Indirubin-3′-Monoxime Blocks Vascular Smooth Muscle Cell Proliferation by Inhibition of Signal Transducer and Activator of Transcription 3 Signaling and Reduces Neointima Formation In Vivo

Complementary and Alternative Therapies for Psoriasis

Despite recent advancements in psoriasis treatment, challenges in management persist. Recently, there has been a rising interest amongst patients in complementary and alternative medicines (CAM), driven by the desire for more natural, holistic approaches and dissatisfaction with conventional treatments. Up to 41% of patients with psoriasis reported using alternative therapies and 39.5% use complementary therapies (Murphy EC, Nussbaum D, Prussick R, Friedman AJ (2019) Use of complementary and alternative medicine by patients with psoriasis. J Am Acad Dermatol 81:280-283). Despite their rapidly growing prevalence, literature on CAM therapies for psoriasis is lacking, making their recommendation difficult. Since the last systematic review on this topic published in 2018, evidence for new alternative therapies has emerged, promoting a further investigation of their efficacy (Gamret AC, Price A, Fertig RM, Lev-Tov H, Nichols AJ (2018) Complementary and Alternative Medicine Therapies for Psoriasis: A Systematic Review. JAMA Dermatol 154:1330-1337). This systematic review aims to compile recent literature on the most studied alternative therapies for psoriasis and further discuss their effectiveness in order to counsel clinicians in guiding patients on the use of these non-standard approaches. A literature search was conducted in the PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov databases for randomized controlled trials (RCT) on complementary and alternative therapies in psoriasis from March 2018 through April 2024, resulting in 12 studies being included in this review. The preliminary results for many treatments such as curcumin, dietary modification and additions, indigo naturalis, meditation, acupuncture, and balneotherapy showed positive clinical effects. However, additional well-designed randomized trials are needed to confirm the potential beneficial effects and to establish safety of use.

Ntsr1 contributes to pulmonary hypertension by enhancing endoplasmic reticulum stress via JAK2-STAT3-Thbs1 signaling

Pulmonary hypertension (PH) is a severe clinical syndrome with pulmonary vascular remodeling and poor long-term prognosis. Neurotensin receptor 1 (Ntsr1), serve as one of the G protein-coupled receptors (GPCRs), implicates in various biological processes, but the potential effects of Ntsr1 in PH development are unclear. The Sugen/Hypoxia (SuHx) or monocrotaline (MCT) induced rat PH model was used in our study and the PH rats showed aggravated pulmonary artery remodeling and increased right ventricular systolic pressure (RVSP). Our results revealed that Ntsr1 induced endoplasmic reticulum (ER) stress response via ATF6 activation contributed to the development of PH. Moreover, RNA-sequencing (RNA-seq) and phosphoproteomics were performed and the Ntsr1-JAK2-STAT3-thrombospondin 1 (Thbs1)-ATF6 signaling was distinguished as the key pathway. In vitro, pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition showed enhanced proliferation and migration properties, which could be inhibited by Ntsr1 knockdown, JAK2 inhibitor (Fedratinib) treatment, STAT3 inhibitior (Stattic) treatment, Thbs1 knockdown or ATF6 knockdown. In addition, adeno-associated virus 1 (AAV1) were used to knockdown the expression of Ntsr1, Thbs1 or ATF6 in rats and reversed the phenotype of PH. In summary, our results reveal that Ntsr1-JAK2-STAT3-Thbs1 pathway can induce enhanced ER stress via ATF6 activation and increased PASMC proliferation and migration capacities, which can be mechanism of the pulmonary artery remodeling and PH. Targeting Ntsr1 might be a novel therapeutic strategy to ameliorate PH.

Benefits of topical indigo naturalis nanofibrous patch on psoriatic skin: A transdermal strategy for botanicals

Indigo naturalis (IN) has been extensively used as a topical treatment for psoriasis. However, clinical applications of IN in ointment were hampered by its limited transdermal efficiency and dark stains. To address the aforementioned issues, nanopatches carrying IN were fabricated using poly(ε-caprolactone, PCL)/poly(ethylene oxide, PEO) and topically applied to psoriasiform skin. The ideal ratio of 5% PCL/PEO was established to be 80:20 (w/w), and 15% IN as payload was confirmed. Investigations on the three principal active components of IN release indicated that indirubin and tryptanthrin were released in bursts, while indigo was released in a limited and controlled manner. Further biological analyses confirmed a favorable biocompatibility of amphiphilic IN-PCL/PEO, which coincided with the intended therapeutic outcomes as measured by severity index scoring and pathological evaluations in vivo. The advantages of IN as nanopatches over ointment could be due to improved transdermal distribution of indirubin and tryptanthrin, resulting in effective management of epidermal hyperplasia and blood vessel remodeling. Meanwhile, due to the lower preservation of epidermal indigo, IN-PCL/PEO nanopatches caused no skin coloration. Similarly, during a 4-week topical treatment of IN-PCL/PEO nanopatches, the safety and anti-psoriatic benefits were obtained in an initial human test. The conversion of IN from topical cream to electrospun nanofibers opens up new avenues for bench-to-bedside translation of this herbal therapy and provides mechanistic insight into IN's roles in the management of psoriasis.

Liangxue Jiedu Runzhi ointment in the treatment of mild and moderate psoriasis with blood-heat syndrome: A double-blind randomized controlled trial

INTRODUCTION

Psoriasis is a kind of chronic inflammatory skin disease characterized by erythema, skin hyperplasia, scales and keratinocyte hyperproliferation. Psoriasis Vulgaris, the most common kind of psoriasis, severely deteriorates the life quality of patients. Traditional Chinese Medicine (TCM) is a good choice for the treatment of psoriasis, which has been proved to be safe and effective, and may reduce the recurrence rate. In clinical practice, Liangxue Jiedu Runzhi (LJR) ointment can effectively treat mild and moderate psoriasis with blood-heat syndrome, but there is a lack of evidence-based medical evidence. This trial aims to evaluate the efficacy and safety of LJR ointment for the treatment of mild and moderate psoriasis with blood-heat syndrome.

METHODS

A multicenter, randomized, double-blind, placebo-controlled, and self-controlled clinical trial was carried out according to this paper. The symmetrical rashes of each subject were regarded as the target lesions and were randomly divided into a treatment group (LJR ointment group) and a control group (placebo group). The LJR ointment or placebo ointment were externally administered on bilateral symmetric rashes, twice a day for eight weeks. The follow-up examination was made for subjects every two weeks. The primary research finding was conveyed by Psoriasis Area and Severity Index (PASI) in 8 weeks. The secondary research finding includes adverse events.

RESULTS

46 subjects undergo this research project. The difference between PASI scores of the target lesions in the treatment group and control group is statistically significant were in 8 weeks (P < .001). The percentage of PASI 75 in treatment group and control group were 48% and 15% in week 8, respectively (x2 = 11.33, P < .05). No severe adverse events were reported.

CONCLUSIONS

LJR ointment was proved to have efficacy in the treatment of mild and moderate psoriasis with the blood-heat syndrome.

Animal Models of Neointimal Hyperplasia and Restenosis: Species-Specific Differences and Implications for Translational Research

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Neointimal hyperplasia is the major factor contributing to restenosis after angioplasty procedures.

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Multiple animal models exist to study basic and translational aspects of restenosis formation.

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Animal models differ substantially, and species-specific differences have major impact on the pathophysiology of the model.

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Genetic, dietary, and mechanical interventions determine the translational potential of the animal model used and have to be considered when choosing the model.

The process of restenosis is based on the interplay of various mechanical and biological processes triggered by angioplasty-induced vascular trauma. Early arterial recoil, negative vascular remodeling, and neointimal formation therefore limit the long-term patency of interventional recanalization procedures. The most serious of these processes is neointimal hyperplasia, which can be traced back to 4 main mechanisms: endothelial damage and activation; monocyte accumulation in the subintimal space; fibroblast migration; and the transformation of vascular smooth muscle cells. A wide variety of animal models exists to investigate the underlying pathophysiology. Although mouse models, with their ease of genetic manipulation, enable cell- and molecular-focused fundamental research, and rats provide the opportunity to use stent and balloon models with high throughput, both rodents lack a lipid metabolism comparable to humans. Rabbits instead build a bridge to close the gap between basic and clinical research due to their human-like lipid metabolism, as well as their size being accessible for clinical angioplasty procedures. Every different combination of animal, dietary, and injury model has various advantages and disadvantages, and the decision for a proper model requires awareness of species-specific biological properties reaching from vessel morphology to distinct cellular and molecular features.

Indirubin-3-monoxime and thymoquinone exhibit synergistic efficacy as therapeutic combination in in-vitro and in-vivo models of Lung cancer

In this study, we report the combination of indirubin-3-monoxime (I3M) and thymoquinone (Tq) to have excellent therapeutic efficacy in models of Lung cancer (LC). Preliminary screening was done with A549 cells. Cell cycle, apoptosis and NFκB phosphorylation were determined by flow cytometry, while apoptotic proteins, Akt and mTOR were assessed by western blotting. Mouse xenograft model was used to assess the therapeutic efficacy in-vivo. Synergistic reduction in cell viability was observed with I3M + Tq combinations, which were non-toxic to normal HFL-1 cells. Cell cycle analysis indicated G₁ phase reduction with subsequent accumulation of sub G₀ contents. Annexin V assay revealed higher apoptotic cells with combinations compared to individual treatments with a decrease in Bcl-2/Bax ratio. The combinations exhibited anti-metastasis activity in cell migration in the scratch, scatter and tumour cell migration assays and effectively reduced the tumour growth in mouse xenograft model. Expression levels of p-AKT, p-mTOR, Caspase-3, p-53 and NFκB were significantly reduced in the combination treated mice compared to individual treatments. Results of current study demonstrate clear efficacy of I3M + Tq combinations in LC models mediated by suppressing Akt/mTOR/NFκB signalling. Further research is recommended to transform these findings into novel therapeutic combinations against LC.

Construction and Comprehensive Analysis of Dysregulated Long Noncoding RNA-Associated Competing Endogenous RNA Network in Moyamoya Disease

BACKGROUND

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by chronic progressive stenosis or occlusion of the bilateral internal carotid artery (ICA), the anterior cerebral artery (ACA), and the middle cerebral artery (MCA). MMD is secondary to the formation of an abnormal vascular network at the base of the skull. However, the etiology and pathogenesis of MMD remain poorly understood.

METHODS

A competing endogenous RNA (ceRNA) network was constructed by analyzing sample-matched messenger RNA (mRNA), long non-coding RNA (lncRNA), and microRNA (miRNA) expression profiles from MMD patients and control samples. Then, a protein-protein interaction (PPI) network was constructed to identify crucial genes associated with MMD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were employed with the DAVID database to investigate the underlying functions of differentially expressed mRNAs (DEmRNAs) involved in the ceRNA network. CMap was used to identify potential small drug molecules.

RESULTS

A total of 94 miRNAs, 3649 lncRNAs, and 2294 mRNAs were differentially expressed between MMD patients and control samples. A synergistic ceRNA lncRNA-miRNA-mRNA regulatory network was constructed. Core regulatory miRNAs (miR-107 and miR-423-5p) and key mRNAs (STAT5B, FOSL2, CEBPB, and CXCL16) involved in the ceRNA network were identified. GO and KEGG analyses indicated that the DEmRNAs were involved in the regulation of the immune system and inflammation in MMD. Finally, two potential small molecule drugs, CAY-10415 and indirubin, were identified by CMap as candidate drugs for treating MMD.

CONCLUSIONS

The present study used bioinformatics analysis of candidate RNAs to identify a series of clearly altered miRNAs, lncRNAs, and mRNAs involved in MMD. Furthermore, a ceRNA lncRNA-miRNA-mRNA regulatory network was constructed, which provides insights into the novel molecular pathogenesis of MMD, thus giving promising clues for clinical therapy.

Natural products as important tyrosine kinase inhibitors

As an important source of drugs, natural products play an important role in the discovery and development of new drugs. More than 60% of anti-tumor drugs are closely related to natural products. At the same time, as the main cause of tumors, the abnormal activity of tyrosine kinase has become an important target for clinical treatment. Although, small molecule targeted drugs dominate the cancer treatment. Natural active products are driving the development of new tyrosine kinase inhibitors with their unique mode of action and molecular structure diversity. Obtaining new chemical entities with tyrosine kinase inhibitory activity from natural active products will bring new breakthroughs in the research of anticancer drugs. In this paper, different tyrosine kinases are mainly classified as targets, and natural products and derivatives which have been found to inhibit tyrosine kinase activity have been described. It is hoped that by analyzing the different aspects of the source, structural characteristics, mechanism of action and biological activity of these natural products, we will find new members that can be developed into drugs and promote the development of anti-tumor drugs.

Inhibitory effects of indirubin-3'-monoxime against human osteosarcoma

Indirubin is widely used as the active component of "Dangui Luhui Wan" in ancient China. However, its effects against the osteosarcoma (OS), the most common primary malignancy, are still unknown. In our present study, we investigated the effects of the Indirubin-3'-monoxime (I3M), a derivative of indirubin with better water solubility, against the OS cells. We found I3M inhibited OS cell proliferation in a dose-dependent manner. Flow cytometry assays showed that I3M could not only induce OS cell apoptosis in a time- and dose-dependent manner but also regulate the cell cycle distribution. Additionally, we demonstrated that several Bcl-2 family members, cyclin-dependent kinases (CDKs) and cyclins contributed to this process. Furthermore, out data verified that I3M suppressed OS cell migration and invasion by decreasing MMP-2 and MMP-9 levels. Moreover, survivin and focal adhesion kinase (FAK) might play important roles in the anti-OS effects of I3M. The administration of I3M also inhibited the OS cell growth in mice. Taken together, our results indicated the inhibitory effects of I3M against human OS and thus might be an efficient candidate for OS chemotherapy.

Rational combinations of indirubin and arylidene derivatives exhibit synergism in human non-small cell lung carcinoma cells

Rational combination of natural and synthetic derivatives to treat lung cancer has advantages of both efficacy and safety. Herein, the combination of indirubin-3-monoxime (I3M), a chemical derived from Chinese herbal medicine and FXY-1, a synthetic arylidene derivative, was tested for combined activity in lung cancer cells. A dose-dependent synergistic reduction in cell viability was recorded with the combinations in A549 and NCI-H460 cells. Combination treatments of I3M and FXY-1 showed antimetastatic effects in both cells. Cell cycle analysis revealed G₁ growth phase reduction with subsequent accumulation of sub G₀ contents. Annexin V assay revealed higher apoptotic cells with combinations compared to individual treatments. I3M + FXY-1 combination significantly decreased the antiapoptotic Bcl-2 protein and increased pro-apoptotic Bax protein levels. These results demonstrate efficacy of I3M + FXY-1 in lung cancer cells and suggest further preclinical research in animal models to develop it into a new form combination chemotherapeutic against lung cancer. PRACTICAL APPLICATIONS: Current investigation will open new options in rational combinations of natural and synthetic compounds to treat cancer. The observed efficacy and safety of the combinations will add to the advantage of higher therapeutic window in formulating treatment regimens. The antimetastatic effects by the combinations provides promising efficacy in controlling the lung cancer progression. A detailed in vivo investigation is recommended to transform the combinations to novel chemotherapeutic options against lung cancer.

Long non-coding RNA MALAT1 regulates angiogenesis following oxygen-glucose deprivation/reoxygenation

Long non-coding RNAs (lncRNAs) have been identified as playing critical roles in multiple diseases. However, little is known regarding their roles and mechanisms in post-stroke angiogenesis. Our studies focused on deciphering the functional roles and the underlying mechanisms of the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the process of angiogenesis following oxygen-glucose deprivation/reoxygenation (OGD/R). We characterized the up-regulation of MALAT1 expression in the process of angiogenesis after hypoxic injury in vivo and in vitro. We further showed that compared with the empty vector, MALAT1 knockdown had significantly reduced the capacity for angiogenesis, which was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT), scratching, cell cycle and immunofluorescent staining. Thus, our findings suggest that MALAT1 may mediate proangiogenic function in OGD/R. To further explore the potential mechanisms, we used lentiviruses expressing shMALAT1 and empty vector; the results revealed that shMALAT1 reduced the expression of 15-lipoxygenase 1 (15-LOX1), vascular endothelial growth factor (VEGF) and the phosphorylation of signal transducers and activators of transcription 3 (pSTAT3). Taken together, our results are the first to propose that MALAT1 may regulate angiogenesis through the 15-LOX1/STAT3 signalling pathway, and they may provide a critical target for the treatment of hypoxic injury and an avenue for therapeutic angiogenesis.

Indirubin suppresses ovarian cancer cell viabilities through the STAT3 signaling pathway

Background

Indirubin is the active component of Danggui Longhui Wan, a traditional Chinese medicine formulation. Due to its anti-inflammation and anti-tumor effects, indirubin has been widely used for the treatment of inflammation, cancer, and other chronic disease. Herein, we aimed to investigate the role and mechanism of indirubin in human ovarian cancer cell proliferation.

Materials and methods

The cell viability was determined by Cell Counting Kit-8 and colony formation assays by treatment with different dosages of indirubin over 72 hours. Apoptosis was examined by flow cytometry with fluorescein isothiocyanate Annexin V Apoptosis Detection Kit. Western blot assay was finally applied to analyze the expression of cancer-related STAT3 pathway and its downstream proteins.

Results

Indirubin was found to significantly inhibit cell viability and induce apoptosis in 2 human ovarian cancer cell lines. Mechanistic studies revealed that indirubin treatment led to reduced levels of phosphorylated-STAT3, thus repressing the downstream pro-survival proteins and elevating pro-apoptosis ones.

Conclusion

Our study provided the evidence for anti-survival activity of indirubin by inhibiting cell viability and inducing apoptosis in human ovarian cancer cells, which involved impaired STAT3 signaling pathway. Our findings further support indirubin as a potential drug candidate against human ovarian cancer.

Vascular smooth muscle cell proliferation as a therapeutic target. Part 1: molecular targets and pathways

Cardiovascular diseases are a major cause of human death worldwide. Excessive proliferation of vascular smooth muscle cells contributes to the etiology of such diseases, including atherosclerosis, restenosis, and pulmonary hypertension. The control of vascular cell proliferation is complex and encompasses interactions of many regulatory molecules and signaling pathways. Herein, we recapitulated the importance of signaling cascades relevant for the regulation of vascular cell proliferation. Detailed understanding of the mechanism underlying this process is essential for the identification of new lead compounds (e.g., natural products) for vascular therapies.

Vascular smooth muscle cell proliferation as a therapeutic target. Part 2: Natural products inhibiting proliferation

Many natural products have been so far tested regarding their potency to inhibit vascular smooth muscle cell proliferation, a process involved in atherosclerosis, pulmonary hypertension and restenosis. Compounds studied in vitro and in vivo as VSMC proliferation inhibitors include, for example indirubin-3'-monoxime, resveratrol, hyperoside, plumericin, pelargonidin, zerumbone and apamin. Moreover, taxol and rapamycin, the most prominent compounds applied in drug-eluting stents to counteract restenosis, are natural products. Numerous studies show that natural products have proven to yield effective inhibitors of vascular smooth muscle cell proliferation and ongoing research effort might result in the discovery of further clinically relevant compounds.

Constituents of Mediterranean Spices Counteracting Vascular Smooth Muscle Cell Proliferation: Identification and Characterization of Rosmarinic Acid Methyl Ester as a Novel Inhibitor

SCOPE

Aberrant vascular smooth muscle cell (VSMC) proliferation is involved in atherosclerotic plaque formation and restenosis. Mediterranean spices have been reported to confer cardioprotection, but their direct influence on VSMCs has largely not been investigated. This study aims at examining rosmarinic acid (RA) and 11 related constituents for inhibition of VSMC proliferation in vitro, and at characterizing the most promising compound for their mode of action and influence on neointima formation in vivo.

METHODS AND RESULTS

RA, rosmarinic acid methyl ester (RAME), and caffeic acid methyl ester inhibit VSMC proliferation in a resazurin conversion assay with IC50 s of 5.79, 3.12, and 6.78 µm, respectively. RAME significantly reduced neointima formation in vivo in a mouse femoral artery cuff model. Accordingly, RAME leads to an accumulation of VSMCs in the G0 /G1 cell-cycle phase, as indicated by blunted retinoblastoma protein phosphorylation upon mitogen stimulation and inhibition of cyclin-dependent kinase 2 in vitro.

CONCLUSION

RAME represses PDGF-induced VSMC proliferation in vitro and reduces neointima formation in vivo. These results recommend RAME as an interesting compound with VSMC-inhibiting potential. Future metabolism and pharmacokinetics studies might help to further evaluate the potential relevance of RAME and other spice-derived polyphenolics for vasoprotection.

Clinical efficacy and IL-17 targeting mechanism of Indigo naturalis as a topical agent in moderate psoriasis

Background

Indigo naturalis is a Traditional Chinese Medicine (TCM) ingredient long-recognized as a therapy for several inflammatory conditions, including psoriasis. However, its mechanism is unknown due to lack of knowledge about the responsible chemical entity. We took a different approach to this challenge by investigating the molecular profile of Indigo naturalis treatment and impacted pathways.

Methods

A randomized, double-blind, placebo-controlled clinical study was conducted using Indigo naturalis as topical monotherapy to treat moderate plaque psoriasis in a Chinese cohort (n = 24). Patients were treated with Indigo naturalis ointment (n = 16) or matched placebo (n = 8) twice daily for 8 weeks, with 1 week of follow-up.

Results

At week 8, significant improvements in Psoriasis Area and Severity Index (PASI) scores from baseline were observed in Indigo naturalis-treated patients (56.3% had 75% improvement [PASI 75] response) compared with placebo (0.0%). A gene expression signature of moderate psoriasis was established from baseline skin biopsies, which included the up-regulation of the interleukin (IL)-17 pathway as a key component; Indigo naturalis treatment resulted in most of these signature genes returning toward normal, including down-regulation of the IL-17 pathway. Using an in vitro keratinocyte assay, an IL-17-inhibitory effect was observed for tryptanthrin, a component of Indigo naturalis.

Conclusions

This study demonstrated the clinical efficacy of Indigo naturalis in moderate psoriasis, and exemplified a novel experimental medicine approach to understand TCM targeting mechanisms.

Trial registration

NCT01901705.

Electronic supplementary material

The online version of this article (10.1186/s12906-017-1947-1) contains supplementary material, which is available to authorized users.

Xanthohumol Blocks Proliferation and Migration of Vascular Smooth Muscle Cells in Vitro and Reduces Neointima Formation in Vivo

Xanthohumol (1) is a principal prenylated chalcone found in hops. The aim of this study was to examine its influence on platelet-derived growth factor (PDGF)-BB-triggered vascular smooth muscle cell (VSMC) proliferation and migration in vitro and on experimentally induced neointima formation in vivo. Quantification of resazurin conversion indicated that 1 can inhibit PDGF-BB-induced VSMC proliferation concentration-dependently (IC₅₀ = 3.49 μM). Furthermore, in a wound-healing assay 1 potently suppresses PDGF-BB-induced VSMC migration at 15 μM. Tested in a mouse femoral artery cuff model, 1 significantly reduces neointima formation. Taken together, we show that 1 represses PDGF-BB-induced VSMC proliferation and migration in vitro as well as neointima formation in vivo. This novel activity suggests 1 as an interesting candidate for further studies addressing a possible therapeutic application to counteract vascular proliferative disease.

Age-associated downregulation of vasohibin-1 in vascular endothelial cells

Vasohibin-1 (VASH1) is an angiogenesis-inhibiting factor synthesized by endothelial cells (ECs) and it also functions to increase stress tolerance of ECs, which function is critical for the maintenance of vascular integrity. Here, we examined whether the expression of VASH1 would be affected by aging. We passaged human umbilical vein endothelial cells (HUVECs) and observed that VASH1 was downregulated in old HUVECs. This decrease in VASH1 expression with aging was confirmed in mice. To explore the mechanism of this downregulation, we compared the expression of microRNAs between old and young HUVECs by performing microarray analysis. Among the top 20 microRNAs that were expressed at a higher level in old HUVECs, the third highest microRNA, namely miR-22-3p, had its binding site on the 3' UTR of VASH1 mRNA. Experiments with microRNA mimic and anti-miR revealed that miR-22-3p was involved at least in part in the downregulation of VASH1 in ECs during replicative senescence. We then clarified the significance of this defective expression of VASH1 in the vasculature. When a cuff was placed around the femoral arteries of wild-type mice and VASH1-null mice, neointimal formation was augmented in the VASH1-null mice accompanied by an increase in adventitial angiogenesis, macrophage accumulation in the adventitia, and medial/neointimal proliferating cells. These results indicate that in replicative senescence, the downregulation of VASH1 expression in ECs was caused, at least in part, by the alteration of microRNA expression. Such downregulation of VASH1 might be involved in the acceleration of age-associated vascular diseases.

Increased aerobic glycolysis is important for the motility of activated VSMC and inhibited by indirubin-3'-monoxime

Increased aerobic glycolysis is a recognized feature of multiple cellular phenotypes and offers a potential point for drug interference, as pursued by anti-tumor agents targeting the Warburg effect. This study aimed at examining the role of aerobic glycolysis for migration of vascular smooth muscle cells (VSMC) and its susceptibility to the small molecule indirubin-3′-monoxime (I3MO). Activation of VSMC with platelet-derived growth factor (PDGF) resulted in migration and increased glycolytic activity which was accompanied by an increased glucose uptake and hexokinase (HK) 2 expression. Inhibition of glycolysis or hexokinase by pharmacological agents or siRNA-mediated knockdown significantly reduced the migratory behavior in VSMC without affecting cell viability or early actin cytoskeleton rearrangement. I3MO, previously recognized as inhibitor of VSMC migration, was able to counteract the PDGF-activated increase in glycolysis and HK2 abundance. Activation of signal transducer and activator of transcription (STAT) 3 could be identified as crucial event in upregulation of HK2 and glycolytic activity in PDGF-stimulated VSMC and as point of interference for I3MO. I3MO did not inhibit hypoxia-inducible factor (HIF)1α-dependent transcription nor influence miRNA 143 levels, other potential regulators of HK2 levels. Overall, we demonstrate that increased aerobic glycolysis is an important factor for the motility of activated VSMC and that the anti-migratory property of I3MO may partly depend on impairment of glycolysis via a compromised STAT3/HK2 signaling axis.

Drugs from nature targeting inflammation (DNTI): a successful Austrian interdisciplinary network project

ABSTRACT

Inflammation is part of numerous pathological conditions, which are lacking satisfying treatment and effective concepts of prevention. A national research network project, DNTI, involving scientists from six Austrian universities as well as several external partners aimed to identify and characterize natural products capable of combating inflammatory processes specifically in the cardiovascular system. The combined use of computational techniques with traditional knowledge, high-tech chemical analysis and synthesis, and a broad range of in vitro, cell-based, and in vivo pharmacological models led to the identification of a series of promising anti-inflammatory drug lead candidates. Mechanistic studies contributed to a better understanding of their mechanism of action and delivered new knowledge on the molecular level of inflammatory processes. Herein, the used approaches and selected highlights of the results of this interdisciplinary project are presented.

GRAPHICAL ABSTRACT

Plumericin inhibits proliferation of vascular smooth muscle cells by blocking STAT3 signaling via S-glutathionylation

The etiology of atherosclerosis and restenosis involves aberrant inflammation and proliferation, rendering compounds with both anti-inflammatory and anti-mitogenic properties as promising candidates for combatting vascular diseases. A recent study identified the iridoid plumericin as a new scaffold inhibitor of the pro-inflammatory NF-κB pathway in endothelial cells. We here examined the impact of plumericin on the proliferation of primary vascular smooth muscle cells (VSMC). Plumericin inhibited serum-stimulated proliferation of rat VSMC. It arrested VSMC in the G1/G0-phase of the cell cycle accompanied by abrogated cyclin D1 expression and hindered Ser 807/811-phosphorylation of retinoblastoma protein. Transient depletion of glutathione by the electrophilic plumericin led to S-glutathionylation as well as hampered Tyr705-phosphorylation and activation of the transcription factor signal transducer and activator of transcription 3 (Stat3). Exogenous addition of glutathione markedly prevented this inhibitory effect of plumericin on Stat3. It also overcame downregulation of cyclin D1 expression and the reduction of biomass increase upon serum exposure. This study revealed an anti-proliferative property of plumericin towards VSMC which depends on plumericin's thiol reactivity and S-glutathionylation of Stat3. Hence, plumericin, by targeting at least two culprits of vascular dysfunction -inflammation and smooth muscle cell proliferation -might become a promising electrophilic lead compound for vascular disease therapy.

Cuff-Induced Neointimal Formation in Mouse Models

Ischemic heart failure caused by atherosclerosis is a major cause of death worldwide. Although remarkable technological advances have been made in the treatment of coronary heart disease, there is as yet no treatment that can sufficiently suppress the progression of atherosclerosis, including neointimal thickening. Therefore, a precise understanding of the mechanism of neointimal hyperplasia will provide the development of new technologies. Both ApoE-KO and LDLR-KO mice have been employed to generate other relevant mouse models of cardiovascular disease through breeding strategies. Although these mice are effective tools for the investigation of atherosclerosis, development of a progressive atherosclerotic lesion takes a long time, resulting in increase of both the costs and the space needed for the research. Thus, it is necessary to develop simpler tools that would allow easy evaluation of atherosclerosis in mouse models. In this review, we discuss our experience in generating mouse models of cuff-induced injury of the femoral artery and attempt to provide a better understanding of cuff-induced neointimal formation.

Discovery and resupply of pharmacologically active plant-derived natural products: A review

Medicinal plants have historically proven their value as a source of molecules with therapeutic potential, and nowadays still represent an important pool for the identification of novel drug leads. In the past decades, pharmaceutical industry focused mainly on libraries of synthetic compounds as drug discovery source. They are comparably easy to produce and resupply, and demonstrate good compatibility with established high throughput screening (HTS) platforms. However, at the same time there has been a declining trend in the number of new drugs reaching the market, raising renewed scientific interest in drug discovery from natural sources, despite of its known challenges. In this survey, a brief outline of historical development is provided together with a comprehensive overview of used approaches and recent developments relevant to plant-derived natural product drug discovery. Associated challenges and major strengths of natural product-based drug discovery are critically discussed. A snapshot of the advanced plant-derived natural products that are currently in actively recruiting clinical trials is also presented. Importantly, the transition of a natural compound from a "screening hit" through a "drug lead" to a "marketed drug" is associated with increasingly challenging demands for compound amount, which often cannot be met by re-isolation from the respective plant sources. In this regard, existing alternatives for resupply are also discussed, including different biotechnology approaches and total organic synthesis. While the intrinsic complexity of natural product-based drug discovery necessitates highly integrated interdisciplinary approaches, the reviewed scientific developments, recent technological advances, and research trends clearly indicate that natural products will be among the most important sources of new drugs also in the future.

Nonprenylated Xanthones from Gentiana lutea, Frasera caroliniensis, and Centaurium erythraea as Novel Inhibitors of Vascular Smooth Muscle Cell Proliferation

Aberrant proliferation of vascular smooth muscle cells (VSMC) plays a major role in restenosis, the pathological renarrowing of the blood vessel lumen after surgical treatment of stenosis. Since available anti-proliferative pharmaceuticals produce unfavorable side effects, there is high demand for the identification of novel VSMC proliferation inhibitors. A natural product screening approach using a resazurin conversion assay enabled the identification of gentisin (1) from Gentiana lutea as a novel inhibitor of VSMC proliferation with an IC₅₀ value of 7.84 µM. Aiming to identify further anti-proliferative compounds, 13 additional nonprenylated xanthones, isolated from different plant species, were also tested. While some compounds showed no or moderate activity at 30 µM, 1-hydroxy-2,3,4,5-tetramethoxyxanthone (4), swerchirin (6), and methylswertianin (7) showed IC₅₀ values between 10.2 and 12.5 µM. The anti-proliferative effect of 1, 4, 6, and 7 was confirmed by the quantification of DNA synthesis (BrdU incorporation) in VSMC. Cell death quantification (determined by LDH release in the culture medium) revealed that the compounds are not cytotoxic in the investigated concentration range. In conclusion, nonprenylated xanthones are identified as novel, non-toxic VSMC proliferation inhibitors, which might contribute to the development of new therapeutic applications to combat restenosis.

Indirubin and Indirubin Derivatives for Counteracting Proliferative Diseases

Indirubin is the active component of Danggui Longhui Wan, a traditional Chinese medicine formulation. The encouraging clinical results from the 1980s obtained in chronic myelocytic leukemia patients treated with indirubin stimulated numerous studies on this compound. These investigations explored the use of indirubin in different types of cancer and reported the synthesis of novel derivatives with improved chemical and pharmacokinetic properties. In this paper, we review the impressive progress that has been made in elucidating the mechanistic understanding of how indirubin and its derivatives affect physiological and pathophysiological processes, mainly by inhibition of cell proliferation and induction of cell death. Furthermore, we survey the therapeutic use of these compounds in combating proliferative diseases such as cancer, restenosis, and psoriasis.

Human placenta-derived multipotent mesenchymal stromal cells involved in placental angiogenesis via the PDGF-BB and STAT3 pathways

We studied the smooth muscle cell differentiation capability of human placental multipotent mesenchymal stromal cells (hPMSCs) and identified how endothelial cells recruit hPMSCs participating in vessel formation. hPMSCs from term placentas were induced to differentiate into smooth muscle cells under induction conditions and different matrix substrates. We assessed endothelial cells from umbilical veins for platelet-derived growth factor (PDGF)-BB expression and to induce hPMSC PDGFR-beta and STAT3 activation. Endothelial cells were co-cultured with hPMSCs for in vitro angiogenesis. Cell differentiation ability was then further assessed by mouse placenta transplantation assay. hPMSCs can differentiate into smooth muscle cells; collagen type I and IV or laminin support this differentiation. Endothelial cells expressed significant levels of PDGF-BB and activated STAT3 transcriptional activity in hPMSCs. Endothelial cell-conditioned medium induced hPMSC migration, which was inhibited by STAT3 small interfering RNA transfection or by pretreatement with PDGFR-beta-blocking antibody but not by PDGFR-alpha-blocking antibody or isotype immunoglobulin G (IgG; P < 0.001). hPMSCs can incorporate into endothelial cells with tube formation and promote endothelial cells, forming capillary-like networks than endothelial cells alone (tube lengths: 12 024.1 ± 960.1 vs. 9404.2 ± 584.7 pixels; P < 0.001). Capillary-like networks were significantly reduced by hPMSCs pretreated with PDGFR-beta-blocking antibody but not by PDGFR-alpha-blocking antibody or isotype IgG (P < 0.001). Transplantation of hPMSCs into mouse placentas revealed incorporation of the hPMSCs into vessel walls, which expressed alpha-smooth muscle actin, calponin, and smooth muscle myosin (heavy chain) in vivo. In conclusion, endothelial cell-hPMSC interactions occur during vessel development of placenta. Placental endothelial cell-derived PDGF-BB recruits hPMSCs involved in vascular development via PDGFR-beta/STAT3 activation.

Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through G₀/G₁ to S phase of the cell cycle, as measured by [³H]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at G₀/G₁ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

Identification and characterization of [6]-shogaol from ginger as inhibitor of vascular smooth muscle cell proliferation

SCOPE

Vascular smooth muscle cell (VSMC) proliferation is involved in the pathogenesis of cardiovascular disease, making the identification of new counteracting agents and their mechanisms of action relevant. Ginger and its constituents have been reported to improve cardiovascular health, but no studies exist addressing a potential interference with VSMC proliferation.

METHODS AND RESULTS

The dichloromethane extract of ginger inhibited VSMC proliferation when monitored by resazurin metabolic conversion (IC50 = 2.5 μg/mL). The examination of major constituents from ginger yielded [6]-shogaol as the most active compound (IC50 = 2.7 μM). In the tested concentration range [6]-shogaol did not exhibit cytotoxicity toward VSMC and did not interfere with endothelial cell proliferation. [6]-shogaol inhibited DNA synthesis and induced accumulation of the VSMC in the G0 /G1 cell-cycle phase accompanied with activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2)/HO-1 pathway. Since [6]-shogaol lost its antiproliferative activity in the presence of the heme oxygenase-1 (HO-1) inhibitor tin protoporphyrin IX, HO-1 induction appears to contribute to the antiproliferative effect.

CONCLUSION

This study demonstrates for the first time inhibitory potential of ginger constituents on VSMC proliferation. The presented data suggest that [6]-shogaol exerts its antiproliferative effect through accumulation of cells in the G0 /G1 cell-cycle phase associated with activation of the Nrf2/HO-1 pathway.

Emerging translational approaches to target STAT3 signalling and its impact on vascular disease

Acute and chronic inflammation responses characterize the vascular remodelling processes in atherosclerosis, restenosis, pulmonary arterial hypertension, and angiogenesis. The functional and phenotypic changes in diverse vascular cell types are mediated by complex signalling cascades that initiate and control genetic reprogramming. The signalling molecule's signal transducer and activator of transcription 3 (STAT3) plays a key role in the initiation and continuation of these pathophysiological changes. This review highlights the pivotal involvement of STAT3 in pathological vascular remodelling processes and discusses potential translational therapies, which target STAT3 signalling, to prevent and treat cardiovascular diseases. Moreover, current clinical trials using highly effective and selective inhibitors of STAT3 signalling for distinct diseases, such as myelofibrosis and rheumatoid arthritis, are discussed with regard to their vascular (side-) effects and their potential to pave the way for a direct use of these molecules for the prevention or treatment of vascular diseases.

Scoparone interferes with STAT3-induced proliferation of vascular smooth muscle cells

Scoparone, which is a major constituent of Artemisia capillaries, has been identified as an anticoagulant, hypolipidemic, vasorelaxant, anti-oxidant and anti-inflammatory drug, and it is used for the traditional treatment of neonatal jaundice. Therefore, we hypothesized that scoparone could suppress the proliferation of VSMCs by interfering with STAT3 signaling. We found that the proliferation of these cells was significantly attenuated by scoparone in a dose-dependent manner. Scoparone markedly reduced the serum-stimulated accumulation of cells in the S phase and concomitantly increased the proportion of cells in the G0/G1 phase, which was consistent with the reduced expression of cyclin D₁, phosphorylated Rb and survivin in the VSMCs. Cell adhesion markers, such as MCP-1 and ICAM-1, were significantly reduced by scoparone. Interestingly, this compound attenuated the increase in cyclin D promoter activity by inhibiting the activities of both the WT and active forms of STAT3. Similarly, the expression of a cell proliferation marker induced by PDGF was decreased by scoparone with no change in the phosphorylation of JAK2 or Src. On the basis of the immunofluorescence staining results, STAT3 proteins phosphorylated by PDGF were predominantly localized to the nucleus and were markedly reduced in the scoparone-treated cells. In summary, scoparone blocks the accumulation of STAT3 transported from the cytosol to the nucleus, leading to the suppression of VSMC proliferation through G1 phase arrest and the inhibition of Rb phosphorylation. This activity occurs independent of the form of STAT3 and upstream of kinases, such as Jak and Src, which are correlated with abnormal vascular remodeling due to the presence of an excess of growth factors following vascular injury. These data provide convincing evidence that scoparone may be a new preventative agent for the treatment of cardiovascular diseases.

Capsaicin from chili ( Capsicum spp.) inhibits vascular smooth muscle cell proliferation

Accelerated vascular smooth muscle cell (VSMC) proliferation is implied in cardiovascular disease and significantly contributes to vessel lumen reduction following surgical interventions such as percutaneous transluminal coronary angioplasty or bypass surgery. Therefore, identification and characterization of compounds and mechanisms able to counteract VSMC proliferation is of potential therapeutic relevance. This work reveals the anti-proliferative effect of the natural product capsaicin from Capsicum spp. by quantification of metabolic activity and DNA synthesis in activated VSMC. The observed in vitro activity profile of capsaicin warrants further research on its mechanism of action and potential for therapeutic application.

Antiplatelet action of indirubin-3'-monoxime through suppression of glycoprotein VI-mediated signal transduction: a possible role for ERK signaling in platelets

We investigated the antiplatelet activity of indirubin-3'-monoxime (I3O) and the underlying mechanisms. In a rat carotid artery injury model, oral administration (20 mg/kg/day) of I3O for 3 days significantly prolonged occlusion time, and ADP- and collagen-induced platelet aggregation. In washed platelets in vitro, I3O potently inhibited collagen-induced platelet aggregation by suppressing phospholipase Cγ2 (PLCγ2) phosphorylation, subsequently blocking diacylglycerol and arachidonic acid (AA) formation, P-selectin secretion and the production of thromboxane B2. Platelet aggregation induced by phorbol-12-myristate 13-acetate, a protein kinase C (PKC) activator, was inhibited by I3O. Both I3O and U0126, an extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor, markedly reduced collagen-induced phosphorylation of ERK1/2 and p47, resulting in the blockade of cyclooxygenase (COX)-mediated AA metabolite production in AA-treated platelets. I3O suppressed phosphorylation of JNK, p38, GSK-3β, and AKT. I3O inhibited glycoprotein VI (GPVI), as a collagen receptor, by suppressing the phosphorylation of tyrosine kinase Syk of GPVI and the phosphorylation of PLCγ2 and ERK1/2 stimulated by convulxin, as a specific stimulator. Our results indicate that an antiplatelet effect of I3O is due to the suppression of GPVI-mediated signaling pathways. In collagen-stimulated platelets, ERK1/2 phosphorylation is adenylyl cyclase-dependent and leads to the modulation of PKC-p47 signaling and COX-1-mediated AA-metabolic pathways.

Indirubin-3'-monoxime exerts a dual mode of inhibition towards leukotriene-mediated vascular smooth muscle cell migration

Aims

The small molecule indirubin-3′-monoxime (I3MO) has been shown to inhibit vascular smooth muscle cell (VSMC) proliferation and neointima formation in vivo. The influence of I3MO on VSMC migration and vascular inflammation, two additional key players during the onset of atherosclerosis and restenosis, should be investigated.

Methods and results

We examined the influence of I3MO on VSMC migration, with focus on monocyte-derived leukotrienes (LTs) and platelet-derived growth factors (PDGFs) as elicitors. Exogenous LTB4 and cysteinyl leukotrienes as well as LT-enriched conditioned medium of activated primary human monocytes induced VSMC migration, which was inhibited by I3MO. I3MO also blunted migration of VSMC stimulated with the PDGF, the strongest motogen tested in this study. Induction of haem oxygenase 1 accounted for this anti-migratory activity of I3MO in VSMC. Notably, I3MO not only interfered with the migratory response in VSMC, but also suppressed the production of pro-migratory LT in monocytes. Conditioned media from monocytes that were activated in the presence of I3MO failed to induce VSMC migration. In cell-based and cell-free assays, I3MO selectively inhibited 5-lipoxygenase (5-LO), the key enzyme in LT biosynthesis, with an IC₅₀ in the low micromolar range.

Conclusion

Our study reveals a novel dual inhibitory mode of I3MO on LT-mediated VSMC migration: (i) I3MO interferes with pro-migratory signalling in VSMC and (ii) I3MO suppresses LT biosynthesis in monocytes by direct inhibition of 5-LO. These inhibitory actions on both migratory stimulus and response complement the previously demonstrated anti-proliferative properties of I3MO and may further promote I3MO as promising vasoprotective compound.

GSTpi protects against angiotensin II-induced proliferation and migration of vascular smooth muscle cells by preventing signal transducer and activator of transcription 3 activation

Angiotensin II (Ang II)-elicited excessive proliferation, hypertrophy and migration of vascular smooth muscle cells (VSMCs) are vital to the pathogenesis of atheroclerosis. Glutathione S-transferase pi (GSTpi) exists extensively in various kinds of cells and protects cells against different stresses. However, knowledge remains limited about what GSTpi acts in VSMCs. We investigated the effect of GSTpi on Ang II-induced VSMC proliferation, hypertrophy and migration and its latent mechanism. Overexpression and RNAi experiments demonstrated that GSTpi inhibited Ang II-induced proliferation, hypertrophy and migration of VSMCs and arrested progression of cell cycle from G0/G1 to S phase. Immunoprecipitation, mass spectrometry and confocal microscopy analyses showed that GSTpi directly associated with signal transducer and activator of transcription 3 (STAT3) to prevent Ang II-triggered binding of Src to STAT3 and thus suppressed Ang II-stimulated phosphorylation and nuclear translocation of STAT3, as well as cyclin D1 expression. In contrast, GSTpi didn't affect Ang II-activated extracellular signal-regulated kinase (ERK1/2). GSTpi acts as a negative regulator to prevent Ang II-triggered proliferative signaling in VSMCs, suggesting that it may protect vessels against the stresses associated with atherosclerosis formation.

12/15-lipoxygenase contributes to platelet-derived growth factor-induced activation of signal transducer and activator of transcription 3

We showed previously that the small molecule indirubin-3′-monoxime (I3MO) prevents vascular smooth muscle cell (VSMC) proliferation by selectively inhibiting signal transducer and activator of transcription 3 (STAT3). Looking for the underlying upstream molecular mechanism, we here reveal the important role of reactive oxygen species (ROS) for PDGF-induced STAT3 activation in VSMC. We show that neither NADPH-dependent oxidases (Noxes) nor mitochondria, but rather 12/15-lipoxygenase (12/15-LO) are pivotal ROS sources involved in the redox-regulated signal transduction from PDGFR to STAT3. Accordingly, pharmacological and genetic interference with 12/15-LO activity selectively inhibited PDGF-induced Src activation and STAT3 phosphorylation. I3MO is able to blunt PDGF-induced ROS and 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) production, indicating an inhibitory action of I3MO on 12/15-LO and consequently on STAT3. We identify 12/15-LO as a hitherto unrecognized signaling hub in PDGF-triggered STAT3 activation and show for the first time a negative impact of I3MO on 12/15-LO.

An indirubin derivative, indirubin-3'-monoxime suppresses oral cancer tumorigenesis through the downregulation of survivin

Oral cancer is the fourth most common cause of death from cancer in Taiwanese men. Indirubin-3'-monoxime (I3M), a potent cyclin-dependent kinase inhibitor, has therapeutic effects in other cancer cells. In this study, we carried out in vitro assays to test cell viability, cell cycle progression, apoptosis, cell migration and invasion in this cancer type. In addition, using an oral tumorigenic animal model, we examined target gene and protein expression using real time qPCR, immunoblotting and immunohistochemical staining. Our results demonstrate that I3M has an anti-proliferative effect in both Cal-27 and HSC-3 oral cancer cell lines and that treatment of Cal-27 and HSC-3 cells with I3M results in apoptosis through the activation of cytochrome c. In addition, I3M interrupts the cell cycle in Cal-27 cells in a dose-dependent manner by arresting cells in the G2/M phase. We also found that I3M suppresses migration and invasion in Cal-27 cells by inhibiting the expression of focal adhesion kinase, urokinase-type plasminogen inhibitor, and matrix metalloproteinase 9. Moreover, we identified survivin as a target protein in I3M-treated oral cancer cells. Using an oral cancer mouse model, we demonstrate that topical application of an adhesive gel composed of I3M and poly(vinyl alcohol) (I3M/PVA) has dose-dependent anti-tumorigenic effects. Following treatment, the expression of survivin protein and mRNA was downregulated in cancerous tissues. Furthermore, plasma survivin levels were also reduced in the I3M-treated mice. These results suggest that topical application of I3M, a drug synthesized from indirubin, which is found in Qing-Dai - has therapeutic potential for treating oral cancer.

Sirolimus-loaded stealth colloidal systems attenuate neointimal hyperplasia after balloon injury: a comparison of phospholipid micelles and liposomes

Restenosis after angioplasty remains a serious complication in clinical cardiology. This study aims to investigate the stealth colloidal systems for local intra-arterial drug delivery. Micelles from polyethylene glycol conjugated with phosphatidylethanolamine and PEGylated liposomes loaded with sirolimus were prepared and characterized with regard to their loading efficiency, particle size distribution, zeta potential, morphology, nuclear magnetic resonance spectroscopy, drug release profile and stability. The antirestenotic effects of the sirolimus-loaded micelles (14 nm) and liposomes (90 nm) were evaluated and compared in the rat carotid injury model following local intravascular delivery. In comparison to control groups, treatment of balloon injured rats with drug loaded micelles and nanoliposomes significantly reduced vascular stenosis by 42% and 19%, respectively (P<0.05). In addition, the luminal area was significantly enlarged by 39% and 60% following treatment with sirolimus-loaded liposomes and micelles, respectively (P<0.05). Immunohistochemistry revealed that sirolimus-loaded nanocarriers suppressed cell proliferation (Ki67-positive cells) as compared to control groups without affecting the density of smooth muscle actin staining. These results suggest that both colloidal nanocarriers could serve as effective intramural drug delivery systems for the treatment of restenosis; however, phospholipid based micelles provided better antirestenotic effects than PEGylated liposomes.

5,8-Dimethoxy-2-Nonylamino-Naphthalene-1,4-Dione Inhibits Vascular Smooth Muscle Cell Proliferation by Blocking Autophosphorylation of PDGF-Receptor β

As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced [(3)H]-thymidine incorporation, cell cycle progression from G0/G1 to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptorβ(PDGF-Rβ) enhanced by PDGF at Tyr(579), Tyr(716), Tyr(751), and Tyr(1021) residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and PLCγ1. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-Rβ autophosphorylation, and subsequently PDGF-Rβ-mediated downstream signaling pathways.

Glial responses after chorda tympani nerve injury

The chorda tympani (CT) nerve innervates lingual taste buds and is susceptible to damage during dental and inner ear procedures. Interruption of the CT results in a disappearance of taste buds, which can be accompanied by taste disturbances. Because the CT usually regenerates to reinnervate taste buds successfully within a few weeks, a persistence of taste disturbances may indicate alterations in central nervous function. Peripheral injury to other sensory nerves leads to glial responses at central terminals, which actively contribute to abnormal sensations arising from nerve damage. Therefore, the current study examined microglial and astrocytic responses in the first central gustatory relay, the nucleus of the solitary tract (nTS), after transection of the CT. Damage to the CT resulted in significant microglial responses in terms of morphological reactivity and an increased density of microglial cells from 2 to 20 days after injury. This increased microglial population resulted primarily from microglial proliferation from 1.5 to 3 days, which was supplemented by microglial migration within subdivisions of the nTS between days 2 and 3. Unlike other nerve injuries, CT injury did not result in recruitment of bone marrow-derived precursors. Astrocytes also reacted in the nTS with increased levels of glial fibrillary acidic protein (GFAP) by 3 days, although none showed evidence of cell division. GFAP levels remained increased at 30 days, by which time microglial responses had resolved. These results show that nerve damage to the CT results in central glial responses, which may participate in long-lasting taste alterations following CT lesion.

Perivascular innate immune events modulate early murine vein graft adaptations

OBJECTIVE

Innate immunity drives numerous cardiovascular pathologies. Vein bypass grafting procedures are frequently accompanied by low-grade wound contamination. We hypothesized that a peri-graft innate immune challenge, via an outside-in route, augments inflammatory responses, which subsequently drive a component of negative vein graft wall adaptations; moreover, adipose tissue mediates this immune response.

METHODS

The inferior vena cava from a donor mouse was implanted into the common carotid artery of a recipient mouse utilizing a validated cuff technique (9-week-old male C57BL/6J mice). Slow-release low-dose (5 μg) lipopolysaccharide (LPS) (n = 9) or vehicle (n = 9) was applied peri-graft; morphologic analysis was completed (day 28). In parallel, vein-grafted mice received peri-graft LPS (n = 12), distant subcutaneous LPS (n = 6), or vehicle (n = 12), then day-1 and -3 harvest of grafts and adipose tissue for cytokines and toll-like receptor (TLR) signaling mRNA expression (qRT-PCR).

RESULTS

All recipient mice survived, and all vein grafts were patent. Acute low-dose local LPS challenge enhanced vein graft lumen loss (P = .04) and tended to augment intimal hyperplasia (P = .06). The surgical trauma of vein grafting universally upregulated key pro- and anti-inflammatory mediators within the day-1 graft wall, but varied on TLR signaling gene expression. Local and distant LPS accentuated these patterns until at least postoperative day 3. LPS challenge enhanced the inflammatory response in adipose tissue (locally > distantly); local LPS upregulated adipose TLR-4 dramatically.

CONCLUSIONS

Perivascular and distant inflammatory challenges potentiate the magnitude and duration of inflammatory responses in the early vein graft wall, negatively modulating wall adaptations, and thus, potentially contribute to vein graft failure. Furthermore, surgery activates innate immunity in adipose tissue, which is augmented (regionally > systemically) by LPS. Modulation of these local and distant inflammatory signaling networks stands as a potential strategy to enhance the durability of vascular interventions such as vein grafts.

Identification of ostruthin from Peucedanum ostruthium rhizomes as an inhibitor of vascular smooth muscle cell proliferation

Inhibition of vascular smooth muscle cell (VSMC) proliferation is of substantial interest in combating cardiovascular disease. A dichloromethane extract from the rhizomes of Peucedanum ostruthium, a traditionally used Austrian medicinal plant with anti-inflammatory properties, was examined for a putative antiproliferative activity in rat aortic VSMC. This extract inhibited serum (10%)-induced VSMC proliferation concentration dependently. Further identification and biological testing of its major constituents revealed that the coumarin ostruthin (7) is the major antiproliferative substance. In summary, a new bioactivity of P. ostruthium rhizomes is described, and 7 has been identified as the responsible compound.

15-Lipoxygenase-1-enhanced Src-Janus kinase 2-signal transducer and activator of transcription 3 stimulation and monocyte chemoattractant protein-1 expression require redox-sensitive activation of epidermal growth factor receptor in vascular wall remodeling

To understand the mechanisms by which 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) activates signal transducer and activator of transcription 3 (STAT3), we studied the role of epidermal growth factor receptor (EGFR). 15(S)-HETE stimulated tyrosine phosphorylation of EGFR in a time-dependent manner in vascular smooth muscle cells (VSMCs). Interference with EGFR activation blocked 15(S)-HETE-induced Src and STAT3 tyrosine phosphorylation, monocyte chemoattractant protein-1 (MCP-1) expression and VSMC migration. 15(S)-HETE also induced tyrosine phosphorylation of Janus kinase 2 (Jak2) in VSMCs, and its inhibition substantially reduced STAT3 phosphorylation, MCP-1 expression, and VSMC migration. In addition, Src formed a complex with EGFR and Jak2, and its inhibition completely blocked Jak2 and STAT3 phosphorylation, MCP-1 expression, and VSMC migration. 15(S)-HETE induced the production of H(2)O(2) via an NADPH oxidase-dependent manner and its scavengers, N-acetyl cysteine (NAC) and catalase suppressed 15(S)-HETE-stimulated EGFR, Src, Jak2, and STAT3 phosphorylation and MCP-1 expression. Balloon injury (BI) induced EGFR, Src, Jak2, and STAT3 phosphorylation, and inhibition of these signaling molecules attenuated BI-induced MCP-1 expression and smooth muscle cell migration from the medial to the luminal surface resulting in reduced neointima formation. In addition, inhibition of EGFR blocked BI-induced Src, Jak2, and STAT3 phosphorylation. Similarly, interference with Src activation suppressed BI-induced Jak2 and STAT3 phosphorylation. Furthermore, adenovirus-mediated expression of dnJak2 also blocked BI-induced STAT3 phosphorylation. Consistent with the effects of 15(S)-HETE on the activation of EGFR-Src-Jak2-STAT3 signaling in VSMCs in vitro, adenovirus-mediated expression of 15-lipoxygenase 1 (15-Lox1) enhanced BI-induced EGFR, Src, Jak2, and STAT3 phosphorylation leading to enhanced MCP-1 expression in vivo. Blockade of Src or Jak2 suppressed BI-induced 15-Lox1-enhanced STAT3 phosphorylation, MCP-1 expression, and neointima formation. In addition, whereas dominant negative Src blocked BI-induced 15-Lox1-enhanced Jak2 phosphorylation, dnJak2 had no effect on Src phosphorylation. Together, these observations demonstrate for the first time that the 15-Lox1-15(S)-HETE axis activates EGFR via redox-sensitive manner, which in turn mediates Src-Jak2-STAT3-dependent MCP-1 expression leading to vascular wall remodeling.