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Amato F, Strotmann R, Castello R, Bruns R, Ghori V, Johne A, Berghoff K, Venkatakrishnan K, Terranova N. Explainable machine learning prediction of edema adverse events in patients treated with tepotinib. Clin Transl Sci 2024; 17:e70010. [PMID: 39222377 PMCID: PMC11368086 DOI: 10.1111/cts.70010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 07/05/2024] [Accepted: 08/04/2024] [Indexed: 09/04/2024] Open
Abstract
Tepotinib is approved for the treatment of patients with non-small-cell lung cancer harboring MET exon 14 skipping alterations. While edema is the most prevalent adverse event (AE) and a known class effect of MET inhibitors including tepotinib, there is still limited understanding about the factors contributing to its occurrence. Herein, we apply machine learning (ML)-based approaches to predict the likelihood of occurrence of edema in patients undergoing tepotinib treatment, and to identify factors influencing its development over time. Data from 612 patients receiving tepotinib in five Phase I/II studies were modeled with two ML algorithms, Random Forest, and Gradient Boosting Trees, to predict edema AE incidence and severity. Probability calibration was applied to give a realistic estimation of the likelihood of edema AE. Best model was tested on follow-up data and on data from clinical studies unused while training. Results showed high performances across all the tested settings, with F1 scores up to 0.961 when retraining the model with the most relevant covariates. The use of ML explainability methods identified serum albumin as the most informative longitudinal covariate, and higher age as associated with higher probabilities of more severe edema. The developed methodological framework enables the use of ML algorithms for analyzing clinical safety data and exploiting longitudinal information through various covariate engineering approaches. Probability calibration ensures the accurate estimation of the likelihood of the AE occurrence, while explainability tools can identify factors contributing to model predictions, hence supporting population and individual patient-level interpretation.
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Affiliation(s)
- Federico Amato
- Swiss Data Science Center (EPFL and ETH Zurich)LausanneSwitzerland
| | | | - Roberto Castello
- Swiss Data Science Center (EPFL and ETH Zurich)LausanneSwitzerland
| | - Rolf Bruns
- The healthcare business of Merck KGaADarmstadtGermany
| | - Vishal Ghori
- Ares Trading S.A., Eysins, Switzerland, an affiliate of Merck KGaA, DarmstadtGermany
| | - Andreas Johne
- The healthcare business of Merck KGaADarmstadtGermany
| | | | | | - Nadia Terranova
- Quantitative PharmacologyAres Trading S.A., Lausanne, Switzerland, an affiliate of Merck KGaADarmstadtGermany
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2
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Huang M, Liu Y, Cheng Y, Dai W. Role of inflammatory biomarkers in mediating the effect of lipids on spontaneous intracerebral hemorrhage: a two-step, two-sample Mendelian randomization study. Front Neurol 2024; 15:1411555. [PMID: 39170073 PMCID: PMC11337198 DOI: 10.3389/fneur.2024.1411555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/29/2024] [Indexed: 08/23/2024] Open
Abstract
Background Spontaneous intracerebral hemorrhage (sICH) is a form of stroke with high mortality rates and significant neurological implications for patients. Abnormalities in lipid metabolism have been implicated in various cardiovascular diseases, yet their relationship with sICH remains insufficiently explored, particularly concerning their association with inflammatory factors. Methods Employing a two-sample, two-step Mendelian Randomization approach, combined with data from GWAS datasets, to investigate the causal relationship between plasma lipid levels and sICH. Additionally, the role of inflammatory factors in this relationship was examined, and sensitivity analyses were conducted to ensure the robustness of the results. Results The results indicate a significant causal relationship between 19 plasma lipid metabolites and sICH. Furthermore, mediation analysis revealed that three distinct lipids, namely Sterol ester (27:1/20:2), Phosphatidylcholine (16:0_20:4), and Sphingomyelin (d34:1), exert their influence on sICH through inflammatory factors. TRAIL (OR: 1.078, 95% CI: 1.016-1.144, p = 0.013) and HGF (OR: 1.131, 95% CI: 1.001-1.279, p = 0.049) were identified as significant mediators. Conclusion This study provides new evidence linking abnormalities in lipid metabolism with sICH and elucidates the role of inflammatory factors as mediators. These findings contribute to a better understanding of the pathogenesis of sICH and offer novel insights and therapeutic strategies for its prevention and treatment.
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Affiliation(s)
- Mingsheng Huang
- Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yiheng Liu
- Department of Cardiology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuan Cheng
- Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Weiran Dai
- Department of Cardiology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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3
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Xiong W, Hietala SF, Nyberg J, Papasouliotis O, Johne A, Berghoff K, Goteti K, Dong J, Girard P, Venkatakrishnan K, Strotmann R. Exposure-response analyses for the MET inhibitor tepotinib including patients in the pivotal VISION trial: support for dosage recommendations. Cancer Chemother Pharmacol 2022; 90:53-69. [PMID: 35771259 PMCID: PMC9300558 DOI: 10.1007/s00280-022-04441-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 05/10/2022] [Indexed: 11/24/2022]
Abstract
Purpose Tepotinib is a highly selective MET inhibitor approved for treatment of non-small cell lung cancer (NSCLC) harboring METex14 skipping alterations. Analyses presented herein evaluated the relationship between tepotinib exposure, and efficacy and safety outcomes. Methods Exposure–efficacy analyses included data from an ongoing phase 2 study (VISION) investigating 500 mg/day tepotinib in NSCLC harboring METex14 skipping alterations. Efficacy endpoints included objective response, duration of response, and progression-free survival. Exposure–safety analyses included data from VISION, plus four completed studies in advanced solid tumors/hepatocellular carcinoma (30–1400 mg). Safety endpoints included edema, serum albumin, creatinine, amylase, lipase, alanine aminotransferase, aspartate aminotransferase, and QT interval corrected using Fridericia’s method (QTcF). Results Tepotinib exhibited flat exposure–efficacy relationships for all endpoints within the exposure range observed with 500 mg/day. Tepotinib also exhibited flat exposure–safety relationships for all endpoints within the exposure range observed with 30–1400 mg doses. Edema is the most frequently reported adverse event and the most frequent cause of tepotinib dose reductions and interruptions; however, the effect plateaued at low exposures. Concentration-QTc analyses using data from 30 to 1400 mg tepotinib resulted in the upper bounds of the 90% confidence interval being less than 10 ms for the mean exposures at the therapeutic (500 mg) and supratherapeutic (1000 mg) doses. Conclusions These analyses provide important quantitative pharmacologic support for benefit/risk assessment of the 500 mg/day dosage of tepotinib as being appropriate for the treatment of NSCLC harboring METex14 skipping alterations. Registration Numbers NCT01014936, NCT01832506, NCT01988493, NCT02115373, NCT02864992. Supplementary Information The online version contains supplementary material available at 10.1007/s00280-022-04441-3.
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Affiliation(s)
- Wenyuan Xiong
- Merck Institute of Pharmacometrics, Lausanne, Switzerland
| | | | | | | | | | | | - Kosalaram Goteti
- EMD Serono Research and Development Institute Inc., Billerica, MA, USA
| | - Jennifer Dong
- EMD Serono Research and Development Institute Inc., Billerica, MA, USA
| | - Pascal Girard
- Merck Institute of Pharmacometrics, Lausanne, Switzerland
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4
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Hongjin W, Han C, Baoxiang J, Shiqi Y, Xiaoyu X. Reconstituting neurovascular unit based on the close relations between neural stem cells and endothelial cells: an effective method to explore neurogenesis and angiogenesis. Rev Neurosci 2021; 31:143-159. [PMID: 31539363 DOI: 10.1515/revneuro-2019-0023] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 06/10/2019] [Indexed: 12/12/2022]
Abstract
The discovery of neural stem cells (NSCs) and their microenvironment, the NSC niche, brought new therapeutic strategies through neurogenesis and angiogenesis for stroke and most neurodegenerative diseases, including Alzheimer's disease. Based on the close links between NSCs and endothelial cells, the integration of neurogenesis and angiogenesis of the NSC niche is also a promising area to the neurovascular unit (NVU) modeling and is now offering a powerful tool to advance our understanding of the brain. In this review, critical aspects of the NVU and model systems are discussed. First, we briefly describe the interaction of each part in the NSC niche. Second, we introduce the co-culture system, microfluidic platforms, and stem cell-derived 3D reconstitution used in NVU modeling based on the close relations between NSCs and endothelial cells, and various characteristics of cell interactions in these systems are also described. Finally, we address the challenges in modeling the NVU that can potentially be overcome by employing strategies for advanced biomaterials and stem cell co-culture use. Based on these approaches, researchers will continue to develop predictable technologies to control the fate of stem cells, achieve accurate screening of drugs for the nervous system, and advance the clinical application of NVU models.
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Affiliation(s)
- Wang Hongjin
- College of Pharmaceutical Sciences and Chinese Medicine, Southwest University, Chongqing 400715, China.,Chongqing Key Laboratory of New Drug Screening From Traditional Chinese Medicine, Chongqing 400715, China.,Pharmacology of Chinese Materia Medica-Key Discipline Constructed by the State Administration of Traditional Chinese Medicine, Chongqing 400715, China
| | - Chen Han
- College of Pharmaceutical Sciences and Chinese Medicine, Southwest University, Chongqing 400715, China.,Chongqing Key Laboratory of New Drug Screening From Traditional Chinese Medicine, Chongqing 400715, China.,Pharmacology of Chinese Materia Medica-Key Discipline Constructed by the State Administration of Traditional Chinese Medicine, Chongqing 400715, China
| | - Jiang Baoxiang
- College of Pharmaceutical Sciences and Chinese Medicine, Southwest University, Chongqing 400715, China.,Chongqing Key Laboratory of New Drug Screening From Traditional Chinese Medicine, Chongqing 400715, China.,Pharmacology of Chinese Materia Medica-Key Discipline Constructed by the State Administration of Traditional Chinese Medicine, Chongqing 400715, China
| | - Yu Shiqi
- College of Pharmaceutical Sciences and Chinese Medicine, Southwest University, Chongqing 400715, China.,Chongqing Key Laboratory of New Drug Screening From Traditional Chinese Medicine, Chongqing 400715, China.,Pharmacology of Chinese Materia Medica-Key Discipline Constructed by the State Administration of Traditional Chinese Medicine, Chongqing 400715, China
| | - Xu Xiaoyu
- College of Pharmaceutical Sciences and Chinese Medicine, Southwest University, Chongqing 400715, China.,Chongqing Key Laboratory of New Drug Screening From Traditional Chinese Medicine, Chongqing 400715, China.,Pharmacology of Chinese Materia Medica-Key Discipline Constructed by the State Administration of Traditional Chinese Medicine, Chongqing 400715, China
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5
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Wang G, Wang J, Guan R. Novel Phospholipid-Based Labrasol Nanomicelles Loaded Flavonoids for Oral Delivery with Enhanced Penetration and Anti-Brain Tumor Efficiency. Curr Drug Deliv 2021; 17:229-245. [PMID: 32039682 DOI: 10.2174/1567201817666200210120950] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 07/27/2019] [Accepted: 01/30/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Owing to the rich anticancer properties of flavonoids, there is a need for their incorporation into drug delivery vehicles like nanomicelles for safe delivery of the drug into the brain tumor microenvironment. OBJECTIVE This study, therefore, aimed to prepare the phospholipid-based Labrasol/Pluronic F68 modified nano micelles loaded with flavonoids (Nano-flavonoids) for the delivery of the drug to the target brain tumor. METHODS Myricetin, quercetin and fisetin were selected as the initial drugs to evaluate the biodistribution and acute toxicity of the drug delivery vehicles in rats with implanted C6 glioma tumors after oral administration, while the uptake, retention, release in human intestinal Caco-2 cells and the effect on the brain endothelial barrier were investigated in Human Brain Microvascular Endothelial Cells (HBMECs). RESULTS The results demonstrated that nano-flavonoids loaded with myricetin showed more evenly distributed targeting tissues and enhanced anti-tumor efficiency in vivo without significant cytotoxicity to Caco-2 cells and alteration in the Trans Epithelial Electric Resistance (TEER). There was no pathological evidence of renal, hepatic or other organs dysfunction after the administration of nanoflavonoids, which showed no significant influence on cytotoxicity to Caco-2 cells. CONCLUSION In conclusion, Labrasol/F68-NMs loaded with MYR and quercetin could enhance antiglioma effect in vitro and in vivo, which may be better tools for medical therapy, while the pharmacokinetics and pharmacodynamics of nano-flavonoids may ensure optimal therapeutic benefits.
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Affiliation(s)
- Gang Wang
- Department of Pharmaceutics, Shanghai Eighth People's Hospital, Jiangsu University, Shanghai 200235, China
| | - Junjie Wang
- Department of Pharmaceutics, Shanghai Eighth People's Hospital, Jiangsu University, Shanghai 200235, China.,Hubei University of Medicine, Shiyan City, Hubei Province 442000, China
| | - Rui Guan
- Hubei University of Medicine, Shiyan City, Hubei Province 442000, China
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Mesenchymal stem cells regulate the Th17/Treg cell balance partly through hepatocyte growth factor in vitro. Stem Cell Res Ther 2020; 11:91. [PMID: 32111238 PMCID: PMC7049226 DOI: 10.1186/s13287-020-01612-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/15/2020] [Accepted: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
Introduction Mesenchymal stem cells (MSCs) exert immunomodulatory functions by inducing the development and differentiation of naive T cells into T cells with an anti-inflammatory regulatory T cell (Treg) phenotype. Our previous study showed that hepatocyte growth factor (HGF) secreted by MSCs had immunomodulatory effects in the context of lipopolysaccharide (LPS) stimulation. We hypothesized that HGF is a key factor in the MSC-mediated regulation of the T helper 17 (Th17) cell/regulatory T (Treg) cell balance. Methods We investigated the effects of MSCs on the differentiation of CD4+ T cells and the functions of Th17/Treg cells in response to LPS stimulation by performing in vitro coculture experiments. MSCs were added to the upper chambers of cell culture inserts, and CD4+ T cells were plated in the lower chambers, followed by treatment with LPS or an anti-HGF antibody. Th17 (CD4+CD3+RORrt+) and Treg (CD4+CD25+Foxp3+) cell frequencies were analysed by flow cytometry, and the expression of Th17 cell- and Treg cell-related cytokines in the CD4+ T cells or culture medium was measured by quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Neutrophil functions were determined by flow cytometry after a coculture with Th17/Treg cells. Results The percentage of CD4+CD25+Foxp3+ cells was significantly increased in the CD4+ T cell population, while the percentage of CD4+CD3+RORrt+ cells was significantly decreased after MSC coculture. However, the MSC-induced effect was significantly inhibited by the anti-HGF antibody (p < 0.05). Furthermore, MSCs significantly inhibited the CD4+ T cell expression of IL-17 and IL-6 but increased the expression of IL-10 (p < 0.05 or p < 0.01); these effects were inhibited by the anti-HGF antibody (p < 0.05). In addition, CD4+ T cells cocultured with MSCs significantly inhibited neutrophil phagocytic and oxidative burst activities (p < 0.05 or p < 0.01); however, these MSC-induced effects were inhibited by the anti-HGF antibody (p < 0.05). Conclusion These data suggested that MSCs induced the conversion of fully differentiated Th17 cells into functional Treg cells and thereby modulated the Th17/Treg cell balance in the CD4+ T cell population, which was partly attributed to HGF secreted by the MSCs.
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The contribution of platelets to intravascular arrest, extravasation, and outgrowth of disseminated tumor cells. Clin Exp Metastasis 2020; 37:47-67. [PMID: 31758288 DOI: 10.1007/s10585-019-10009-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/15/2019] [Indexed: 12/16/2022]
Abstract
Platelets are primarily known for their contribution to hemostasis and subsequent wound healing. In addition to these functions, platelets play a role in the process of metastasis. Since the first study that suggested a metastasis-promoting function for platelets was published in 1968, various mechanisms have been proposed to explain how platelets contribute to the metastatic process. These include roles in the intravascular arrest of tumor cells, in tumor cell transendothelial migration, in the degradation of basement membrane barriers, in migration and invasion at the metastatic site, and in the proliferation of disseminated tumor cells. Nevertheless, conflicting observations about the role of platelets in these processes have also been reported. Here, we review the in vivo evidence that supports a role for platelets in metastasis formation, propose several scenarios for the contribution of platelets to tumor cell arrest and transendothelial migration, and discuss the evidence that platelets contribute to metastatic invasion and outgrowth.
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8
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Fu P, Shaaya M, Harijith A, Jacobson JR, Karginov A, Natarajan V. Sphingolipids Signaling in Lamellipodia Formation and Enhancement of Endothelial Barrier Function. CURRENT TOPICS IN MEMBRANES 2018; 82:1-31. [PMID: 30360778 DOI: 10.1016/bs.ctm.2018.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sphingolipids, first described in the brain in 1884, are important structural components of biological membranes of all eukaryotic cells. In recent years, several lines of evidence support the critical role of sphingolipids such as sphingosine, sphingosine-1-phosphate (S1P), and ceramide as anti- or pro-inflammatory bioactive lipid mediators in a variety of human pathologies including pulmonary and vascular disorders. Among the sphingolipids, S1P is a naturally occurring agonist that exhibits potent barrier enhancing property in the endothelium by signaling via G protein-coupled S1P1 receptor. S1P, S1P analogs, and other barrier enhancing agents such as HGF, oxidized phospholipids, and statins also utilize the S1P/S1P1 signaling pathway to generate membrane protrusions or lamellipodia, which have been implicated in resealing of endothelial gaps and maintenance of barrier integrity. A better understanding of sphingolipids mediated regulation of lamellipodia formation and barrier enhancement of the endothelium will be critical for the development of sphingolipid-based therapies to alleviate pulmonary disorders such as sepsis-, radiation-, and mechanical ventilation-induced acute lung injury.
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Affiliation(s)
- Panfeng Fu
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Mark Shaaya
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Anantha Harijith
- Department of Pediatrics, University of Illinois at Chicago, Chicago, IL, United States
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Andrei Karginov
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Viswanathan Natarajan
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States; Department of Medicine, University of Illinois at Chicago, Chicago, IL, United States.
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Sowa K, Nito C, Nakajima M, Suda S, Nishiyama Y, Sakamoto Y, Nitahara-Kasahara Y, Nakamura-Takahashi A, Ueda M, Kimura K, Okada T. Impact of Dental Pulp Stem Cells Overexpressing Hepatocyte Growth Factor after Cerebral Ischemia/Reperfusion in Rats. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:281-290. [PMID: 30151417 PMCID: PMC6108066 DOI: 10.1016/j.omtm.2018.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 07/26/2018] [Indexed: 02/07/2023]
Abstract
Hepatocyte growth factor (HGF) has neuroprotective effects against ischemia-induced injuries. Dental pulp stem cell (DPSC) transplantation attenuates tissue injury in the brain of rats with post-transient middle cerebral artery occlusion. We sought to determine whether DPSCs that overexpress HGF can enhance their therapeutic effects on brain damage post-ischemia/reperfusion injury. Treatment with DPSCs overexpressing HGF reduced infarct volumes compared to unmodified DPSC treatment at 3 and 7 days post-transient middle cerebral artery occlusion. The use of unmodified DPSCs and DPSCs overexpressing HGF was associated with improved motor function compared to that with administration of vehicle at 7 days post-transient middle cerebral artery occlusion. DPSCs overexpressing HGF significantly inhibited microglial activation and pro-inflammatory cytokine production along with suppression of neuronal degeneration. Post-reperfusion, DPSCs overexpressing HGF attenuated the decreases in tight junction proteins, maintained blood-brain barrier integrity, and increased microvessel density in peri-infarct areas. The administration of DPSCs overexpressing HGF during the acute phase of stroke increased their neuroprotective effects by modulating inflammation and blood-brain barrier permeability, thereby promoting improvements in post-ischemia/reperfusion brain injury.
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Affiliation(s)
- Kota Sowa
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Chikako Nito
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Masataka Nakajima
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Satoshi Suda
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Yasuhiro Nishiyama
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Yuki Sakamoto
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Yuko Nitahara-Kasahara
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Cell and Gene Therapy, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Aki Nakamura-Takahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Pharmacology, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Masayuki Ueda
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Neurology and Stroke Medicine, Tokyo Metropolitan Tama Medical Center, Tokyo 183-8524, Japan
| | - Kazumi Kimura
- Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
| | - Takashi Okada
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.,Department of Cell and Gene Therapy, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan
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Freese C, Hanada S, Fallier-Becker P, Kirkpatrick CJ, Unger RE. Identification of neuronal and angiogenic growth factors in an in vitro blood-brain barrier model system: Relevance in barrier integrity and tight junction formation and complexity. Microvasc Res 2016; 111:1-11. [PMID: 27988246 DOI: 10.1016/j.mvr.2016.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/18/2016] [Accepted: 12/03/2016] [Indexed: 12/01/2022]
Abstract
We previously demonstrated that the co-cultivation of endothelial cells with neural cells resulted in an improved integrity of the in vitro blood-brain barrier (BBB), and that this model could be useful to evaluate the transport properties of potential central nervous system disease drugs through the microvascular brain endothelial. In this study we have used real-time PCR, fluorescent microscopy, protein arrays and enzyme-linked immunosorbent assays to determine which neural- and endothelial cell-derived factors are produced in the co-culture and improve the integrity of the BBB. In addition, a further improvement of the BBB integrity was achieved by adjusting serum concentrations and growth factors or by the addition of brain pericytes. Under specific conditions expression of angiogenic, angiostatic and neurotrophic factors such as endostatin, pigment epithelium derived factor (PEDF/serpins-F1), tissue inhibitor of metalloproteinases (TIMP-1), and vascular endothelial cell growth factor (VEGF) closely mimicked the in vivo situation. Freeze-fracture analysis of these cultures demonstrated the quality and organization of the endothelial tight junction structures and their association to the two different lipidic leaflets of the membrane. Finally, a multi-cell culture model of the BBB with a transendothelial electrical resistance up to 371 (±15) Ω×cm2 was developed, which may be useful for preliminary screening of drug transport across the BBB and to evaluate cellular crosstalk of cells involved in the neurovascular unit.
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Affiliation(s)
- Christian Freese
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Sanshiro Hanada
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, University of Tuebingen, Geschwister-Scholl-Platz, 72074 Tuebingen, Germany.
| | - C James Kirkpatrick
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Ronald E Unger
- REPAIR-lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University Mainz and European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Langenbeckstr. 1, 55131 Mainz, Germany.
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Chong YJ, Musa NF, Ng CH, Shaari K, Israf DA, Tham CL. Barrier protective effects of 2,4,6-trihydroxy-3-geranyl acetophenone on lipopolysaccharides-stimulated inflammatory responses in human umbilical vein endothelial cells. JOURNAL OF ETHNOPHARMACOLOGY 2016; 192:248-255. [PMID: 27404229 DOI: 10.1016/j.jep.2016.07.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 06/06/2016] [Accepted: 07/09/2016] [Indexed: 06/06/2023]
Abstract
PHARMOCOLOGICAL RELEVANCE 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA), is a phloroglucinol compound found naturally in Melicope ptelefolia. Melicope ptelefolia has been used traditionally for centuries as natural remedy for wound infections and inflammatory diseases. AIM OF THE STUDY Endothelial barrier dysfunction is a pathological hallmark of many diseases and can be caused by lipopolysaccharides (LPS) stimulation. Therefore, this study aims to investigate the possible barrier protective effects of tHGA upon LPS-stimulated inflammatory responses in human umbilical vein endothelial cells (HUVECs). MATERIALS AND METHODS HUVECs were pretreated with tHGA prior to LPS stimulation, where inflammatory parameters including permeability, monocyte adhesion and migration, and release of pro-inflammatory mediators were examined. Additionally, the effect of tHGA on F-actin rearrangement and adhesion protein expression of LPS-stimulated HUVECs was evaluated. RESULTS It was found that pretreatment with tHGA inhibited monocyte adhesion and transendothelial migration, reduced endothelial hyperpermeability and secretion of prostaglandin E2 (PGE2). Additionally, tHGA inhibited cytoskeletal rearrangement and adhesion protein expression on LPS-stimulated HUVECs. CONCLUSION As the regulation of endothelial barrier dysfunction can be one of the therapeutic strategies to improve the outcome of inflammation, tHGA may be able to preserve vascular barrier integrity of endothelial cells following LPS-stimulated dysfunction, thereby endorsing its potential usefulness in vascular inflammatory diseases.
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Affiliation(s)
- Yi Joong Chong
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43300, Malaysia
| | - Nazmi Firdaus Musa
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43300, Malaysia
| | - Chean Hui Ng
- Faculty of Science, Universiti Putra Malaysia, Serdang 43300, Malaysia
| | - Khozirah Shaari
- Faculty of Science, Universiti Putra Malaysia, Serdang 43300, Malaysia
| | - Daud Ahmad Israf
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43300, Malaysia
| | - Chau Ling Tham
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43300, Malaysia.
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Puszkiel A, White-Koning M, Dupin N, Kramkimel N, Thomas-Schoemann A, Noé G, Chapuis N, Vidal M, Goldwasser F, Chatelut E, Blanchet B. Plasma vemurafenib exposure and pre-treatment hepatocyte growth factor level are two factors contributing to the early peripheral lymphocytes depletion in BRAF-mutated melanoma patients. Pharmacol Res 2016; 113:709-718. [DOI: 10.1016/j.phrs.2016.06.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 01/11/2023]
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Posthemorrhagic shock mesenteric lymph enhances monolayer permeability via F-actin and VE-cadherin. J Surg Res 2016; 203:47-55. [PMID: 27338534 DOI: 10.1016/j.jss.2016.01.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 01/05/2016] [Accepted: 01/27/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND Vascular hyperpermeability plays a critical role in the development of refractory hypotension after severe hemorrhagic shock. Posthemorrhagic shock mesenteric lymph (PHSML) return has been shown to be involved in regulation of vascular hyperpermeability. The present study was conducted to investigate the effect of PHSML on permeability of endothelial cells in vitro. MATERIALS AND METHODS A hemorrhagic shock model (40 ± 2 mm Hg for 90 min, followed by fluid resuscitation) was used for collection of PHSML. Two separated PHSMLs were collected from period 0-3 h (early) and period 3-6 h (late) after resuscitation and diluted into concentration of 4% or 10%. The human umbilical vein endothelial cells (HUVECs) were then treated with these PHSMLs for 6 h. The monolayer cellular permeability to FITC-albumin was observed by using the costar transwell system. The multiple approaches including scanning electron microscope, fluorescent cytochemistry staining, and Western blotting were also used to assess the changes in cellular morphologic and the expressions of F-actin and VE-cadherin. RESULTS The treatments with either early or late PHSML resulted in morphologic injuries, increased cellular permeability, and decreased expression of F-actin in HUVECs. In contrast, only early PHSML, but not late PHSML, reduced the VE-cadherin expression. CONCLUSIONS These results indicate that the PHSML in vitro increases the cellular permeability of HUVECs through suppression of F-actin and VE-cadherin.
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Wu L, Ramirez SH, Andrews AM, Leung W, Itoh K, Wu J, Arai K, Lo EH, Lok J. Neuregulin1-β decreases interleukin-1β-induced RhoA activation, myosin light chain phosphorylation, and endothelial hyperpermeability. J Neurochem 2015; 136:250-7. [PMID: 26438054 DOI: 10.1111/jnc.13374] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/17/2015] [Accepted: 09/03/2015] [Indexed: 12/14/2022]
Abstract
Neuregulin-1 (NRG1) is an endogenous growth factor with multiple functions in the embryonic and postnatal brain. The NRG1 gene is large and complex, transcribing more than twenty transmembrane proteins and generating a large number of isoforms in tissue and cell type-specific patterns. Within the brain, NRG1 functions have been studied most extensively in neurons and glia, as well as in the peripheral vasculature. Recently, NRG1 signaling has been found to be important in the function of brain microvascular endothelial cells, decreasing IL-1β-induced increases in endothelial permeability. In the current experiments, we have investigated the pathways through which the NRG1-β isoform acts on IL-1β-induced endothelial permeability. Our data show that NRG1-β increases barrier function, measured by transendothelial electrical resistance, and decreases IL-1β-induced hyperpermeability, measured by dextran-40 extravasation through a monolayer of brain microvascular endothelial cells plated on transwells. An investigation of key signaling proteins suggests that the effect of NRG1-β on endothelial permeability is mediated through RhoA activation and myosin light chain phosphorylation, events which affect filamentous actin morphology. In addition, AG825, an inhibitor of the erbB2-associated tyrosine kinase, reduces the effect of NRG1-β on IL-1β-induced RhoA activation and myosin light chain phosphorylation. These data add to the evidence that NRG1-β signaling affects changes in the brain microvasculature in the setting of neuroinflammation. We propose the following events for neuregulin-1-mediated effects on Interleukin-1 β (IL-1β)-induced endothelial hyperpermeability: IL-1β leads to RhoA activation, resulting in an increase in phosphorylation of myosin light chain (MLC). Phosphorylation of MLC is known to result in actin contraction and alterations in the f-actin cytoskeletal structure. These changes are associated with increased endothelial permeability. Neuregulin-1β acts through its transmembrane receptors to activate intracellular signaling pathways which inhibit IL-1β-induced RhoA activation and MLC phosphorylation, thereby preserving the f-actin cytoskeletal structure and endothelial barrier function.
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Affiliation(s)
- Limin Wu
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Department of Neurology, the First Bethune Hospital of Jilin University, Changchun, Jilin, China
| | - Servio H Ramirez
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA.,The Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Allison M Andrews
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Wendy Leung
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Kanako Itoh
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Jiang Wu
- Department of Neurology, the First Bethune Hospital of Jilin University, Changchun, Jilin, China
| | - Ken Arai
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Josephine Lok
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA.,Department of Pediatrics, Pediatric Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Interaction between mesenchymal stem cells and endothelial cells restores endothelial permeability via paracrine hepatocyte growth factor in vitro. Stem Cell Res Ther 2015; 6:44. [PMID: 25888925 PMCID: PMC4431320 DOI: 10.1186/s13287-015-0025-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/19/2014] [Accepted: 02/27/2015] [Indexed: 01/11/2023] Open
Abstract
Introduction Mesenchymal stem cells (MSCs) have potent stabilising effects on vascular endothelium injury, inhibiting endothelial permeability in lung injury via paracrine hepatocyte growth factor (HGF). Recently, it has been indicated that MSCs secrete more factors by MSC-endothelial cell (MSC-EC) interactions. We hypothesised that MSC-EC interactions restore endothelial permeability induced by lipopolysaccharide (LPS) via paracrine HGF. Methods We investigated the endothelial permeability induced by LPS under two co-culture conditions. Human pulmonary microvascular endothelial cells (HPMECs) were added into the upper chambers of cell-culture inserts, while two different co-culture conditions were used in the lower side of the transwells, as follows: (1) MSC-EC interaction group: MSCs and HPMECs contact co-culture; (2) MSC group: MSCs only. The endothelial paracellular and transcellular permeabilities in the upper side of transwells were detected. Then the concentration of HGF was measured in the culture medium by using an enzyme-linked immunosorbent assay kit, followed by neutralisation of HGF with anti-HGF antibody in the co-culture medium. In addition, adherens junction and cytoskeleton protein expressions were measured by Western blot and immunofluorescence. HPMEC proliferation was analysed by bromodeoxyuridine incorporation assay. Results The paracellular permeability significantly increased after LPS stimulation in a dose-dependent and time-dependent manner. Meanwhile, MSC-EC interaction more significantly decreased endothelial paracellular and transcellular permeability induced by LPS. Moreover, HGF levels in the MSC-EC interaction group were much higher than those of the MSC group. However, neutralising HGF with anti-HGF antibody inhibited the role of MSC-EC interaction in improving endothelial permeability. Compared with the MSC group, MSC-EC interaction increased vascular endothelial (VE)-cadherin and occludin protein expression, reduced caveolin-1 protein expression in HPMECs, and restored remodelling of F-actin and junctional localisation of VE-cadherin. Furthermore, the proliferation ratio in the MSC-EC interaction group was higher than that of the MSC group. However, the effects of MSCs were significantly blocked by anti-HGF antibody. Conclusions These data suggested that MSC-EC interaction decreased endothelial permeability induced by LPS, which was attributed mainly to HGF secreted by MSCs. The main mechanisms by which HGF restored the integrity of endothelial monolayers were remodelling of endothelial intercellular junctions, decreasing caveolin-1 protein expression, and inducing proliferation in HPMECs. Electronic supplementary material The online version of this article (doi:10.1186/s13287-015-0025-1) contains supplementary material, which is available to authorized users.
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Hydrocortisone enhances the barrier properties of HBMEC/ciβ, a brain microvascular endothelial cell line, through mesenchymal-to-endothelial transition-like effects. Fluids Barriers CNS 2015; 12:7. [PMID: 25763180 PMCID: PMC4355132 DOI: 10.1186/s12987-015-0003-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/22/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Because in vitro blood-brain barrier (BBB) models are important tools for studying brain diseases and drug development, we recently established a new line of conditionally immortalized human brain microvascular endothelial cells (HBMEC/ciβ) for use in such models. Since one of the most important functional features of the BBB is its strong intercellular adhesion, in this study, we aimed at improving HBMEC/ciβ barrier properties by means of culture media modifications, thus enhancing their use for future BBB studies. In addition, we simultaneously attempted to obtain insights on related mechanistic properties. METHODS Several types of culture media were prepared in an effort to identify the medium most suitable for culturing HBMEC/ciβ. The barrier properties of HBMEC/ciβ were examined by determining Na(+)-fluorescein permeability and transendothelial electric resistance (TEER). Endothelial marker mRNA expression levels were determined by quantitative real-time polymerase chain reaction. Adherens junction (AJ) formation was examined by immunocytochemistry. Cell migration ability was analyzed by scratch assay. Furthermore, cellular lipid composition was examined by liquid chromatography-time-of-flight mass spectrometry. RESULTS Our initial screening tests showed that addition of hydrocortisone (HC) to the basal medium significantly reduced the Na(+)-fluorescein permeability and increased the TEER of HBMEC/ciβ monolayers. It was also found that, while AJ proteins were diffused in the cytoplasm of HBMEC/ciβ cultured without HC, those expressed in cells cultured with HC were primarily localized at the cell border. Furthermore, this facilitation of AJ formation by HC was in concert with increased endothelial marker mRNA levels and increased ether-type phosphatidylethanolamine levels, while cell migration was retarded in the presence of HC. CONCLUSIONS Our results show that HC supplementation to the basal medium significantly enhances the barrier properties of HBMEC/ciβ. This was associated with a marked phenotypic alteration in HBMEC/ciβ through orchestration of various signaling pathways. Taken together, it appears that overall effects of HC on HBMEC/ciβ could be summarized as facilitating endothelial differentiation characteristics while concurrently retarding mesenchymal characteristics.
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Odijk M, van der Meer AD, Levner D, Kim HJ, van der Helm MW, Segerink LI, Frimat JP, Hamilton GA, Ingber DE, van den Berg A. Measuring direct current trans-epithelial electrical resistance in organ-on-a-chip microsystems. LAB ON A CHIP 2015; 15:745-52. [PMID: 25427650 DOI: 10.1039/c4lc01219d] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Trans-epithelial electrical resistance (TEER) measurements are widely used as real-time, non-destructive, and label-free measurements of epithelial and endothelial barrier function. TEER measurements are ideal for characterizing tissue barrier function in organs-on-chip studies for drug testing and investigation of human disease models; however, published reports using this technique have reported highly conflicting results even with identical cell lines and experimental setups. The differences are even more dramatic when comparing measurements in conventional Transwell systems with those obtained in microfluidic systems. Our goal in this work was therefore to enhance the fidelity of TEER measurements in microfluidic organs-on-chips, specifically using direct current (DC) measurements of TEER, as this is the most widely used method reported in the literature. Here we present a mathematical model that accounts for differences measured in TEER between microfluidic chips and Transwell systems, which arise from differences in device geometry. The model is validated by comparing TEER measurements obtained in a microfluidic gut-on-a-chip device versus in a Transwell culture system. Moreover, we show that even small gaps in cell coverage (e.g., 0.4%) are sufficient to cause a significant (~80%) drop in TEER. Importantly, these findings demonstrate that TEER measurements obtained in microfluidic systems, such as organs-on-chips, require special consideration, specifically when results are to be compared with measurements obtained from Transwell systems.
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Affiliation(s)
- Mathieu Odijk
- BIOS/Lab-on-Chip Group, MESA+ Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P. O. Box 217, 7500 AE Enschede, The Netherlands.
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Beppu M, Sawai S, Misawa S, Sogawa K, Mori M, Ishige T, Satoh M, Nomura F, Kuwabara S. Serum cytokine and chemokine profiles in patients with chronic inflammatory demyelinating polyneuropathy. J Neuroimmunol 2015; 279:7-10. [DOI: 10.1016/j.jneuroim.2014.12.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/14/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
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MiR-181a regulates blood-tumor barrier permeability by targeting Krüppel-like factor 6. J Cereb Blood Flow Metab 2014; 34:1826-36. [PMID: 25182666 PMCID: PMC4269760 DOI: 10.1038/jcbfm.2014.152] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/29/2014] [Accepted: 07/28/2014] [Indexed: 12/18/2022]
Abstract
Blood-tumor barrier (BTB) constitutes an efficient organization of tight junctions that impairs the delivery of therapeutic drugs. However, the methods and molecular mechanisms underlying the BTB opening remain elusive. MicroRNAs (miRNAs) have recently emerged as key regulators of various biologic processes and therapeutic targets. In this study, we have identified microRNA-181a (miR-181a) as a critical miRNA in opening BTB. MicroRNA-181a expression was upregulated in glioma endothelial cells (GECs), which were obtained by coculturing endothelial cells (ECs) with glioma cells. Overexpression of miR-181a resulted in an impaired and permeability increased BTB, and meanwhile reduced the expression of zonula occluden (ZO)-1, occludin, and claudin-5. Kruppel-like factor 6 (KLF6), a transcription factor of the zinc-finger family, was downregulated in GECs. Mechanistic investigations defined it as a direct and functional downstream target of miR-181a, which was involved in the regulation of BTB permeability and the expression of ZO-1, occludin, and claudin-5. Furthermore, luciferase assays and chromatin immunoprecipitation assays showed that KLF6 upregulated the promoter activities and interacted with the promoters of ZO-1, occludin, and claudin-5 in GECs. Collectively, we showed the possibility that overexpression of miR-181a contributes to the increased permeability of BTB by targeting KLF6, thereby revealing potential therapeutic targets for the treatment of brain gliomas.
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