TNF-α induces matrix metalloproteinase-9-dependent soluble intercellular adhesion molecule-1 release via TRAF2-mediated MAPKs and NF-κB activation in osteoblast-like MC3T3-E1 cells

Cerebral Aneurysm: Filling the Gap Between Pathophysiology and Nanocarriers

Intracranial aneurysms, characterized by abnormal dilations of cerebral arteries, pose significant health risks due to their potential to rupture, leading to subarachnoid hemorrhage with high mortality and morbidity rates. This paper aim is to explore the innovative application of nanoparticles in treating intracranial aneurysms, offering a promising avenue for enhancing current therapeutic strategies. We took into consideration the pathophysiology of cerebral aneurysms, focusing on the role of hemodynamic stress, endothelial dysfunction, and inflammation in their development and progression. By comparing cerebral aneurysms with other types, such as aortic aneurysms, we identify pathophysiological similarities and differences that could guide the adaptation of treatment approaches. The review highlights the potential of nanoparticles to improve drug delivery, targeting, and efficacy while minimizing side effects. We discuss various nanocarriers, including liposomes and polymeric nanoparticles, and their roles in overcoming biological barriers and enhancing therapeutic outcomes. Additionally, we discuss the potential of specific compounds, such as Edaravone and Tanshinone IIA, when used in conjunction with nanocarriers, to provide neuroprotective and anti-inflammatory benefits. By extrapolating insights from studies on aortic aneurysms, new research directions and therapeutic strategies for cerebral aneurysms are proposed. This interdisciplinary approach underscores the potential of nanoparticles to positively influence the management of intracranial aneurysms, paving the way for personalized treatment options that could significantly improve patient outcomes.

Integrated bioinformatic analysis of protein landscape in gingival crevicular fluid unveils sequential bioprocess in orthodontic tooth movement

BACKGROUND

The biological mechanisms driving orthodontic tooth movement (OTM) remain incompletely understood. Gingival crevicular fluid (GCF) is an important indicator of the periodontal bioprocess, providing valuable cues for probing the molecular mechanisms of OTM.

METHODS

A rigorous review of the clinical studies over the past decade was conducted after registering the protocol with PROSPERO and adhering to inclusion criteria comprising human subjects, specified force magnitudes and force application modes. The thorough screening investigated differentially expressed proteins (DEPs) in GCF associated with OTM. Protein-protein interaction (PPI) analysis was carried out using the STRING database, followed by further refinement through Cytoscape to isolate top hub proteins.

RESULTS

A comprehensive summarization of the OTM-related GCF studies was conducted, followed by an in-depth exploration of biomarkers within the GCF. We identified 13 DEPs, including ALP, IL-1β, IL-6, Leptin, MMP-1, MMP-3, MMP-8, MMP-9, PGE2, TGF-β1, TNF-α, OPG, RANKL. Bioinformatic analysis spotlighted the top 10 hub proteins and their interactions involved in OTM. Based on these findings, we have proposed a hypothetic diagram for the time-course bioprocess in OTM, which involves three phases containing sequential cellular and molecular components and their interplay network.

CONCLUSIONS

This work has further improved our understanding to the bioprocess of OTM, suggesting biomarkers as potential modulating targets to enhance OTM, mitigate adverse effects and support real-time monitoring and personalized orthodontic cycles.

Probiotic LB101 alleviates dry eye in mice by suppressing matrix metalloproteinase-9 expression through the regulation of gut microbiota-involved NF-κB signaling

Tear matrix metalloproteinase (MMP)-9 is an inflammatory signal in patients with dry eye (DE). In the present study, to understand the action mechanism of probiotic LB101 (Lactobacillus plantarum NK151 and Bifidobacterium bifidum NK175 [4:1] mix) against DE, we investigated its effect on tear amount and inflammatory marker expression levels in mice with unilateral exorbital lacrimal gland excision/atropine-benzalkonium chloride application (EB) or fecal microbiota transplantation from mice with EB (eFMT). Oral gavage of LB101 increased EB-suppressed tear amount and decreased EB-induced blinking number. Furthermore, LB101 decreased EB-induced TNF-α, IL-1β, and MMP-9 expression, TNF-α+ and NF-κB+CD11c+ cell populations, and edema in the conjunctiva, while EB-suppressed IL-10 and occludin expression increased. LB101 also decreased EB-induced TNF-α and IL-1β expression and NF-κB+CD11c+ cell population in the colon. eFMT also decreased tear amount and increased blinking number in the transplanted mice. eFMT increased TNF-α, IL-1β, and MMP-9 expression and TNF-α+ and NF-κB+CD11c+ cell populations in the conjunctiva and TNF-α and IL-1β expression and NF-κB+CD11c+ cell populations in the colon. Oral gavage of LB101 increased eFMT-suppressed tear amount and decreased eFMT-induced blinking number. Furthermore, LB101 decreased TNF-α, IL-1β, and MMP-9 expression, TNF-α+ and NF-κB+CD11c+ cell populations, and edema in the conjunctiva and TNF-α and IL-1β expression and NF-κB+CD11c+ cell population in the colon, while eFMT-suppressed IL-10 and occludin expression decreased. Furthermore, LB101 increased eFMT-suppressed Muribaculaceae, Prevotellaceae, and Lactobacillaceae populations in the gut microbiota, while eFMT-induced Bacteroidaceae population decreased. These findings suggest that DE may cause gut dysbiosis, which may be a risk factor for DE, and LB101 may alleviate DE with gut inflammation by suppressing the expression of MMP-9 and proinflammatory cytokines TNF-α and IL-1β with the regulation of gut microbiota-involved NF-κB signaling.

Equine Embryonic Stem Cell-Derived Tenocytes are Insensitive to a Combination of Inflammatory Cytokines and Have Distinct Molecular Responses Compared to Primary Tenocytes

Tissue fibrosis following tendon injury is a major clinical problem due to the increased risk of re-injury and limited treatment options; however, its mechanism remains unclear. Evidence suggests that insufficient resolution of inflammation contributes to fibrotic healing by disrupting tenocyte activity, with the NF-κB pathway being identified as a potential mediator. Equine embryonic stem cell (ESC) derived tenocytes may offer a potential cell-based therapy to improve tendon regeneration, but how they respond to an inflammatory environment is largely unknown. Our findings reveal for the first time that, unlike adult tenocytes, ESC-tenocytes are unaffected by IFN-γ, TNFα, and IL-1β stimulation; producing minimal changes to tendon-associated gene expression and generating 3-D collagen gel constructs indistinguishable from unstimulated controls. Inflammatory pathway analysis found these inflammatory cytokines failed to activate NF-κB in the ESC-tenocytes. However, NF-κB could be activated to induce changes in gene expression following stimulation with NF-κB pharmaceutical activators. Transcriptomic analysis revealed differences between cytokine and NF-κB signalling components between adult and ESC-tenocytes, which may contribute to the mechanism by which ESC-tenocytes escape inflammatory stimuli. Further investigation of these molecular mechanisms will help guide novel therapies to reduce fibrosis and encourage superior tendon healing.

Distinguishing the impact of distinct obstructive sleep apnea syndrome (OSAS) and obesity related factors on human monocyte subsets

Obstructive sleep apnea syndrome (OSAS) and obesity go hand in hand in the majority of patients and both are associated with a systemic inflammation, immune disturbance and comorbidities such as cardiovascular disease. However, the unambiguous impact of OSAS and obesity on the individual inflammatory microenvironment and the immunological consequences of human monocytes has not been distinguished yet. Therefore, aim of this study was to investigate the impact of OSAS and obesity related factors on the inflammatory microenvironment by performing flow cytometric whole blood measurements of CD14/CD16 monocyte subsets in normal weight OSAS patients, patients with obesity but without OSAS, and patients with OSAS and obesity, compared to healthy donors. Moreover, explicitly OSAS and obesity related plasma levels of inflammatory mediators adiponectin, leptin, lipocalin and metalloproteinase-9 were determined and the influence of different OSAS and obesity related factors on cytokine secretion and expression of different adhesion molecules by THP-1 monocytes was analysed. Our data revealed a significant redistribution of circulating classical and intermediate monocytes in all three patient cohorts, but differential effects in terms of monocytic adhesion molecules CD11a, CD11b, CD11c, CX3CR1, CD29, CD49d, and plasma cytokine levels. These data were reflected by differential effects of OSAS and obesity related factors leptin, TNFα and hypoxia on THP-1 cytokine secretion patterns and expression of adhesion molecules CD11b and CD49d. In summary, our data revealed differential effects of OSAS and obesity, which underlines the need for a customized therapeutic regimen with respect to the individual weighting of these overlapping diseases.

Network Pharmacology and Experimental Validation Explore the Pharmacological Mechanisms of Herb Pair for Treating Rheumatoid Arthritis

OBJECTIVE

This study aimed to elucidate the multitarget mechanism of the Mori Ramulus - Taxilli Herba (MT) herb pair in treating rheumatoid arthritis (RA).

METHODS

The targets of the herb pair and RA were predicted from databases and screened through cross-analysis. The core targets were obtained using protein-protein interaction (PPI) network analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Finally, animal experiments were conducted to validate the anti-RA effect and mechanism of this herb pair.

RESULTS

This approach successfully identified 9 active compounds of MT that interacted with 6 core targets (AKT1, TNF, IL6, TP53, VEGFA, and IL1β). Pathway and functional enrichment analyses revealed that MT had significant effects on the TNF and IL-17 signaling pathways. The consistency of interactions between active components and targets in these pathways was confirmed through molecular docking. Moreover, the potential therapeutic effect of MT was verified in vivo, demonstrating its ability to effectively relieve inflammation by regulating these targeted genes and pathways.

CONCLUSION

The present work suggests that the therapeutic effect of MT herb pair on RA may be attributed to its ability to regulate the TNF signaling pathway and IL-17 signaling pathway.

Biologics in peripheral ulcerative keratitis

Over the past two decades biologic therapies have seen a rapid uptake in the management of ocular inflammation. Peripheral ulcerative keratitis (PUK), once a harbinger of blindness and mortality in refractory rheumatological disease, is now increasingly being treated with these agents. We conducted a review to evaluate the evidence base for this application and to provide a road map for their clinical usage in PUK, including dosage and adverse effects. A literature search across Medline, Embase and Cochrane Database of Systematic Reviews was undertaken to identify all patients with PUK that were treated with a biologic in a peer viewed article. Overall, whilst the evidence base for biologic use in PUK was poor, reported cases demonstrate an increasingly powerful and effective role for biologics in refractory PUK. This was particularly the case for rituximab in PUK secondary to granulomatous with polyangiitis.

Downregulation of RUNX1-Activated Osteopontin Facilitates Burn Wound Healing by Activating the MAPK Pathways

Burn wounds require intervention to ensure timely progression to reduce morbidity and mortality. The migrative and proliferative capabilities of keratinocytes are impaired in wounds. Matrix metalloproteinases (MMPs) can degrade the extracellular matrix (ECM), allowing epithelial cells to migrate. As reported, osteopontin can regulate cell migration, cell adhesion, and ECM invasion in endothelial and epithelial cells, and its expression is significantly increased in chronic wounds. Therefore, this study investigates the biological functions of osteopontin and its related mechanisms involved in burn wounds. We established cellular and animal models of burn injury. Levels of osteopontin, RUNX1, MMPs, collagen I, CK19, PCNA, and pathway-associated proteins were measured by RT-qPCR, western blotting, and immunofluorescence staining. Cell viability and migration were examined by CCK-8 and wound scratch assays. Histological changes were analyzed by hematoxylin and eosin staining and Masson's trichrome staining. For in vitro analysis, osteopontin silencing facilitated the growth and migration of HaCaT cells and promoted ECM degradation in HaCaT cells. Mechanistically, RUNX1 bound to osteopontin promoter, and RUNX1 upregulation attenuated the promoting efficacy of osteopontin silencing on cell growth and migration and ECM degradation. Additionally, RUNX1-activated osteopontin inactivated the MAPK signaling pathway. For in vivo analysis, osteopontin depletion facilitated burn wound healing by promoting reepithelialization and ECM degradation. In conclusion, RUNX1 activates the osteopontin expression at the transcriptional level and osteopontin depletion facilitates the recovery of burn wounds by promoting the migration of keratinocytes and reepithelization and ECM degradation by activating the MAPK pathway.

TNFα induces matrix metalloproteinase-9 expression in monocytic cells through ACSL1/JNK/ERK/NF-kB signaling pathways

Studies have established the association between increased plasma levels of matrix metalloproteinase (MMP)-9 and adipose tissue inflammation. Tumor necrosis factor α (TNFα) was elevated in obesity and is involved in the induction of MMP-9 in monocytic cells. However, the underlying molecular mechanism was incompletely understood. As per our recent report, TNFα mediates inflammatory responses through long-chain acyl-CoA synthetase 1 (ACSL1). Therefore, we further investigated the role of ACSL1 in TNFα-mediated MMP-9 secretion in monocytic cells. THP-1 cells and primary monocytes were used to study MMP-9 expression. mRNA and protein levels of MMP-9 were determined by qRT-PCR and ELISA, respectively. Signaling pathways were studied using Western blotting, inhibitors, and NF-kB/AP1 reporter cells. We found that THP-1 cells and primary human monocytes displayed increased MMP-9 mRNA expression and protein secretion after incubation with TNFα. ACSL1 inhibition using triacsin C significantly reduced the expression of MMP-9 in the THP-1 cells. However, the inhibition of β-oxidation and ceramide biosynthesis did not affect the TNFα-induced MMP-9 production. Using small interfering RNA-mediated ACSL1 knockdown, we further confirmed that TNFα-induced MMP-9 expression/secretion was significantly reduced in ACSL1-deficient cells. TNFα-mediated MMP-9 expression was also significantly reduced by the inhibition of ERK1/ERK2, JNK, and NF-kB. We further observed that TNFα induced phosphorylation of SAPK/JNK (p54/46), ERK1/2 (p44/42 MAPK), and NF-kB p65. ACSL1 inhibition reduced the TNFα-mediated phosphorylation of SAPK/JNK, c-Jun, ERK1/2, and NF-kB. In addition, increased NF-κB/AP-1 activity was inhibited in triacsin C treated cells. Altogether, our findings suggest that ACSL1/JNK/ERK/NF-kB axis plays an important role in the regulation of MMP-9 induced by TNFα in monocytic THP-1 cells.

Naringenin and proanthocyanidins pre-treatment decreases synthesis and activity of gelatinases induced by zoledronic acid in a dental implant surface in vitro model

OBJECTIVE

To assess the effects of pre-treatment with proanthocyanidins (PA) flavonoids, from grape seed extract, and synthetic naringenin (NA) on the synthesis of matrix metalloproteinases (MMPs) gelatinases and their tissue inhibitors (TIMPs), as well as the gelatinolytic activity of MMPs by human gingival fibroblasts (HGF) and osteoblasts (Ob) exposed to zoledronic acid (ZA) in a dental implant surface in vitro model.

DESIGN

The highest non-cytotoxic concentrations of NA and PA were determined for HGF (10 μg/mL; defined by previous study) and Ob (0.5 μg/mL; defined by prestoBlue assay). Then, HFG and Ob were individually seeded onto titanium discs, and after 24 h, cells were pre-treated (or not) with NA or PA, followed (or not) by exposure to ZA. Next, MMP-2, MMP-9, TIMP-1, TIMP-2 synthesis (ELISA), and gelatinolytic activity (in situ zymography) was evaluated. Data were analyzed by one-way ANOVA and Tukey tests (α = 0.05).

RESULTS

ZA treatment increased the synthesis (p < 0.05) and activity of MMPs; flavonoids pre-treatment controlled ZA-induced gelatinolytic effects, down-regulating MMPs synthesis (p < 0.05) and activity by HGF and Ob. For HGF, NA and PA pre-treatment did not up-regulate TIMP synthesis after ZA exposure (p > 0.05); for Ob, TIMP-2 was up-regulated (p < 0.05) by flavonoids, followed by ZA.

CONCLUSIONS

NA and PA pre-treatment provides interesting results in the modulation of ZA deleterious effects, down-regulating MMP-2 and MMP-9 synthesis and activity by HGF and Ob and up-regulating TIMP-2 by Ob.

Diabetes mellitus induces a novel inflammatory network involving cancer progression: Insights from bioinformatic analysis and in vitro validation

Background

Patients with diabetes mellitus (DM) have a higher incidence of malignant tumors than people without diabetes, but the underlying molecular mechanisms are still unclear.

Methods

To investigate the link between DM and cancer, we screened publicly available databases for diabetes and cancer-related genes (DCRGs) and constructed a diabetes-based cancer-associated inflammation network (DCIN). We integrated seven DCRGs into the DCIN and analyzed their role in different tumors from various perspectives. We also investigated drug sensitivity and single-cell sequencing data in colon adenocarcinoma as an example. In addition, we performed in vitro experiments to verify the expression of DCRGs and the arachidonic acid metabolic pathway.

Results

Seven identified DCRGs, including PPARG, MMP9, CTNNB1, TNF, TGFB1, PTGS2, and HIF1A, were integrated to construct a DCIN. The bioinformatics analysis showed that the expression of the seven DCRGs in different tumors was significantly different, which had varied effects on diverse perspectives. Single-cell sequencing analyzed in colon cancer showed that the activity of the DCRGs was highest in Macrophage and the lowest in B cells among all cell types in adenoma and carcinoma tissue. In vitro experiments showed that the DCRGs verified by western bolt and PEG2 verified by ELISA were all highly expressed in COAD epithelial cells stimulated by high glucose.

Conclusion

This study, for the first time, constructed a DCIN, which provides novel insights into the underlying mechanism of how DM increases tumor occurrence and development. Although further research is required, our results offer clues for new potential therapeutic strategies to prevent and treat malignant tumors.

Cellular and Molecular Mechanisms Associating Obesity to Bone Loss

Obesity is an alarming disease that favors the upset of other illnesses and enhances mortality. It is spreading fast worldwide may affect more than 1 billion people by 2030. The imbalance between excessive food ingestion and less energy expenditure leads to pathological adipose tissue expansion, characterized by increased production of proinflammatory mediators with harmful interferences in the whole organism. Bone tissue is one of those target tissues in obesity. Bone is a mineralized connective tissue that is constantly renewed to maintain its mechanical properties. Osteoblasts are responsible for extracellular matrix synthesis, while osteoclasts resorb damaged bone, and the osteocytes have a regulatory role in this process, releasing growth factors and other proteins. A balanced activity among these actors is necessary for healthy bone remodeling. In obesity, several mechanisms may trigger incorrect remodeling, increasing bone resorption to the detriment of bone formation rates. Thus, excessive weight gain may represent higher bone fragility and fracture risk. This review highlights recent insights on the central mechanisms related to obesity-associated abnormal bone. Publications from the last ten years have shown that the main molecular mechanisms associated with obesity and bone loss involve: proinflammatory adipokines and osteokines production, oxidative stress, non-coding RNA interference, insulin resistance, and changes in gut microbiota. The data collection unveils new targets for prevention and putative therapeutic tools against unbalancing bone metabolism during obesity.

Tumour necrosis factor alpha, interleukin 1 beta and interferon gamma have detrimental effects on equine tenocytes that cannot be rescued by IL-1RA or mesenchymal stromal cell-derived factors

Tendon injuries occur commonly in both human and equine athletes, and poor tendon regeneration leads to functionally deficient scar tissue and an increased frequency of re-injury. Despite evidence suggesting inadequate resolution of inflammation leads to fibrotic healing, our understanding of the inflammatory pathways implicated in tendinopathy remains poorly understood, meaning successful targeted treatments are lacking. Here, we demonstrate IL-1β, TNFα and IFN-γ work synergistically to induce greater detrimental consequences for equine tenocytes than when used individually. This includes altering tendon associated and matrix metalloproteinase gene expression and impairing the cells' ability to contract a 3-D collagen gel, a culture technique which more closely resembles the in vivo environment. Moreover, these adverse effects cannot be rescued by direct suppression of IL-1β using IL-1RA or factors produced by BM-MSCs. Furthermore, we provide evidence that NF-κB, but not JNK, P38 MAPK or STAT 1, is translocated to the nucleus and able to bind to DNA in tenocytes following TNFα and IL-1β stimulation, suggesting this signalling cascade may be responsible for the adverse downstream consequences of these inflammatory cytokines. We suggest a superior approach for treatment of tendinopathy may therefore be to target specific signalling pathways such as NF-κB.

Selective inhibition of soluble tumor necrosis factor signaling reduces abdominal aortic aneurysm progression

Background

Tumor necrosis factor (TNF) is pathologically elevated in human abdominal aortic aneurysms (AAA). Non-selective TNF inhibition-based therapeutics are approved for human use but have been linked to several side effects. Compounds that target the proinflammatory soluble form of TNF (solTNF) but preserve the immunomodulatory capabilities of the transmembrane form of TNF (tmTNF) may prevent these side effects. We hypothesize that inhibition of solTNF signaling prevents AAA expansion.

Methods

The effect of the selective solTNF inhibitor, XPro1595, and the non-selective TNF inhibitor, Etanercept (ETN) was examined in porcine pancreatic elastase (PPE) induced AAA mice, and findings with XPro1595 was confirmed in angiotensin II (ANGII) induced AAA in hyperlipidemic apolipoprotein E (Apoe) -/- mice.

Results

XPro1595 treatment significantly reduced AAA expansion in both models, and a similar trend (p = 0.06) was observed in PPE-induced AAA in ETN-treated mice. In the PPE aneurysm wall, XPro1595 improved elastin integrity scores. In aneurysms, mean TNFR1 levels reduced non-significantly (p = 0.07) by 50% after TNF inhibition, but the histological location in murine AAAs was unaffected and similar to that in human AAAs. Semi-quantification of infiltrating leucocytes, macrophages, T-cells, and neutrophils in the aneurysm wall were unaffected by TNF inhibition. XPro1595 increased systemic TNF levels, while ETN increased systemic IL-10 levels. In ANGII-induced AAA mice, XPro1595 increased systemic TNF and IL-5 levels. In early AAA development, proteomic analyses revealed that XPro1595 significantly upregulated ontology terms including "platelet aggregation" and "coagulation" related to the fibrinogen complex, from which several proteins were among the top regulated proteins. Downregulated ontology terms were associated with metabolic processes.

Conclusion

In conclusion, selective inhibition of solTNF signaling reduced aneurysm expansion in mice, supporting its potential as an attractive treatment option for AAA patients.

Tumor necrosis factor-α and matrix metalloproteinase-9 cooperatively exacerbate neurovascular degeneration in the neonatal rat retina

Matrix metalloproteinases (MMPs) and tumor necrosis factor (TNF)-α contribute to the pathogenesis of several ocular diseases. Previous studies have shown that MMP-9 activation plays an important role in capillary degeneration in injured retinas. In this study, we aimed to determine the roles of TNF-α in capillary degeneration and MMP-9 activation in the injured retina. In rats, retinal injury was induced by intravitreal injection of N-methyl-D-aspartic acid (NMDA, 200 nmol) at postnatal day 7. We examined (1) the effects of blocking MMP-9 and TNF-α signaling pathway on capillary degeneration, (2) changes in protein levels and distribution of MMP-9 and TNF-α, and (3) the interaction between MMP-9 and TNF-α in regulating the expression level of each protein in retinas of NMDA-injected eyes. Intravitreal injection of GM6001, an MMP inhibitor, or TNF-α neutralizing antibody (anti-TNF-α Ab) attenuated capillary degeneration in retinas of NMDA-injected eyes. Protein levels of TNF-α increased 2 h after NMDA injection, whereas those of MMP-9 increased 4 h after the injection. Anti-TNF-α Ab suppressed activation of MMP-9 in retinas of NMDA-injected eyes, whereas GM6001 diminished the TNF-α protein expression. Incubation of recombinant TNF-α with supernatants of homogenized retina increased protein levels and activity of MMP-9. These results suggest that TNF-α and MMP-9 collaboratively increase their expression levels in the retina following neurodegeneration, thus leading to retinal capillary degeneration. The cooperative interaction between MMP-9 and TNF-α could be involved in the exacerbation of retinal neurovascular degeneration.

Matrix Effectors in the Pathogenesis of Keratinocyte-Derived Carcinomas

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), referred to as keratinocyte carcinomas, are skin cancer with the highest incidence. BCCs, rarely metastasize; whereas, though generally not characterized by high lethality, approximately 2–4% of primary cSCCs metastasize with patients exhibiting poor prognosis. The extracellular matrix (ECM) serves as a scaffold that provides structural and biological support to cells in all human tissues. The main components of the ECM, including fibrillar proteins, proteoglycans (PGs), glycosaminoglycans (GAGs), and adhesion proteins such as fibronectin, are secreted by the cells in a tissue-specific manner, critical for the proper function of each organ. The skin compartmentalization to the epidermis and dermis compartments is based on a basement membrane (BM), a highly specialized network of ECM proteins that separate and unify the two compartments. The stiffness and assembly of BM and tensile forces affect tumor progenitors' invasion at the stratified epithelium's stromal border. Likewise, the mechanical properties of the stroma, e.g., stiffness, are directly correlated to the pathogenesis of the keratinocyte carcinomas. Since the ECM is a pool for various growth factors, cytokines, and chemokines, its' intense remodeling in the aberrant cancer tissue milieu affects biological functions, such as angiogenesis, adhesion, proliferation, or cell motility by regulating specific signaling pathways. This review discusses the structural and functional modulations of the keratinocyte carcinoma microenvironment. Furthermore, we debate how ECM remodeling affects the pathogenesis of these skin cancers.

Quercetin exerts anti-inflammatory effects via inhibiting tumor necrosis factor-α-induced matrix metalloproteinase-9 expression in normal human gastric epithelial cells

BACKGROUND

Gastric injury is the most common digestive system disease worldwide and involves inflammation, which can lead to gastric ulcer or gastric cancer (GC). Matrix metallopeptidase-9 [MMP-9 (gelatinase-B)] plays an important role in inflammation and GC progression. Quercetin and quercetin-rich diets represent potential food supplements and a source of medications for treating gastric injury given their anti-inflammatory activities. However, the effects and mechanisms of action of quercetin on human chronic gastritis and whether quercetin can relieve symptoms remain unclear.

AIM

To assess whether tumor necrosis factor-α (TNF-α)-induced MMP-9 expression mediates the anti-inflammatory effects of quercetin in normal human gastric mucosal epithelial cells.

METHODS

The normal human gastric mucosa epithelial cell line GES-1 was used to establish a normal human gastric epithelial cell model of TNF-α-induced MMP-9 protein overexpression to evaluate the anti-inflammatory effects of quercetin. The cell counting Kit-8 assay was used to evaluate the effects of varying quercetin doses on cell viability in the normal GES-1 cell line. Cell migration was measured using Transwell assay. The expression of proto-oncogene tyrosine-protein kinase Src (c-Src), phospho (p)-c-Src, extracellular-signal-regulated kinase 2 (ERK2), p-ERK1/2, c-Fos, p-c-Fos, nuclear factor kappa B (NF-κB/p65), and p-p65 and the effects of their inhibitors were examined using Western blot analysis and measurement of luciferase activity. p65 expression was detected by immunofluorescence. MMP-9 mRNA and protein levels were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and gelatin zymography, respectively.

RESULTS

qRT-PCR and gelatin zymography showed that TNF-α induced MMP-9 mRNA and protein expression in a dose- and time-dependent manner. These effects were reduced by the pretreatment of GES-1 cells with quercetin or a TNF-α antagonist (TNFR inhibitor) in a dose- and time-dependent manner. Quercetin and TNF-α antagonists decreased the TNF-α-induced phosphorylation of c-Src, ERK1/2, c-Fos, and p65 in a dose- and time-dependent manner. Quercetin, TNF-α antagonist, PP1, U0126, and tanshinone IIA (TSIIA) reduced TNF-α-induced c-Fos phosphorylation and AP-1-Luciferase (Luc) activity in a dose- and time-dependent manner. Pretreatment with quercetin, TNF-α antagonist, PP1, U0126, or Bay 11-7082 reduced TNF-α-induced p65 phosphorylation and translocation and p65-Luc activity in a dose- and time-dependent manner. TNF-α significantly increased GES-1 cell migration, and these results were reduced by pretreatment with quercetin or a TNF-α antagonist.

CONCLUSION

Quercetin significantly downregulates TNF-α-induced MMP-9 expression in GES-1 cells via the TNFR-c-Src-ERK1/2 and c-Fos or NF-κB pathways.

Perioperative Intravenous Lidocaine and Metastatic Cancer Recurrence - A Narrative Review

Cancer is a major global health problem and the second leading cause of death worldwide. When detected early, surgery provides a potentially curative intervention for many solid organ tumours. Unfortunately, cancer frequently recurs postoperatively. Evidence from laboratory and retrospective clinical studies suggests that the choice of anaesthetic and analgesic agents used perioperatively may influence the activity of residual cancer cells and thus affect subsequent recurrence risk. The amide local anaesthetic lidocaine has a well-established role in perioperative therapeutics, whether used systemically as an analgesic agent or in the provision of regional anaesthesia. Under laboratory conditions, lidocaine has been shown to inhibit cancer cell behaviour and exerts beneficial effects on components of the inflammatory and immune responses which are known to affect cancer biology. These findings raise the possibility that lidocaine administered perioperatively as a safe and inexpensive intravenous infusion may provide significant benefits in terms of long term cancer outcomes. However, despite the volume of promising laboratory data, robust prospective clinical evidence supporting beneficial anti-cancer effects of perioperative lidocaine treatment is lacking, although trials are planned to address this. This review provides a state of the art summary of the current knowledge base and recent advances regarding perioperative lidocaine therapy, its biological effects and influence on postoperative cancer outcomes.

Relative mRNA and protein stability of epigenetic regulators in musculoskeletal cell culture models

Control of gene expression by epigenetic regulators is fundamental to tissue development and homeostasis. Loss-of-function (LOF) studies using siRNAs for epigenetic regulators require that RNA interference rapidly reduces the cellular levels of the corresponding mRNAs and/or proteins. The most abundant chromatin structural proteins (i.e., the core histones H2A, H2B, H3 and H4) have relatively long half-lives and do not turn over rapidly, although their mRNAs are labile. The question arises whether epigenetic regulatory enzymes (e.g., Ezh2) or proteins that interact with histones via selective modifications (e.g., Cbx1 to Cbx8, Brd4) are stable or unstable. Therefore, we performed classical α-amanitin and cycloheximide inhibition assays that block, respectively, mRNA transcription and protein translation in mouse MC3T3 osteoblasts, ATDC5 chondrocytes and C2C12 myoblasts. We find that mRNA levels of Cbx proteins and Ezh2 were significantly depleted after 24 hrs, while their corresponding proteins remained relatively stable. As positive control, the half-life of the labile cyclin D1 protein was found to be less than 1 hr. Our study suggests that histone code readers and writers are relatively stable chromatin-related proteins, which is consistent with their long-term activities in maintaining chromatin organization and phenotype identity. These findings have conceptual ramifications for the interpretation of RNAi experiments that reduce the mRNA but not protein levels of epiregulatory proteins. We propose that siRNAs for at least some epigenetic regulatory proteins may exert their biological effects by blocking translation and new protein synthesis rather than by decreasing pre-existing protein pools.

MMP13 Expression Is Increased Following Mutant α-Synuclein Exposure and Promotes Inflammatory Responses in Microglia

α-Synuclein is a 140-amino acid protein that readily misfolds and is associated with the Lewy body pathology found in sporadic and genetic forms of Parkinson's disease. We and others have shown that wild-type α-synuclein is a damage-associated molecular pattern that directly elicits a proinflammatory response in microglia through toll-like receptor activation. Here we investigated the direct effect of oligomeric mutant α-synuclein (A53T) on microglia morphology and activation. We found that misfolded A53T increased quantitative measures of amoeboid cell morphology, NFκB nuclear translocation and the expression of prototypical proinflammatory molecules. We also demonstrated that A53T increased expression of MMP13, a matrix metalloproteinase that remodels the extracellular matrix. To better understand the role of MMP13 in synucleinopathies, we further characterized the role of MMP13 in microglial signaling. We showed exposure of microglia to MMP13 induced a change in morphology and promoted the release of TNFα and MMP9. Notably, IL1β was not released indicating that the pathway involved in MMP13 activation of microglia may be different than the A53T pathway. Lastly, MMP13 increased the expression of CD68 suggesting that the lysosomal pathway might be altered by this MMP. Taken together this study shows that mutant α-synuclein directly induces a proinflammatory phenotype in microglia, which includes the expression of MMP13. In turn, MMP13 directly alters microglia supporting the need for multi-target therapies to treat Parkinson's disease patients.

The COX-2-derived PGE2 autocrine contributes to bradykinin-induced matrix metalloproteinase-9 expression and astrocytic migration via STAT3 signaling

Background

The matrix metalloproteinase-9 (MMP-9) is up-regulated by several proinflammatory mediators in the central nervous system (CNS) diseases. Increasing reports show that MMP-9 expression is an inflammatory biomarker of several CNS disorders, including the CNS inflammation and neurodegeneration. Bradykinin (BK) is a common proinflammatory mediator and elevated in several brain injury and inflammatory disorders. The raised BK may be detrimental effects on the CNS that may aggravate brain inflammation through MMP-9 up-regulation or cyclooxygenase-2 (COX-2)-derived prostaglandin E₂ (PGE₂) production in brain astrocytes. However, the relationship between BK-induced MMP-9 expression and COX-2-derived PGE₂ release in brain astrocytes remains unclear.

Methods

Herein we used rat brain astrocytes (RBA) to investigate the role of the COX-2/PGE₂ system in BK-induced MMP-9 expression. We used zymographic, RT-PCR, EIA, and Western blotting analyses to confirm that BK induces MMP-9 expression via a COX-2/PGE₂-dependent pathway.

Results

Our results show activation of native COX-2 by BK led to PGE₂ production and release. Subsequently, PGE₂ induced MMP-9 expression via PGE₂ receptor (EP)-mediated c-Src, Jak2, ERK1/2, and then activated signal transducer and activator of transcription 3 (STAT3) signaling pathway. Finally, up-regulation of MMP-9 by BK via the pathway may promote astrocytic migration.

Conclusion

These results demonstrated that a novel autocrine pathway for BK-induced MMP-9 protein expression is mediated through activation of STAT3 by native COX-2/PGE₂-mediated c-Src/Jak2/ERK cascades in brain astrocytes.

CCL4 Inhibition in Atherosclerosis: Effects on Plaque Stability, Endothelial Cell Adhesiveness, and Macrophages Activation

Atherosclerosis is an arterial inflammatory disease. The circulating level of the C-C chemokine ligand (CCL4) is increased in atherosclerotic patients. This study aimed to investigate whether CCL4 inhibition could retard the progression of atherosclerosis. In ApoE knockout mice, CCL4 antibody treatment reduced circulating interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α levels and improved lipid profiles accompanied with upregulation of the liver X receptor. CCL4 inhibition reduced the atheroma areas and modified the progression of atheroma plaques, which consisted of a thicker fibrous cap with a reduced macrophage content and lower matrix metalloproteinase-2 and -9 expressions, suggesting the stabilization of atheroma plaques. Human coronary endothelial cells (HCAECs) and macrophages were stimulated with TNF-α or oxidized LDL (ox-LDL). The induced expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were attenuated by the CCL4 antibody or CCL4 si-RNA. CCL4 inhibition reduced the adhesiveness of HCAECs, which is an early sign of atherogenesis. CCL4 blockade reduced the activity of metalloproteinase-2 and -9 and the production of TNF-α and IL-6 in stimulated macrophages. The effects of CCL4 inhibition on down-regulating adhesion and inflammation proteins were obtained through the nuclear factor kappa B (NFκB) signaling pathway. The direct inhibition of CCL4 stabilized atheroma and reduced endothelial and macrophage activation. CCL4 may be a novel therapeutic target for modulating atherosclerosis.

Role of metalloproteinases and TNF-α in obesity-associated asthma in mice

Numerous population studies conducted worldwide indicate that the prevalence of asthma is higher in obese versus lean individuals. It has been reported that sensitized lean mice has a better recovery of lung inflammation in asthma. Extracellular matrix (ECM) plays an essential role in the structural support of the lungs regulating the airways diameter, thus preventing its collapse during expiration. ECM renewal by metalloproteinase (MMPs) enzymes is critical for pulmonary biology. There seems to be an imbalance of MMPs activity in asthma and obesity, which can impair the lung remodeling process. In this study, we characterized the pulmonary ECM of obese and lean mice, non-sensitized and sensitized with ovalbumin (OVA). Pharmacological intervention was performed by using anti-TNF-α, and MMP-8 and MMP-9 inhibitors in obese and lean sensitized mice. Activity of MMPs was assessed by gelatinase electrophorese, western blotting and zymogram in situ. Unbalance of MMP-2, MMP-8, MMP-9 and MMP-12 was detected in lung tissue of OVA-sensitized obese mice, which was accompanied by high degradation, corroborating an excessive deposition of types I and III collagen in pulmonary matrix of obese animals. Inhibitions of TNF-α and MMP-9 reduced this MMP imbalance, clearly suggesting a positive effect on pulmonary ECM. Obese and lean mice presented diverse phenotype of asthma regarding the ECM compounds and the inhibition of MMPs pathway could be a good alternative to regulate the activity in ECM lungs of asthmatic obese individuals.

Gene expression in human liver fibrosis associated with Echinococcus granulosus sensu lato

Liver fibrosis is a dynamic process that occurs in response to chronic liver disease resulting from factors such as chronic infections, autoimmune reactions, allergic responses, toxins, radiation, and infectious agents. Among the infectious agents, multicellular parasites cause chronic inflammation and fibrosis. Twenty-five patients with different stages of cystic echinococcosis (CE) were enrolled in the study. The expression of ACTA2, COL3A1, IFN-γ, MMP2, MMP9, TGF-β1, and TNF-α genes was determined by qRT-PCR in healthy and fibrotic liver tissue of the CE patients. TGF-β1 expression was evaluated by immunohistochemistry, and histology was conducted to assess the development of liver fibrosis. Expression of MMP9, ACTA2, COL3A1, and MMP2 was found significantly higher in the fibrotic tissue compared to healthy tissue. We observed a significant correlation between TGF-β1 and TNF-α gene expressions and liver fibrosis. The mRNA level of IFN-γ was lower in the fibrotic than in the healthy hepatic tissue. Immunohistochemistry analysis revealed TGF-β1 upregulation in the fibrotic tissue. Histology showed inflammation and fibrosis to be significantly higher in the fibrotic tissue. The findings of this study suggest that Echinococcus granulosussensu lato can promotes fibrosis through the overexpression of TGF-β1, MMP9, ACTA2, COL3A1, and MMP2. The downregulation of IFN-γ mRNA in fibrotic samples is probably due to the increased production of TGF-β1 and the suppression of potential anti-fibrotic role of IFN-γ during advanced liver injury caused by E. granulosussensu lato.

Intestinal Organoids as a Tool for Inflammatory Bowel Disease Research

Inflammatory Bowel Diseases (IBD) are difficult to model as freshly acquired tissues are short-lived, provide data as a snapshot in time, and are not always accessible. Many patients with IBD are non-responders to first-line treatments, and responders are prone to developing resistance to treatment over time—resulting in reduced patient quality of life, increased time to remission, and potential relapse. IBD is heterogenous and we are yet to fully understand the mechanisms of disease; thus, our ability to diagnose and prescribe optimal treatment remains ineffective. Intestinal organoids are derived from patient tissues expanded in vitro. Organoids offer unique insight into individual patient disease and are a potential route to personalized treatments. However, organoid models do not contain functional microbial and immune cell components. In this review, we discuss immune cell subsets in the context of IBD, and the requirement of immune cell and microbial components in organoid models for IBD research.

Minocycline impairs TNF-α-induced cell fusion of M13SV1-Cre cells with MDA-MB-435-pFDR1 cells by suppressing NF-κB transcriptional activity and its induction of target-gene expression of fusion-relevant factors

Background

To date, several studies have confirmed that driving forces of the inflammatory tumour microenvironment trigger spontaneous cancer cell fusion. However, less is known about the underlying factors and mechanisms that facilitate inflammation-induced cell fusion of a cancer cell with a normal cell. Recently, we demonstrated that minocycline, a tetracycline antibiotic, successfully inhibited the TNF-α-induced fusion of MDA-MB-435 cancer cells with M13SV1 breast epithelial cells. Here, we investigated how minocycline interferes with the TNF-α induced signal transduction pathway.

Methods

A Cre-LoxP recombination system was used to quantify the fusion of MDA-MB-435-pFDR1 cancer cells and M13SV1-Cre breast epithelial cells. The impact of minocycline on the TNF-α signalling pathway was determined by western blotting. The transcriptional activity of NF-κB was characterised by immunocytochemistry, western blot and ChIP analyses. An NF-κB-luciferase reporter assay was indicative of NF-κB activity.

Results

Minocycline treatment successfully inhibited the TNFR1-TRAF2 interaction in both cell types, while minocycline abrogated the phosphorylation of IκBα and NF-κB-p65 to suppress nuclear NF-κB and its promotor activity only in M13SV1-Cre cells, which attenuated the expression of MMP9 and ICAM1. In MDA-MB-435-pFDR1 cells, minocycline increased the activity of NF-κB, leading to greater nuclear accumulation of NF-κB-p65, thus increasing promoter activity to stimulate the expression of ICAM1. Even though TNF-α also activated all MAPKs (ERK1/2, p38 and JNK), minocycline differentially affected these kinases to either inhibit or stimulate their activation. Moreover, SRC activation was analysed as an upstream activator of MAPKs, but no activation by TNF-α was revealed. The addition of several specific inhibitors that block the activation of SRC, MAPKs, AP-1 and NF-κB confirmed that only NF-κB inhibition was successful in inhibiting the TNF-α-induced cell fusion process.

Conclusion

Minocycline is a potent inhibitor in the TNF-α-induced cell fusion process by targeting the NF-κB pathway. Thus, minocycline prevented NF-κB activation and nuclear translocation to abolish the target-gene expression of MMP9 and ICAM1 in M13SV1-Cre cells, resulting in reduced cell fusion frequency.

Metformin Monotherapy Downregulates Diabetes-Associated Inflammatory Status and Impacts on Mortality

Aging is the main risk factor for developing diabetes and other age-related diseases. One of the most common features of age-related comorbidities is the presence of low-grade chronic inflammation. This is also the case of metabolic syndrome and diabetes. At the subclinical level, a pro-inflammatory phenotype was shown to be associated with Type-2 diabetes mellitus (T2DM). This low to mid-grade inflammation is also present in elderly individuals and has been termed inflammaging. Whether inflammation is a component of aging or exclusively associated with age-related diseases in not entirely known. We used clinical data and biological readouts in a group of individuals stratified by age, diabetes status and comorbidities to investigate this aspect. While aging is the main predisposing factor for several diseases there is a concomitant increased level of pro-inflammatory cytokines. DM patients show an increased level of sTNFRll, sICAM-1, and TIMP-1 when compared to Healthy, Non-DM and Pre-DM individuals. These inflammatory molecules are also associated with insulin resistance and metabolic syndrome in Non-DM and pre-DM individuals. We also show that metformin monotherapy was associated with significantly lower levels of inflammatory molecules, like TNFα, sTNFRI, and sTNFRII, when compared to other monotherapies. Longitudinal follow up indicates a higher proportion of death occurs in individuals taking other monotherapies compared to metformin monotherapy. Together our finding shows that chronic inflammation is present in healthy elderly individuals and exacerbated with diabetes patients. Likewise, metformin could help target age-related chronic inflammation in general, and reduce the predisposition to comorbidities and mortality.

Osteoblastic PLEKHO1 contributes to joint inflammation in rheumatoid arthritis

Background

Osteoblasts participating in the inflammation regulation gradually obtain concerns. However, its role in joint inflammation of rheumatoid arthritis (RA) is largely unknown. Here, we investigated the role of osteoblastic pleckstrin homology domain-containing family O member 1 (PLEKHO1), a negative regulator of osteogenic lineage activity, in regulating joint inflammation in RA.

Methods

The level of osteoblastic PLEKHO1 in RA patients and collagen-induced arthritis (CIA) mice was examined. The role of osteoblastic PLEKHO1 in joint inflammation was evaluated by a CIA model and a K/BxN serum-transfer arthritis (STA) model which were induced in osteoblast-specific Plekho1 conditional knockout mice and mice expressing high Plekho1 exclusively in osteoblasts, respectively. The effect of osteoblastic PLEKHO1 inhibition was explored in a CIA mice model and a non-human primate arthritis model. The mechanism of osteoblastic PLEKHO1 in regulating joint inflammation were performed by a series of in vitro studies.

Results

PLEKHO1 was highly expressed in osteoblasts from RA patients and CIA mice. Osteoblastic Plekho1 deletion ameliorated joint inflammation, whereas overexpressing Plekho1 only within osteoblasts exacerbated local inflammation in CIA mice and STA mice. PLEKHO1 was required for TRAF2-mediated RIP1 ubiquitination to activate NF-κB for inducing inflammatory cytokines production in osteoblasts. Moreover, osteoblastic PLEKHO1 inhibition diminished joint inflammation and promoted bone formation in CIA mice and non-human primate arthritis model.

Conclusions

These data strongly suggest that the highly expressed PLEKHO1 in osteoblasts contributes to joint inflammation in RA. Targeting osteoblastic PLEKHO1 may exert dual therapeutic action of alleviating joint inflammation and promoting bone formation in RA.

Acute Inflammatory Responses to Exercise in Patients with Abdominal Aortic Aneurysm

PURPOSE

Inflammation and extracellular matrix degeneration contribute to abdominal aortic aneurysm (AAA) development. We aimed to assess the effect of exercise intensity on circulating biomarkers of inflammation and extracellular matrix degeneration in patients with AAA and healthy older adults.

METHODS

Twenty patients with AAA (74 ± 6 yr) and 20 healthy males (72 ± 5 yr) completed moderate-intensity cycling at 40% peak power output, higher-intensity intervals at 70% peak power output, and control (rest) on separate days. Circulating matrix metalloproteinase-9 (MMP-9), transforming growth factor beta 1, interleukin-6 (IL-6), IL-10, and tumor necrosis factor alpha (TNF-α) were analyzed at rest and 0 to 90 min postexercise.

RESULTS

Biomarkers at baseline were similar between groups. IL-6 responses to exercise were similar between groups, with a greater increase in ΔIL-6 after moderate-intensity compared with higher-intensity exercise (P < 0.001). Delta MMP-9 showed a 118-ng·mL (95% confidence interval = 23 to 214, P = 0.02) greater increase immediately after higher-intensity exercise compared with changes in control in both groups. Delta MMP-9 then decreased by 114 ng·mL (18 to 211, P = 0.02) 90 min after higher-intensity exercise compared with the changes in control. Delta TNF-α was not different between protocols in healthy adults. In patients with AAA, delta TNF-α showed a greater decrease after higher-intensity compared with moderate-intensity exercise (-6.1 pg·mL, -8.5 to -3.6, P < 0.001) and control (-4.9 pg·mL, -7.4 to -2.4, P < 0.001). IL-10 and transforming growth factor beta 1 did not change in either group.

CONCLUSIONS

These findings suggest that a bout of higher-intensity exercise elicits a greater anti-inflammatory response compared with moderate-intensity exercise, which may be further augmented in patients with AAA. Exercise-induced reductions in biomarkers associated with AAA progression may represent a protective effect of exercise in patients with AAA.

The Activity of Matrix Metalloproteinases (MMP-2, MMP-9) and Their Tissue Inhibitors (TIMP-1, TIMP-3) in the Cerebral Cortex and Hippocampus in Experimental Acanthamoebiasis

The pathological process occurring within the central nervous system (CNS) as a result of the infection by Acanthamoeba spp. is not fully understood. Therefore, the aim of this study was to determine whether Acanthamoeba spp. may affect the levels of matrix metalloproteinases (MMP-2,-9), their tissue inhibitors (TIMP-1,-3) and MMP-9/TIMP-1, MMP-2/TIMP-3 ratios in the cerebral cortex and hippocampus, in relation to the host’s immunological status. Our results showed that Acanthamoeba spp. infection can change the levels of MMP and TIMP in the CNS and may be amenable targets for limiting amoebic encephalitis. The increase in the activity of matrix metalloproteinases during acanthamoebiasis may be primarily the result of inflammation process, probably an increased activity of proteolytic processes, but also (to a lesser extent) a defense mechanism preventing the processes of neurodegeneration.

Colorectal Cancer and Mitochondrial Dysfunctions of the Adjunct Adipose Tissues: A Case Study

Excess body weight has been causally linked to an increased risk of different cancer types, including colorectal cancer (CRC) but the mechanisms underlying this association are practically unknown. We investigate redox state-superoxide (SO) generation rate, activity of complex I in electron transport chain (ETC) of mitochondria and of dinitrosyl iron complexes by electron paramagnetic resonance; activity of matrix metalloproteinase (gelatinase) MMP-2 and MMP-9 by gel zymography of adipose tissues (AT) from 46 patients (64.0 ± 1.6 y.o.) with CRC (II-III stages, pT2-3N0-2M0) in the AT adjacent to tumor (ATAT) and at a distance of 3 cm from the tumor (ATD) to follow the connection of the AT redox state with some of the tumor microenvironment indicators. We have incubated the AT species with the tumor necrosis factor α (TNF-α) to follow its influence on the measured values. As a control, normal AT (NAT) obtained during the liposuction is used. Tumor-induced changes in mitochondrial ETC of ATAT, particularly for Complex I, lead to the enhanced SO generation and consequent oxidative modifications of DNA in ATAT (up to 6.1 times higher than that in NAT and 3.7 times higher than that in ATD, p < 0.05). Gelatinase activity in ATAT is significantly higher than in ATD. A considerable effect of TNF-α on ATAT and ATD (but not on NAT, i.e., only on the tissues where the reprogramming of metabolism has already occurred under the influence of tumor) manifested in increase of cellular hypoxia, gelatinase activity, and SO generation rate is observed. The results can be used for better understanding the mechanism(s) of metabolic symbiosis of tumor and AT as well as serving as a basis for new therapeutic approaches.

Lysophosphatidic Acid Promotes Expression and Activation of Matrix Metalloproteinase 9 (MMP9) in THP-1 Cells via Toll-Like Receptor 4/Nuclear Factor-κB (TLR4/NF-κB) Signaling Pathway

BACKGROUND Lysophosphatidic acid (LPA) is an active compound of oxidized low-density lipoprotein that serves as an endogenous TLR4 ligand. Ligand activation of TLR4 activates nuclear factor-kappaB (NF-κB) and the transcription of NF-κB-regulated inflammatory cytokines, which are involved in the development of atherosclerosis. MMP9 is a member of the MMP family and can affect plaque stability. However, the mechanism responsible for the effect of LPA on the expression and activation of MMP9 has not been fully elucidated. In the present study we examined the effect of LPA on MMP9 expression and activity in THP-1 cells and the involvement of Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway in this effect. MATERIAL AND METHODS Human THP-1 cells were treated with 0-10 μM LPA for 4 h, or treated with 1 μM LPA for 0-8 h, and were then transfected with TLR4-specific siRNA or treated with 20 μg/ml cafestol acid phenethyl ester (CAPE, an NF-κB inhibitor). MMP9 mRNA and protein levels were measured by quantitative RT-PCR and Western blot analysis, respectively, and MMP9 activity was measured by zymography. RESULTS LPA upregulated MMP9 mRNA and protein levels and MMP9 activity in THP-1 cells in both concentration- and time-dependent manners. Transfection of cells with TLR4-siRNA-2 or treatment with CAPE significantly inhibited the upregulated MMP9 expression and activation. This inhibition was further enhanced by combining the TLR4-siRNA-2 transfection and CAPE pretreatment. CONCLUSIONS LPA can promote MMP9 expression and enhance MMP9 activity in THP-1 cells, in part via the TLR4/NF-kB signaling pathway.

Matrix metalloproteinase-9 (MMP9) is involved in the TNF-α-induced fusion of human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells

Background

In addition to physiological events such as fertilisation, placentation, osteoclastogenesis, or tissue regeneration/wound healing, cell fusion is involved in pathophysiological conditions such as cancer. Cell fusion, which applies to both the proteins and conditions that induce the merging of two or more cells, is not a fully understood process. Inflammation/pro-inflammatory cytokines might be a positive trigger for cell fusion. Using a Cre-LoxP-based cell fusion assay we demonstrated that the fusion between human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells was induced by the pro-inflammatory cytokine tumour necrosis factor-α (TNF-α).

Methods

The gene expression profile of the cells in the presence of TNF-α and under normoxic and hypoxic conditions was analysed by cDNA microarray analysis. cDNA microarray data were verified by qPCR, PCR, Western blot and zymography. Quantification of cell fusion events was determined by flow cytometry. Proteins of interest were either blocked or knocked-down using a specific inhibitor, siRNA or a blocking antibody.

Results

The data showed an up-regulation of various genes, including claudin-1 (CLDN1), ICAM1, CCL2 and MMP9 in M13SV1-Cre and/or MDA-MB-435-pFDR1 cells. Inhibition of these proteins using a blocking ICAM1 antibody, CLDN1 siRNA or an MMP9 inhibitor showed that only the blockage of MMP9 was correlated with a decreased fusion rate of the cells. Likewise, the tetracycline-based antibiotic minocycline, which exhibits anti-inflammatory properties, was also effective in both inhibiting the TNF-α-induced MMP9 expression in M13SV1-Cre cells and blocking the TNF-α-induced fusion frequency of human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells.

Conclusions

The matrix metalloproteinase-9 (MMP9) is most likely involved in the TNF-α-mediated fusion of human M13SV1-Cre breast epithelial cells and human MDA-MB-435-pFDR1 cancer cells. Likewise, our data indicate that the tetracycline-based antibiotic minocycline might exhibit anti-fusogenic properties because it inhibits a cell fusion-related mechanism.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0226-1) contains supplementary material, which is available to authorized users.

The IL-6/STAT3 pathway regulates adhesion molecules and cytoskeleton of endothelial cells in thromboangiitis obliterans

Thromboangiitis obliterans (TAO) (also known as Buerger's disease) is an inflammatory vascular disease that predominantly affects small- and medium-sized blood vessels of extremities. Endothelial cells play critical roles in the initiation and progression of this disease, but the underlying mechanisms remain unclear. In the present study, we demonstrate that patients with TAO had significantly higher levels of interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in their plasmas, and the involved arterial tissues expressed higher levels of phosphorylated signal transducer and activator of transcription 3 (p-STAT3), ICAM-1 and VCAM-1. In exploring the molecular mechanisms with human aortic endothelial cells (HAECs), we found that recombinant IL-6 activated the STAT3 pathway, leading to the upregulation and overproduction of ICAM-1 and VCAM-1. RhoA (Ras homolog family member A), eNOS (endothelial nitric oxide synthase) and MMP-9 (matrix metalloproteinase-9) participated in this cellular signaling, and their interaction regulated the expression of ICAM-1 and VCAM-1. The activated STAT3 pathway by IL-6 also modulated the cytoskeleton of HAECs by regulating phosphorylation of focal adhesion kinase (FAK) and acetylation of α-tubulin through interplaying with RhoA. In summary, the present results indicate that activation of the IL-6/STAT3 pathway contributes to the pathogenesis of TAO by regulating cellular adhesion molecules and cytoskeleton of vascular endothelial cells, suggesting that targeting this pathway may provide a potential approach for the management of TAO.

Glycine improves the remodeling process of tenocytes in vitro

Tendinitis changes the biochemical and morphological properties of the tendon, promoting an increase of activity of metalloproteinases and disorganization of collagen bundles. Tenocytes, the primary cells in tendon, are scattered throughout the collagenic fibers, and are responsible of tendon remodeling and tissue repair in pathological condition. In vivo, glycine, component of the typical Gly-X-Y collagen tripeptide, showed beneficial effects in biochemical and biomechanical properties of Achilles tendon with tendinitis. In this study, we analyzed the effect of glycine in tenocytes subjected to inflammation. Tenocytes from Achilles tendon of rats were treated with TNF-α (10 ng/mL) with and without previous treatment with glycine (20 mM). Cell proliferation and migration were evaluated, as well as the expression of matrix molecules such as glycosaminoglycans, metalloproteinases (MMPs), TIMPs, and collagen I. Glycine can revert the inflammation due to the action of TNF-α by controlling the MMPs quantity and activity. These data indicated that the molecules involved to remodeling process of extracellular matrix are modulated both by TNF-α and the availability of collagen precursors; in fact, this study indicates the glycine can be useful for treatment of inflammation and for modulating tenocytes metabolism in tendons.

S100A4 drives non-small cell lung cancer invasion, associates with poor prognosis, and is effectively targeted by the FDA-approved anti-helminthic agent niclosamide

S100A4 (metastasin-1), a metastasis-associated protein and marker of the epithelial to mesenchymal transition, contributes to several hallmarks of cancer and has been implicated in the progression of several types of cancer. However, the impacts of S100A4 signaling in lung cancer progression and its potential use as a target for therapy in lung cancer have not been properly explored. Using established lung cancer cell lines, we demonstrate that S100A4 knockdown reduces cell proliferation, invasion and three-dimensional invasive growth, while overexpression of S100A4 increases invasive potential. In patient-derived tissues, S100A4 is preferentially elevated in lung adenocarcinoma. This elevation is associated with lymphovascular invasion and decreased overall survival. In addition, depletion of S100A4 by shRNA inhibits NF-κB activity and decreases TNFα-induced MMP9 expression. Furthermore, inhibition of the NF-κB/MMP9 axis decreases lung carcinoma invasive potential. Niclosamide, a reported inhibitor of S100A4, blocks expression and function of S100A4 with a reduction in proliferation, invasion and NF-κB-mediated MMP9 expression. Collectively, this study highlights the importance of the S100A4/NF-κB/MMP9 axis in lung cancer invasion and provides a rationale for targeting S100A4 to combat lung cancer.

Treponema pallidum flagellins stimulate MMP-9 and MMP-13 expression via TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes

Syphilis is a chronic disease caused by Treponema pallidum and the pathogenesis is still unclear. T. pallidum infection induced inflammatory responses are involved in the immunopathological damage in skin and other tissues. Flagellin, the monomeric subunit of bacterial flagella, is a classic pathogen associated molecular patterns (PAMPs) that interacts to TLR5 and induces inflammatory responses. Keratinocytes, as immune sentinels recognize the PAMPs via TLRs, play an important role in skin innate immune response. Matrix metalloproteinases (MMPs) expressed by keratinocytes are involved in skin inflammatory responses and promoting pathogens invasion. In this study, we demonstrate that FlaB1, FlaB2 and FlaB3, the flagellins of T. pallidum, induced MMP-9 and MMP-13 production in human immortalized keratinocytes cell line HaCaT. Silencing of TLR5, but not TLR2 and TLR4 attenuated MMP-9 and MMP-13 expressions induced by T. pallidum flagellins. MMP-9 and MMP-13 expressions were also be abrogated by transfection with a dominant negative (DN) plasmid of MyD88. We also found that treatment of HaCaT cells with FlaB1, FlaB2 and FlaB3 activate the MAPK and NF-κB signaling pathways. Inhibited of ERK, JNK, p38 and NF-κB suppressed MMP-9 expression induced by the FlaB1. MMP-13 expression was found to be suppressed by pretreatment with inhibitors of ERK, JNK and NF-κB, but not p38. These findings demonstrate that T. pallidum flagellins (FlaB1, FlaB2 or FlaB3) can stimulate MMP-9 and MMP-13 expression through TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes, which could contribute to the pathogenesis of T. pallidum infection.

Expression of matrix metalloproteinase-11 is increased under conditions of insulin resistance

AIM

To investigate matrix metalloproteinase-11 (MMP-11) expression in adipose tissue dysfunction, using in vitro and in vivo models of insulin resistance.

METHODS

Culture of mouse 3T3-L1 preadipocytes were induced to differentiation into mature 3T3-L1 adipocytes. Cellular insulin resistance was induced by treating differentiated cultured adipocytes with hypoxia and/or tumor necrosis factor (TNF)-α, and transcriptional changes were analyzed in each condition thereafter. For the in vivo studies, MMP-11 expression levels were measured in white adipose tissue (WAT) from C57BL/6J mice that underwent low fat diet or high-fat feeding in order to induce obesity and obesity-related insulin resistance. Statistical analysis was carried out with GraphPad Prism Software.

RESULTS

MMP-11 mRNA expression levels were significantly higher in insulin resistant 3T3-L1 adipocytes compared to control cells (1.46 ± 0.49 vs 0.83 ± 0.21, respectively; P < 0.00036). The increase in MMP-11 expression was observed even in the presence of TNF-α alone (3.79 ± 1.11 vs 1 ± 0.17, P < 0.01) or hypoxia alone (1.79 ± 0.7 vs 0.88 ± 0.1, P < 0.00023). The results obtained in in vitro experiments were confirmed in the in vivo model of insulin resistance. In particular, MMP-11 mRNA was upregulated in WAT from obese mice compared to lean mice (5.5 ± 2.8 vs 1.1 ± 0.7, respectively; P < 3.72E-08). The increase in MMP-11 levels in obese mice was accompanied by the increase in typical markers of fibrosis, such as collagen type VI alpha 3 (Col6α3), and fibroblast-specific protein 1.

CONCLUSION

Our results indicate that dysregulation of MMP-11 expression is an early process in the adipose tissue dysfunction, which leads to obesity and obesity-related insulin resistance.

Tumor Necrosis Factor (TNF) Bioactivity at the Site of an Acute Cell-Mediated Immune Response Is Preserved in Rheumatoid Arthritis Patients Responding to Anti-TNF Therapy

The impact of anti-tumor necrosis factor (TNF) therapies on inducible TNF-dependent activity in humans has never been evaluated in vivo. We aimed to test the hypothesis that patients responding to anti-TNF treatments exhibit attenuated TNF-dependent immune responses at the site of an immune challenge. We developed and validated four context-specific TNF-inducible transcriptional signatures to quantify TNF bioactivity in transcriptomic data. In anti-TNF treated rheumatoid arthritis (RA) patients, we measured the expression of these biosignatures in blood, and in skin biopsies from the site of tuberculin skin tests (TSTs) as a human experimental model of multivariate cell-mediated immune responses. In blood, anti-TNF therapies attenuated TNF bioactivity following ex vivo stimulation. However, at the site of the TST, TNF-inducible gene expression and genome-wide transcriptional changes associated with cell-mediated immune responses were comparable to that of RA patients receiving methotrexate only. These data demonstrate that anti-TNF agents in RA patients do not inhibit inducible TNF activity at the site of an acute inflammatory challenge in vivo, as modeled by the TST. We hypothesize instead that their therapeutic effects are limited to regulating TNF activity in chronic inflammation or by alternative non-canonical pathways.

TNF-α-induced IL-6 and MMP-9 expression in immortalized ameloblastoma cell line established by hTERT

OBJECTIVE

Ameloblastoma (AM) shows locally invasive behaviour. However, biological investigations regarding regulation of gene expression associated with AM pathological features are difficult to perform, because AM cells can be passaged for a few generations due to senescence. We report a newly established immortalized AM cell line, AMB cells, by transfection with human telomerase reverse transcriptase (hTERT). Furthermore, we examined whether TNF-α modulates bone resorption-related genes, IL-6 and MMP-9 in cooperation with TGF-β or IFN-γ.

MATERIALS AND METHODS

Following transfection of an hTERT expression vector into AM cells using a non-viral method, the effects of cytokines on the expressions of IL-6 and MMP-9 mRNA were examined using real-time PCR. TNF-α-induced NF-κB activity was examined by western blotting and transcription factor assays.

RESULTS

AMB cells continued to grow for more than 100 population doublings. Stimulation with TNF-α increased IL-6 and MMP-9 mRNA expressions, as well as NF-κB activation. Furthermore, TGF-β and IFN-γ dramatically increased TNF-α-mediated expressions of MMP-9 and IL-6 mRNA, respectively, while those responses were suppressed by NF-κB inhibitor.

CONCLUSION

We established an immortalized AM cell line by hTERT transfection. TNF-α-mediated regulation of MMP-9 and IL-6 via NF-κB may play an important role in the pathological behaviour of AMs, such as bone resorption.

Tumor necrosis factor-α modifies the effects of Shiga toxin on glial cells

Shiga toxin (STX) is one of the main factors inducing hemorrhagic colitis and hemolytic-uremic syndrome (HUS) in infections with STX-producing Escherichia coli (STEC). Approximately 62% of patients with HUS showed symptoms of encephalopathy in the 2011 Japanese outbreak of STEC infections. At that time, we reported elevated serum concentrations of tumor necrosis factor (TNF)-α in patients with acute encephalopathy during the HUS phase. In the current study, we investigated whether TNF-α augments the effects of STX in glial cell lines and primary glial cells. We found that TNF-α alone or STX in combination with TNF-α activates nuclear factor-κB (NF-κB) signaling and inhibits growth of glial cells. The magnitude of the NF-κB activation and the inhibition of cell growth by the STX and TNF-α combination was greater than that obtained with TNF-α alone or STX alone. Thus, this in vitro study reveals the role of TNF-α in glial cells during STEC infections.

A Molecular View of Pathological Microcalcification in Breast Cancer

Breast microcalcification is a potential diagnostic indicator for non-palpable breast cancers. Microcalcification type I (calcium oxalate) is restricted to benign tissue, whereas type II (calcium hydroxyapatite) occurs both in benign as well as in malignant lesions. Microcalcification is a pathological complication of the mammary gland. Over the past few decades, much attention has been paid to exploit this property, which forms the basis for advances in diagnostic procedures and imaging techniques. The mechanism of its formation is still poorly understood. Hence, in this paper, we have attempted to address the molecular mechanism of microcalcification in breast cancer. The central theme of this communication is "how a subpopulation of heterogeneous breast tumor cells attains an osteoblast-like phenotype, and what activities drive the process of pathophysiological microcalcification, especially at the invasive or infiltrating front of breast tumors". The role of bone morphogenetic proteins (BMPs) and tumor associated macrophages (TAMs) along with epithelial to mesenchymal transition (EMT) in manipulating this pathological process has been highlighted. Therefore, this review offers a novel insight into the mechanism underlying the development of microcalcification in breast carcinomas.

shRNA Depletion of cIAP1 Sensitizes Human Ovarian Cancer Cells to Anticancer Agent-Induced Apoptosis

Emerging evidence suggests a potential role of cellular inhibitor of apoptosis protein 1 (cIAP1) in the development of human ovarian cancer. However, its function in the progression of ovarian cancer has not been clearly determined. Our study aimed to investigate the effect of cIAP1 gene depletion on the chemosensitivity of ovarian cancer cells. We developed a novel short hairpin RNA (shRNA) plasmid specifically targeting cIAP1. Cell proliferation, invasion, and apoptosis of the shRNA-transfected cells were evaluated using MTT, Transwell chamber, and flow cytometric assays, respectively. The concentration of MMP-9 in the supernatant was detected by ELISA. Targeted depletion of cIAP1 by shRNA significantly reduced expression levels of cIAP1 mRNA and protein, leading to inhibition of cell proliferation and invasion capability in SKOV3 cells. At the same time, cIAP1 downregulation decreased the secretion of MMP-9. shRNA depletion of cIAP1 enhanced chemosensitivity of ovarian cancer cells to Taxol and carboplatin-induced apoptosis. cIAP1 is associated with tumor progression in human ovarian cancer. Therefore, cIAP1 might be a potential target for therapeutic anticancer drugs.

Levels of Matrix Metalloproteinases in Arthroplasty Patients and Their Correlation With Inflammatory and Thrombotic Activation Processes

An imbalance of matrix metalloproteinases (MMPs) and their inhibitors is thought to play a major role in the pathophysiology of joint diseases. The aim of this study is to provide additional insights into the relevance of MMP levels in arthroplasty patients in relation to inflammation and thrombosis. Deidentified plasma samples from 100 patients undergoing total hip arthroplasty or total knee arthroplasty were collected preoperatively, on postoperative day 1, and on postoperative day 3. Tissue inhibitor of MMP 4, tumor necrosis factor α (TNF-α), pro-MMP1, MMP3, MMP9, MMP13, and d-dimer were measured using enzyme-linked immunosorbent assay kits. A biochip array was used to profile interleukin (IL) 2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), interferon gamma, TNF-α, IL-1α, IL-1β, monocyte chemoattractant protein 1, and endothelial growth factor (EGF) levels. The levels of MMP1, MMP9, MMP13, and TNF-α were elevated preoperatively in arthroplasty patients when compared to healthy individuals. The concentrations of MMP1 and MMP9 increased slightly in postsurgical samples. d-Dimer levels were elevated preoperatively, increased postoperatively, and started decreasing on postoperative day 3. Significant correlations between MMP9 with TNF-α, IL-6, IL-8, VEGF, and EGF were identified. Elevated preoperative MMP1, MMP9, and MMP13 concentrations suggest that they may play a role in the pathogenesis of arthritis. There is also evidence of increased coagulation activity and possible upregulation of several MMPs postsurgically. Correlation analysis indicates that MMP9 levels may potentially be related to inflammation and thrombosis in arthroplasty patients.

NDRG2 Expression Decreases Tumor-Induced Osteoclast Differentiation by Down-regulating ICAM1 in Breast Cancer Cells

Bone matrix is properly maintained by osteoclasts and osteoblasts. In the tumor microenvironment, osteoclasts are increasingly differentiated by the various ligands and cytokines secreted from the metastasized cancer cells at the bone metastasis niche. The activated osteoclasts generate osteolytic lesions. For this reason, studies focusing on the differentiation of osteoclasts are important to reduce bone destruction by tumor metastasis. The N-myc downstream-regulated gene 2 (NDRG2) has been known to contribute to the suppression of tumor growth and metastasis, but the precise role of NDRG2 in osteoclast differentiation induced by cancer cells has not been elucidated. In this study, we demonstrate that NDRG2 expression in breast cancer cells has an inhibitory effect on osteoclast differentiation. RAW 264.7 cells, which are monocytic preosteoclast cells, treated with the conditioned media (CM) of murine breast cancer cells (4T1) expressing NDRG2 are less differentiated into the multinucleated osteoclast-like cells than those treated with the CM of 4T1-WT or 4T1-mock cells. Interestingly, 4T1 cells stably expressing NDRG2 showed a decreased mRNA and protein level of intercellular adhesion molecule 1 (ICAM1), which is known to enhance osteoclast maturation. Osteoclast differentiation was also reduced by ICAM1 knockdown in 4T1 cells. In addition, blocking the interaction between soluble ICAM1 and ICAM1 receptors significantly decreased osteoclastogenesis of RAW 264.7 cells in the tumor environment. Collectively, these results suggest that the reduction of ICAM1 expression by NDRG2 in breast cancer cells decreases osteoclast differentiation, and demonstrate that excessive bone resorption could be inhibited via ICAM1 down-regulation by NDRG2 expression.

NF-kappaB Signaling Pathways in Neurological Inflammation: A Mini Review

The NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells) transcription factor family is a pleiotropic regulator of many cellular signaling pathways, providing a mechanism for the cells in response to a wide variety of stimuli linking to inflammation. The stimulated cells will be regulated by not only the canonical but also non-canonical NF-κB pathways. To initiate both of these pathways, IκB-degradation triggers NF-κB release and the nuclear translocated-heterodimer (or homodimer) can associate with the κB sites of promoter to regulate the gene transcriptions. NF-κB ubiquitously expresses in neurons and the constitutive NF-κB activation is associated with processing of neuronal information. NF-κB can regulate the transcription of genes such as chemokines, cytokines, proinflammatory enzymes, adhesion molecules, proinflammatory transcription factors, and other factors to modulate the neuronal survival. In neuronal insult, NF-κB constitutively active in neuron cell bodies can protect neurons against different injuries and regulate the neuronal inflammatory reactions. Besides neurons, NF-κB transcription factors are abundant in glial cells and cerebral blood vessels and the diverse functions of NF-κB also regulate the inflammatory reaction around the neuronal environment. NF-κB transcription factors are abundant in the brain and exhibit diverse functions. Several central nerve system (CNS) diseases are linked to NF-κB activated by inflammatory mediators. The RelA and c-Rel expression produce opposite effects on neuronal survival. Importantly, c-Rel expression in CNS plays a critical role in anti-apoptosis and reduces the age-related behaviors. Moreover, the different subunits of NF-κB dimer formation can modulate the neuroninflammation, neuronal protection, or neurotoxicity. The diverse functions of NF-κB depend on the subunits of the NF-κB dimer-formation which enable us to develop a therapeutic approach to neuroinflammation based on a new concept of inflammation as a strategic tool in neuronal cells. However, the detail role of NF-κB in neuroinflammation, remains to be clarified. In the present article, we provide an updated review of the current state of our knowledge about relationship between NF-κB and neuroinflammation.

Tumor necrosis factor-alpha induces VCAM-1-mediated inflammation via c-Src-dependent transactivation of EGF receptors in human cardiac fibroblasts

BACKGROUND

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine and elevated in the regions of tissue injury and inflammatory diseases. The deleterious effects of TNF-α on fibroblasts may aggravate heart inflammation mediated through the up-regulation of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1). However, the mechanisms underlying TNF-α-induced VCAM-1 expression in cardiac fibroblasts remain unknown. This study aimed to investigate the roles of TNF-α in VCAM-1 expression and its effects on human cardiac fibroblasts (HCFs).

RESULTS

The primary culture HCFs were used in this study. The results obtained with Western blotting, real time-quantitative PCR, and promoter activity analyses showed that TNF-α-induced VCAM-1 expression was mediated through TNF receptor (TNFR) 1-dependent gene up-regulation. Activation of TNFR1 by TNF-α transactivated c-Src-dependent EGF receptor (EGFR) linking to PI3K/Akt cascade, and then led to transcriptional activity of NF-κB. Moreover, the results of promoter reporter assay demonstrated that the phosphorylated p65 NF-κB turned on VCAM-1 gene expression. Subsequently, up-regulation of VCAM-1 promoted monocytes adhesion to HCFs challenged with TNF-α determined by cell adhesion assay.

CONCLUSIONS

Taken together, these results indicate that in HCFs, activation of NF-κB by c-Src-mediated transactivation of EGFR/PI3K/Akt cascade is required for TNF-α-induced VCAM-1 expression. Finally, increased VCAM-1 enhances monocytes adhering to HCFs challenged with TNF-α. Understanding the mechanisms of VCAM-1 up-regulated by TNF-α on HCFs may provide rationally therapeutic interventions for heart injury or inflammatory diseases.