Matrix metalloproteinase-1 produced by human CXCL12-stimulated natural killer cells

Fibroblast activation protein regulates natural killer cell migration, extravasation and tumor infiltration

Natural killer (NK) cells play a critical role in physiologic and pathologic conditions such as pregnancy, infection, autoimmune disease and cancer. In cancer, numerous strategies have been designed to exploit the cytolytic properties of NK cells, with variable success. A major hurdle to NK-cell focused therapies is NK cell recruitment and infiltration into tumors. While the chemotaxis pathways regulating NK recruitment to different tissues are well delineated, the mechanisms human NK cells employ to physically migrate are ill-defined. We show for the first time that human NK cells express fibroblast activation protein (FAP), a cell surface protease previously thought to be primarily expressed by activated fibroblasts. FAP degrades the extracellular matrix to facilitate cell migration and tissue remodeling. We used novel in vivo zebrafish and in vitro 3D culture models to demonstrate that FAP knock out and pharmacologic inhibition restrict NK cell migration, extravasation, and invasion through tissue matrix. Notably, forced overexpression of FAP promotes NK cell invasion through matrix in both transwell and tumor spheroid assays, ultimately increasing tumor cell lysis. Additionally, FAP overexpression enhances NK cells invasion into a human tumor in immunodeficient mice. These findings demonstrate the necessity of FAP in NK cell migration and present a new approach to modulate NK cell trafficking and enhance cell-based therapy in solid tumors.

Effects of a co-stimulation with S-PRG filler eluate and muramyl dipeptide (MDP) on matrix metalloproteinase-1 production by human dental pulp fibroblast-like cells

The present study investigated the effects of a co-stimulation with surface reaction-type pre-reacted glass-ionomer (S-PRG) filler eluate and muramyl dipeptide (MDP) on matrix metalloproteinase (MMP)-1 production by human dental pulp fibroblast-like cells (hDPFs). S-PRG filler eluate contains 6 ions (F, Na, Al, B, Sr, and Si) released from S-PRG filler. Each S-PRG filler eluate and MDP stimulation enhanced MMP-1 production by hDPFs. The co-stimulation with S-PRG filler eluate and MDP enhanced MMP-1 production more than the MDP stimulation alone. A similar stimulation induced the phosphorylation of ERK 1/2. The increased secretion of MMP-1 and enhanced phosphorylation of ERK 1/2 by the co-stimulation with S-PRG filler eluate and MDP were suppressed by the selective and potent CaSR antagonist NPS 2143. Since strontium binds to CaSR, these results suggest that the enhanced production of MMP-1 by the co-stimulation with S-PRG filler eluate and MDP was due to the effects of strontium.

CFI-402257, a TTK inhibitor, effectively suppresses hepatocellular carcinoma

Deregulation of cell cycle is a typical feature of cancer cells. Normal cells rely on the strictly coordinated spindle assembly checkpoint (SAC) to maintain the genome integrity and survive. However, cancer cells could bypass this checkpoint mechanism. In this study, we showed the clinical relevance of threonine tyrosine kinase (TTK) protein kinase, a central regulator of the SAC, in hepatocellular carcinoma (HCC) and its potential as therapeutic target. Here, we reported that a newly developed, orally active small molecule inhibitor targeting TTK (CFI-402257) effectively suppressed HCC growth and induced highly aneuploid HCC cells, DNA damage, and micronuclei formation. We identified that CFI-402257 also induced cytosolic DNA, senescence-like response, and activated DDX41-STING cytosolic DNA sensing pathway to produce senescence-associated secretory phenotypes (SASPs) in HCC cells. These SASPs subsequently led to recruitment of different subsets of immune cells (natural killer cells, CD4⁺ T cells, and CD8⁺ T cells) for tumor clearance. Our mass cytometry data illustrated the dynamic changes in the tumor-infiltrating immune populations after treatment with CFI-402257. Further, CFI-402257 improved survival in HCC-bearing mice treated with anti-PD-1, suggesting the possibility of combination treatment with immune checkpoint inhibitors in HCC patients. In summary, our study characterized CFI-402257 as a potential therapeutic for HCC, both used as a single agent and in combination therapy.

Recruited and Tissue-Resident Natural Killer Cells in the Lung During Infection and Cancer

Natural killer (NK) cells are an important component of the innate immune system, and have a key role in host defense against infection and in tumor surveillance. Tumors and viruses employ remarkably similar strategies to avoid recognition and killing by NK cells and so much can be learnt by comparing NK cells in these disparate diseases. The lung is a unique tissue environment and immune cells in this organ, including NK cells, exist in a hypofunctional state to prevent activation against innocuous stimuli. Upon infection, rapid NK cell infiltration into the lung occurs, the amplitude of which is determined by the extent of inflammation and damage. Activated NK cells kill infected cells and produce pro-inflammatory cytokines and chemokines to recruit cells of the adaptive immune system. More recent evidence has shown that NK cells also play an additional role in resolution of inflammation. In lung cancer however, NK cell recruitment is impaired and those that are present have reduced functionality. The majority of lung NK cells are circulatory, however recently a small population of tissue-resident lung NK cells has been described. The specific role of this subset is yet to be determined, but they show similarity to resident memory T cell subsets. Whether resident or recruited, NK cells are important in the control of pulmonary infections, but equally, can drive excessive inflammation if not regulated. In this review we discuss how NK cells are recruited, controlled and retained in the specific environment of the lung in health and disease. Understanding these mechanisms in the context of infection may provide opportunities to promote NK cell recruitment and function in the lung tumor setting.

Stem cells-derived natural killer cells for cancer immunotherapy: current protocols, feasibility, and benefits of ex vivo generated natural killer cells in treatment of advanced solid tumors

Nowadays, natural killer (NK) cell-based immunotherapy provides a practical therapeutic strategy for patients with advanced solid tumors (STs). This approach is adaptively conducted by the autologous and identical NK cells after in vitro expansion and overnight activation. However, the NK cell-based cancer immunotherapy has been faced with some fundamental and technical limitations. Moreover, the desirable outcomes of the NK cell therapy may not be achieved due to the complex tumor microenvironment by inhibition of intra-tumoral polarization and cytotoxicity of implanted NK cells. Currently, stem cells (SCs) technology provides a powerful opportunity to generate more effective and universal sources of the NK cells. Till now, several strategies have been developed to differentiate types of the pluripotent and adult SCs into the mature NK cells, with both feeder layer-dependent and/or feeder laye-free strategies. Higher cytokine production and intra-tumoral polarization capabilities as well as stronger anti-tumor properties are the main features of these SCs-derived NK cells. The present review article focuses on the principal barriers through the conventional NK cell immunotherapies for patients with advanced STs. It also provides a comprehensive resource of protocols regarding the generation of SCs-derived NK cells in an ex vivo condition.

Chemokines and the extracellular matrix: Set of targets for tumor development and treatment

The extracellular matrix (ECM) consists of various molecules that support tissue cells, including proteins, fibronectin, laminin, collagen IV, and glycosaminoglycans. In addition to interactions between the ECM and cells, the ECM also interacts with chemokines, and growth factors, and these interactions ensure cell survival, development, differentiation, and migration of both immune system cells and tumor cells. This review provides an overview of the mechanisms of interaction between the ECM and chemokines, focusing on the tumor microenvironment and the modulation of these elements as a target for therapies in several types of cancer.

Chemokine Therapy in Cats With Experimental Renal Fibrosis and in a Kidney Disease Pilot Study

Background: Chronic tubulointerstitial fibrosis is a common final pathway leading to end stage kidney disease in cats and has no effective treatment. The use of cell-based molecules to treat kidney fibrosis may be a promising approach. The objectives were to test the effects of intra-renal chemokine CXCL12 injection in a pre-clinical cat model of unilateral ischemia/reperfusion (I/R)-induced kidney fibrosis and then, within a clinical pilot study, test the safety/feasibility of CXCL12 injection in cats that might have early chronic kidney disease (CKD). Methods: Pre-clinical: Thirty cats received intra-renal injection of 100, 200, or 400 ng of recombinant human CXCL12, or sterile saline, into the I/R kidney 70 days post-injury, or were non-injured, non-injected controls (n = 6/group). Kidney collagen content was quantified 4 months post-treatment using Masson's Trichrome and Picrosirius Red (PSR) stained tissues. In a separate study (n = 2) exploring short-term effects of CXCL12, 200 ng CXCL12 was injected into I/R kidneys and then harvested either 30 min (n = 1) or 1 month (n = 1) post-injection. Kidney concentrations of CXCL12, matrix metalloproteinase 1 (MMP-1), and lysyl oxidase-like enzyme 2 (LOXL-2) were quantified via ELISA. Clinical Pilot: 14 client-owned cats with potential early kidney disease received a single-treatment, bilateral intra-renal injection of 200 ng CXCL12 (n = 7), or received no injection (n = 7). Blood/urine samples were collected monthly for 9 months to assess renal function and CKD staging. Results: Pre-clinical: I/R increased the affected kidney collagen content, which both mid and high doses of CXCL12 restored to normal (ps < 0.05 vs. untreated). I/R increased collagen fiber width, which both mid and high doses of CXCL12 restored to normal (p < 0.001 vs. untreated). Early changes in kidney MMP-1, associated with collagen breakdown, and subsequent decreases in LOXL-2, associated with collagen cross-linking, in response to CXCL12 treatment may contribute to these findings. Clinical Pilot: Bilateral intra-renal injection of CXCL12 using ultrasound guidance in cats with CKD was feasible and safe in a general practice clinical setting with no obvious side effects noted during the 9-month follow-up period. Conclusions: Intra-renal injection of CXCL12 may prove to be an effective treatment for kidney fibrosis in cats with CKD. Additional mechanistic and clinical evaluations are needed.

Innate Lymphoid Cells in the Malignant Melanoma Microenvironment

Simple Summary

Innate lymphoid cells (ILCs) are the innate counterparts of adaptive immune cells. Emerging data indicate that they are also key players in the progression of multiple tumors. In this review we briefly describe ILCs’ functions in the skin, lungs and liver. Next, we analyze the role of ILCs in primary cutaneous melanoma and in its most frequent and deadly metastases, those in liver and lung. We focus on their dual anti– and pro-tumoral functions, depending on the cross-interactions among them and with the surrounding stromal cells that form the tumor microenvironment (TME) in each organ. Next, we detail the role of extracellular vesicles secreted to the TME by ILCs and melanoma on both cell populations. We conclude that the identification of markers and tools to allow the modulation of individual ILC subsets, in addition to the development of standardized protocols, is essential for addressing the therapeutic modulation of ILCs.

Abstract

The role of innate lymphoid cells (ILCs) in cancer progression has been uncovered in recent years. ILCs are classified as Type 1, Type 2, and Type 3 ILCs, which are characterized by the transcription factors necessary for their development and the cytokines and chemokines they produce. ILCs are a highly heterogeneous cell population, showing both anti– and protumoral properties and capable of adapting their phenotypes and functions depending on the signals they receive from their surrounding environment. ILCs are considered the innate counterparts of the adaptive immune cells during physiological and pathological processes, including cancer, and as such, ILC subsets reflect different types of T cells. In cancer, each ILC subset plays a crucial role, not only in innate immunity but also as regulators of the tumor microenvironment. ILCs’ interplay with other immune and stromal cells in the metastatic microenvironment further dictates and influences this dichotomy, further strengthening the seed-and-soil theory and supporting the formation of more suitable and organ-specific metastatic environments. Here, we review the present knowledge on the different ILC subsets, focusing on their interplay with components of the tumor environment during the development of primary melanoma as well as on metastatic progression to organs, such as the liver or lung.

Characterization of Rhesus Macaque Liver-Resident CD49a+ NK Cells During Retrovirus Infections

CD49a⁺ tissue resident NK cells have been implicated in memory-like NK cell responses, but while this population is well-characterized in mice and in humans, they are poorly described in non-human primates (NHP) which are particularly critical for modeling human viral infections. Others and we have shown that memory-like NK cells are enriched in the liver and because of the importance of NHP in modeling HIV infection, understanding the immunobiology of CD49a⁺ NK cells in SIV-infected rhesus macaques is critical to explore the role of this cell type in retroviral infections. In this study mononuclear cells isolated from livers, spleens, and peripheral whole blood were analyzed in acutely and chronically lentivirus-infected and experimentally-naïve Indian rhesus macaques (RM). NK cells were then identified as CD45⁺CD14⁻CD20⁻CD3⁻NKG2A/C⁺ cells and characterized using multiparametric flow-cytometry. Our data show that in RM, CD49a⁺ NK cells increase in the liver following retroviral infections [median = 5.2% (naïve) vs. median = 9.48% (SIV+) or median = 16.8% (SHIV+)]. In contrast, there is little change in CD49a⁺ NK frequencies in whole blood or spleens of matched animals. In agreement with human and murine data we also observed that CD49a⁺ NK cells were predominantly Eomes^low T-bet^low, though these frequencies are elevated in infected animal cohorts. Functionally, our data suggests that infection alters TNF-α, IFN-γ, and CD107a expression in stimulated CD49a⁺ NK cells. Specifically, our analyses found a decrease in CD49a⁺ CD107a⁺ TNFα⁺ IFNγ⁻ NK cells, with a simultaneous increase in CD49a⁺ CD107a⁺ TNFα⁻ IFNγ⁺ NK cells and the non-responsive CD49a⁺ CD107a⁻ TNFα⁻ IFNγ⁻ NK cell population following infection, suggesting both pathogenic and inflammatory changes in the NK cell functional profile. Our data also identified significant global differences in polyfunctionality between CD49a⁺ NK cells in the naïve and chronic (SHIV+) cohorts. Our work provides the first characterization of CD49a⁺ NK cells in tissues from RM. The significant similarities between CD49a⁺ NK cells from RM and what is reported from human samples justifies the importance of studying CD49a⁺ NK cells in this species to support preclinical animal model research.

Engineered Three-Dimensional Tumor Models to Study Natural Killer Cell Suppression

A critical hurdle associated with natural killer (NK) cell immunotherapies is inadequate infiltration and function in the solid tumor microenvironment. Well-controlled 3D culture systems could advance our understanding of the role of various biophysical and biochemical cues that impact NK cell migration in solid tumors. The objectives of this study were to establish a biomaterial which (i) supports NK cell migration and (ii) recapitulates features of the in vivo solid tumor microenvironment, to study NK infiltration and function in a 3D system. Using peptide-functionalized poly(ethylene glycol)-based hydrogels, the extent of NK-92 cell migration was observed to be largely dependent on the density of integrin binding sites and the presence of matrix metalloproteinase degradable sites. When lung cancer cells were encapsulated into the hydrogels to create tumor microenvironments, the extent of NK-92 cell migration and functional activity was dependent on the cancer cell type and duration of 3D culture. NK-92 cells showed greater migration into the models consisting of nonmetastatic A549 cells relative to metastatic H1299 cells, and reduced migration in both models when cancer cells were cultured for 7 days versus 1 day. In addition, the production of NK cell-related pro-inflammatory cytokines and chemokines was reduced in H1299 models relative to A549 models. These differences in NK-92 cell migration and cytokine/chemokine production corresponded to differences in the production of various immunomodulatory molecules by the different cancer cells, namely, the H1299 models showed increased stress ligand shedding and immunosuppressive cytokine production, particularly TGF-β. Indeed, inhibition of TGF-β receptor I in NK-92 cells restored their infiltration in H1299 models to levels similar to that in A549 models and increased overall infiltration in both models. Relative to conventional 2D cocultures, NK-92 cell mediated cytotoxicity was reduced in the 3D tumor models, suggesting the hydrogel serves to mimic some features of the biophysical barriers in in vivo tumor microenvironments. This study demonstrates the feasibility of a synthetic hydrogel system for investigating the biophysical and biochemical cues impacting NK cell infiltration and NK cell-cancer cell interactions in the solid tumor microenvironment.

α2β1 Integrin Is Required for Optimal NK Cell Proliferation during Viral Infection but Not for Acquisition of Effector Functions or NK Cell-Mediated Virus Control

NK cells play an important role in antiviral resistance. The integrin α2, which dimerizes with integrin β1, distinguishes NK cells from innate lymphoid cells 1 and other leukocytes. Despite its use as an NK cell marker, little is known about the role of α2β1 in NK cell biology. In this study, we show that in mice α2β1 deficiency does not alter the balance of NK cell/ innate lymphoid cell 1 generation and slightly decreases the number of NK cells in the bone marrow and spleen without affecting NK cell maturation. NK cells deficient in α2β1 had no impairment at entering or distributing within the draining lymph node of ectromelia virus (ECTV)-infected mice or at becoming effectors but proliferated poorly in response to ECTV and did not increase in numbers following infection with mouse CMV (MCMV). Still, α2β1-deficient NK cells efficiently protected from lethal mousepox and controlled MCMV titers in the spleen. Thus, α2β1 is required for optimal NK cell proliferation but is dispensable for protection against ECTV and MCMV, two well-established models of viral infection in which NK cells are known to be important.

Inflammation-Nature's Way to Efficiently Respond to All Types of Challenges: Implications for Understanding and Managing "the Epidemic" of Chronic Diseases

Siloed or singular system approach to disease management is common practice, developing out of traditional medical school education. Textbooks of medicine describe a huge number of discrete diseases, usually in a systematic fashion following headings like etiology, pathology, investigations, differential diagnoses, and management. This approach suggests that the body has a multitude of ways to respond to harmful incidences. However, physiology and systems biology provide evidence that there is a simple mechanism behind this phenotypical variability. Regardless if an injury or change was caused by trauma, infection, non-communicable disease, autoimmune disorders, or stress, the typical physiological response is: an increase in blood supply to the area, an increase in white cells into the affected tissue, an increase in phagocytic activity to remove the offending agent, followed by a down-regulation of these mechanisms resulting in healing. The cascade of inflammation is the body's unique mechanism to maintain its integrity in response to macroscopic as well as microscopic injuries. We hypothesize that chronic disease development and progression are linked to uncontrolled or dysfunctional inflammation to injuries regardless of their nature, physical, environmental, or psychological. Thus, we aim to reframe the prevailing approach of management of individual diseases into a more integrated systemic approach of treating the "person as a whole," enhancing the patient experience, ability to a make necessary changes, and maximize overall health and well-being. The first part of the paper reviews the local immune cascades of pro- and anti-inflammatory regulation and the interconnected feedback loops with neural and psychological pathways. The second part emphasizes one of nature's principles at work-system design and efficiency. Continually overwhelming this finely tuned system will result in systemic inflammation allowing chronic diseases to emerge; the pathways of several common conditions are described in detail. The final part of the paper considers the implications of these understandings for clinical care and explore how this lens could shape the physician-patient encounter and health system redesign. We conclude that healthcare professionals must advocate for an anti-inflammatory lifestyle at the patient level as well as at the local and national levels to enhance population health and well-being.

Molecular Mechanisms Directing Migration and Retention of Natural Killer Cells in Human Tissues

A large body of data shows that Natural Killer (NK) cells are immune effectors exerting a potent cytolytic activity against tumors and virus infected cells. The discovery and characterization of several inhibitory and activating receptors unveiled most of the mechanisms allowing NK cells to spare healthy cells while selectively attacking abnormal tissues. Nevertheless, the mechanisms ruling NK cell subset recirculation among the different compartments of human body have only lately started to be investigated. This is particularly true for pathological settings such as tumors or infected tissues but also for para-physiological condition like pregnant human uterine mucosa. It is becoming evident that the microenvironment associated to a particular clinical condition can deeply influence the migratory capabilities of NK cells. In this review we describe the main mechanisms and stimuli known to regulate the expression of chemokine receptors and other molecules involved in NK cell homing to either normal or pathological/inflamed tissues, including tumors or organs such as lung and liver. We will also discuss the role played by the chemokine/chemokine receptor axes in the orchestration of physiological events such as NK cell differentiation, lymphoid organ retention/egress and recruitment to decidua during pregnancy.

Angiogenin and the MMP9-TIMP2 axis are up-regulated in proangiogenic, decidual NK-like cells from patients with colorectal cancer

NK cells are effector lymphocytes involved in tumor immunosurveillance; however, in patients with solid malignancies, NK cells have compromised functions. We have previously reported that lung tumor-associated NK cells (TANKs; peripheral blood) and tumor-infiltrating NK cells (TINKs) show proangiogenic, decidual NK-like (dNK) phenotype. In this study, we functionally and molecularly investigated TINKs and TANKs from blood and tissue samples of patients with colorectal cancer (CRC), a neoplasm in which inflammation and angiogenesis have clinical relevance, and compared them to NK cells from controls and patients with nononcologic inflammatory bowel disease. CRC TINKs/TANKs showed decreased expression for the activatory marker NKG2D, impaired degranulation activity, a decidual-like NK polarization toward the CD56^brightCD16^dim/-CD9⁺CD49⁺ subset. TINKs and TANKs secreted cytokines with proangiogenic activities, and induce endothelial cell proliferation, migration, adhesion, and the formation of capillary-like structures in vitro. dNK cells release specific proangiogenic factors; among which, angiogenin and invasion-associated enzymes related to the MMP9-TIMP1/2 axis. Here, we describe, for the first time, to our knowledge, the expression of angiogenin, MMP2/9, and TIMP by TANKs in patients with CRC. This phenotype could be relevant to the invasive capabilities and proangiogenic functions of CRC-NK cells and become a novel biomarker. STAT3/STAT5 activation was observed in CRC-TANKs, and treatment with pimozide, a STAT5 inhibitor, reduced endothelial cell capability to form capillary-like networks, inhibiting VEGF and angiogenin production without affecting the levels of TIMP1, TIMP2, and MMP9, indicating that STAT5 is involved in cytokine modulation but not invasion-associated molecules. Combination of Stat5 or MMP inhibitors with immunotherapy could help repolarize CRC TINKs and TANKs to anti-tumor antimetastatic ones.-Bruno, A., Bassani, B., D'Urso, D. G., Pitaku, I., Cassinotti, E., Pelosi, G., Boni, L., Dominioni, L., Noonan, D. M., Mortara, L., Albini, A. Angiogenin and the MMP9-TIMP2 axis are up-regulated in proangiogenic, decidual NK-like cells from patients with colorectal cancer.

Natural killer cells and tumor metastasis

Natural killer (NK) cells are cytotoxic lymphocytes that recognize tumor cells or stressed cells through 'missing-self' signals, such as altered or absent expression of MHC class I molecules. The function of NK cells is regulated by the activation or inhibition of receptors present on their surface. The activation of NK cells results in cytotoxic activity on target cells through release of toxic granules and inflammatory cytokines. However, NK cells infiltrating tumors have been frequently shown to exhibit a skewed phenotype that includes decreased antitumor activity and enhanced protumor activities, such as angiogenesis and metastasis. In fact, many studies have reported that tumor microenvironments induce a protumor phenotype in NK cells. Here, we review the biological properties of NK cells in the context of tumorigenesis and tumor progression, with a specific focus on the interactions between NK cells and critical tumor microenvironments, such as epithelial-to-mesenchymal transition, matrix metalloproteinases, and tumor-associated chronic inflammation in tumor metastasis.

Anticancer properties of nimbolide and pharmacokinetic considerations to accelerate its development

Nimbolide is one of the main components in the leaf extract of Azadirachta indica (A. indica). Accumulating evidence from various in vitro and in vivo studies indicates that nimbolide possesses potent anticancer activity against several types of cancer and also shows potential chemopreventive activity in animal models. The main mechanisms of action of nimbolide include anti-proliferation, induction of apoptosis, inhibition of metastasis and angiogenesis, and modulation of carcinogen-metabolizing enzymes. Although multiple pharmacodynamic (PD) studies have been carried out, nimbolide is still at the infant stage in the drug development pipeline due to the lack of systematic pharmacokinetic (PK) studies and long-term toxicological studies. Preclinical PK and toxicological studies are vital in determining the dosage range to support the safety of nimbolide for first-in-human clinical trials. In this review, we will provide a comprehensive summary for the current status of nimbolide as an anticancer and chemopreventive lead compound, and highlight the importance of systematic preclinical PK and toxicological studies in accelerating the process of application of nimbolide as a therapeutic agent against various malignancies.

Nimbolide inhibits invasion and migration, and down-regulates uPAR chemokine gene expression, in two breast cancer cell lines

OBJECTIVES

Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in women, worldwide. Urokinase type plasminogen activator (uPA) is a serine protease that is involved in cancer progression, especially invasion and metastasis of breast cancer. Nimbolide is a potent cytotoxic limnoid isolated from Azadirachta indica. Our previous studies have shown that nimbolide elicits pleiotropic effects on breast cancer cells; however, its roles in invasion and migration have not previously been fully elucidated.

MATERIALS AND METHODS

Protein expression of pEGFR, VEGFR, NFκB, IKKα, IKKβ, MMP-2, MMP-9 and TIMP-2 were analysed by western blotting. We also analysed expressions of uPA, uPAR genes and chemokines by real-time PCR. Breast cancer cell invasion was assessed by transwell invasion assay and cell migration analysed by scratch wound healing assay.

RESULTS

Our results showed that reduced protein expression of pEGFR, VEGFR, NFκB, IKKα, β, MMP-2, MMP-9 and TIMP-2 was higher in nimbolide-treated breast cancer cells. mRNA expression of uPA, uPAR, chemokines and their receptors were also significantly reduced in response to nimbolide treatment. Nimbolide inhibited breast cancer cell migration and invasion as shown in transwell invasion and wound healing assays.

CONCLUSION

These results clearly proved inhibitory effects of nimbolide on tumour cell invasion and migration by down-regulating proteins critically involved in regulation of cell invasion and metastasis, suggesting a possible therapeutic role of nimbolide for breast cancer.

Effects of JNK1/2 on the inflammation cytokine TNF-α-enhanced production of MMP-3 in human dental pulp fibroblast-like cells

AIM

To investigate the effects of the c-Jun N-terminal kinase (JNK1/2) on the inflammation cytokine tumour necrosis factor-alpha (TNF-α)-enhanced production of matrix metalloproteinase-3 (MMP-3) in human dental pulp fibroblast-like cells (HPFs).

METHODOLOGY

HPFs were grown from pulp explants from healthy donors. Primary cultures were established by culturing the cells for 20 to 30 days. The experiments with HPFs were performed between passages 3 and 10. The HPFs were incubated in serum-free medium containing TNF-α for 24 h. The medium in each well was prepared in SDS sample buffer and was analysed for MMP-3 by Western blotting.

RESULTS

JNK inhibitor SP601245 markedly inhibited the production of MMP-3 in TNF-α-stimulated human dental pulp fibroblasts. MMP-3 production was enhanced by TNF-α in HPFs; silencing JNK1 and JNK2 expression inhibited this activation. cAMP response element-binding protein (CREB) was activated by TNF-α in HPFs; silencing JNK1 and JNK2 expression inhibited this activation.

CONCLUSION

The activation of CREB via JNK pathways in the presence of TNF-α occurred with enhancement of MMP-3 production in dental pulp fibroblasts.

Combined treatment with a CXCL12 analogue and antibiotics improves survival and neutrophil recruitment and function in murine sepsis

Previous studies demonstrated that the CXCL12 peptide analogue CTCE-0214 (CTCE) has beneficial effects in experimental sepsis induced by cecal ligation and puncture (CLP). We examined the hypothesis that CTCE recruits neutrophils (PMN) to the site of infection, enhances PMN function and improves survival of mice in CLP-induced sepsis with antibiotic treatment. Septic mice (n=15) were administered imipenem (25mg/kg) and CTCE (10 mg/kg) subcutaneously vs. vehicle control at designated intervals post-CLP. CTCE treatment increased PMN recruitment in CLP-induced sepsis as evidenced by increased PMN in blood by 2.4±0.6 fold at 18h, 2.9±0.6 fold at 24h, respectively and in peritoneal fluid by 2.0±0.2 fold at 24h vs. vehicle control. CTCE treatment reduced bacterial invasion in blood (CFU decreased 77±11%), peritoneal fluid (CFU decreased 78±9%) and lung (CFU decreased 79±8% vs. CLP vehicle). The improved PMN recruitment and bacterial clearance correlated with reduced mortality with CTCE treatment (20% vs. 67% vehicle controls). In vitro studies support the notion that CTCE augments PMN function by enhancing phagocytic activity (1.25±0.02 fold), increasing intracellular production of ROS (32±4%) and improving bacterial killing (CFU decreased 27±3%). These composite findings support the hypothesis that specific CXCL12 analogues with ancillary antibiotic treatment are beneficial in experimental sepsis, in part, by augmenting PMN recruitment and function. This article is protected by copyright. All rights reserved.

Enamel matrix derivative protein enhances production of matrixmetalloproteinase-2 by osteoblasts

Background

Matrix metalloproteinases (MMPs) degrade the extracellular matrix (ECM) and regulate remodeling and regeneration of bone. Enamel matrix derivative (EMD) protein has been used clinically for periodontal regeneration, although its molecular mechanisms are not clear. We evaluated the role of matrix metalloproteinases (MMPs) in regulating EMD-dependent degradation of gelatin on oeoblast-like cell line MG63.

Methods

MG-63 cells (osteoblast cell line) were incubated with 100 μg/ml EMD protein in the presence or absence of MMP-2 tissue inhibitor for 20 h followed by incubation on DQ-gelatin-coated plates for 4 h. MG-63 cells (1 × 10⁶) were preincubated with SB203580 for 30 min at 37°C and were then placed in 100 μg/ml EMD protein for 24 h. Conditioned media were collected and detected by Western blot analysis.

Results

EMD protein enhanced cell-mediated degradation of gelatin, which was inhibited by the MMP inhibitor TIMP-2. Furthermore, MMP-2 was produced by MG63 cells in response to EMD protein in a P38 MAPK-dependent manner. In addition, blocking of p38 MAPK activation by SB203580 significantly inhibited generation of the active form of MMP-2.

Conclusion

P38 MAPK pathway promotes expression MMP-2 in EMD activated osteoblasts, which in turn stimulates periodontal regeneration by degrading matrix proteins in periodontal connective tissue.

Understanding the impact of 2D and 3D fibroblast cultures on in vitro breast cancer models

The utilization of 3D, physiologically relevant in vitro cancer models to investigate complex interactions between tumor and stroma has been increasing. Prior work has generally focused on the cancer cells and, the role of fibroblast culture conditions on tumor-stromal cell interactions is still largely unknown. Here, we focus on the stroma by comparing functional behaviors of human mammary fibroblasts (HMFs) cultured in 2D and 3D and their effects on the invasive progression of breast cancer cells (MCF10DCIS.com). We identified increased levels of several paracrine factors from HMFs cultured in 3D conditions that drive the invasive transition. Using a microscale co-culture model with improved compartmentalization and sensitivity, we demonstrated that HMFs cultured in 3D intensify the promotion of the invasive progression through the HGF/c-Met interaction. This study highlights the importance of the 3D stromal microenvironment in the development of multiple cell type in vitro cancer models.

Matrix metalloproteinases in cytotoxic lymphocytes impact on tumour infiltration and immunomodulation

To efficiently combat solid tumours, endogenously or adoptively transferred cytotoxic T cells and natural killer (NK) cells, need to leave the vasculature, traverse the interstitium and ultimately infiltrate the tumour mass. During this locomotion and migration in the three dimensional environment many obstacles need to be overcome, one of which is the possible impediment of the extracellular matrix. The first and obvious one is the sub-endothelial basement membrane but the infiltrating cells will also meet other, both loose and tight, matrix structures that need to be overridden. Matrix metalloproteinases (MMPs) are believed to be one of the most important endoprotease families, with more than 25 members, which together have function on all known matrix components. This review summarizes what is known on synthesis, expression patterns and regulation of MMPs in cytotoxic lymphocytes and their possible role in the process of tumour infiltration. We also discuss different functions of MMPs as well as the possible use of other lymphocyte proteases for matrix degradation.

Effects of IL-2 on MMP expression in freshly isolated human NK cells and the IL-2-independent NK cell line YT

Interleukin-2 is an important activation factor for natural killer (NK) cells but its effect on NK cell matrix metalloproteinases (MMP) production and matrix degradation is less well investigated. We have used freshly isolated human NK cells and the IL-2-independent NK cell line, YT, to investigate the effects of IL-2 stimulation on NK cell invasion of Matrigel and on MMP expression and production. In YT cells, we found opposing early and late effects of IL-2 stimulation with an early (2 h) increase in MMP-9 protein level and enhanced migration in the Matrigel invasion assay and by 30 hours a decreased mRNA expression of MMP-2, MMP-9, MMP-13, MT3-MMP, and MT6-MMP. We also found a preculture period of 48 hours with IL-2 to negatively affect YT cell migration. We furthermore found that freshly isolated human NK cells Matrigel invasion was MMP-dependent and it increased in response to IL-2. Importantly, in freshly isolated human NK cells we did not see a downregulation of MMPs after 24 hours IL-2 stimulation, but instead a significant upregulation of MT6-MMP mRNA. Because of the cellular localisation of MT6-MMP, which ensures a focalized proteolytic activity, and its high expression compared with the other MMPs in freshly isolated human NK cells makes it of interest to study further.

CXCR4 antagonist AMD3100 attenuates colonic damage in mice with experimental colitis

AIM: To investigate the effects of the chemokine stromal cell-derived factor-1 (CXCL12) receptor (CXCR4) antagonist AMD3100 on colonic inflammation and epithelial barrier in dextran sulfate sodium (DSS)-induced colitis in mice.

METHODS: Experimental colitis was induced by administration of 5% DSS for 7 d, and assays performed on intestinal segments from the ileocecal valve to the anus. Colonic morphology was examined by hematoxylin and eosin staining. Colonic cytokines were determined by enzyme-linked immunosorbent assay. Myeloperoxidase (MPO) activity (indicator of inflammatory infiltration) was observed spectrophotometrically. Gut permeability was assessed by mucosal-to-serosal clearance of fluorescein isothiocyanate-conjugated dextran 4000 (FD4) in everted gut sacs. The apoptosis of colonic epithelium was assessed by Hoechst-33342 staining. To further elucidate the role of CXCR4 in colonic inflammation, we also investigated the effect of AMD3100 on migration and cytokine production of isolated peripheral blood mononuclear cells (PBMCs).

RESULTS: DSS-induced colitis was characterized by morphologic changes, as well as increased colonic cytokines, inflammatory infiltration, epithelial apoptosis, and intestinal permeability in mice. In AMD3100-treated mice, epithelial destruction, inflammatory infiltration, and submucosal edema were markedly reduced; colonic tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interferon-γ (IFN-γ) levels, as well as MPO activity were significantly decreased. Increased intestinal permeability in DSS-treated mice was significantly reduced by AMD3100. The number of apoptotic cells in colitis mice was markedly increased after DSS administration, and decreased when treated with the CXCR4 antagonist AMD3100. In pre-activated PBMCs, CXCL12 stimulation significantly increased the migration of PBMCs, and was inhibited by AMD3100. Moderately increased TNF-α, IL-6, and IFN-γ from CXCL12-treated PBMCs were also reduced by AMD3100.

CONCLUSION: The CXCR4 antagonist AMD3100 exerts therapeutic effects on experimental colitis by inhibiting colonic inflammation and enhancing epithelial barrier integrity.

CXCR4/SDF1 mediate hypoxia induced chondrosarcoma cell invasion through ERK signaling and increased MMP1 expression

Background

Chondrosarcoma is a disease that does not respond to conventional cytotoxic chemotherapy and expression of MMP1 is a marker for a poor prognosis. The mechanism of increased MMP1 expression in chondrosarcoma is not completely known. Our goal is to identify molecular pathways that could serve as therapeutic targets. Chondrosarcoma become hypoxic as they grow, are capable of eliciting an angiogenic response, and typically metastasize to the lungs. The present study determined the effect of hypoxia and specifically HIF-1a on expression of CXCR4 and MMP1 and their role in chondrosarcoma cell invasion.

Results

CXCR4 and its ligand, SDF1, are upregulated in primary chondrosarcoma tumors compared to normal articular cartilage, and CXCR4 was upregulated in chondrosarcoma cell line JJ compared to normal chondrocytes. Hypoxia and specifically HIF-1a increased CXCR4 and MMP1 expression in JJ cell line and chondrosarcoma invasion in vitro. The hypoxia mediated increase in MMP1 expression and chondrosarcoma invasion could be inhibited by siRNA directed at HIF-1a or CXCR4, the CXCR4 inhibitor AMD3100, as well as with ERK inhibitor U0126 and ERK siRNA.

Conclusions

Chondrosarcoma cell invasion is increased by hypoxia induced expression of CXCR4 and MMP1 and is mediated by HIF-1a and ERK. Both invasion and MMP1 can be inhibited with CXCR4 blockade, suggesting that CXCR4/SDF1 signaling may be a therapeutic target for chondrosarcoma.

Role of chemokines in the biology of natural killer cells

Natural killer (NK) cells represent a major subpopulation of lymphocytes. These cells have effector functions as they recognize and kill transformed cells as well as microbially infected cells. In addition, alloreactive NK cells have been successfully used to treat patients with acute myeloid leukemia and other hematological malignancies. NK cells are also endowed with immunoregulatory functions since they secrete cytokines such as IFN-γ, which favor the development of T helper 1 (Th1) cells, and chemokines such as CCL3/MIP-1α and CCL4/MIP-1β, which recruit various inflammatory cells into sites of inflammation. In human blood, NK cells are divided into CD56(bright) CD16(dim) and CD56(dim) CD16(bright) subsets. These subsets have different phenotypic expression and may have different functions; the former subset is more immunoregulatory and the latter is more cytolytic. The CD56(bright)CD16(dim) NK cells home into tissues such as the peripheral lymph nodes (LNs) under physiological conditions because they express the LN homing receptor CCR7 and they respond to CCL19/MIP-3β and CCL21/SLC chemokines. They also distribute into adenoid tissues or decidual uterus following the CXCR3/CXCL10 or CXCR4/CXCL12 axis. On the other hand, both NK cell subsets migrate into inflammatory sites, with more CD56(dim)CD16(bright) NK cells distributing into inflamed liver and lungs. CCR5/CCL5 axis plays an important role in the accumulation of NK cells in virally infected sites as well as during parasitic infections. CD56(bright)CD16(dim) cells also migrate into autoimmune sites such as inflamed synovial fluids in patients having rheumatoid arthritis facilitated by the CCR5/CCL3/CCL4/CCL5 axis, whereas they distribute into inflamed brains aided by the CX₃CR1/CX₃CL1 axis. On the other hand, CD56(dim)CD16(bright) NK cells accumulate in the liver of patients with primary biliary disease aided by the CXCR1/CXCL8 axis. However, the types of chemokines that contribute to their accumulation in target organs during graft vs. host (GvH) disease are not known. Further, chemokines activate NK cells to become highly cytolytic cells known as CC chemokine-activated killer (CHAK) cells that kill tumor cells. In summary, chemokines whether secreted in an autocrine or paracrine fashion regulate various biological functions of NK cells. Depending on the tissue and the chemokine secreted, NK cells may ameliorate the disease such as their roles in combating tumors or virally infected cells, and their therapeutic potentials in treating leukemias and other hematological malignancies, as well as reducing the incidence of GvH disease. In contrast, they may exacerbate the disease by damaging the affected tissues through direct cytotoxicity or by the release of multiple inflammatory cytokines and chemokines. Examples are their deleterious roles in autoimmune diseases such as rheumatoid arthritis and primary biliary cirrhosis.

Exercise-induced up-regulation of MMP-1 and IL-8 genes in endurance horses

Background

The stress response is a critical factor in the training of equine athletes; it is important for performance and for protection of the animal against physio-pathological disorders.

In this study, the molecular mechanisms involved in the response to acute and strenuous exercise were investigated using peripheral blood mononuclear cells (PBMCs).

Results

Quantitative real-time PCR (qRT-PCR) was used to detect modifications in transcription levels of the genes for matrix metalloproteinase-1 (MMP-1) and interleukin 8 (IL-8), which were derived from previous genome-wide expression analysis. Significant up-regulation of these two genes was found in 10 horses that had completed a race of 90–120 km in a time-course experimental design.

Conclusion

These results suggest that MMP-1 and IL-8 are both involved in the exercise-induced stress response, and this represents a starting point from which to understand the adaptive responses to this phenomenon.

Human NK cell lines migrate differentially in vitro related to matrix interaction and MMP expression

Matrix metalloproteinases (MMPs) are thought to be of importance for the migratory ability of natural killer (NK) cells. Their expression and production may influence the amount of tumour-infiltrating NK cells and thereby any therapeutic capability. In this study, we sought to investigate the importance of MMPs for human NK cells' ability to degrade and migrate through the extracellular matrix (ECM). The two human NK cell lines, NK-92 and YT, migratory ability, MMP expression and production as well as their morphological appearance when cultured in the ECM equivalent Matrigel were analysed and compared. The quantitatively more migratory NK-92 cells were found to express invadopodia/podosomes at a significantly higher degree when cultured in Matrigel and gave rise to a general disintegration of the Matrigel. The NK-92 cells had a higher mRNA expression of MMP-2, -9, -13, MT1-, MT3- and MT6-MMP and a significantly higher production of MMP-9 compared to YT cells. These differences could explain the substantial functional difference observed between the two cell lines with respect to migratory capacity. In addition, the number of Matrigel invading NK-92 cells decreased significantly in the presence of the MMP inhibitor GM6001, demonstrating that MMPs have a critical function in their migration.

Chemokine signaling in cancer: Implications on the tumor microenvironment and therapeutic targeting

Chemokines are soluble factors shown to play important roles in regulating immune cell recruitment during inflammatory responses and defense against foreign pathogens. De-regulated expression and activity of several chemokine signaling pathways have been implicated in cancer progression, including: CCL2, CCL5, CXCL1 and CXCL12. While studies in the past have focused the role of these chemokine signaling pathways in regulating immune responses, emerging studies show that these molecules regulate diverse cellular processes including angiogenesis, and regulation of epithelial cell growth and survival. New evidence indicates that chemokines are critical for cancer progression and indicate complex and diverse functions in the tumor microenvironment. This review will focus on the contributions of chemokine signaling in regulating cancer microvironment and discuss the utility of targeting or delivering chemokines in cancer therapeutics.

Impaired TCR signaling through dysfunction of lipid rafts in sphingomyelin synthase 1 (SMS1)-knockdown T cells

During T cell activation, TCRs cluster at the center of the T cell-antigen-presenting cell interface forming the central supramolecular activation cluster. Although it has been suggested that sphingolipid- and cholesterol-rich microdomains, termed lipid rafts, form platforms for the regulation and transduction of TCR signals, an actual role for membrane sphingomyelin (SM), a key component of lipid rafts, has not been reported. After cloning a gene responsible for SM synthesis, sphingomyelin synthase (SMS) 1, we established a SM-knockdown cell line (Jurkat-SMS1/kd) by transfection of SMS1-short-interfering RNA into Jurkat T cells, which is deficient in membrane expression of SM. Upon CD3 stimulation, expression of CD69 (the earliest leukocyte activation antigen), activation-induced cell adhesion and proliferation as well as TCR clustering was severely impaired in Jurkat-SMS1/kd cells. CD3-induced tyrosine phosphorylation and association of linker for activation of T cell with ZAP-70 and Grb2 and phosphorylation of protein kinase C (PKC) were also severely impaired in Jurkat-SMS1/kd cells. Finally, translocation of TCR, ZAP-70 and PKC into lipid rafts was markedly decreased in Jurkat-SMS1/kd cells. These findings indicate that membrane SM is crucial for TCR signal transduction, leading to full T cell activation through lipid raft function.

Emdogain stimulates matrix degradation by osteoblasts

Emdogain has been used clinically for periodontal regeneration, although the underlying molecular mechanisms are not clear at present. In this study, we hypothesized that Emdogain stimulated degradation of type I collagen via osteoblasts. We showed that Emdogain enhanced cell-mediated degradation of type I collagen in an MMP-dependent manner. Although MG-63 cells spontaneously produced a zymogen form of MMP-1, treatment with Emdogain significantly induced the generation of the active form of this enzyme. We demonstrated that MMP-3 was produced from MG63 cells in response to Emdogain in a MEK1/2-dependent manner. Concomitantly, blocking of MEK1/2 activation by U0126 significantly inhibited the generation of the active form of MMP-1 without affecting the total production of this collagenase. These results suggest that Emdogain facilitates tissue regeneration through the activation of the collagenase, MMP-1, that degrades matrix proteins in bone tissue microenvironments.