively, this study represented a modality to explore novel relationships in a proteome complex and highlighted the functional roles of cathepsin D in treatment options for different subtypes of breast cancer.

Water-Soluble Pristine C60 Fullerene Inhibits Liver Alterations Associated with Hepatocellular Carcinoma in Rat

Excessive production of reactive oxygen species is the main cause of hepatocellular carcinoma (HCC) initiation and progression. Water-soluble pristine C₆₀ fullerene is a powerful and non-toxic antioxidant, therefore, its effect under rat HCC model and its possible mechanisms were aimed to be discovered. Studies on HepG2 cells (human HCC) demonstrated C₆₀ fullerene ability to inhibit cell growth (IC₅₀ = 108.2 μmol), to induce apoptosis, to downregulate glucose-6-phosphate dehydrogenase, to upregulate vimentin and p53 expression and to alter HepG2 redox state. If applied to animals experienced HCC in dose of 0.25 mg/kg per day starting at liver cirrhosis stage, C₆₀ fullerene improved post-treatment survival similar to reference 5-fluorouracil (31 and 30 compared to 17 weeks) and inhibited metastasis unlike the latter. Furthermore, C₆₀ fullerene substantially attenuated liver injury and fibrosis, decreased liver enzymes, and normalized bilirubin and redox markers (elevated by 1.7–7.7 times under HCC). Thus, C₆₀ fullerene ability to inhibit HepG2 cell growth and HCC development and metastasis and to improve animal survival was concluded. C₆₀ fullerene cytostatic action might be realized through apoptosis induction and glucose-6-phosphate dehydrogenase downregulation in addition to its antioxidant activity.

Special Issue on "Cellular and Molecular Mechanisms Underlying the Pathogenesis of Hepatic Fibrosis"

This Special issue contains 48 contributions highlighting novel findings and current concepts in basic and clinical liver fibrosis research. These articles emphasize issues on pathogenesis, cellular mediators, modulators, molecular pathways, disease-specific therapies, scoring systems, as well as novel preclinical animal models for the study of liver fibrogenesis. This editorial aims to briefly summarize the content of these papers.

R-spondin3 promotes the tumor growth of choriocarcinoma JEG-3 cells

R-spondin3 (RSPO3), an activator of Wnt/β-catenin signaling, plays a key role in tumorigenesis of various cancers, but its role in choriocarcinoma remains unknown. To investigate the effect of RSPO3 on the tumor growth of choriocarcinoma JEG-3 cells, the expression of RSPO3 in human term placenta was detected, and a stable RSPO3-overexpressing JEG-3 cell line was established via lentivirus-mediated transduction. The expression of biomarkers involved in tumorigenicity was detected in the RSPO3-overexpressing JEG-3 cells, and cell proliferation, invasion, migration, and apoptosis were investigated. Moreover, soft agar clonogenic assays and xenograft tumorigenicity assays were performed to assess the effect of RSPO3 on tumor growth in vitro and in vivo. The results showed that RSPO3 was widely expressed in human term placenta and overexpression of RSPO3 promoted the proliferation and inhibited the migration, invasion, and apoptosis of the JEG-3 cells. Meanwhile, RSPO3 overexpression promoted tumor growth both in vivo and in vitro. Further investigation showed that the phosphorylation levels of Akt, phosphatidylinositol 3-kinase (PI3K), and ERK as well the expression of β-catenin and proliferating cell nuclear antigen (PCNA) were increased in the RSPO3-overexpressing JEG-3 cells and tumor xenograft. Taken together, these data indicate that RSPO3 promotes the tumor growth of choriocarcinoma via Akt/PI3K/ERK signaling, which supports RSPO3 as an oncogenic driver promoting the progression of choriocarcinoma.