Advanced Generation Therapeutics: Biomimetic Nanodelivery System for Tumor Immunotherapy.

Tumor immunotherapy is a safe and effective strategy for precision medicine. However, immunotherapy for most cancer cases still ends in failure, with the root causes of the immunosuppressive and extraordinary heterogeneity of the solid tumors microenvironment. The emerging biomimetic nanodelivery system provides a promising tactic to improve the immunotherapy effect while reducing the adverse reactions on nontarget cells. Herein, we summarize the relationship between tumor occurrence and tumor immune microenvironment, mechanism of tumor immune escape, immunotherapy classification (including adoptive cellular therapy, cytokines, cancer vaccines, and immune checkpoint inhibitors) and recommend target cells for immunotherapy first, and then emphatically introduce the recent advances and applications of the latest biomimetic nanodelivery systems (e.g., immune cells, erythrocytes, tumor cells, platelets, bacteria) in tumor immunotherapy. Meanwhile, we separately summarize the application of tumor vaccines. Finally, the predictable challenges and perspectives in a forward exploration of biomimetic nanodelivery systems for tumor immunotherapy are also discussed.

Biomembrane-wrapped gene delivery nanoparticles for cancer therapy.

As a promising strategy, gene delivery for cancer treatment accepts encouraging progress due to its high efficacy, low toxicity, and exclusive selectivity. However, the delivery efficiency, specific biological distribution, targeted uptake, and biosafety of naked nucleic acid agents still face serious challenges, which limit further clinical application. To overcome the above bottleneck, safe and efficient functional nanovectors are developed to improve the delivery efficiency of nucleic acid agents. In recent years, emerging membrane-wrapped biomimetic nanoparticles (MBNPs) based on the concept of "imitating nature" are well known for their advantages, such as low immunogenicity and long cycle time, and especially play a crucial role in improving the overall efficiency of gene delivery and reducing adverse reactions. Therefore, combining MBNPs and gene delivery is an effective strategy to enhance tumor treatment efficiency. This review presents the mechanism of gene therapy and the current obstacles to gene delivery. Remarkably, the latest development of gene delivery MBNPs and the strategies to overcome these obstacles are summarized. Finally, the future challenges and prospects of gene delivery MBNPs toward clinical transformation are introduced. The principal purpose of this review is to discuss the biomedical potential of gene delivery MBNPs for cancer therapy and to provide guidance for further enhancing the efficiency of tumor gene therapy.

Research Progress of Traditional Chinese Medicine Monomers in Reversing Multidrug Resistance of Breast Cancer.

Breast cancer is a malignant disease with an increasing incidence. Chemotherapy is still an important means for breast cancer treatment, but multidrug resistance (MDR) greatly limits its clinical application. Therefore, the high-efficiency MDR reversal agents are urgently needed. Traditional Chinese medicine (TCM) monomers have unique advantages in reversing chemotherapeutic MDR because of its low toxicity, high efficiency, and ability to impact multiple targets. This review firstly summarizes the major mechanisms of MDR in breast cancer, including the reduced accumulation of intracellular chemotherapeutic drugs, the promoted inactivation of intracellular chemotherapeutic drugs, and the enhanced damage repair ability of DNA, etc., and secondly highlights the research progress of 15 kinds of TCM monomers, including curcumin, resveratrol, emodin, apigenin, tetrandrine, gambogic acid, matrine, paeonol, schisandrin B, [Formula: see text]-elemene, astragaloside IV, berberine, puerarin, tanshinone IIA, and quercetin, in reversing MDR of breast cancer. This review also provides the suggestion for the future research of MDR reversal agents in breast cancer.

Role of Iron-Related Oxidative Stress and Mitochondrial Dysfunction in Cardiovascular Diseases.

Iron is indispensable in numerous biologic processes, but abnormal iron regulation and accumulation is related to pathological processes in cardiovascular diseases. However, the underlying mechanisms still need to be further explored. Iron plays a key role in metal-catalyzed oxidative reactions that generate reactive oxygen species (ROS), which can cause oxidative stress. As the center for oxygen and iron utilization, mitochondria are vulnerable to damage from iron-induced oxidative stress and participate in processes involved in iron-related damage in cardiovascular disease, although the mechanism remains unclear. In this review, the pathological roles of iron-related oxidative stress in cardiovascular diseases are summarized, and the potential effects and mechanisms of mitochondrial iron homeostasis and dysfunction in these diseases are especially highlighted.

Reversal of Hypoxic Pulmonary Hypertension by Hypoxia-Inducible Overexpression of Angiotensin-(1-7) in Pulmonary Endothelial Cells.

Hypoxia-induced pulmonary vascular constriction and structure remodeling are the main causes of hypoxic pulmonary hypertension. In the present study, an adeno-associated virus vector, containing Tie2 promoter and hypoxia response elements, was designed and named HTSFcAng(1-7). Its targeting, hypoxic inducibility, and vascular relaxation were examined in vitro, and its therapeutic effects on hypobaric hypoxia-induced pulmonary hypertension were examined in rats. Transfection of HTSFcAng(1-7) specifically increased the expression of angiotensin-(1-7) in endothelial cells in normoxia. Hypoxia increased the expression of angiotensin-(1-7) in HTSFcAng(1-7)-transfected endothelial cells. The condition medium from HTSFcAng(1-7)-transfected endothelial cells inhibited the hypoxia-induced proliferation of pulmonary artery smooth muscle cells, relaxed the pulmonary artery rings, totally inhibited hypoxia-induced early contraction, enhanced maximum relaxation, and reversed phase II constriction to sustained relaxation. In hypoxic pulmonary hypertension rats, treatment with HTSFcAng(1-7) by nasal drip adeno-associated virus significantly reversed hypoxia-induced hemodynamic changes and pulmonary artery-wall remodeling, accompanied by the concomitant overexpression of angiotensin-(1-7), mainly in the endothelial cells in the lung. Therefore, hypoxia-inducible overexpression of angiotensin-(1-7) in pulmonary endothelial cells may be a potential strategy for the gene therapy of hypoxic pulmonary hypertension.

[Matrine alleviates N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric mucosal damage in rats and its mechanism].

Objective To investigate the effect of matrine on gastric mucosal injury induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in rats and its mechanism. Methods A total of 75 Wister rats were randomly divided into a control group, a model group and three matrine-treated groups (100, 150 and 200 mg/kg). Except for the control group, the other groups were treated with MNNG to establish the models of gastric mucosal injury in the rats. After the models were successfully established, the rats in the three matrine-treated groups were administrated 100, 150, 200 mg/kg matrine, respectively, for successive 45 days. After the last administration, the body mass, daily intake of drinking water and dietary of rats were measured. And then the tissue samples were collected after the rats were sacrificed. The levels of interleukin 1ß (IL-1ß), IL-4, interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) were measured by ELISA in gastric mucosa. HE staining was used to observe the pathological changes of gastric mucosa tissue. Immunohistochemical staining was performed to evaluate the expression of vascular endothelial growth factor C (VEGF-C) and vascular endothelial growth factor receptor 3 (VEGFR3) in gastric mucosa. The protein levels of Bcl2, BAX, caspase-3, cytochrome C (Cyt-C), Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor κB p65 (NF-κB p65) were determined by Western blotting. Results The body mass, daily intake of drinking water and dietary increased in matrine-treated rats in comparison with the model group. In addition, compared with the model group, matrine significantly reduced the expression levels of VEGF-C, VEGFR3, BAX, caspase-3, Cyt-C, TLR4, MyD88 and NF-κB p65, and increase Bcl2 protein level in the gastric mucosa tissues. Conclusion Matrine can reduce gastric mucosal damage induced by MNNG in rats, which is related to the down-regulation of VEGF-C/VEGFR3 and NF-κB/TLR4 signaling pathway.

Distal airway stem cells ameliorate bleomycin-induced pulmonary fibrosis in mice.

BACKGROUND: Idiopathic pulmonary fibrosis is characterized by loss of lung epithelial cells and inexorable progression of fibrosis with no effective and approved treatments. The distal airway stem/progenitor cells (DASCs) have been shown to have potent regenerative capacity after lung injury. In this work, we aimed to define the role of mouse DASCs (mDASCs) in response to bleomycin-induced lung fibrosis in mice. METHODS: The mDASCs were isolated, expanded in vitro, and labeled with GFP by lentiviral infection. The labeled mDASCs were intratracheally instilled into bleomycin-induced pulmonary fibrosis mice on day 7. Pathological change, collagen content, α-SMA expression, lung function, and mortality rate were assessed at 7, 14, and 21 days after bleomycin administration. Tissue section and direct fluorescence staining was used to show the distribution and differentiation of mDASCs in lung. RESULTS: The transplanted mDASCs could incorporate, proliferate, and differentiate into type I pneumocytes in bleomycin-injured lung. They also inhibited fibrogenesis by attenuating the deposition of collagen and expression of α-SMA. In addition, mDASCs improved pulmonary function and reduce mortality in bleomycin-induced pulmonary fibrosis mice. CONCLUSIONS: The data strongly suggest that mDASCs could ameliorate bleomycin-induced pulmonary fibrosis by promotion of lung regeneration and inhibition of lung fibrogenesis.

[Cyanidin-3-O-glucoside inhibits proliferation of colorectal cancer cells by targeting TOPK].

Objective To explore the influence of cyanidin-3-O-glucoside (C3G) on the proliferation of colorectal cancer cells and its mechanism. Methods In vitro binding and in vitro kinase assay were used to detect the binding ability of C3G and T-LAK cell-originated protein kinase (TOPK) and its effect on TOPK activity. Soft AGAR test was used to detect the effect of C3G on the clonal ability of colon cancer cells. The cytotoxicity of C3G was determined by MTS assay. E. coli BL21 was used to express GST-histone H3 fusion protein. The effect of C3G on the clonogenesis of colon cancer cells with silenced TOPK was examined by lentivirus infection. The phosphorylation of histone H3 by C3G in HCT116 cells was determined by Western blotting. A mouse model of xenograft was established to study the phosphorylation level of histone H3 by immunohistochemical staining. Results C3G was directly bound to TOPK in vitro and inhibited TOPK activity. C3G inhibited the proliferation and clone formation of colon cancer cells in a concentration-dependent manner. Silencing TOPK decreased the sensitivity of colon cancer cells to C3G. C3G inhibited the phosphorylation of histone H3 downstream of TOPK in a time- and concentration-dependent manner. In addition, C3G inhibited tumor growth in mice with xenograft tumors from colon cancer tissues of a patient. Conclusion C3G can inhibit colorectal cancer growth by targeting TOPK.

Resveratrol alleviate hypoxic pulmonary hypertension via anti-inflammation and anti-oxidant pathways in rats.

Resveratrol, a plant-derived polyphenolic compound and a phytoestrogen, was shown to possess multiple protective effects including anti-inflammatory response and anti-oxidative stress. Hypoxic pulmonary hypertension (HPH) is a progressive disease characterized by sustained vascular resistance and marked pulmonary vascular remodeling. The exact mechanisms of HPH are still unclear, but inflammatory response and oxidative stress was demonstrated to participate in the progression of HPH. The present study was designed to investigate the effects of resveratrol on HPH development. Sprague-Dawley rats were challenged by hypoxia exposure for 28 days to mimic hypoxic pulmonary hypertension along with treating resveratrol (40 mg/kg/day). Hemodynamic and pulmonary pathomorphology data were then obtained, and the anti-proliferation effect of resveratrol was determined by in vitro assays. The anti-inflammation and anti-oxidative effects of resveratrol were investigated in vivo and in vitro. The present study showed that resveratrol treatment alleviated right ventricular systolic pressure and pulmonary arterial remodeling induced by hypoxia. In vitro experiments showed that resveratrol notably inhibited proliferation of pulmonary arterial smooth muscle cells in an ER-independent manner. Data showed that resveratrol administration inhibited HIF-1 α expression in vivo and in vitro, suppressed inflammatory cells infiltration around the pulmonary arteries, and decreased ROS production induced by hypoxia in PAMSCs. The inflammatory cytokines' mRNA levels of tumor necrosis factor α, interleukin 6, and interleukin 1ß were all suppressed by resveratrol treatment. The in vitro assays showed that resveratrol inhibited the expression of HIF-1 α via suppressing the MAPK/ERK1 and PI3K/AKT pathways. The antioxidant axis of Nuclear factor erythroid-2 related factor 2/ Thioredoxin 1 (Nrf-2/Trx-1) was up-regulated both in lung tissues and in cultured PASMCs. In general, the current study demonstrated that resveratrol may prevent pulmonary hypertension through its anti-proliferation, anti-inflammation and antioxidant effects. Hence, the present data may offer novel targets and promising pharmacological perspective for treating hypoxic pulmonary hypertension.

Epigallocatechin-3-gallate suppresses alveolar epithelial cell apoptosis in seawater aspiration-induced acute lung injury via inhibiting STAT1-caspase-3/p21 associated pathway.

The apoptosis of alveolar epithelial cells is important in seawater aspiration­induced acute lung injury (ALI). The present study aimed to investigate whether epigallocatechin-3-gallate (EGCG) is able to suppress apoptosis in alveolar epithelial cells in seawater aspiration­induced ALI in vivo and in vitro, and the possible mechanisms underlying it. The results indicated that seawater aspiration­induced ALI in rats is accompanied by increased apoptosis in lung tissue cells and the expression of apoptosis­associated proteins, caspase­3 and p21. EGCG pretreatment significantly ameliorated seawater aspiration­induced ALI. Furthermore, EGCG decreased seawater aspiration­induced apoptosis and the expression of caspase­3 and p21 in lung tissue cells. Seawater­challenged A549 cells experienced increased apoptosis and elevated levels of phosphorylated­signal transducer and activator of transcription 1 (P­STAT1). EGCG pretreatment of the cells resulted in significantly decreased seawater­induced apoptosis and lower levels of STAT1 and P­STAT1 in A549 cells. This suggests that EGCG suppresses alveolar epithelial cell apoptosis in seawater aspiration­induced ALI via inhibiting the STAT1-caspase-3/p21 associated pathway.

miR-29a-3p attenuates hypoxic pulmonary hypertension by inhibiting pulmonary adventitial fibroblast activation.

Activation of pulmonary adventitial fibroblasts plays a key role in the pulmonary vascular remodeling in hypoxic pulmonary hypertension. Previous studies showed that miRNAs participated in the regulation of fibroblast activation. This study explored the role of miR-29 in the activation of pulmonary adventitial fibroblasts and the therapeutic potential in hypoxic pulmonary hypertension. We found that hypoxia-induced pulmonary adventitial fibroblasts activation was accompanied with a drastic decrease of miR-29a-3p expression. Knockdown of hypoxia-inducible factor-1 α or Smad3 reversed the hypoxia-induced decrease of miR-29-3p in cultured pulmonary adventitial fibroblasts. In vitro, miR-29a-3p mimic inhibited the hypoxia-induced proliferation, migration, and secretion of pulmonary adventitial fibroblasts, suppressed the hypoxia-induced expression of α-smooth muscle actin and extracellular matrix collagen in pulmonary adventitial fibroblasts; however, miR-29a-3p inhibitor mimicked the effect of hypoxia on the activation of pulmonary adventitial fibroblasts. Further studies revealed that preventative or therapeutic administration of miR-29a-3p significantly decreased pulmonary artery pressure and right ventricle hypertrophy index and ameliorated pulmonary vascular remodeling in hypoxic pulmonary hypertension rats. These findings suggest that miR-29a-3p regulates the activation and phenotype of pulmonary adventitial fibroblasts in hypoxia and has preventative and therapeutic potential in hypoxic pulmonary hypertension.

Epigallocatechin-3-gallate ameliorates seawater aspiration-induced acute lung injury via regulating inflammatory cytokines and inhibiting JAK/STAT1 pathway in rats.

Signal transducers and activators of transcriptions 1 (STAT1) play an important role in the inflammation process of acute lung injury (ALI). Epigallocatechin-3-gallate (EGCG) exhibits a specific and strong anti-STAT1 activity. Therefore, our study is to explore whether EGCG pretreatment can ameliorate seawater aspiration-induced ALI and its possible mechanisms. We detected the arterial partial pressure of oxygen, lung wet/dry weight ratios, protein content in bronchoalveolar lavage fluid, and the histopathologic and ultrastructure staining of the lung. The levels of IL-1, TNF-α, and IL-10 and the total and the phosphorylated protein level of STAT1, JAK1, and JAK2 were assessed in vitro and in vivo. The results showed that EGCG pretreatment significantly improved hypoxemia and histopathologic changes, alleviated pulmonary edema and lung vascular leak, reduced the production of TNF-α and IL-1, and increased the production of IL-10 in seawater aspiration-induced ALI rats. EGCG also prevented the seawater aspiration-induced increase of TNF-α and IL-1 and decrease of IL-10 in NR8383 cell line. Moreover, EGCG pretreatment reduced the total and the phosphorylated protein level of STAT1 in vivo and in vitro and reduced the phosphorylated protein level of JAK1 and JAK2. The present study demonstrates that EGCG ameliorates seawater aspiration-induced ALI via regulating inflammatory cytokines and inhibiting JAK/STAT1 pathway in rats.

CXCR4-mediated osteosarcoma growth and pulmonary metastasis is promoted by mesenchymal stem cells through VEGF.

Chemokines and chemokine receptor 4 (CXCR4) play an important role in metastasis. CXCR4 is also expressed in the human osteosarcoma cell line 9607-F5M2 (F5M2), which has a high tumorigenic ability and potential for spontaneous pulmonary metastasis. Mesenchymal stem cells (MSCs) contribute to the formation of the tumor stroma and promote metastasis. However, mechanisms underlying the promotion of osteosarcoma growth and pulmonary metastasis by MSCs are still elusive. Our study co-injected the human MSCs and F5M2 cells into the caudal vein of nude mice. The total number of tumor nodules per lung was significantly increased in the F5M2+MSC group compared to the other groups (control, F5M2 cells alone and MSCs alone) at week six. Moreover, a high number of Dil-labeled MSCs was present also at the osteosarcoma metastasis sites in the lung. Using Transwell assays, we found that F5M2 cells migrate towards MSCs, while the CXCR4 inhibitor AMD3100 decreased the migration potential of F5M2 cells towards MSCs. Furthermore, upon treatment with F5M2-conditioned medium, MSCs expressed and secreted higher levels of VEGF as determined by immunohistochemistry, western blotting and ELISA, respectively. Importantly, co-cultured with F5M2 cells, MSCs expressed and secreted higher VEGF levels, while AMD3100 dramatically decreased the VEGF secretion by MSCs. However, CXCR4 expression on F5M2 cells was not significantly increased in the co-culture system. Additionally, VEGF increased the proliferation of both MSCs and F5M2 cells. These findings suggest that CXCR4-mediated osteosarcoma growth and pulmonary metastasis are promoted by MSCs through VEGF.

Tanshinone IIA inhibits hypoxia-induced pulmonary artery smooth muscle cell proliferation via Akt/Skp2/p27-associated pathway.

We previously showed that tanshinone IIA ameliorated the hypoxia-induced pulmonary hypertension (HPH) partially by attenuating pulmonary artery remodeling. The hypoxia-induced proliferation of pulmonary artery smooth muscle cells (PASMCs) is one of the major causes for pulmonary arterial remodeling, therefore the present study was performed to explore the effects and underlying mechanism of tanshinone IIA on the hypoxia-induced PASMCs proliferation. PASMCs were isolated from male Sprague-Dawley rats and cultured in normoxic (21%) or hypoxic (3%) condition. Cell proliferation was measured with 3 - (4, 5 - dimethylthiazal - 2 - yl) - 2, 5 - diphenyltetrazoliumbromide assay and cell counting. Cell cycle was measured with flow cytometry. The expression of of p27, Skp-2 and the phosphorylation of Akt were measured using western blot and/or RT-PCR respectively. The results showed that tanshinone IIA significantly inhibited the hypoxia-induced PASMCs proliferation in a concentration-dependent manner and arrested the cells in G1/G0-phase. Tanshinone IIA reversed the hypoxia-induced reduction of p27 protein, a cyclin-dependent kinase inhibitor, in PASMCs by slowing down its degradation. Knockdown of p27 with specific siRNA abolished the anti-proliferation of tanshinone IIA. Moreover, tanshinone IIA inhibited the hypoxia-induced increase of S-phase kinase-associated protein 2 (Skp2) and the phosphorylation of Akt, both of which are involved in the degradation of p27 protein. In vivo tanshinone IIA significantly upregulated the hypoxia-induced p27 protein reduction and downregulated the hypoxia-induced Skp2 increase in pulmonary arteries in HPH rats. Therefore, we propose that the inhibition of tanshinone IIA on hypoxia-induce PASMCs proliferation may be due to arresting the cells in G1/G0-phase by slowing down the hypoxia-induced degradation of p27 via Akt/Skp2-associated pathway. The novel information partially explained the anti-remodeling property of tanshinone IIA on pulmonary artery in HPH.

Functional expression of ERG1 potassium channels in rat alveolar macrophages.

Alveolar macrophages (AMs) play a vital role in lung immunity. The recent studies demonstrated that potassium channels were associated with macrophage functions, such as activation, migration and cytokines secretion. However, less is known regarding the expression and function of ERG channels in AMs. Our study showed that ERG1 channel expressed in rat alveolar macrophage, and the expression level was increased when AMs were stimulated with LPS. Furthermore, blockade of ERG1 channels with E4031 down-regulated the mature of ERG1 protein, inhibited NF-κB translocation into the nucleus, and reduced LPS-stimulated IL-6 and IL-1ß secretion. These results imply that ERG1 channels are functionally expressed in rat alveolar macrophages and play an important role in inflammatory response.

Human ether-à-go-go gene potassium channels are regulated by EGFR tyrosine kinase.

Human ether á-go-go gene potassium channels (hEAG1 or Kv10.1) are expressed in brain and various human cancers and play a role in neuronal excitement and tumor progression. However, the functional regulation of hEAG channels by signal transduction is not fully understood. The present study was therefore designed to investigate whether hEAG1 channels are regulated by protein tyrosine kinases (PTKs) in HEK 293 cells stably expressing hEAG1 gene using whole-cell patch voltage-clamp, immunoprecipitation, Western blot, and mutagenesis approaches. We found that the selective epidermal growth factor receptor (EGFR) kinase inhibitor AG556 (10 µM), but not the platelet growth factor receptor (PDGFR) kinase inhibitor AG1295 (10 µM) or the Src-family inhibitor PP2 (10 µM), can inhibit hEAG1 current, and the inhibitory effect can be reversed by the protein tyrosine phosphatase (PTP) inhibitor orthovanadate. Immunoprecipitation and Western blot analysis revealed that tyrosine phosphorylation level of hEAG1 channels was reduced by AG556, and the reduction was significantly countered by orthovanadate. The hEAG1 mutants Y90A, Y344A and Y485A, but not Y376A and Y479A, exhibited reduced response to AG556. Interestingly, the inhibition effect of AG556 was lost in triple mutant hEAG1 channels at Y90, Y344, and Y485 with alanine. These results demonstrate for the first time that hEAG1 channel activity is regulated by EGFR kinase at the tyrosine residues Tyr90, Try344, and Try485. This effect is likely involved in regulating neuronal activity and/or tumor growth.

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.

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-1ß 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.

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

BACKGROUND: Pulmonary vascular structure remodeling (PVSR) is a hallmark of pulmonary hypertension. P27(kip1), one of critical cyclin-dependent kinase inhibitors, has been shown to mediate anti-proliferation effects on various vascular cells. Beta-estradiol (ß-E2) has numerous biological protective effects including attenuation of hypoxic pulmonary hypertension (HPH). In the present study, we employed ß-E2 to investigate the roles of p27(kip1) and its closely-related kinase (Skp-2) in the progression of PVSR and HPH. METHODS: Sprague-Dawley rats treated with or without ß-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 ß-E2 under hypoxia exposure. Western blotting or reverse transcriptional polymerase chain reaction (RT-PCR) were adopted to test p27(kip1), Skp-2 and Akt-P changes in rat lung tissue and cultured PASMCs. RESULTS: Chronic 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 p27(kip1) in rats. Whereas, ß-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 p27(kip1). Study also showed that ß-E2 application suppressed the proliferation of PASMCs and elevated the expression of p27(kip1) 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 ß-E2. CONCLUSIONS: Our results suggest that ß-E2 can effectively attenuate PVSR and HPH. The underlying mechanism may partially be through the increased p27(kip1) by inhibiting Skp-2 through Akt signal pathway. Therefore, targeting up-regulation of p27(kip1) or down-regulation of Skp-2 might provide new strategies for treatment of HPH.

Pharmacology of cardiac potassium channels.

Cardiac K(+) channels are cardiomyocyte membrane proteins that regulate K(+) ion flow across the cell membrane on the electrochemical gradient and determine the resting membrane potential and the cardiac action potential morphology and duration. Several K(+) channels have been well studied in the human heart. They include the transient outward K(+) current I(to1), the ultra-rapidly activating delayed rectifier current I(Kur), the rapidly and slowly activating delayed rectifier currents I(Kr) and I(Ks), the inward rectifier K(+) current I(K1), and ligand-gated K(+) channels, including adenosine-5'-triphosphate (ATP)-sensitive K(+) current (I(KATP)) and acetylcholine-activated current (I(KACh)). Regional differences of K(+) channel expression contribute to the variable morphologies and durations of cardiac action potentials from sinus node and atrial to ventricular myocytes, and different ventricular layers from endocardium and midmyocardium to epicardium. They also show different responses to endogenous regulators and/or pharmacological agents. K(+) channels are well-known targets for developing novel anti-arrhythmic drugs that can effectively prevent/inhibit cardiac arrhythmias. Especially, atrial-specific K(+) channel currents (I(Kur) and I(KACh)) are the targets for developing atrial-selective anti-atrial fibrillation drugs, which has been greatly progressed in recent years. This chapter concentrates on recent advances in intracellular signaling regulation and pharmacology of cardiac K(+) channels under physiological and pathophysiological conditions.