Conditional targeting in mice reveals that hepatic homogentisate 1,2-dioxygenase activity is essential in reducing circulating homogentisic acid and for effective therapy in the genetic disease alkaptonuria

Abstract Alkaptonuria is an inherited disease caused by homogentisate 1,2-dioxygenase (HGD) deficiency. Circulating homogentisic acid (HGA) is elevated and deposits in connective tissues as ochronotic pigment. In this study, we aimed to define developmental and adult HGD tissue expression and determine the location and amount of gene activity required to lower circulating HGA and rescue the alkaptonuria phenotype. We generated an alkaptonuria mouse model using a knockout-first design for the disruption of the HGD gene. Hgd tm1a −/− mice showed elevated HGA and ochronosis in adulthood. LacZ staining driven by the endogenous HGD promoter was localised to only liver parenchymal cells and kidney proximal tubules in adulthood, commencing at E12.5 and E15.5 respectively. Following removal of the gene trap cassette to obtain a normal mouse with a floxed 6th HGD exon, a double transgenic was then created with Mx1-Cre which conditionally deleted HGD in liver in a dose dependent manner. 20% of HGD mRNA remaining in liver did not rescue the disease, suggesting that we need more than 20% of liver HGD to correct the disease in gene therapy. Kidney HGD activity which remained intact reduced urinary HGA, most likely by increased absorption, but did not reduce plasma HGA nor did it prevent ochronosis. In addition, downstream metabolites of exogenous 13C6-HGA, were detected in heterozygous plasma, revealing that hepatocytes take up and metabolise HGA. This novel alkaptonuria mouse model demonstrated the importance of targeting liver for therapeutic intervention, supported by our observation that hepatocytes take up and metabolise HGA.

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Gene therapy via canalostomy approach preserves auditory and vestibular functions in a mouse model of Jervell and Lange-Nielsen syndrome type 2

Nature Communications ◽

10.1038/s41467-020-20808-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xuewen Wu ◽

Li Zhang ◽

Yihui Li ◽

Wenjuan Zhang ◽

Jianjun Wang ◽

...

Keyword(s):

Gene Therapy ◽

Mouse Model ◽

Inner Ear ◽

Viral Vectors ◽

Survival Rates ◽

Semicircular Canals ◽

Dependent Manner ◽

Syndrome Type ◽

Dose Dependent

AbstractMutations in voltage-gated potassium channel KCNE1 cause Jervell and Lange-Nielsen syndrome type 2 (JLNS2), resulting in congenital deafness and vestibular dysfunction. We conducted gene therapy by injecting viral vectors using the canalostomy approach in Kcne1−/− mice to treat both the hearing and vestibular symptoms. Results showed early treatment prevented collapse of the Reissner’s membrane and vestibular wall, retained the normal size of the semicircular canals, and prevented the degeneration of inner ear cells. In a dose-dependent manner, the treatment preserved auditory (16 out of 20 mice) and vestibular (20/20) functions in mice treated with the high-dosage for at least five months. In the low-dosage group, a subgroup of mice (13/20) showed improvements only in the vestibular functions. Results supported that highly efficient transduction is one of the key factors for achieving the efficacy and maintaining the long-term therapeutic effect. Secondary outcomes of treatment included improved birth and litter survival rates. Our results demonstrated that gene therapy via the canalostomy approach, which has been considered to be one of the more feasible delivery methods for human inner ear gene therapy, preserved auditory and vestibular functions in a dose-dependent manner in a mouse model of JLNS2.

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P062 Dose-dependent differential effects of vedolizumab therapy on adhesion of regulatory and effector T cells

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjz203.191 ◽

2020 ◽

Vol 14 (Supplement_1) ◽

pp. S165-S166

Author(s):

E Becker ◽

M Wiendl ◽

A Schulz-Kuhnt ◽

I Atreya ◽

R Atreya ◽

...

Keyword(s):

T Cell ◽

Mouse Model ◽

T Cell Subsets ◽

Dependent Manner ◽

Differential Effects ◽

Preferential Binding ◽

Exposure Levels ◽

Differential Binding ◽

Dose Dependent

Abstract Background Vedolizumab has emerged as an important pillar of treatment in inflammatory bowel disease (IBD). However, for unknown reasons, not all patients respond to therapy. Earlier clinical studies suggested decreased response rates in the highest compared with medium dosage groups. Interestingly, vedolizumab has been shown to inhibit the homing of both regulatory (Treg) and effector T (Teff) cells and previous data from our group suggested different effect sizes in both populations. Thus, we hypothesised that the non-linear exposure–efficacy correlation might be explained by dose-dependent differential effects of vedolizumab on Treg and Teff homing. Therefore, we studied functional effects of different vedolizumab exposure levels on Treg and Teff cell trafficking. Methods The α4β7 expression on different human T-cell subsets as well as the binding characteristics of vedolizumab to these cells at different exposure levels was analysed via flow cytometry. Functional effects of different vedolizumab concentrations on the adhesion of Tregs and Teffs to mucosal addressin cell adhesion molecule 1 (MAdCAM-1) were analysed using dynamic in vitro adhesion assays, transmigration assays and in vivo homing assays in a humanised mouse model. The in vivo binding of vedolizumab to Tregs and Teffs in patients receiving therapy was quantified and correlated with the corresponding serum levels. Results We found a preferential binding of vedolizumab to Tregs at an exposure with 0.4 µg/ml vedolizumab that shifted to a preferential binding to Teffs at an exposure with 10 µg/ml. Further increase of vedolizumab to 50 µg/ml led to equal binding to Tregs and Teffs (Figure 1). Consistently, at 10 µg/ml, dynamic adhesion of Tregs to MAdCAM-1 was increased compared with Teffs, but no difference was noted at 50 µg/ml. Additionally, a higher number of Treg compared with Teff cells were able to transmigrate in a MAdCAM-1-dependent manner at a concentration of 10 µg/ml vedolizumab. Preliminary data from homing experiments in a humanised mouse model and from IBD patients treated with vedolizumab support the notion that differential binding preferences depending on the exposure level can also be observed in vivo. Conclusion Our findings support a dose-dependent differential binding of vedolizumab to different T-cell subpopulations and suggest that an optimal ‘window’ of exposure exists, in which effects on Teffs predominate over Tregs. While offering a potential explanation for earlier findings in dose-ranging studies, our data might lay the basis for the establishment of individualised dose optimisation in IBD patients.

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Nucleoside uptake in rat liver parenchymal cells

Biochemical Journal ◽

10.1042/bj3170835 ◽

1996 ◽

Vol 317 (3) ◽

pp. 835-842 ◽

Cited By ~ 14

Author(s):

Joan MERCADER ◽

Mireia GOMEZ-ANGELATS ◽

Belén del SANTO ◽

Javier CASADO ◽

Antonio F. FELIPE ◽

...

Keyword(s):

Rat Liver ◽

Nucleoside Transport ◽

Transport Systems ◽

Dependent Manner ◽

Transport Activity ◽

Liver Parenchymal ◽

Uridine Uptake ◽

High Concentrations ◽

Parenchymal Cells ◽

Dose Dependent

Rat liver parenchymal cells express Na+-dependent and Na+-independent nucleoside transport activity. The Na+-dependent component shows kinetic properties and substrate specificity similar to those reported for plasma membrane vesicles [Ruiz-Montasell, Casado, Felipe and Pastor-Anglada (1992) J. Membr. Biol. 128, 227–233]. This transport activity shows apparent Km values for uridine in the range 8–13 μM and a Vmax of 246 pmol of uridine per 3 min per 106 cells. Most nucleosides, including the analogue formycin B, cis-inhibit Na+-dependent uridine transport, although thymidine and cytidine are poor inhibitors. Inosine and adenosine inhibit Na+-dependent uridine uptake in a dose-dependent manner, reaching total inhibition. Guanosine also inhibits Na+-dependent uridine uptake, although there is some residual transport activity (35% of the control values) that is resistant to high concentrations of guanosine but may be inhibited by low concentrations of adenosine. The transport activity that is inhibited by high concentrations of thymidine is similar to the guanosine-resistant fraction. These observations are consistent with the presence of at least two Na+-dependent transport systems. Na+-dependent uridine uptake is sensitive to N-ethylmaleimide treatment, but Na+-independent transport is not. Nitrobenzylthioinosine (NBTI) stimulates Na+-dependent uridine uptake. The NBTI effect involves a change in Vmax, it is rapid, dose-dependent, does not need preincubation and can be abolished by depleting the Na+ transmembrane electrochemical gradient. Na+-independent uridine transport seems to be insensitive to NBTI. Under the same experimental conditions, NBTI effectively blocks most of the Na+-independent uridine uptake in hepatoma cells. Thus the stimulatory effect of NBTI on the concentrative nucleoside transporter of liver parenchymal cells cannot be explained by inhibition of nucleoside efflux.

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Evidence that estrogen receptor β enhances MMP-13 promoter activity in HIG-82 cells and that this enhancement can be influenced by ligands and involves specific promoter sites

Biochemistry and Cell Biology ◽

10.1139/o07-016 ◽

2007 ◽

Vol 85 (3) ◽

pp. 326-336 ◽

Cited By ~ 11

Author(s):

Ting Lu ◽

Yamini Achari ◽

Jerome B. Rattner ◽

David A. Hart

Keyword(s):

Estrogen Receptor ◽

Promoter Activity ◽

Estrogen Receptor Β ◽

Mrna Levels ◽

Dependent Manner ◽

Connective Tissues ◽

Matrix Metalloproteinase 13 ◽

Promoter Construct ◽

The Impact ◽

Dose Dependent

Degradation of articular cartilage is characteristic of osteoarthritis, and matrix metalloproteinase-13 (MMP-13) has been implicated in this condition. Estrogen receptors (ERs) are present in connective tissues, indicating these tissues' potential responsiveness to estrogen. We based this study on the hypothesis that estrogen receptor β (ERβ) can modulate MMP-13 promoter activity. Transfection of cells with ERβ constructs led to the induction of the endogenous MMP-13 gene, as evidenced by increased mRNA levels. The results also indicated that MMP-13 promoter construct activity in the HIG-82 cell line significantly increased when ERβ was present, and that estrogen downregulated this response in a dose-dependent manner. ERβ was shown to enhance MMP-13 expression somewhat more strongly than ERα, and the impact of a number of selective ER modulators (tamoxifen, raloxifene, and ICI 182,780) on ERβ enhancement of promoter activity was found to be significantly less than that of estrogen. Furthermore, transcription regulatory sites in the MMP-13 promoter, specifically AP-1 and PEA-3, were shown to act in conjunction to mediate ERβ effects. Thus, ERβ likely influences MMP-13 promoter expression in normal and disease processes.

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AV-65, a Novel Inhibitor of the Wnt/β-Catenin Signaling Pathway, Inhibits the Proliferation of Myeloma Cells.

Blood ◽

10.1182/blood.v114.22.2866.2866 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2866-2866

Author(s):

Hisayuki Yao ◽

Eishi Ashihara ◽

Rina Nagao ◽

Shinya Kimura ◽

Hideyo Hirai ◽

...

Keyword(s):

Gene Expression ◽

Mouse Model ◽

Signaling Pathway ◽

Small Molecule ◽

Conflicts Of Interest ◽

Flow Cytometric Analysis ◽

Cancer Cell Line ◽

Dependent Manner ◽

Dose Dependent

Abstract Abstract 2866 Poster Board II-842 Although new molecular targeting agents against multiple myeloma (MM) have been developed, MM still remains an incurable disease. It is important to continue to investigate new therapeutic agents based on the biology of MM cells. β-catenin is the downstream effector of Wnt signaling and it regulates genes implicated in malignant progression. We have demonstrated that blockade of Wnt/β-catenin signaling pathway inhibits the progression of MM by using RNA interference methods with an in vivo mouse model (Ashihara E, et al. Clin Cancer Res 15:2731, 2009.). In this study, we investigated the effects of AV-65, a novel inhibitor of the Wnt/β-catenin signaling pathway, on MM cells. The system to identify a series of small molecule compounds using a biomarker driven approach has been established. A gene expression biomarker signature reporting on the inhibition of Wnt/β-catenin signaling was generated upon treatment of a colon cancer cell line with β-catenin siRNA. This gene expression signatiure was used to screen a small molecule compound library to identify compounds which mimic knockdown of β-catenin and thus potentially inhibit the Wnt/β-catenin signaling pathway. One compound series, LC-363, was discovered from this screen and validated as novel Wnt/β-catenin signaling inhibitors (Strovel JW, et al. ASH meeting, 2007.). We investigated the inhibitory effects of AV-65, one of LC-363 compounds, on MM cell proliferation. AV-65 inhibited the proliferation of MM cells in a time- and a dose-dependent manner and the values of IC50 at 72 hrs were ranging from 11.7 to 82.1 nM. AV-65 also showed an inhibitory effect on the proliferation of RPMI8226/LR-5 melphalan-resistant MM cells (provided from Dr. William S. Dalton). In flow cytometric analysis, apoptotic cells were increased by AV-65 treatment in a time- and a dose-dependent manner. Western blotting analysis showed that β-catenin was ubiquitinated and that the expression of nuclear β-catenin diminished (Figure 1). Moreover, AV-65 suppressed T-cell factor transcriptional activities, resulting in the decrease of c-myc expression. Taken together, AV-65 promotes the degradation of β-catenin, resulting in the induction of apoptosis of MM cells. We next investigated the in vivo effects of AV-65 using an orthotopic MM-bearing mouse model. AV-65 inhibits the growth of MM cells and significantly prolongs the survival rates (Figure 2). In conclusion, AV-65 inhibited the proliferation of MM cells via inhibition of the Wnt/β-catenin signaling pathway. AV-65 is a promising therapeutic agent for treatment of MM. Disclosures: No relevant conflicts of interest to declare.

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Genetic or Enzymatic Disruption of Aromatase Inhibits the Growth of Ectopic Uterine Tissue

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.87.7.8683 ◽

2002 ◽

Vol 87 (7) ◽

pp. 3460-3466 ◽

Cited By ~ 34

Author(s):

Zongjuan Fang ◽

Sijun Yang ◽

Bilgin Gurates ◽

Mitsutoshi Tamura ◽

Evan Simpson ◽

...

Keyword(s):

Enzyme Activity ◽

Mouse Model ◽

Lesion Size ◽

Dependent Manner ◽

Wild Type ◽

Uterine Tissue ◽

Abdominal Organs ◽

Letrozole Treatment ◽

Key Enzyme ◽

Dose Dependent

Aromatase P450 (P450arom) is the key enzyme for the biosynthesis of estrogen that is essential for the growth of human endometriosis, a pathology characterized by endometrium-like tissue on the peritoneal surfaces of abdominal organs manifest by pelvic pain and infertility. Surgically transplanted autologous uterine tissue to ectopic sites on the peritoneum in mice has been used as an animal model to study endometriosis. Using this mouse model, we evaluated the roles of the P450arom gene and aromatase enzyme activity in the growth of endometriosis represented by ectopic uterine tissues in mice. Endometriosis was induced surgically in the following groups of mice: 1) untreated transgenic mice with disrupted P450arom gene (ArKO); 2) ArKO mice treated with systemic estrogen; 3) untreated wild-type (WT) mice; 4) WT mice treated with estrogen; 5) WT mice treated with the aromatase inhibitor, letrozole; and 6) WT mice treated with letrozole and estrogen. Each group contained eight mice; +/+ littermates of ArKO mice were used as WT controls. Treatment with estrogen increased the size of ectopic uterine tissues in ArKO and WT mice significantly. The ectopic uterine lesions in untreated and estrogen-treated ArKO mice were strikingly smaller than those in untreated and estrogen-treated WT controls, respectively. Systemic treatment of WT mice with letrozole significantly decreased the lesion size in a dose-dependent manner. The addition of estrogen to letrozole treatment increased the ectopic lesion size, although these lesions were significantly smaller than those in mice treated with estrogen only. As tissue controls, the effects of these conditions on normally located (eutopic) uterine tissue were evaluated. The effects of disruption of the P450arom gene and treatments with letrozole and estrogen seemed to be more profound on ectopic tissues, suggesting that ectopic tissues might be more sensitive to estrogen for growth. We conclude that both an intact P450arom gene and the presence of aromatase enzyme activity are essential for the growth of ectopic uterine tissue in a mouse model of endometriosis.

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Characterization of adenosine receptor(s) involved in adenosine-induced bronchoconstriction in an allergic mouse model

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00353.2002 ◽

2003 ◽

Vol 284 (6) ◽

pp. L1012-L1019 ◽

Cited By ~ 33

Author(s):

Ming Fan ◽

Weixi Qin ◽

S. Jamal Mustafa

Keyword(s):

Mouse Model ◽

Adenosine Receptor ◽

Receptor Subtypes ◽

Dependent Manner ◽

Transcript Levels ◽

Allergen Sensitization ◽

Selective Agonist ◽

Dose Dependent ◽

Allergic Mouse

We recently reported that adenosine caused bronchoconstriction and enhanced airway inflammation in an allergic mouse model. In this study, we further report the characterization of the subtype of adenosine receptor(s) involved in bronchoconstriction. 5′-( N-ethylcarboxamido)adenosine (NECA), a nonselective adenosine agonist, elicited bronchoconstriction in a dose-dependent manner. Little effects of N 6-cyclopentyladenosine (A1-selective agonist) and 2- p-(2-carboxyethyl)phenethylamino-5′- N-ethylcarboxamidoadenosine (A2A-selective agonist) compared with NECA were observed in this model. 2-Chloro- N 6-(3-iodobenzyl)-9-[5-(methylcarbamoyl)-β-d-ribofuranosyl]adenosine, an A3-selective receptor agonist, produced a dose-dependent bronchoconstrictor response, which was blocked by selective A3 antagonist 2,3-diethyl-4,5-dipropyl-6-phenylpyridine-3-thiocarboxylate-5-carboxylate (MRS1523). However, MRS1523 only partially inhibited NECA-induced bronchoconstriction. Neither selective A1 nor A2A antagonists affected NECA-induced bronchoconstriction. Enprofylline, a relatively selective A2B receptor antagonist, blocked partly NECA-induced bronchoconstriction. Furthermore, a combination of enprofylline and MRS1523 completely abolished NECA-induced bronchoconstrictor response. Using RT-PCR, we found that all four adenosine receptor subtypes are expressed in control lungs. Allergen sensitization and challenge significantly increased transcript levels of the A2B and A3receptors, whereas the A1 receptor message decreased. No change in transcript levels of A2A receptors was observed after allergen sensitization and challenge. These findings suggest that A2B and A3 adenosine receptors play an important role in adenosine-induced bronchoconstriction in our allergic mouse model. Finally, whether the airway effects of the receptor agonists/antagonists are direct or indirect needs further investigations.

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Piperine Plays an Anti-Inflammatory Role inStaphylococcus aureusEndometritis by Inhibiting Activation of NF-κB and MAPK Pathways in Mice

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2016/8597208 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Wen-jun Zhai ◽

Zhen-biao Zhang ◽

Nian-nian Xu ◽

Ying-fang Guo ◽

Changwei Qiu ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Inflammatory Response ◽

Mouse Model ◽

Biological Activities ◽

Dependent Manner ◽

Pathogenic Microorganisms ◽

Histopathological Changes ◽

Natural Medicine ◽

Anti Inflammatory ◽

Dose Dependent

Endometritis is commonly caused by pathogenic microorganisms, includingStaphylococcus aureus(S. aureus). Piperine, which is a natural medicine, has shown a variety of biological activities. To explore the effect and mechanism of piperine onS. aureusendometritis, a mouse model ofS. aureusendometritis was successfully established in the present study. Histopathological changes were observed with H&E staining, cytokines were analyzed by ELISA, mRNA was analyzed by qPCR, and proteins were detected by western blot. The results showed that piperine could significantly alleviate inflammatory injury inS. aureusendometritis. The qPCR and ELISA results showed that piperine effectively reduced theS. aureus-induced overexpression of TNF-α, IL-1β, and IL-6 but increased the expression of IL-10. TheS. aureus-induced inflammation was related to TLR-2 and TLR-4 because the results showed that their expression was increased inS. aureusinfection but then decreased with piperine treatment. To further confirm that piperine caused an anti-inflammatory response by targeting NF-κB and MAPKs, the expression of I-κB, p65, p38, ERK, and JNK was measured. The phosphorylation of I-κB, p65, p38, ERK, and JNK was inhibited by piperine in a dose-dependent manner. All of the results indicated that piperine may be a potential anti-inflammatory drug both in endometritis and in otherS. aureus-induced diseases.

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P0348THE DUAL ENDOTHELIN ETA AND ANGIOTENSIN AT1 RECEPTOR BLOCKER SPARSENTAN PROTECTS AGAINST THE DEVELOPMENT OF ALBUMINURIA AND GLOMERULOSCLEROSIS IN THE GDDY MOUSE MODEL OF IGA

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p0348 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Hajime Nagasawa ◽

Hitoshi Suzuki ◽

Celia Jenkinson ◽

Seiji Ueda ◽

Yusuke Fukao ◽

...

Keyword(s):

Mouse Model ◽

Plasma Levels ◽

Dependent Manner ◽

Phase 3 ◽

New Approach ◽

At1 Receptor Blocker ◽

Mesangioproliferative Glomerulonephritis ◽

Endothelin Type A Receptor ◽

Dose Dependent

Abstract Background and Aims gddY mice are an IgA nephropathy (IgAN)-prone mouse model that develops albuminuria by 8 weeks (wks) of age with glomerular IgA, IgG, and C3 deposits and progressive mesangioproliferative glomerulonephritis. A previous study in the ddY mouse model, the more genetically heterogeneous predecessor of gddY mice, using the endothelin type A receptor (ETAR) antagonist FR139317 resulted in amelioration of proteinuria and preservation of kidney function. Treatment of ddY mice with the angiotensin II type 1 receptor (AT1R) blocker valsartan resulted in significant protection from glomerulosclerosis (GS) without a significant prevention in proteinuria. Here we examined the effect of sparsentan (SP), a dual ETAR and AT1R blocker, currently in phase 3 trials for focal segmental glomerulosclerosis and IgAN, on the development of albuminuria and GS in gddY mice. Method gddY mice at 4 wks of age were fed with control (C) chow (n=5) or chow containing 900 ppm (n=10) or 1800 ppm (n=10) SP (approximately 180 and 360 mg/kg/day) for 8 wks. Albuminuria (U-Alb) was assessed at 4, 6, 8, and 12 wks of age and plasma levels of SP were determined at 8 am and 4 pm at wks 6, 8, and 12. Kidney biopsies were taken at the end of the study at 12 wks of age for processing and 30 glomeruli per animal were scored for the percentage of GS. Results gddY mice fed SP in the diet for 8 wks from 4 wks of age demonstrated significantly (*P<0.05) decreased U-Alb compared to mice fed the C diet in a dose-dependent manner (Figure 1). The development of GS in mice fed the diet containing 1800 ppm SP was significantly (*P<0.05) attenuated compared to C diet (Figure 2). Plasma levels of SP taken at 8 am and 4 pm after 8 wks of treatment were (mean±SD) 281±107 and 105±62 ng/ml for 900 ppm SP respectively, and 774±674 and 304±176 ng/ml for 1800 ppm SP, respectively. Weight gain in mice fed SP was not different from mice that received C diet. Conclusion Eight weeks of treatment with SP attenuated increases in albuminuria and GS associated with the development of IgAN in gddY mice. If translated to the clinic, these data support SP as a new approach to the treatment of IgAN.

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Anticonvulsant effect of dipropofol by enhancing native GABA currents in cortical neurons in mice

Journal of Neurophysiology ◽

10.1152/jn.00241.2018 ◽

2018 ◽

Vol 120 (3) ◽

pp. 1404-1414 ◽

Cited By ~ 5

Author(s):

Jingliang Zhang ◽

Xiaoling Chen ◽

Matti Kårbø ◽

Yi Zhao ◽

Long An ◽

...

Keyword(s):

Patch Clamp ◽

Mouse Model ◽

Kainic Acid ◽

Neuronal Excitability ◽

Brain Slices ◽

Anticonvulsant Effect ◽

Dependent Manner ◽

Whole Cell ◽

Whole Cell Patch Clamp ◽

Dose Dependent

Temporal lobe epilepsy (TLE), the most common pharmacoresistant focal epilepsy disorder, remains a major unmet medical need. Propofol is used as a short-acting medication for general anesthesia and refractory status epilepticus with issues of decreased consciousness and memory loss. Dipropofol, a derivative of propofol, has been reported to exert antioxidative and antibacterial activities. Here we report that dipropofol exerted anticonvulsant activity in a mouse model of kainic acid-induced seizures. Whole cell patch-clamp recordings of brain slices from the medial entorhinal cortex (mEC) revealed that dipropofol hyperpolarized the resting membrane potential and reduced the number of action potential firings, resulting in suppression of cortical neuronal excitability. Furthermore, dipropofol activated native tonic GABAA currents of mEC layer II stellate neurons in a dose-dependent manner with an EC50 value of 9.3 ± 1.6 μM (mean ± SE). Taken together, our findings show that dipropofol activated GABAA currents and exerted anticonvulsant activities in mice, thus possessing developmental potential for new anticonvulsant therapy. NEW & NOTEWORTHY The anticonvulsant effect of dipropofol was shown in a mouse model of kainic acid-induced seizures. Whole cell patch-clamp recordings of brain slices showed suppression of cortical neuronal excitability by dipropofol. Dipropofol activated the native tonic GABAA currents in a dose-dependent manner.

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