MMP-2 Activation Research Articles

Exendin-4 inhibits MMP-9 activation and reduces infarct growth after focal cerebral ischemia in hyperglycemic mice

Exendin-4 inhibits MMP-9 activation and reduces infarct growth after focal cerebral ischemia in hyperglycemic mice

108 Skin inflammation is associated with matrix remodelling and MMP expression and activation in hidradenitis suppurativa

108 Skin inflammation is associated with matrix remodelling and MMP expression and activation in hidradenitis suppurativa

Hypoxia-inducible factor-1α is involved in isoflurane-induced blood-brain barrier disruption in aged rats model of POCD

Prolonged exposure to inhaled anesthetics may lead to postoperative cognitive dysfunction (POCD). Nevertheless, the underlying mechanisms are not known. Hypoxia-inducible factor-1α (HIF-1α) and its target gene vascular endothelial growth factor (VEGF) were shown to be activated by inhaled anesthetics. The aim of the present study was to determine the role of HIF-1α in isoflurane-induced blood–brain barrier (BBB) disruption and resultant cognitive impairment. After a 4-h exposure to 1.5% isoflurane in 20-month-old rats, increases in vascular permeability, and disrupted BBB ultrastructure were accompanied by the degradation of tight junction proteins occludin and collagen type IV in brain blood vessels. Increases in HIF-1α and VEGF proteins and activation of MMP-2 in the hippocampus were also observed in the hippocamp of isoflurane-exposed rats compared with control rats. Pharmacological inhibition of HIF-1α activation by 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1) markedly suppressed the expression of HIF-1α, VEGF and MMP-2, and mitigated the severity of BBB disruption.YC-1 pretreatment also significantly attenuated isoflurane-induced cognitive deficits in the Morris water maze task. Overall, our results demonstrate that hippocampal HIF-1α/VEGF signaling seems to be the upstream mechanism of isoflurane-induced cognitive impairment, and provides apotential preventive and therapeutic target for POCD.

Abstract P526: MMP-2 Activation By S-glutathiolation Decreases Calponin-1 During Vascular Remodeling In Hypertension

Aim: Antioxidant tempol may decrease MMP-2 activation by S-glutathiolation as it reduces oxidative stress, and then prevents calponin-1 cleavage and aortic remodeling in hypertension. Methods: Male Wistar rats were submitted to the two kidney-one clip (2K-1C) model of hypertension or sham surgery and were treated with tempol (18 mg/kg/day) or water by gavage for one week. Systolic blood pressure (SBP) was accessed by tail-cuff plethysmography. Aortas were used to perform in situ zymography, immunofluorescence for dihydroethidium and calponin-1, immunohistochemistry for nitrotyrosine, co-immunoprecipitation for glutathione followed by Western blot for MMP-2 and histomorphology. Two-way ANOVA followed by Bonferroni test was done (Ethics Committee approval number: 0015/2017). Results: SBP increased in 2K-1C rats compared to Sham group (156±2.9 vs. 128.6±4.1, p<0.05) and tempol did not reduce it (147.3±4.7, p>0.05). Morphological analysis showed increased that 2K-1C aortas had increased media to lumen ratio (M/L) (8.6±0.7 vs. 6.5±0.2) and cross-sectional area (CSA) (1.4x10 6 ±1.5x10 5 vs. 9.7x10 5 ±4.2x10 4 ) (p<0.05 vs. Sham), but tempol did not decrease them (M/L: 7.9±0.8; CSA: 1.3x10 6 ±1.3x10 5 , p>0.05 vs. 2K-1C). However, tempol decreased 2K-1C-induced increased nitrotyrosine levels (5.9x10 5 ±1.3x10 4 vs. 4.0x10 5 ±6.1x10 4 ), dihydroethidium (16.9±1.7 vs. 8.9±1.1) and MMP-2 activity (57.5±6.4 vs. 39.4±2.6; p<0.05). All four groups presented S-glutathiolation of MMP-2, however, the levels of calponin-1 were only reduced in aortas from 2K-1C rats (17.2±1.5 vs. 28.5±1.2, p<0.05 vs. Sham groups) and tempol reverted such loss (23.6±1.6, p<0.05 vs. 2K-1C). As calponin-1 is a potential intracellular target of MMP-2 in VSMC, these results suggest that the intracellular activation of MMP-2 may be more pronounced in hypertension. Different concentrations of tempol (0.5, 1 or 1.5 mM) did not directly inhibit MMP-2 activity in gelatin zymography (respectively: 4.6x10 6 ±7.4x10 4 , 4.9x10 6 ±1.2x10 5 and 4.8x10 6 ±1.5x10 5 vs. 4.6x10 6 ±2.2x10 5 ; p>0.05). Conclusion: Increased oxidative stress may contribute to activate aortic MMP-2 by S-glutathiolation in early hypertension, thus resulting in calponin-1 loss and maladaptive remodeling.

Selective suppression of the JNK-MMP2/9 signal pathway by tetramethylpyrazine attenuates neuropathic pain in rats

BackgroundActivated astrocytes release matrix metalloproteinase-2/9 (MMP-2/9) to induce central sensitization and maintain neuropathic pain. However, the mechanisms involved in the activation of MMP-2/9 on astrocytes during pain remain poorly understood. Meanwhile, there is a lack of effective treatment to inhibit the activation of MMP-2/9 on astrocytes. In this study, we aim to investigate the effect of tetramethylpyrazine (TMP), a natural compound with analgesic effects but unknown mechanisms, on MMP-2/9 in neuropathic pain.MethodsThe nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in rats (n = 6). Cell signaling was assayed using western blotting (n = 6) and immunohistochemistry (n = 5). The astrocyte cell line C8-D1A was cultured to investigate the in vitro effects.ResultsTMP significantly attenuated the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain, inhibited the activation of astrocytes, and decreased the expression of MMP-2/9. Furthermore, our results indicated that TMP could selectively suppress JNK activity but had no notable effects on ERK and p38. Our study also revealed that the effect of TMP may be dependent on the inhibition of TAK1.ConclusionsInhibition of astrocyte activation in the spinal cord by tetramethylpyrazine may have utility in the treatment of CCI-induced neuroinflammation, and our results further implicate JNK-MMP-2/9 as a novel target for the attenuation of neuropathic pain.

S1P inhibits trophoblast-mediated collagen breakdown via a decrease in activation of MMP2; a potential mechanism for reduced invasiveness

S1P inhibits trophoblast-mediated collagen breakdown via a decrease in activation of MMP2; a potential mechanism for reduced invasiveness

The Red Algae Compound 3-Bromo-4,5-dihydroxybenzaldehyde Protects Human Keratinocytes on Oxidative Stress-Related Molecules and Pathways Activated by UVB Irradiation.

Skin exposure to ultraviolet B (UVB) irradiation leads to the generation of reactive oxygen species (ROS). Excessive ROS cause aging of the skin via basement membrane/extracellular matrix degradation by matrix metalloproteinases (MMPs). We recently demonstrated that 3-bromo-4,5-dihydroxybenzaldehyde (BDB), a natural compound of red algae, had a photo-protective effect against UVB-induced oxidative stress in human keratinocytes. The present study focused on the effect of BDB on UVB-irradiated photo-aging in HaCaT keratinocytes and the underlying mechanism. BDB significantly impeded MMP-1 activation and expression, and abrogated the activation of mitogen-activated protein kinases and intracellular Ca2+ level in UVB-irradiated HaCaT cells. Moreover, BDB decreased the expression levels of c-Fos and phospho-c-Jun and the binding of activator protein-1 to the MMP-1 promoter induced by UVB irradiation. These results offer evidence that BDB is potentially useful for the prevention of UVB-irradiated skin damage.

Visceral adipose tissue-derived serine protease inhibitor prevents the development of monocrotaline-induced pulmonary arterial hypertension in rats.

Visceral adipose tissue-derived serine protease inhibitor (vaspin), a recently identified adipocytokine, inhibits inflammation, migration, and apoptosis of vascular cells. We have recently demonstrated that chronic administration of vaspin to spontaneously hypertensive rats partly prevents systemic hypertension through inhibiting inflammation and remodeling of vascular wall. Pulmonary arterial (PA) hypertension (PAH) is caused by PA remodeling, contractile dysfunction, and inflammatory responses. We tested the hypothesis that vaspin could prevent development of PAH in animal model. PAH was induced by a single intraperitoneal injection of monocrotaline (MCT; 60mg/kg), and vaspin (1μg/kg/day) was treated for 14days from the day of MCT injection. PA pressure and contractile reactivity of isolated intrapulmonary artery (IPA) were measured. Using isolated lung tissues, IPA wall thickness and fibrosis, matrix metalloproteinase (MMP) activity, and reactive oxygen species (ROS) generation were examined. For in vitro study, after rat PA smooth muscle cells (PASMCs) were stimulated with interleukin (IL)-1β (10ng/ml, 48h) in the presence of vaspin (5ng/ml, 30min), MMP activity and ROS generation were examined. Vaspin significantly attenuated MCT-induced rise in PA pressure, while it had no influence on impairment of relaxing function in IPA. Vaspin significantly prevented MCT-induced IPA fibrosis but not hypertrophy. Vaspin significantly inhibited MCT-induced ROS generation and MMP-2 activation in lung tissues. In addition, vaspin significantly inhibited IL-1β-induced ROS generation and MMP-2 activation in PASMCs. In summary, we for the first time demonstrate that vaspin prevents MCT-induced PAH at least in part via inhibiting ROS/MMP-2/fibrosis pathway.

Alpha-1 Antitrypsin-Deficient Macrophages Have Increased Matriptase-Mediated Proteolytic Activity.

Alpha-1 antitrypsin (AAT) deficiency-associated emphysema is largely attributed to insufficient inhibition of neutrophil elastase released from neutrophils. Correcting AAT levels using augmentation therapy only slows disease progression, and that suggests a more complex process of lung destruction. Because alveolar macrophages (Mɸ) express AAT, we propose that the expression and intracellular accumulation of mutated Z-AAT (the most common mutation) compromises Mɸ function and contributes to emphysema development. Extracellular matrix (ECM) degradation is a hallmark of emphysema pathology. In this study, Mɸ from individuals with Z-AAT (Z-Mɸ) have greater proteolytic activity on ECM than do normal Mɸ. This abnormal Z-Mɸ activity is not abrogated by supplementation with exogenous AAT and is likely the result of cellular dysfunction induced by intracellular accumulation of Z-AAT. Using pharmacologic inhibitors, we show that several classes of proteases are involved in matrix degradation by Z-Mɸ. Importantly, compared with normal Mɸ, the membrane-bound serine protease, matriptase, is present in Z-Mɸ at higher levels and contributes to their proteolytic activity on ECM. In addition, we identified matrix metalloproteinase (MMP)-14, a membrane-anchored metalloproteinase, as a novel substrate for matriptase, and showed that matriptase regulates the levels of MMP-14 on the cell surface. Thus, high levels of matriptase may contribute to increased ECM degradation by Z-Mɸ, both directly and through MMP-14 activation. In summary, the expression of Z-AAT in Mɸ confers increased proteolytic activity on ECM. This proteolytic activity is not rescued by exogenous AAT supplementation and could thus contribute to augmentation resistance in AAT deficiency-associated emphysema.

ApoE Influences the Blood-Brain Barrier Through the NF-\u03baB/MMP-9 Pathway After Traumatic Brain Injury

Apolipoprotein E (ApoE), encoded by the ApoE gene (APOE), influences the outcomes of traumatic brain injury (TBI), but the mechanism remains unclear. The present study aimed to investigate the effects of different ApoEs on the outcome of TBI and to explore the possible mechanisms. Controlled cortical impact (CCI) was performed on APOEε3 (E3) and APOEε4 (E4) transgenic mice, APOE-KO (KO) mice, and wild type (WT) mice to construct an in vivo TBI model. Neurological deficits, blood brain barrier (BBB) permeability and brain edema were detected at days 1, 3, and 7 after TBI. The results revealed no significant differences among the four groups at day 1 or day 3 after injury, but more severe deficits were found in E4 and KO mice than in E3 and WT mice. Furthermore, a significant loss of tight junction proteins was observed in E4 and KO mice compared with E3 and WT mice at day 7. Additionally, more expression and activation of NF-κB and MMP-9 were found in E4 mice compared with E3 mice. Different ApoEs had distinct effects on neuro-function and BBB integrity after TBI. ApoE3, but not E4, might inhibit the NF-κB/MMP-9 pathway to alleviate BBB disruption and improve TBI outcomes.

Noncanonical Decapentaplegic Signaling Activates Matrix Metalloproteinase 1 To Restrict Hedgehog Activity and Limit Ectopic Eye Differentiation in Drosophila.

One of the pertinent issues associated with cellular plasticity is to understand how the delicate balance between the determined state of cells and the extent to which they can transdetermine is maintained. Employing the well-established model of generating ectopic eyes in developing wing discs of Drosophila by ectopic eyeless expression, we provide evidence for the genetic basis of this mechanism. By both loss-of-function and gain-of-function genetic analyses, we demonstrate that Matrix metalloproteinase 1 (Mmp1) plays an important role in regulating the extent of ectopic ommatidial differentiation. Transcriptional activation of ectopic Mmp1 by the morphogen Decapentaplegic (Dpp) is not triggered by its canonical signaling pathway which involves Mad. Rather, Dpp activates an alternate cascade involving dTak1 and JNK, to induce ectopic Mmp1 expression. Mutational analyses reveal that Mmp1 negatively regulates ectopic eye differentiation by restricting the rate of proliferation and the levels of expression of retinal-determining genes dachshund and eyes absent This is primarily achieved by restricting the range of Hedgehog (Hh) signaling. Importantly, the increase in proliferation and upregulation of target retinal-determining genes, as observed upon attenuating Mmp1 activity, gets significantly rescued when ectopic eyes are generated in wing discs of hh heterozygous mutants. In conjunction with the previously established instructive and permissive roles of Dpp in facilitating ectopic eye differentiation in wing discs, the outcome of this study sheds light on a mechanism by which Dpp plays a dual role in modulating the delicate balance between the determined state of cells and the extent they can transdetermine.

Conjugation of gold nanoparticles and recombinant human endostatin modulates vascular normalization via interruption of anterior gradient 2-mediated angiogenesis.

Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize vessels by interfering anterior gradient 2-mediated angiogenesis in metastatic colorectal cancer.

The effect of tomatine on metastasis related matrix metalloproteinase (MMP) activities in breast cancer cell model

Breast cancer is one of the most common malignancies in women and metastasis is the cause of morbidity and mortality in patients. In the development of metastasis, the matrix metalloproteinase (MMP) family has a very important role in tumor development. MMP-2 and MMP-9 work together for extracellular matrix (ECM) cleavage to increase migration. Tomatine is a secondary metabolite that has a natural defense role against plants, fungi, viruses and bacteria that are synthesized from tomato. In additıon, tomatine is also known that it breaks down the cell membrane and is a strong inhibitor in human cancer cells. In this study, it was aimed to evaluate the effect of tomatine on cytotoxicity, apoptosis and matrix metalloproteinase inhibition in MCF-7 cell lines.Human breast cancer cell line (MCF-7) was used as a cell line. In MCF-7 cells, the IC50 dose of tomatine was determined to be 7.07μM. According to the control cells, apoptosis increased 3.4 fold in 48thh. Activation of MMP-2, MMP-9 and MMP-9\\NGAL has been shown to decrease significantly in cells treated with tomatine by gelatin zymography compared to the control. As a result, matrix metalloproteinase activity and cell proliferation were suppressed by tomatine and this may provide support in treatment methods.

The Novel HDAC8 Inhibitor WK2-16 Attenuates Lipopolysaccharide-Activated Matrix Metalloproteinase-9 Expression in Human Monocytic Cells and Improves Hypercytokinemia In Vivo.

Dysregulated human monocytes/macrophages can synthesize and secrete matrix metalloproteinases (MMPs), which play important roles in the progression of sepsis. In this study, we investigated the effects and mechanism of a novel histone deacetylase (HDAC8) inhibitor, (E)-N-hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (WK2-16), on MMP-9 production and activation in stimulated human monocytic THP-1 cells. Our results demonstrated that the acetylation level of structural maintenance of chromosomes 3 (SMC3) was up-regulated by WK2-16 in THP-1 cells. Consistently, an in vitro enzyme study demonstrated that WK2-16 selectively inhibited HDAC8 activity. Moreover, the WK2-16 concentration dependently suppressed MMP-9-mediated gelatinolysis induced by tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS). Additionally, WK2-16 significantly inhibited both MMP-9 protein and mRNA expression without cellular toxicity. Nevertheless, WK2-16 suppressed the extracellular levels of interleukin (IL)-6 from LPS-stimulated THP-1 cells. For the signaling studies, WK2-16 had no effect on LPS/TLR4 downstream signaling pathways, such as the NF-κB and ERK/JNK/P38 MAPK pathways. On the other hand, WK2-16 enhanced the recruitment of acetylated Yin Yang 1 (YY1) with HDAC1. Finally, in vivo studies indicated that WK2-16 could reduce the serum levels of TNF-α and IL-6 in endotoxemic mice. These results suggested that HDAC8 inhibition might provide a novel therapeutic strategy of hypercytokinemia in sepsis.

Critical role of SIK3 in mediating high salt and IL-17 synergy leading to breast cancer cell proliferation.

Chronic inflammation is a well-known precursor for cancer development and proliferation. We have recently demonstrated that high salt (NaCl) synergizes with sub-effective interleukin (IL)-17 to induce breast cancer cell proliferation. However, the exact molecular mechanisms mediating this effect are unclear. In our current study, we adopted a phosphoproteomic-based approach to identify salt modulated kinase-proteome specific molecular targets. The phosphoprotemics based binary comparison between heavy labelled MCF-7 cells treated with high salt (Δ0.05 M NaCl) and light labelled MCF-7 cells cultured under basal conditions demonstrated an enhanced phosphorylation of Serine-493 of SIK3 protein. The mRNA transcript and protein expression analysis of SIK3 in MCF-7 cells demonstrated a synergistic enhancement following co-treatment with high salt and sub-effective IL-17 (0.1 ng/mL), as compared to either treatments alone. A similar increase in SIK3 expression was observed in other breast cancer cell lines, MDA-MB-231, BT20, and AU565, while non-malignant breast epithelial cell line, MCF10A, did not induce SIK3 expression under similar conditions. Biochemical studies revealed mTORC2 acted as upstream mediator of SIK3 phosphorylation. Importantly, cell cycle analysis by flow cytometry demonstrated SIK3 induced G0/G1-phase release mediated cell proliferation, while SIK3 silencing abolished this effect. Also, SIK3 induced pro-inflammatory arginine metabolism, as evidenced by upregulation of the enzymes iNOS and ASS-1, along with downregulation of anti-inflammatory enzymes, arginase-1 and ornithine decarboxylase. Furthermore, gelatin zymography analysis has demonstrated that SIK3 induced expression of tumor metastatic CXCR4 through MMP-9 activation. Taken together, our data suggests a critical role of SIK3 in mediating three important hallmarks of cancer namely, cell proliferation, inflammation and metastasis. These studies provide a mechanistic basis for the future utilization of SIK3 as a key drug discovery target to improve breast cancer therapy.

P 186 - Mechanisms involved in chronic effects of doxorubicin in rat hearts

Doxorubicin (DOX) is chemotherapeutic agent frequently used in treatment of many types of malignancies. Limitation of its use is toxicity on several organs. The aim of study was to investigate mechanisms involved in chronic effects of DOX on rat hearts and to search for effects of flavonoid quercetin (QCT) on DOX-induced changes. In the study, male Wistar rats were used. DOX was administered by i.p. injection of seven doses (cumulative dose 15 mg.kg-1). QCT (20 mg/kg/day) was administered 3 weeks during and 3 weeks after DOX treatment. DOX induced subcellular alterations of cardiomyocytes and disorganizations of cardiac extracellular space. Effects of DOX were associated with MMP-2 activation, decreased SOD activity, increased superoxide content, caspase-3 activation, and iNOS induction. QCT prevented the deleterious effects of DOX on ultrastructure of the tissue of left ventricle and reversed the DOX-induced effects on MMP-2 activation. QCT application also prevented effects of DOX on apoptosis induction and SOD inhibition. Moreover, QCT increased myocardial resistance to ischemia/reperfusion injury in DOX-treated rat hearts. These effects of QCT were linked to Akt kinase/GSK-3s/beta-catenin signaling and associated with connexin-43 up-regulation.

Feedback regulation of ALDOA activates the HIF-1α/MMP9 axis to promote lung cancer progression

Distant metastasis and recurrence are the greatest challenges in the clinical management of lung cancer. Despite advances in targeted therapies, high mortality rates persist. Therefore, alternative therapeutic interventions are urgently required. Accumulating evidence indicates that normalizing tumor metabolism may be a way to increase therapeutic efficacy and to reduce tumor malignancy. Here, we analyzed integrated transcriptomics data and an shRNA library against glycolytic enzymes and found that elevated Aldolase A expression is highly correlated with metastatic potential and a poor prognosis in patients with non-small cell lung cancer (NSCLC). We validated our in silico findings with an immunohistochemical analysis of clinical samples. Aldolase A silencing significantly suppressed metastatic potential both in vitro and in vivo, whereas the ectopic overexpression of Aldolase A resulted in the opposite phenotype. Furthermore, our microarray and Ingenuity Pathway Analyses (IPA) revealed that Aldolase A-driven lung cancer metastasis was closely linked to hypoxia inducible factor 1 alpha (HIF-1α)-downstream signaling. Importantly, Aldolase A overexpression may promote the release of lactate to block PHD activities and further induce HIF-1α stabilization. Aldolase A and nuclear HIF-1α overexpression levels were positively correlated and were significantly associated with a poorer survival rate in lung cancer patients (P = 0.008 for Overall Survival, P = 0.021 for Disease-free Survival). Furthermore, MMP9, a downstream target of HIF-1α, was significantly upregulated after ALDOA overexpression. A MMP9 inhibitor significantly inhibited cell invasion and migration in ALDOA-HIF-1α axis-induced lung cancer.In summary, our results reveal the molecular mechanism of Aldolase A in promoting lung cancer metastasis via PHD-mediated stabilization of HIF-1α and the subsequent activation of MMP9. The ALDOA-HIF-1α axis may provide a new therapeutic target for metastatic lung cancer treatment.

Dioscin suppresses TGF-β1-induced epithelial-mesenchymal transition and suppresses A549 lung cancer migration and invasion

Epithelial-to-mesenchymal transition (EMT), an important cellular process, occurs during cancer development and progression, has a crucial role in metastasis by enhancing the motility of tumor cells. Dioscin is a polyphenolic component isolated from Phyllanthus amarus, which exhibits a wide range of pharmacological and physiological activities, such as anti-tumor, anti-inflammatory, anti-obesity, anti-fungal, and anti-viral activities. However, the possible role of dioscin in the EMT is unclear. We investigated the suppressive effect of dioscin on the EMT. Transforming growth factor-beta 1 (TGF-β1) is known to induce EMT in a number of cancer cell types and promote lung adenocarcinoma migration and invasion. To verify the inhibitory role of dioscin in lung cancer migration and invasion, we investigated the use of dioscin as inhibitors of TGF-β1-induced EMT in A549 lung cancer cells in vitro. Here, we found that dioscin prominently increased expression of the epithelial marker E-cadherin and expression of the mesenchymal marker N-cadherin and Snail during the TGF-β1-induced EMT. In addition, dioscin inhibited the TGF-β1-induced increase in cell migration and invasion of A549 lung cancer cells. Also, dioscin remarkably inhibited TGF-β1-regulated activation of MMP-2/9, Smad2, and p38. Taken together, our findings provide new evidence that dioscin suppresses lung cancer migration, and invasion in vitro by inhibiting the TGF-β1-induced EMT.

Exosomes from NSC-34 Cells Transfected with hSOD1-G93A Are Enriched in miR-124 and Drive Alterations in Microglia Phenotype.

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disorder affecting motor neurons (MNs). Evidences indicate that ALS is a non-cell autonomous disease in which glial cells participate in both disease onset and progression. Exosomal transfer of mutant copper-zinc superoxide dismutase 1 (mSOD1) from cell-to-cell was suggested to contribute to disease dissemination. Data from our group and others showed that exosomes from activated cells contain inflammatory-related microRNAs (inflamma-miRNAs) that recapitulate the donor cell. While glia-derived exosomes and their effects in neurons have been addressed by several studies, only a few investigated the influence of motor neuron (MN)-derived exosomes in other cell function, the aim of the present study. We assessed a set of inflamma-miRs in NSC-34 MN-like cells transfected with mutant SOD1(G93A) and extended the study into their derived exosomes (mSOD1 exosomes). Then, the effects produced by mSOD1 exosomes in the activation and polarization of the recipient N9 microglial cells were investigated. Exosomes in coculture with N9 microglia and NSC-34 cells [either transfected with either wild-type (wt) human SOD1 or mutant SOD1(G93A)] showed to be transferred into N9 cells. Increased miR-124 expression was found in mSOD1 NSC-34 cells and in their derived exosomes. Incubation of mSOD1 exosomes with N9 cells determined a sustained 50% reduction in the cell phagocytic ability. It also caused a persistent NF-kB activation and an acute generation of NO, MMP-2, and MMP-9 activation, as well as upregulation of IL-1β, TNF-α, MHC-II, and iNOS gene expression, suggestive of induced M1 polarization. Marked elevation of IL-10, Arginase 1, TREM2, RAGE, and TLR4 mRNA levels, together with increased miR-124, miR-146a, and miR-155, at 24 h incubation, suggest the switch to mixed M1 and M2 subpopulations in the exosome-treated N9 microglial cells. Exosomes from mSOD1 NSC-34 MNs also enhanced the number of senescent-like positive N9 cells. Data suggest that miR-124 is translocated from the mSOD1 MNs to exosomes, which determine early and late phenotypic alterations in the recipient N9-microglial cells. In conclusion, modulation of the inflammatory-associated miR-124, in mSOD1 NSC-34 MNs, with potential benefits in the cargo of their exosomes may reveal a promising therapeutic strategy in halting microglia activation and associated effects in MN degeneration.

MMPs/TIMPs imbalances in the peripheral blood and cerebrospinal fluid are associated with the pathogenesis of HIV-1-associated neurocognitive disorders

HIV-1-associated neurocognitive disorders (HAND) continue to be a major concern in the infected population, despite the widespread use of combined antiretroviral therapy (cART). Growing evidence suggests that an imbalance between matrix metalloproteinases (MMPs) and endogenous tissue inhibitors of MMPs (TIMPs) contributes to the pathogenesis of HAND. In our present study, we examined protein levels and enzymatic activities of MMPs and TIMPs in both plasma and cerebrospinal fluid (CSF) samples from HIV-1 patients with or without HAND and HIV-1-negative controls. Imbalances between MMPs and TIMPs with distinct patterns were revealed in both the peripheral blood and CSF of HIV-1 patients, especially those with HAND. In the peripheral blood, the protein levels of MMP-2, MMP-9, TIMP-1, TIMP-2, and the enzymatic activities of MMP-2 and MMP-9 were increased in HIV-1 patients with or without HAND when compared with HIV-1-negative controls. The enzymatic activity of MMP-2, but not MMP-9, was further increased in plasma samples of HAND patients than that of HIV-1 patients without HAND. Notably, the ratio of MMP-2/TIMP-2 in plasma was significantly increased in HAND patients, not in patients without HAND. In the CSF, MMP-2 activity was increased, but the ratio of MMP-2/TIMP-2 was not altered. De novo induction and activation of MMP-9 in the CSF of HAND patients was particularly prominent. The imbalances between MMPs and TIMPs in the blood and CSF were related to the altered profiles of inflammatory cytokines/chemokines and monocyte activation in these individuals. In addition, plasma from HIV-1 patients directly induced integrity disruption of an in vitro blood-brain barrier (BBB) model, leading to increased BBB permeability and robust transmigration of monocytes/macrophages. These results indicate that imbalances between MMPs and TIMPs are involved in BBB disruption and are implicated in the pathogenesis of neurological disorders such as HAND in HIV-1 patients.