Peng-Tao Zhao

Antiinflammatory effects of matrine in LPS-induced acute lung injury in mice

Matrine is one of the main active components of Chinese herb Sophora flavescens Ait (Kushen), which has been demonstrated to be effective in suppressing inflammation. The aim of the present study is to investigate the effect of matrine on LPS-induced lung injury. Lung injury was assessed by histological study and wet to dry weight ratios, as well as cell count and protein content in bronchoalveolar lavage fluid. We also detected MPO activity reflecting neutrophil infiltration and MDA activity examining oxidative stress in lung tissues. Cytokines and ROS production in cells were monitored by ELISA and flow cytometry, respectively. The results showed that high dose of matrine significantly reduced the mortality rate of mice with LPS administration. Treatment with matrine improved LPS-induced lung histopathologic changes, alleviated pulmonary edema and lung vascular leak, inhibited MPO and MDA activity,and reduced the production of inflammatory mediators including TNF-α, IL-6 and HMGB1. In vitro, matrine administration reduced the production of ROS and inflammatory factors, which was possibly associated with inhibition of NF-κB. In conclusion, the current study demonstrated that matrine exhibited a protective effect on LPS-induced acute lung injury by inhibiting of the inflammatory response, which may involve the suppression of ROS and tissue oxidative stress.

Tanshinone IIA ameliorates seawater exposure-induced lung injury by inhibiting aquaporins (AQP) 1 and AQP5 expression in lung

Aquaporins (AQPs), a family of transmembrane water channels, mediate physiological response to changes of fluid volume and osmolarity. It is still unknown what role of AQPs plays in seawater drowning-induced acute lung injury (ALI) and whether pharmacologic modulation of AQPs could alleviate the severity of ALI caused by seawater aspiration. In our study, the results from RT-PCR and Western blotting showed that intratracheal installation of seawater up-regulated the mRNA and protein levels of AQP1 and AQP5 in lung tissues. Furthermore, we found that treatment of tanshinone IIA (TIIA, one of the main active components from Chinese herb Danshen) significantly reduced the elevation of AQP1 and AQP5 expression induced by seawater in rats, A549 cells and primary alveolar type II cells. Treatment of TIIA also improved lung histopathologic changes and blood-gas indices, and reduced lung edema and vascular leakage. These findings demonstrated that AQP1 and AQP5 might play an important role in the development of lung edema and lung injury, and that treatment with TIIA could significantly alleviate seawater exposure-induced ALI, which was probably through the inhibition of AQP1 and AQP5 over-expression in lungs.

Beta-estradiol attenuates hypoxic pulmonary hypertension by stabilizing the expression of p27kip1 in rats

BackgroundPulmonary vascular structure remodeling (PVSR) is a hallmark of pulmonary hypertension. P27kip1, one of critical cyclin-dependent kinase inhibitors, has been shown to mediate anti-proliferation effects on various vascular cells. Beta-estradiol (β-E2) has numerous biological protective effects including attenuation of hypoxic pulmonary hypertension (HPH). In the present study, we employed β-E2 to investigate the roles of p27kip1 and its closely-related kinase (Skp-2) in the progression of PVSR and HPH.MethodsSprague-Dawley rats treated with or without β-E2 were challenged by intermittent chronic hypoxia exposure for 4 weeks to establish hypoxic pulmonary hypertension models, which resemble moderate severity of hypoxia-induced PH in humans. Subsequently, hemodynamic and pulmonary pathomorphology data were gathered. Additionally, pulmonary artery smooth muscle cells (PASMCs) were cultured to determine the anti-proliferation effect of β-E2 under hypoxia exposure. Western blotting or reverse transcriptional polymerase chain reaction (RT-PCR) were adopted to test p27kip1, Skp-2 and Akt-P changes in rat lung tissue and cultured PASMCs.ResultsChronic hypoxia significantly increased right ventricular systolic pressures (RVSP), weight of right ventricle/left ventricle plus septum (RV/LV+S) ratio, medial width of pulmonary arterioles, accompanied with decreased expression of p27kip1 in rats. Whereas, β-E2 treatment repressed the elevation of RVSP, RV/LV+S, attenuated the PVSR of pulmonary arterioles induced by chronic hypoxia, and stabilized the expression of p27kip1. Study also showed that β-E2 application suppressed the proliferation of PASMCs and elevated the expression of p27kip1 under hypoxia exposure. In addition, experiments both in vivo and in vitro consistently indicated an escalation of Skp-2 and phosphorylated Akt under hypoxia condition. Besides, all these changes were alleviated in the presence of β-E2.ConclusionsOur results suggest that β-E2 can effectively attenuate PVSR and HPH. The underlying mechanism may partially be through the increased p27kip1 by inhibiting Skp-2 through Akt signal pathway. Therefore, targeting up-regulation of p27kip1 or down-regulation of Skp-2 might provide new strategies for treatment of HPH.

Tanshinone IIA modulates pulmonary vascular response to agonist and hypoxia primarily via inhibiting Ca2+ influx and release in normal and hypoxic pulmonary hypertension rats

The present study was designed to investigate the vascular effects and underlying mechanisms of tanshinone IIA on isolated rat pulmonary artery. Isometric tension was recorded in the arteries from normal and hypoxic pulmonary hypertension rats under normoxia or hypoxia condition. The results showed that tanshinone IIA exerted a biphasic effect on rat pulmonary artery. The constriction was attenuated by endothelium-denudation but was enhanced by inhibition of nitric oxide synthase. Pretreatment with tetraethylammonium (Ca2+-activated K+ channel inhibitor) upward shifted the concentration-response curve without affecting the maximum dilatation. Pretreatment with zinc protoporphyrin IX (heme oxygenase-1 inhibitor), 4-aminopyridine (KV channel inhibitor), glibenclamide (KATP channel inhibitor) or BaCl2 (inwardly rectifying K+ channel inhibitor) did not affect the vasoreactivity. Meanwhile, tanshinone IIA almost abolished vasoconstriction induced by extracellular Ca2+. Under hypoxia condition, tanshinone IIA eliminated acute hypoxia-induced initial contraction, potentiated following vasorelaxation, attenuated and reversed sustained contraction to relaxation in pulmonary artery from normal rats, and reversed phenylephrine-induced sustained constriction to sustained relaxation in remodeled pulmonary artery from hypoxic pulmonary hypertension rats. We concluded that the mild constrictive effect induced by tanshinone IIA was affected by integrity of endothelium and production of nitric oxide, while the potent dilative effect was endothelium-independent and produced primarily by inhibiting extracellular Ca2+ influx and partially by inhibiting intracellular Ca2+ release, as well as activating Ca2+-activated K+ channels. The modulation of tanshinone IIA on pulmonary vasoreactivity under both acute and chronic hypoxia condition may provide a new insight for curing hypoxic pulmonary hypertension.

Role of Macrophage Migration Inhibitory Factor in the Proliferation of Smooth Muscle Cell in Pulmonary Hypertension

Pulmonary hypertension (PH) contributes to the mortality of patients with lung and heart diseases. However, the underlying mechanism has not been completely elucidated. Accumulating evidence suggests that inflammatory response may be involved in the pathogenesis of PH. Macrophage migration inhibitory factor (MIF) is a critical upstream inflammatory mediator which promotes a broad range of pathophysiological processes. The aim of the study was to investigate the role of MIF in the pulmonary vascular remodeling of hypoxia-induced PH. We found that MIF mRNA and protein expression was increased in the lung tissues from hypoxic pulmonary hypertensive rats. Intensive immunoreactivity for MIF was observed in smooth muscle cells of large pulmonary arteries (PAs), endothelial cells of small PAs, and inflammatory cells of hypoxic lungs. MIF participated in the hypoxia-induced PASMCs proliferation, and it could directly stimulate proliferation of these cells. MIF-induced enhanced growth of PASMCs was attenuated by MEK and JNK inhibitor. Besides, MIF antagonist ISO-1 suppressed the ERK1/2 and JNK phosphorylation induced by MIF. In conclusion, the current finding suggested that MIF may act on the proliferation of PASMCs through the activation of the ERK1/2 and JNK pathways, which contributes to hypoxic pulmonary hypertension.

Tanshinone IIA–Induced Attenuation of Lung Injury in Endotoxemic Mice Is Associated with Reduction of Hypoxia-Inducible Factor 1α Expression

Inhibiting hypoxia-inducible factor (HIF)-1α activity has been proposed as a novel therapeutic target in LPS-induced sepsis syndrome. We have reported that tanshinone IIA (TIIA) can reduce LPS-induced lethality and lung injury in mice, but the precise mechanisms have not been fully described. Therefore, the present study investigated whether the protective effect of TIIA was related to the inhibition of LPS-induced HIF-1α expression and what mechanisms accounted for it. This study showed that TIIA pretreatment improved LPS-induced biochemical and cellular changes and reduced the production of inflammatory cytokines. Pretreatment with TIIA decreased LPS-induced HIF-1α expression in vivo and in vitro. TIIA did not affect the LPS-induced HIF-1α mRNA level but inhibited HIF-1α protein translation by the inhibition of the PI3K/AKT and MAPK pathways and related protein translational regulators, such as p70S6K1, S6 ribosomal protein, 4E-BP1, and eIF4E, and promoted HIF-1α protein degradation via the proteasomal pathway in LPS-stimulated macrophages. These observations partially explain the antiinflammatory effects of TIIA, which provides scientific basis for its application for the treatment of acute lung injury/acute respiratory distress syndrome or sepsis.

Oxymatrine prevents hypoxia- and monocrotaline-induced pulmonary hypertension in rats.

Pulmonary hypertension is a progressive disease characterized by marked pulmonary arterial remodeling and increased vascular resistance. Inflammation and oxidative stress promote the development of pulmonary hypertension. Oxymatrine, one of the main active components of the Chinese herb Sophora flavescens Ait. (Kushen), plays anti-inflammatory and antioxidant protective roles, which effects on pulmonary arteries remain unclear. This study aimed to investigate the effects of oxymatrine on pulmonary hypertension development. Sprague-Dawley rats were exposed to hypoxia for 28 days or injected with monocrotaline, to develop pulmonary hypertension, along with administration of oxymatrine (50mg/kg/day). Hemodynamics and pulmonary arterial remodeling data from the rats were then obtained. The antiproliferative effect of oxymatrine was verified by in vitro assays. The inflammatory cytokine mRNA levels and leukocyte and T cell accumulation in lung tissue were detected. The antioxidative effects of oxymatrine were explored in vitro. Our study shows that oxymatrine treatment attenuated right-ventricular systolic pressure and pulmonary arterial remodeling induced by hypoxia or monocrotaline and inhibited proliferation of pulmonary arterial smooth muscle cells (PASMCs). Increased expression of inflammatory cytokine mRNA and accumulation of leukocytes and T cells around the pulmonary arteries were suppressed with oxymatrine administration. Under hypoxic conditions, oxymatrine significantly upregulated Nrf2 and antioxidant protein SOD1 and HO-1 expression, but downregulated hydroperoxide levels in PASMCs. In summary, this study indicates that oxymatrine may prevent pulmonary hypertension through its antiproliferative, anti-inflammatory, and antioxidant effects, thus providing a promising pharmacological avenue for treating pulmonary hypertension.

Protective effect of bicyclol on lipopolysaccharide-induced acute lung injury in mice.

Bicyclol is synthesized based on schisandrin, which is one of the main active components of Chinese herb Fructus Schisandrae. The purpose of this study is to investigate whether bicyclol has a beneficial effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Bicyclol was given to mice by gavage for three times. ALI was induced by vena caudalis injection of LPS. The last dose of bicyclol was administrated 1 h before LPS given. Mice in each group were sacrificed at different time point after LPS administration. As revealed by survival study, pretreatment with high doses of bicyclol reduced the mortality of mice from ALI. Bicyclol pretreatment significantly improved LPS-induced lung pathological changes, inhibited myeloperoxidase (MPO) activity, and reduced lung/body and lung wet/dry weight ratios. Bicyclol also inhibited the release of TNF-α, IL-1β and HMGB1, whereas simultaneously increased the expression of IL-10. Furthermore, the phosphorylation level of NF-κB p65 was markedly decreased by bicyclol. Taken together, our study showed that bicyclol improves survival rate and attenuates LPS-induced ALI. The protective mechanism may be due to the inhibition of NF-κB activation and regulation of cytokine secretion.

Tanshinone IIA suppresses lung injury and apoptosis, and modulates protein kinase B and extracellular signal-regulated protein kinase pathways in rats challenged with seawater exposure.

1. Tanshinone IIA (TIIA) is one of the main active components of the Chinese herb, Danshen. In the present study, we investigated the role of apoptosis in seawater exposure‐induced acute lung injury (ALI), and explored the effects of TIIA on lung injury, apoptosis, and protein kinase B (Akt) and etracellular signal‐regulated protein kinase (ERK) pathways in seawater‐challenged rats. The rats were randomly divided into four groups: (i) naive group, no drug was given; (ii) TIIA control group, TIIA (50 mg/kg) was given intraperitoneally; (iii) seawater (SW) group, seawater (4 mL/kg) was given; and (iv) TIIA/SW group, TIIA (50 mg/kg) was injected intraperitoneally 10 min after seawater instillation.

Effects of PerClot® on the healing of full-thickness skin wounds in rats

PerClot(®) is a hemostatic material made of polysaccharide from modified starch and has been shown to assist in topical hemostasis. The principal goal in treating surgical and non-surgical wounds is the need for rapid closure of the lesion. This study investigated whether topical application of PerClot(®) could improve impaired wound healing in Sprague-Dawley (SD) rats. Full-thickness skin wounds were created on the back of the rats. Immediately, PerClot(®) was introduced into the wound bed, while wounds receiving starch or nothing served as controls. Wound closure was monitored using well-recognized wound-healing parameters: histological examination for inflammatory cells and fibroblast infiltration, newly formed capillaries, and collagen deposition. Meanwhile, transforming growth factor (TGF-β1) was measured by immunochemistry. Wound closure was significantly accelerated by local application of PerClot(®). Furthermore, PerClot(®)-treated wounds showed significantly increased fibroblast numbers at 5 days post-wounding, and newly formed capillaries at 7 days post-wounding, and collagen regeneration at 7 and 14 days post-wounding. The number of infiltrating fibroblasts expressing TGF-β1 was significantly higher than that in the controls at 7 and 14 days post-wounding. PerClot(®) can improve the wound healing and this effect might involve an increase in the activity of fibroblasts and increased release of TGF-β1.