Inhibition of Collagen Synthesis and Regulation of Cell Motility in Vascular Smooth Muscle Cells by Suppression of Connective Tissue growth Factor Expression Using RNAInterference

1 IntroductionVascular smooth muscle cell (VSMC) hyperplasia plays an important role in both chronic and acute pathologies including atherosclerosis and restenosis. Recent studies have shown that connective tissue growth factor (CTGF) is a novel growth factor involved in the development and progression of atherosclerosis. However, previous data about the role of CTGF on the VSMC is conflicting. Hishikawa et al demonstrated that CTGF could act as a growth inhibitor in human VSMC; but …     

Nicotine Induces Pro-inflammatory Response in Aortic Vascular Smooth Muscle Cells Through a NFκB/Osteopontin Amplification Loop-Dependent Pathway

Nicotine has anti- and pro-inflammatory properties in various cells. Its role in aortic vascular smooth muscle cells (VSMC) was explored. Human aortic VSMC were cultured. After nicotine (1.0 μM) and/or pyrrolidinedithiocarbamic acid (PDTC, 50 μM) treatment, the activation of nuclear factor κB (NFκB) was investigated. The levels of pro-inflammatory cytokines, osteopontin (OPN), interleukin-6 (IL-6), and monocyte chemoattractant protein 1 (MCP-1) were also assessed. After OPN was downregulated by small interfering RNA (siRNA) transfection, the pro-inflammatory effect was reassessed. We found that NFκB was activated after nicotine administration. Nicotine upregulated OPN, IL-6, and MCP-1 expressions, and this effect attenuated after PDTC pretreatment. RNAi knocked down the OPN expression in nicotine-treated cells and abolished its pro-inflammatory effects. We concluded that nicotine induces a pro-inflammatory response in VSMC through a NFκB/osteopontin amplification loop-dependent pathway.     

17Beta-estradiol Promotes Proliferation of Rat Synthetic Vascular Smooth Muscle Cells by Up-regulating Cyclin D_1

1 IntroductionCardiovascular disease (CVD) is the leading cause of morbidity and mortality in women after 50 years of age in most developed countries. Estrogen deficiency plays a key role in causing CVD in women. The cardiovascular protective actions of estrogen are partially mediated by a direct effect on the vessel wall, and the proliferation of vascular smooth muscle cells (VSMC) plays a major role as an initiating event of atherosclerosis. A previous study by us in cooperation with Ca…     

Pyranocoumarins Isolated from Peucedanum praeruptorum Dunn Suppress Lipopolysaccharide-Induced Inflammatory Response in Murine Macrophages Through Inhibition of NF-κB and STAT3 Activation

Praeruptorin C, D, and E (PC, PD, and PE) are three pyranocoumarins isolated from the dried root of Peucedanum praeruptorum Dunn of Umbelliferae. In the present study, we investigated the anti-inflammatory effect of these compounds in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Pyranocoumarins significantly inhibited LPS-induced production of nitric oxide, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The mRNA and protein expressions of inducible nitric oxide synthase, IL-6, and TNF-α were also suppressed by these compounds. Both PD and PE exhibited greater anti-inflammatory activities than PC. Further study showed that pyranocoumarins suppressed the cytoplasmic loss of inhibitor κB-α protein and inhibited the translocation of NF-κB from cytoplasm to nucleus. In addition, pyranocoumarins suppressed LPS-induced STAT3 tyrosine phosphorylation. Taken together, the results suggest that pyranocoumarins may exert anti-inflammatory effects in LPS-stimulated RAW 264.7 macrophages through the inhibition of NF-κB and STAT3 activation.     

Hesperetin Suppresses Inflammatory Responses in Lipopolysaccharide-Induced RAW 264.7 Cells via the Inhibition of NF-κB and Activation of Nrf2/HO-1 Pathways

Hesperetin (Hesp), a common flavanone glycoside, was extracted from the fruit peel of Citrus aurantium L. (Rutaceae). Hesp has been shown to possess various biological properties, including antioxidant, neuroprotective, and anti-inflammatory properties. In this study, we investigated the protective effect of Hesp on inflammatory responses in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Our results indicated that Hesp treatment dramatically suppressed secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β; reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene expression; inhibited NF-κB (p65) phosphorylation; and blocked IκBα phosphorylation and degradation. Further studies revealed Hesp markedly enhanced the heme oxygenase (HO)-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression, which were involved with inducing Nrf2 nuclear translocation and decreasing Keap1 protein expression. Together, these results indicated that the anti-inflammatory effect of Hesp may be associated with NF-κB inhibition and Nrf2/HO-1 activation.     

Thermal Injury Prediction During Cryoplasty Through <Emphasis Type="Italic">In Vitro</Emphasis> Characterization of Smooth Muscle Cell Biophysics and Viability

Restenosis in peripheral arteries is a major health care problem in the United States. Typically, 30–40% of angioplasties result in restenosis and hence alternative treatment techniques are being actively investigated. Cryoplasty, a novel technique involving simultaneous stretching and freezing of the peripheral arteries (e.g., femoral, iliac, popliteal) using a cryogen-filled balloon catheter, has shown the potential to combat restenosis. However, evaluation of the thermal and biophysical mechanisms that affect cellular survival during cryoplasty is lacking. To achieve this, the thermal history in arteries was predicted for different balloon temperatures using a thermal model. Cellular biophysical responses (water transport (WT) and intracellular ice formation (IIF)) were then characterized, using in vitro model systems, based on the thermal model predictions. The thermal and biophysical effects on cell survival were eventually determined. For this study, smooth muscle cells (SMC) isolated from porcine femoral arteries were used in suspensions and attached in vitro systems (monolayer and fibrin gel). Results showed that for different balloon temperatures, the thermal model predicted cooling rates from 2200 to 5 °C/min in the artery. Biophysical parameters (WT & IIF) were higher for SMCs in attached systems as compared to suspensions. The “combined” fit WT parameters for SMCs in suspension (at 5, 10, and 25 °C/min) are L _pg = 0.12 μm/(min atm) and E _Lp = 24.1 kcal/mol. Individual WT parameters for SMCs in attached cell systems at higher cooling rates are approximately an order of magnitude higher compared to suspensions (e.g., at 130 °C/min, WT parameters in monolayer and fibrin TE systems are L _pg = 18.6, 19.4 μm/(min atm) and E _Lp = 112, 127 kcal/mol, respectively). Similarly, IIF parameters assessed at 130 °C/min are higher for SMCs in attached systems than suspensions ( = 1.1, 354, 378 (× 10⁸ (1/m² s)) and κ_o = 1.6, 1.8, 2.1 (× 10⁹ K⁵) for suspensions, monolayer, and fibrin TE, respectively). One possible reason for the differences in IIF kinetics was verified to be the presence of gap junctions, which facilitate cell–cell connections through which ice can propagate. This is reflected by the change in the predicted IIF parameters when a gap junction inhibitor was added and tested in monolayer ( (1/m² s)); κ_o = 2.1 × 10⁹ K⁵). SMC viability was affected by the model system (lower viability in attached systems), the thermal conditions and the biophysics. For e.g., IIF is lethal to cells and SMC viability was verified to be the least in fibrin TE (most % IIF) and the most in suspensions (least % IIF) at all cooling rates. Using the results from the fibrin TE (suggested as the best in vitro system to mimic a restenosis environment), conservative estimates of injury regimes in the artery during cryoplasty is predicted. The results can be used to suggest future optimizations and modifications during cryoplasty and also to design future in vivo studies.

Amyloid Beta Peptides and Th1 Cytokines Modulate Human Brain Vascular Smooth Muscle Tonic Contractile Capacity In Vitro: Relevance to Alzheimer’s Disease?

Alzheimer’s Disease (AD) is a neurodegenerative condition characterized both by the presence of tau protein neurofibrillary tangles and amyloid beta (Aβ) containing extracellular “plaques”. The cleavage of amyloid precursor protein (APP) yields several Aβ peptides. Although Aβ toxicity to neurons has been described extensively, its effects on other components of the neurovasculature such as vascular smooth muscle cells have been less well characterized. AD is now also recognized as a neurovascular disease characterized by cerebral microbleeds and disturbances in autoregulation. AD is also a neuroinflammatory condition in which several proinflammatory cytokines are elevated and may contribute to the intensification of AD severity. Cerebral autoregulation (the mechanism by which brain blood flow is maintained despite changes in perfusion pressure) is extremely tightly controlled in the brain and shows disturbances in AD. The failure of autoregulation in AD may make the brain susceptible to cerebral microbleeds through a reduced capacity to limit blood flow when pressure is increased. Conversely, reduced vasodilation during low flow might could also exacerbate tissue hypoxia. Currently, whether and how Aβ peptides and inflammatory cytokines depress brain smooth muscle cell tonic contraction is not known, but could reveal important targets in the preservation of autoregulation which is disturbed in AD. We used a collagen gel contractility assay to evaluate the influence of Aβ25-35, Aβ1-40 and Aβ1-42 peptides and inflammatory cytokines on the tonic contractility of human brain vascular smooth muscle cells (HBVSMC) as an in vitro model of cerebral autoregulation. We found that 5 and 10 μM Aβ1-42 significantly depressed HBVSM contractility, while Aβ1-40 5–20 μM had no effect on contractility. Conversely, Aβ25-35 (1–50 μM) increased contractility. Interestingly, the inflammatory cytokines TNF-α (20 ng/mL), IL-1β (20 ng/mL) and IFN-γ (1000 U/mL) also depressed HBVSM tonic contractility alone and in combination. These data suggest that both the inflammatory milieu in AD as well as the abundance of Aβ peptides may promote autoregulatory failure and increase brain susceptibility to dysregulated perfusion and microbleeds which are an important and devastating characteristic of AD.     

Low Strength Static Magnetic Field Inhibits the Proliferation, Migration, and Adhesion of Human Vascular Smooth Muscle Cells in a Restenosis Model Through Mediating Integrins β1-FAK, Ca2+ Signaling Pathway

The proliferation, migration, and adhesion of vascular smooth muscle cells (VSMCs) and their interactions with extracellular matrix are key features of atherosclerosis and restenosis. Recently, there has been evidence that magnetic fields exert multiple effects on the biological performance of cells and may aid in the treatment of vascular disease. However, the effect of a static magnetic field (SMF) on human VSMCs still remains unknown. In this study, we aimed to determine the effects of low strength SMF on human VSMCs in an in vitro restenosis model. A SMF was established using neodymium?Cyttrium?Ciron permanent magnet. Human umbilical artery smooth muscle cells (hUASMCs) were isolated and seeded to a fibronectin-coated plate to form an in vitro restenosis model and then exposed to a vertically oriented field of 5?militesla (mT). MTT, transwell, and adhesion assays were used to demonstrate that the proliferation, migration, and adhesion potential of hUASMCs were significantly decreased after exposure to 5?mT SMF for 48?h compared with a non-treated group. Meanwhile, confocal microscopy analysis was used to demonstrate that integrin ??₁ clustering was inhibited by exposure to 5?mT SMF. Furthermore, the phosphorylation of focal adhesion kinase (FAK) was markedly inhibited, and the upregulated cytosolic free calcium had been reversed (p?<?0.05). However, the biological effects of low strength SMF on hUASMCs could be blocked by the administration of GRGDSP??the blockade of integrins. In conclusion, a low strength SMF can influence the proliferation, migration, and adhesion of VSMCs by inhibiting the clustering of integrin ??1, decreasing cytosolic free calcium concentration, and inactivating FAK. With further validation, SMFs may aid in attenuating abnormal VSMCs biological performance and has potential to block atherogenesis and prevent restenosis.     

Agonistic AT1 Receptor Autoantibody Increases in Serum of Patients with Refractory Hypertension and Improves Ca^2＋ Mobilization in Cultured Rat Vascular Smooth Muscle Cells

Agonistic AT1 receptor autoantibodies （AT1-AAs） have been described in the patients with malignant hypertension or preeclampia. Furthermore, AT1-AAs were highly associated with refractory hypertension. Function of vascular smooth muscle cells （VSMCs） is important in the regulation of blood pressure. We investigated and compared the ability of angiotensin II （Ang II） and AT1-AAs to stimulate the intracellular calcium mobilization and cellular proliferation of rat VSMCs. Twenty-two patients with refractory hypertension, 24 patients with non-refractory hypertension and 37 normotensives were recruited. The serum of each patient was detected for the presence of AT1-AAs by ELISA. Ang II and the AT1-AAs from the sera of patients were used to stimulate rat VSMCs in vitro. AT1-AAs were detected in 10/22, 3/24 and 3/37 of patients with refractory hypertension, non-refractory hypertension and normotensives, respectively. AT1-AAs led the increase intracellular calcium mobilization in a dose-dependent manner and cellular proliferation of VSMCs just as Ang II. Both of these effects caused by AT1-AAs were blocked with losartan or a peptide corresponding to a part of the second extracellular loop of AT1 receptor. Since AT1-AAs exhibited pharmacological activity in rat VSMCs just as Ang II, they might play a role in the elevation of peripheral vascular resistance and in vascular remodeling. And AT1-AAs were suggested to involve in resistance to antihypertensive therapy.     

Dynamic Expansion of Gastric Mucosal Doublecortin-Like Kinase 1–Expressing Cells in Response to Parietal Cell Loss Is Regulated by Gastrin

Doublecortin-like kinase 1 (Dclk1) is considered a reliable marker for tuft cells in the gastrointestinal tract. We investigated the dynamic changes of tuft cells associated with mouse models of oxyntic atrophy and metaplasia in the stomach. Increases in the numbers of Dclk1-positive tuft cells were observed in several models of parietal cell loss. However, the expanded population of Dclk1-expressing cells showed a morphologically distinct structure in apical microvilli and acetylated microtubules, which was not seen in the tuft cells present in the normal gastric mucosa. These microvillar sensory cells (MVSCs) showed no evidence of proliferation. The expansion of the MVSCs induced by oxyntic atrophy was reversible after the return of parietal cells. More important, expansion of MVSCs after induced parietal cell loss was not observed in Gast^–/– mice. Although the Dclk1-expressing cells in the normal gastric mucosa were in part derived from Lrig1-expressing stem cells, the Lrig1-lineaged cells did not produce the expanded Dclk1-expressing cells associated with oxyntic atrophy. These studies indicate that loss of parietal cells leads to the reversible emergence of a novel Dclk1-expressing sensory cell population in the gastric mucosa.Tuft cells, also known as brush or caveolated cells, represent an unusual type of epithelial cell present in multiple organs of the digestive system, including the stomach and the intestine.^1–3 Tuft cells are rare in the epithelial cell layer and are characterized by the presence of a luminally directed tuft, which displays a distinct membrane-covered array of microtubules. The presence of the apical tuft apparatus suggests that tuft cells have functions for detection and transmission of environmental signals.⁴ Tuft cells represent a class of solitary chemosensory cells, because they express several chemoreceptor molecules, such as the guanine nucleotide binding protein α-transducing 3 and the G-protein–coupled taste receptor type 1 member 3.⁵ Although tuft cells are continuously renewed in the epithelial cell layer, mitotic tuft cells have not been observed. These findings suggest that tuft cells are post-mitotic and might originate from other sources. In the intestine, a recent report has suggested that tuft cells may differentiate from Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5)-positive progenitor cells.⁶ However, no Lgr5-positive stem cells are present in the body of the stomach, so the identity of cells that can produce or differentiate into tuft cells in the stomach fundus is unclear.Recent studies have reported that doublecortin-like kinase (Dclk1)–expressing cells are present in populations of migrating and post-mitotic neurons and in radial glia cells, known as precursors of neural stem cells.⁷ Dclk1-expressing cells are also proposed as stem/progenitor cells in the organs of the gastrointestinal tract,⁸ and Dclk1 is also present in gastric tuft cells.^1,3 We and several other groups have found that Dclk1-expressing cells are a rare cell lineage in the mouse stomach,^1,9 and the gastric Dclk1-expressing cells appear to represent tuft cells, rather than a stem/progenitor cell population.¹ We have also reported that Dclk1-expressing tuft cells are found in association with invasive neoplastic lesions from the forestomach or glandular transition zone in the Smad3-null mouse stomachs.⁹ Although the Dclk1-expressing cells were highly expanded during gastric tumor progression in the fundic glands of Smad3-null mouse stomach, the Dclk1-expressing cells were not increased in the antrum. Although we did observe a marked increase in Dclk1-positive tuft cells in association with parietal cell loss and the development of spasmolytic polypeptide-expressing metaplasia (SPEM), the precise origin of Dclk1-expressing cells in the stomach remains largely unknown.Herein, we hypothesized that the number of Dclk1-expressing cells may be increased in association with parietal cell loss. We investigated the dynamics of Dclk1-expressing cells in several mouse models of oxyntic atrophy using acute treatment with DMP-777 or L-635, which are parietal cell-specific protonophores and initiate SPEM after acute parietal cell loss,^10–12 and Helicobacter felis infection, a chronic model of SPEM with a strong inflammatory response.¹³ We also examined a model of spontaneous parietal cell loss and metaplasia in the Areg^–/– mouse, which is a unique mouse model for the induction of SPEM and progression of SPEM to intestinal metaplasia.¹⁴ Finally, we compared these findings with oxyntic atrophy and SPEM induced in insulin-gastrin (INS/GAS) transgenic mice¹³ as well as Gast^–/– mice, which demonstrate rapid induction of SPEM after 1 day of DMP-777 treatment.¹² In addition, we sought to identify the lineage of origin for tuft cells in the stomach using defined lineage mapping mouse strains. The results suggest that Dclk1-expressing cells are amplified in the setting of parietal cell loss and that the increase in tuft cells is driven by elevations in gastrin. More important, the Dclk1-expressing cells are rapidly lost from the mucosa on reestablishment of parietal cells and normal gastric lineages. These transiently presenting Dclk1-positive cells have a morphology that is distinct from normal tuft cells, suggesting that they represent a distinct class of sensory cells.     

Paeoniflorin Suppressed High Glucose-Induced Retinal Microglia MMP-9 Expression and Inflammatory Response <Emphasis Type="Italic">via</Emphasis> Inhibition of TLR4/NF-κB Pathway Through Upregulation of SOCS3 in Diabetic Retinopathy

Diabetic retinopathy (DR) is a serious-threatening complication of diabetes and urgently needed to be treated. Evidence has accumulated indicating that microglia inflammation within the retina plays a critical role in DR. Microglial matrix metalloproteinase 9 (MMP-9) has an important role in the destruction of the integrity of the blood-retinal barrier (BRB) associated with the development of DR. MMP-9 was also considered important for regulating inflammatory responses. Paeoniflorin, a monoterpene glucoside, has a potent immunomodulatory effect on microglia. We hypothesized that paeoniflorin could significantly suppress microglial MMP-9 activation induced by high glucose and further relieve DR. BV2 cells were used to investigate the effects and mechanism of paeoniflorin. The activation of MMP-9 was measured by gelatin zymography. Cell signaling was measured by western blot assay and immunofluorescence assay. High glucose increased the activation of MMP-9 in BV2 cells, which was abolished by HMGB1, TLR4, p38 MAPK, and NF-κB inhibition. Phosphorylation of p38 MAPK induced by high glucose was decreased by TLR4 inhibition in BV2 cells. Paeoniflorin induced suppressor of cytokine signaling 3 (SOCS3) expression and reduced MMP-9 activation in BV2 cells. The effect of paeoniflorin on SOCS3 was abolished by the TLR4 inhibitor. In streptozotocin (STZ)-induced diabetes mice, paeoniflorin induced SOCS3 expression and reduced MMP-9 activation. Paeoniflorin suppressed STZ-induced IBA-1 and IL-1β expression and decreased STZ-induced high blood glucose level. In conclusion, paeoniflorin suppressed high glucose-induced retinal microglia MMP-9 expression and inflammatory response via inhibition of the TLR4/NF-κB pathway through upregulation of SOCS3 in diabetic retinopathy.     

Cultures of Human Colonic Epithelial Cells Isolated from Endoscopical Biopsies from Patients with Inflammatory Bowel Disease. Effect of IFNγ, TNFα and IL-1β on Viability,Butyrate Oxidation and IL-8 Secretion

Cytokjne-mediated impairment of viability and metabolic function of epithelial cells has been suggested as a possible early pathogenic event in the development of inflammatory bowel disease (IBD). It is currently unknown whether pro-inflammatory cytokines have a direct effect on human nontransformed colonic epithelial cells. We investigated the effects of TNFα, IFNγ and IL-1β on viability, short chain fatty acid (butyrate) oxidation and IL-8 secretion in human colonic epithelial cell cultures in vitro obtained from macroscopically normal mucosa from IBD patients and controls. Colonic crypts were isolated from endoscopical biopsies by ultra-short (10 min) EDTA/EGTA treatment, and exposed to TNFα, IFNγ and IL-1β for 24 hours. The combination of TNFoc+IFNγ induced a significant decrease in cell viability as judged by methyltetrazoleum (MTT) metabolism which decreased to median 68 % of unexposed cultures (P<0.01). This effect was more pronounced than that observed after addition of TNFα (median 88 %) (P<0.05), but not IFNγ alone (median 78 %), whereas IL-1(3 had no significant effect. Cells from IBD patients were significantly less sensitive to TNFα + IFNγ exposure (median 74 %) compared to cells from controls (median 58 %) (P < 0.05). Butyrate oxidation, as measured by entrapment of CO₂, was not inhibited in cells exposed to TNFα + IFNγ, neither from controls (median 112%) nor from IBD patients (median 108%), suggesting a relative increase of this specific metabolic function in living cells in response to immunoinflammatory stress. IL-8 levels in cell supernatants were increased by TNFα + IFNγ, supporting the role of the epithelium in signalling between luminal factors and mucosal immune cells. In conclusion, we report that TNFα and IFNγ damage and influence human colonic epithelial cell function in vitro and that such mechanisms, if operative in vivo, also may be involved in the pathogenesis of IBD     

Aspergillus fumigatus conidia stimulate lung epithelial cells (TC-1 JHU-1) to produce IL-12, IFNγ, IL-13 and IL-17 cytokines: Modulatory effect of propolis extract

Aspergillus fumigatus conidia are the most prevalent indoors fungal allergens. The interaction between Aspergillus antigens and lung epithelial cells (LECs) result in innate immune functions. The association between Aspergillus conidia and allergic reactions, like allergic bronchopulmonary aspergillosis (ABPA) and asthma have been repeatedly reported. Since conventional therapies for allergy and asthma are limited, finding new promising treatments are inevitable. This study was designed to evaluate the effect of A. fumigatus conidia on IL-12, IFNγ, IL-13 and IL-17 release from mouse LECs and to investigate the effect of propolis on cytokines modulation. Cells were divided to two groups, one was exposed to 3 × 10⁴ conidia of Aspergillus fumigatus and another group was treated by propolis (25 μg/mL) as well as exposed to A. fumigatus conidia. Cytokines IL-13, IL-12, IFNγ and IL-17 were measured at times 0, 6 and 12 hours after exposure using ELISA assay. The results indicated that A. fumigatus could increase the release of the cytokines with IL-13 and IL-17 being the most affected ones whilst treatment with propolis decreased the effects of A. fumigatus on IL-13 and IL-17 production. The results showed that propolis has down regulatory effects on Th2 cytokine, IL-13, and IL-17 production, whereas it caused a significant induction of IL-12, as an important Th1 cytokines by LECs. With respect to the obtained results, propolis extract might be contributed to decrease Th2 responses in allergic asthma phenomenon. However more investigations must be done in future to fully understand its efficacy.