Methylene Blue Delivery Mediated by Focused Ultrasound-Induced Blood-Brain Barrier Disruption Reduces Neural Damage and Amyloid-Beta Plaques by AQP-4 Upregulation.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, causing progressive cognitive decline, memory impairment, and neurological deficits. Methylene blue (MB), an antioxidant, has emerged as a potential drug for the treatment of AD owing to its cognitive improvement and neuroprotective functions. Despite the small molecular size of MB, which can cross the BBB, the therapeutic effective dosage using a BBB-permeable delivery system in a specific brain localization remains unclear. In this study, we presented magnetic resonance-guided focused ultrasound (MRgFUS) as a delivery system to enhance BBB permeability for the effective treatment of AD. MRgFUS using two ultrasound intensities (0.25 and 0.32 MPa) was used to intravenously deliver MB to the hippocampal region. Compared with treatment with 0.25 MPa FUS, treatment with 0.32 MPa FUS significantly enhanced MB brain accumulation. Deposition of amyloid-ß (Aß) plaques and neural cell damage was significantly reduced in 0.32 MPa FUS/MB-treated APP/PS1 mice. Furthermore, aquaporin-4 expression increased significantly in the 0.32 MPa FUS and 0.32 MPa FUS/MB groups without glial fibrillary acidic protein activation. The results from this study demonstrate that FUS improved MB delivery to the brain, and FUS/MB combination treatment reduced the number of Aß plaques. This study revealed the potential of FUS-BBBD as an effective strategy to enhance the efficacy of therapeutic drugs for AD.

A local difference in blood-brain barrier permeability in the caudate putamen and thalamus of a rat brain induced by focused ultrasound.

A blood-brain barrier (BBB) opening induced by focused ultrasound (FUS) has been widely studied as an effective way of treating brain diseases. We investigate the effect of ultrasound's incidence angle at caudate putamen (Cp) and thalamus (Th) of the rat brain by inducing the same power of focused ultrasound that corresponds to the acoustic pressure of 0.65 MPa in free field. The BBB permeability (Ktrans) was quantitatively evaluated with dynamic contrast-enhanced magnetic resonance imaging. The group averaged (n = 11) maximum Ktrans at Cp (0.021 ± 0.012 min-1) was 1.39 times smaller than the Ktrans of Th (0.029 ± 0.01 min-1) with p = 0.00343. The group averaged (n = 6) ultrasound's incidence angles measured using the computed tomography image of rat skulls were compared with the maximum Ktrans and showed a negatively linear relation R2 = 0.7972). The maximum acoustic pressure computed from the acoustic simulation showed higher average acoustic pressures at Th (0.37 ± 0.02 MPa) compared to pressures at Cp (0.32 ± 0.01 MPa) with p = 0.138 × 10-11. More red blood cell were observed at the Th region compared to the Cp region in the tissue staining. These results indicate that localized characteristics of the sonication target within the subject should be considered for safer and more efficient BBB disruption induced by FUS.

An advanced focused ultrasound protocol improves the blood-brain barrier permeability and doxorubicin delivery into the rat brain.

Despite the recent development of a focused ultrasound (FUS) technique for disrupting the blood-brain barrier (BBB) and enabling the delivery of drugs into the targeted brain region, different sonication protocols have not been fully explored. In this study, we suggest a simple and cost-effective protocol that improves the BBB permeability and drug delivery without damaging the tissue. In this protocol, called "FUS+BBBD protocol", an additional FUS stimulation without microbubbles ("FUS protocol"; 0.5, 1.0, or 2.0MPa acoustic pressure, 10ms tone burst, 1Hz pulse repetition frequency, 120s total duration) is applied prior to the conventional BBB disruption with microbubbles ("BBBD protocol"; 0.6∼0.72MPa acoustic pressure, 10ms tone burst, 1Hz pulse repetition frequency, 120s total duration). With the "FUS+BBBD protocol", the magnetic resonance signal intensity and doxorubicin delivery at the targeted brain region were increased by 1.59 and 1.75 times at an FUS intensity of 1.0MPa, respectively, compared to the conventional BBBD. Other conditions also increase the drug delivery, but the increase was smaller than that at 1.0MPa (1.15 times for 0.5MPa and 1.60 times for 2.0MPa). The H&E histopathological analysis of the sonicated brain region using the proposed "FUS+BBBD protocol" showed no significant brain tissue damage at a FUS intensity of 0.5 and 1.0MPa. However, region cavities due to the damage were observed after an FUS intensity of 2.0MPa. These results suggest that the 1.0MPa "FUS+BBBD protocol" increases the BBB permeability and enhances the drug delivery efficiency without noticeable brain tissue damage, compared with the conventional BBBD. Although further studies are needed to determine the underlying mechanism of this effect, drugs that have been reported to be effective in the treatment of brain disease but had limited use due to severe systemic side effects will benefit from the enhanced drug delivery of "FUS+BBBD protocol". Furthermore, the suggested protocol may facilitate the development of new strategies in clinical trials to treat brain disorders with improved drug delivery and safety.

Inhibitory effects of pentacyclic triterpenoids from Astilbe rivularis on TGFBIp-induced inflammatory responses in vitro and in vivo.

Transforming growth factor ß induced protein (TGFBIp) is an extracellular matrix protein which expression in several cell types is greatly increased by TGF-ß. TGFBIp is released by human umbilical vein endothelial cells (HUVECs), and functions as a mediator of experimental sepsis. Pentacyclic triterpenoids bearing a carboxyl group at C-27 position, 3ß,6α-dihydroxyolup-20(29)-ene (1), 3ß,6ß-dihydroxyolean-12-en-27-oic acid (2) and 3ß,24-dihydroxyolean-12-en-27-oic acid (3), are representative bioactive molecules in the genus Astilbe that possess cytotoxic, anti-inflammatory and wounds healing activities. Based on the biological effects of C-27 carboxylated pentacyclic triterpenoids, we investigated the anti-inflammatory effects of compounds 1-3 against TGFBIp-mediated vascular inflammatory responses. The anti-inflammatory activities of compounds 1-3 were determined by measuring permeability, leukocytes adhesion and migration, and activation of pro-inflammatory proteins in TGFBIp-activated human HUVECs and mice. We found that compounds 1-3 inhibited TGFBIp-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of neutrophils to human endothelial cells. Each compound also suppressed TGFBIp-induced hyperpermeability and leukocyte migration in vivo. These results suggest that compounds 1-3 possess anti-inflammatory functions by inhibiting hyperpermeability, expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.

Suppressive effects of three diketopiperazines from marine-derived bacteria on TGFBIp-mediated septic responses in human endothelial cells and mice.

Diketopiperazine is a naturally occurring cyclic dipeptide found from diverse living organisms. The compounds in this structure class have been known with a broad spectrum of bioactivities including anti-inflammatory activities. Transforming growth factor ß-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGF-ß. TGFBIp is released by human umbilical vein endothelial cells and functions as a mediator of experimental sepsis. Here, three (1-3) of diketopiperazines were isolated from two strains of marine-derived bacteria and we hypothesized that 1-3 could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here, we investigated the anti-septic effects and underlying mechanisms of 1-3 against TGFBIp-mediated septic responses. 1-3 effectively inhibited lipopolysaccharide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, 1-3 suppressed cecal ligation and puncture (CLP)-induced sepsis lethality and pulmonary injury. In conclusion, 1-3 suppressed TGFBIp-mediated and CLP-induced septic responses. Therefore, 1-3 could be a potential therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the TGFBIp signaling pathway.

Suppressive effects of polyozellin on TGFBIp-mediated septic responses in human endothelial cells and mice.

Polyozellus multiplex (Thelephoraceae) is a wild mushroom in Korea and Japan and is usually harvested in early autumn for food. Polyozellin, a major constituent of the edible mushroom P multiplex, has been known to exhibit biological activities such as antioxidative and anti-inflammatory effects. Transforming growth factor ß-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGF-ß. TGFBIp is released by human umbilical vein endothelial cells and functions as a mediator of experimental sepsis. We hypothesized that polyozellin could reduce TGFBIp-mediated severe inflammatory responses in human endothelial cells and mice. Here, we investigated the antiseptic effects and underlying mechanisms of polyozellin against TGFBIp-mediated septic responses. Polyozellin effectively inhibited lipopolysaccharide-induced release of TGFBIp and suppressed TGFBIp-mediated septic responses. In addition, polyozellin suppressed cecal ligation and puncture-induced sepsis lethality and pulmonary injury. In conclusion, polyozellin suppressed TGFBIp-mediated and cecal ligation and puncture-induced septic responses. Therefore, polyozellin could be a potential therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the TGFBIp signaling pathway.

Anti-septic effects of dabrafenib on HMGB1-mediated inflammatory responses.

A nucleosomal protein, high mobility group box 1 (HMGB1) is known to be a late mediator of sepsis. Dabrafenib is a B-Raf inhibitor and initially used for the treatment of metastatic melanoma therapy. Inhibition of HMGB1 and renewal of vascular integrity is appearing as an engaging therapeutic strategy in the administration of severe sepsis or septic shock. Here, we examined the effects of dabrafenib (DAB) on the modulation of HMGB1-mediated septic responses. DAB inhibited the release of HMGB1 and downregulated HMGB1-dependent inflammatory responses by enhancing the expressions of cell adhesion molecules (CAMs) in human endothelial cells. In addition, treatment with DAB inhibited the HMGB1 secretion by CLP and sepsis-related mortality and pulmonary injury. This study demonstrated that DAB could be alternative therapeutic options for sepsis or septic shock via the inhibition of the HMGB1 signaling pathway. [BMB Reports 2016; 49(4): 214-219].

Inhibitory effect of polyozellin on secretory group IIA phospholipase A2.

The expression of secretory group IIA phospholipase A2 (sPLA2-IIA) is enhanced by development of inflammatory disorders. In this study, sPLA2-IIA expression was induced in the lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells and mice to evaluate the effect of polyozellin. Polyozellin, a major constituent of a Korea edible mushroom Polyozellus multiplex, has been known to exhibit the biological activities such as anti-oxidative and anti-inflammatory effects. Polyozellin remarkably suppressed the LPS-mediated protein expression and activity of sPLA2-IIA via inhibition of phosphorylation of cytosolic phospholipase A2 and extracellular signal-regulated kinase 1/2. These results demonstrated that polyozellin might play an important role in the modulation of sPLA2-IIA expression and activity in response to the inflammatory diseases.

Flavanones and Chromones from Salicornia herbacea Mitigate Septic Lethality via Restoration of Vascular Barrier Integrity.

Salicornia herbacea is an annual halophytic glasswort that has been employed as a culinary vegetable, salad, and traditional medicinal resource. Chemical investigation of the aerial parts of S. herbacea led to the isolation of two new (1, 2) and known (3) flavanones as well as a new nature-derived (4) and two known chromone derivatives (5, 6). These purified compounds were evaluated for their suppressive potentials against the release of high-mobility group box 1 protein (HMGB1), which has captured attention as a viable target for alleviating serious septic manifestations or septicemia. The phenolic compounds improved the survival rates of cecal ligation and puncture operation (CLP) in murine models, simulating severe septic shock and its related complications, to 40-60%. These results collectively validate that flavanone- and chromone-based secondary metabolites may serve as prospective prodrugs or food additives that may be commercialized for the control of septic complications and lethality.

Anti-inflammatory effects of vicenin-2 and scolymoside in vitro and in vivo.

AIM AND OBJECTIVE: Two structurally related flavonoids found in Cyclopia subternata, namely vicenin-2 and scolymoside, were examined for its effects on inflammatory responses by monitoring the effects of vicenin-2 and scolymoside on lipopolysaccharide (LPS)-mediated vascular inflammatory responses. METHODS: The anti-inflammatory activities of vicenin-2 and scolymoside were determined by measuring permeability,monocytes adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated HUVECs and mice. RESULTS: We found that post-treatment of each compound inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs), and adhesion/transendothelial migration of human neutrophils to human endothelial cells. Each compound induced potent inhibition of phorbol-12-myristate 13-acetate (PMA) and LPS-induced endothelial cell protein C receptor (EPCR)shedding. It also suppressed LPS-induced hyperpermeability and leukocytes migration in vivo. Furthermore,each compound suppressed the production of tumor necrosis factor-α (TNF-α) or Interleukin (IL)-6 and the activation of nuclear factor-κB (NF-κB) or extracellular regulated kinases (ERK) 1/2 by LPS. Moreover, posttreatment with each compound resulted in reduced LPS-induced lethal endotoxemia. CONCLUSION: Vicenin-2 and scolymoside possess anti-inflammatory functions by inhibiting hyperpermeability,expression of CAMs, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.

Novel insight into drug repositioning: Methylthiouracil as a case in point.

Drug repositioning refers to the development of existing drugs for new indications. These drugs may have (I) failed to show efficacy in late stage clinical trials without safety issues; (II) stalled in the development for commercial reasons; (III) passed the point of patent expiry; or (IV) are being explored in new geographic markets. Over the past decade, pressure on the pharmaceutical industry caused by the 'innovation gap' owing to rising development costs and stagnant product output have become major reasons for the growing interest in drug repositioning. Companies that offer a variety of broad platforms for identifying new indications have emerged; some have been successful in building their own pipelines of candidates with reduced risks and timelines associated with further clinical development. The business models and platforms offered by these companies will be validated if they are able to generate positive proof-of-concept clinical data for their repositioned compounds. This review describes the strategy of biomarker-guided repositioning of chemotherapeutic drugs for inflammation therapy, considering the repositioning of methylthiouracil (MTU), an antithyroid drug, as a potential anti-inflammatory reagent.

Ameliorative effect of methylthiouracil on TGFBIp-induced septic responses.

The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases. Transforming growth factor ß-induced protein (TGFBIp) is an extracellular matrix protein whose expression in several cell types is greatly increased by TGF-ß. TGFBIp is released by human umbilical vein endothelial cells (HUVECs), and functions as a mediator of experimental sepsis. Here, we investigated the anti-septic effects and underlying mechanisms of methylthiouracil (MTU), used as antithyroid drug, against TGFBIp-mediated septic responses in HUVECs and mice. The anti-inflammatory activities of MTU were determined by measuring permeability, human neutrophils adhesion and migration, and activation of pro-inflammatory proteins in TGFBIp-activated HUVECs and mice. According to the results, MTU effectively inhibited lipopolysaccharide-induced release of TGFBIp, and suppressed TGFBIp-mediated septic responses, such as hyperpermeability, adhesion and migration of leukocytes, and expression of cell adhesion molecules. In addition, MTU suppressed CLP-induced sepsis lethality and pulmonary injury. Collectively, these results indicate that MTU could be a potential therapeutic agent for treatment of various severe vascular inflammatory diseases via inhibition of the TGFBIp signaling pathway.

Antitcoagulant and antiplatelet activities of scolymoside.

Cyclopia subternata is a medicinal plant commonly used in traditional medicine to relieve pain. Here, the anticoagulant effects of scolymoside, an active compound in C. subternata, were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of thrombin and activated factor X (FXa). The effects of scolymoside on plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) expression were evaluated in tumor necrosis factor (TNF)-α-activated human endothelial cells. Treatment with scolymoside resulted in prolonged aPTT and PT and the inhibition of thrombin and FXa activities and production. In addition, scolymoside inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. Scolymoside also elicited anticoagulant effects in mice, including a significant reduction in the PAI-1 to t-PA ratio. Collectively, these findings indicate that scolymoside possesses anticoagulant activities and could be developed as a novel anticoagulant.