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Huo X, Wang Y, Liu Z, Liu J, Zhu H, Zhou Y, Man Y, Zhou X, Ma H. Electrophysiological and pharmacological properties of the slowpoke channel in the diamondback moth, Plutella xylostella. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 200:105824. [PMID: 38582588 DOI: 10.1016/j.pestbp.2024.105824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/07/2024] [Accepted: 02/07/2024] [Indexed: 04/08/2024]
Abstract
The slowpoke channel responds to the intracellular calcium concentration and the depolarization of the cell membrane. It plays an important role in maintaining the resting potential and regulating the homeostasis of neurons, but it can also regulate circadian rhythm, sperm capacitation, ethanol tolerance, and other physiological processes in insects. This renders it a potentially useful target for the development of pest control strategies. There are relatively few studies on the slowpoke channels in lepidopteran pests, and their pharmacological properties are still unclear. So, in this study, the slowpoke gene of Plutella xylostella (Pxslo) was heterologous expressed in HEK293T cells, and the I-V curve of the slowpoke channel was measured by whole cell patch clamp recordings. Results showed that the slowpoke channel could be activated at -20 mV with 150 μM Ca2+. The subsequent comparison of the electrophysiological characteristics of the alternative splicing site E and G deletions showed that the deletion of the E site enhances the response of the slowpoke channel to depolarization, while the deletion of the G site weakens the response of the slowpoke channel to depolarization. Meanwhile, the nonspecific inhibitors TEA and 4-AP of the Kv channels, and four pesticides were tested and all showed an inhibition effect on the PxSlo channel at 10 or 100 μM, suggesting that these pesticides also target the slowpoke channel. This study enriches our understanding of the slowpoke channel in Lepidopteran insects and can aid in the development of relevant pest management strategies.
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Affiliation(s)
- Xiaoyi Huo
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Longping Branch, College of Biology, Hunan University, Changsha 410125, China
| | - Yinna Wang
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Longping Branch, College of Biology, Hunan University, Changsha 410125, China
| | - Zheming Liu
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Jia Liu
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Hang Zhu
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Yong Zhou
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Yilong Man
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Xiaomao Zhou
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Longping Branch, College of Biology, Hunan University, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China
| | - Haihao Ma
- Institute of Agricultural Biotechnology, Hunan Academy of Agricultural Sciences, Changsha 410125, China; Longping Branch, College of Biology, Hunan University, Changsha 410125, China; Hunan Provincial Key Laboratory of Pesticide Biology and Precise Use Technology, Changsha 410125, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Changsha 410125, China.
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2
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Moldenhauer HJ, Tammen K, Meredith AL. Structural mapping of patient-associated KCNMA1 gene variants. Biophys J 2023:S0006-3495(23)04120-6. [PMID: 38042986 DOI: 10.1016/j.bpj.2023.11.3404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/04/2023] Open
Abstract
KCNMA1-linked channelopathy is a neurological disorder characterized by seizures, motor abnormalities, and neurodevelopmental disabilities. The disease mechanisms are predicted to result from alterations in KCNMA1-encoded BK K+ channel activity; however, only a subset of the patient-associated variants have been functionally studied. The localization of these variants within the tertiary structure or evaluation by pathogenicity algorithms has not been systematically assessed. In this study, 82 nonsynonymous patient-associated KCNMA1 variants were mapped within the BK channel protein. Fifty-three variants localized within cryoelectron microscopy-resolved structures, including 21 classified as either gain of function (GOF) or loss of function (LOF) in BK channel activity. Clusters of LOF variants were identified in the pore, the AC region (RCK1), and near the Ca2+ bowl (RCK2), overlapping with sites of pharmacological or endogenous modulation. However, no clustering was found for GOF variants. To further understand variants of uncertain significance (VUSs), assessments by multiple standard pathogenicity algorithms were compared, and new thresholds for sensitivity and specificity were established from confirmed GOF and LOF variants. An ensemble algorithm was constructed (KCNMA1 meta score (KMS)), consisting of a weighted summation of this trained dataset combined with a structural component derived from the Ca2+-bound and unbound BK channels. KMS assessment differed from the highest-performing individual algorithm (REVEL) at 10 VUS residues, and a subset were studied further by electrophysiology in HEK293 cells. M578T, E656A, and D965V (KMS+;REVEL-) were confirmed to alter BK channel properties in voltage-clamp recordings, and D800Y (KMS-;REVEL+) was assessed as benign under the test conditions. However, KMS failed to accurately assess K457E. These combined results reveal the distribution of potentially disease-causing KCNMA1 variants within BK channel functional domains and pathogenicity evaluation for VUSs, suggesting strategies for improving channel-level predictions in future studies by building on ensemble algorithms such as KMS.
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Affiliation(s)
- Hans J Moldenhauer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kelly Tammen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea L Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland.
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3
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Moldenhauer HJ, Tammen K, Meredith AL. Structural mapping of patient-associated KCNMA1 gene variants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.27.550850. [PMID: 37546746 PMCID: PMC10402178 DOI: 10.1101/2023.07.27.550850] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
KCNMA1-linked channelopathy is a neurological disorder characterized by seizures, motor abnormalities, and neurodevelopmental disabilities. The disease mechanisms are predicted to result from alterations in KCNMA1-encoded BK K+ channel activity; however, only a subset of the patient-associated variants have been functionally studied. The localization of these variants within the tertiary structure or evaluation by pathogenicity algorithms has not been systematically assessed. In this study, 82 nonsynonymous patient-associated KCNMA1 variants were mapped within the BK channel protein. Fifty-three variants localized within cryo-EM resolved structures, including 21 classified as either gain-of-function (GOF) or loss-of-function (LOF) in BK channel activity. Clusters of LOF variants were identified in the pore, the AC region (RCK1), and near the Ca 2+ bowl (RCK2), overlapping with sites of pharmacological or endogenous modulation. However, no clustering was found for GOF variants. To further understand variants of uncertain significance (VUS), assessments by multiple standard pathogenicity algorithms were compared, and new thresholds for sensitivity and specificity were established from confirmed GOF and LOF variants. An ensemble algorithm was constructed (KCNMA1 Meta Score), consisting of a weighted summation of this trained dataset combined with a structural component derived from the Ca 2+ bound and unbound BK channels. KMS assessment differed from the highest performing individual algorithm (REVEL) at 10 VUS residues, and a subset were studied further by electrophysiology in HEK293 cells. M578T, E656A, and D965V (KMS+;REVEL-) were confirmed to alter BK channel properties in voltage-clamp recordings, and D800Y (KMS-;REVEL+) was assessed as benign under the test conditions. However, KMS failed to accurately assess K457E. These combined results reveal the distribution of potentially disease-causing KCNMA1 variants within BK channel functional domains and pathogenicity evaluation for VUS, suggesting strategies for improving channel-level predictions in future studies by building on ensemble algorithms such as KMS.
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4
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Xia C, Liu C, Ren S, Cai Y, Zhang Q, Xia C. Potassium channels, tumorigenesis and targeted drugs. Biomed Pharmacother 2023; 162:114673. [PMID: 37031494 DOI: 10.1016/j.biopha.2023.114673] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023] Open
Abstract
Potassium channels play an important role in human physiological function. Recently, various molecular mechanisms have implicated abnormal functioning of potassium channels in the proliferation, migration, invasion, apoptosis, and cancer stem cell phenotype formation. Potassium channels also mediate the association of tumor cells with the tumor microenvironment. Meanwhile, potassium channels are important targets for cancer chemotherapy. A variety of drugs exert anti-cancer effects by modulating potassium channels in tumor cells. Therefore, there is a need to understand how potassium channels participate in tumor development and progression, which could reveal new, novel targets for cancer diagnosis and treatment. This review summarizes the roles of voltage-gated potassium channels, calcium-activated potassium channels, inwardly rectifying potassium channels, and two-pore domain potassium channels in tumorigenesis and the underlying mechanism of potassium channel-targeted drugs. Therefore, the study lays the foundation for rational and effective drug design and individualized clinical therapeutics.
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Affiliation(s)
- Cong Xia
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China
| | - Can Liu
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China; School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Shuangyi Ren
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China
| | - Yantao Cai
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China
| | - Qianshi Zhang
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China.
| | - Chenglai Xia
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China; School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China.
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5
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Reyes-García J, Díaz-Hernández V, Carbajal-García A, Casas-Hernández MF, Sommer B, Montaño LM. Theophylline-Induced Relaxation Is Enhanced after Testosterone Treatment via Increased K V1.2 and K V1.5 Protein Expression in Guinea Pig Tracheal Smooth Muscle. Int J Mol Sci 2023; 24:ijms24065884. [PMID: 36982957 PMCID: PMC10059212 DOI: 10.3390/ijms24065884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/16/2023] [Accepted: 02/25/2023] [Indexed: 03/30/2023] Open
Abstract
Theophylline is a drug commonly used to treat asthma due to its anti-inflammatory and bronchodilatory properties. Testosterone (TES) has been suggested to reduce the severity of asthma symptoms. This condition affects boys more than girls in childhood, and this ratio reverses at puberty. We reported that guinea pig tracheal tissue chronic exposure to TES increases the expression of β2-adrenoreceptors and enhances salbutamol-induced K+ currents (IK+). Herein, we investigated whether the upregulation of K+ channels can enhance the relaxation response to methylxanthines, including theophylline. Chronic incubation of guinea pig tracheas with TES (40 nM, 48 h) enhanced the relaxation induced by caffeine, isobutylmethylxanthine, and theophylline, an effect that was abolished by tetraethylammonium. In tracheal myocytes, chronic incubation with TES increased theophylline-induced IK+; flutamide reversed this effect. The increase in IK+ was blocked by 4-aminopyridine by ~82%, whereas iberiotoxin reduced IK+ by ~17%. Immunofluorescence studies showed that chronic TES exposure increased the expression of KV1.2 and KV1.5 in airway smooth muscle (ASM). In conclusion, chronic exposure to TES in guinea pig ASM promotes upregulation of KV1.2 and KV1.5 and enhances theophylline relaxation response. Therefore, gender should be considered when prescribing methylxanthines, as teenage boys and males are likely to respond better than females.
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Affiliation(s)
- Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Verónica Díaz-Hernández
- Departamento de Embriología y Genética, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Abril Carbajal-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - María F Casas-Hernández
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Bettina Sommer
- Laboratorio de Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Mexico City 14080, Mexico
| | - Luis M Montaño
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
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Wang Y, Gao T, Shan L, Li K, Liang F, Yu J, Ni Y, Sun P. Iberiotoxin and clofilium regulate hyperactivation, acrosome reaction, and ion homeostasis synergistically during human sperm capacitation. Mol Reprod Dev 2023; 90:129-140. [PMID: 36682071 DOI: 10.1002/mrd.23671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 12/27/2022] [Accepted: 01/11/2023] [Indexed: 01/24/2023]
Abstract
Potassium channels play essential roles in the regulation of male fertility. However, potassium channels mediating K+ currents in human sperm (IKSper ) remain controversial. Besides SLO3, the SLO1 potassium channel is a potential candidate for human sperm KSper. This study intends to elucidate the function of SLO1 potassium channel during human sperm capacitation. Human sperm were treated with iberiotoxin (IbTX, a SLO1 specific inhibitor) and clofilium (SLO3 inhibitor) separately or simultaneously during in vitro capacitation. A computer-assisted sperm analyzer was used to assess sperm motility. The sperm acrosome reaction (AR) was analyzed using fluorescein isothiocyanate-conjugated Pisum sativum agglutinin staining. Sperm protein tyrosine phosphorylation was studied using western blotting. Intracellular Ca2+ , K+ , Cl- , and pH were analyzed using ion fluorescence probes. Independent inhibition with IbTX or clofilium decreased the sperm hyperactivation, AR, and protein tyrosine phosphorylation, and was accompanied by an increase in [K+ ]i , [Cl- ]i , and pHi , but a decrease in [Ca2+ ]i . Simultaneously inhibition with IbTX and clofilium lower sperm hyperactivation and AR more than independent inhibition. The increase in [K+ ]i , [Cl- ]i , and pHi , and the decrease in [Ca2+ ]i were more pronounced. This study suggested that the SLO1 potassium channel may have synergic roles with SLO3 during human sperm capacitation.
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Affiliation(s)
- Yayan Wang
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Department of Gynecology and Obstetrics, Lishui People's Hospital, Lishui, Zhejiang, China
| | - Tian Gao
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Lijun Shan
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Kun Li
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial Laboratory of Experimental Animal's & Nonclinical Laboratory Studies, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Fei Liang
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial Laboratory of Experimental Animal's & Nonclinical Laboratory Studies, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Jianmin Yu
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial Laboratory of Experimental Animal's & Nonclinical Laboratory Studies, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Ya Ni
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial Laboratory of Experimental Animal's & Nonclinical Laboratory Studies, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Peibei Sun
- School of Pharmacy, Hangzhou Medical College, Hangzhou, Zhejiang, China
- Zhejiang Provincial Laboratory of Experimental Animal's & Nonclinical Laboratory Studies, Hangzhou Medical College, Hangzhou, Zhejiang, China
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7
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Potassium channelopathies associated with epilepsy-related syndromes and directions for therapeutic intervention. Biochem Pharmacol 2023; 208:115413. [PMID: 36646291 DOI: 10.1016/j.bcp.2023.115413] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
A number of mutations to members of several CNS potassium (K) channel families have been identified which result in rare forms of neonatal onset epilepsy, or syndromes of which one prominent characteristic is a form of epilepsy. Benign Familial Neonatal Convulsions or Seizures (BFNC or BFNS), also referred to as Self-Limited Familial Neonatal Epilepsy (SeLNE), results from mutations in 2 members of the KV7 family (KCNQ) of K channels; while generally self-resolving by about 15 weeks of age, these mutations significantly increase the probability of generalized seizure disorders in the adult, in some cases they result in more severe developmental syndromes. Epilepsy of Infancy with Migrating Focal Seizures (EIMSF), or Migrating Partial Seizures of Infancy (MMPSI), is a rare severe form of epilepsy linked primarily to gain of function mutations in a member of the sodium-dependent K channel family, KCNT1 or SLACK. Finally, KCNMA1 channelopathies, including Liang-Wang syndrome (LIWAS), are rare combinations of neurological symptoms including seizure, movement abnormalities, delayed development and intellectual disabilities, with Liang-Wang syndrome an extremely serious polymalformative syndrome with a number of neurological sequelae including epilepsy. These are caused by mutations in the pore-forming subunit of the large-conductance calcium-activated K channel (BK channel) KCNMA1. The identification of these rare but significant channelopathies has resulted in a resurgence of interest in their treatment by direct pharmacological or genetic modulation. We will briefly review the genetics, biophysics and pharmacology of these K channels, their linkage with the 3 syndromes described above, and efforts to more effectively target these syndromes.
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8
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Characterization of a Family of Scorpion Toxins Modulating Ca 2+-Activated Cl - Current in Vascular Myocytes. Toxins (Basel) 2022; 14:toxins14110780. [PMID: 36356031 PMCID: PMC9699600 DOI: 10.3390/toxins14110780] [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: 06/01/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/12/2022] Open
Abstract
The pharmacology of calcium-activated chloride current is not well developed. Peptides from scorpion venom present potent pharmacological actions on ionic conductance used to characterize the function of channels but can also be helpful to develop organic pharmacological tools. Using electrophysiological recording coupled with calcium measurement, we tested the potent effect of peptides extracted from Leuirus quinquestratus quinquestratus venom on the calcium-activated chloride current expressed in smooth muscle cells freshly dissociated from rat portal veins. We identified one peptide which selectively inhibited the chloride conductance without effects on either calcium signaling or calcium and potassium currents expressed in this cell type. The synthetic peptide had the same affinity, but the chemical modification of the amino acid sequence altered the efficiency to inhibit the calcium-activated chloride conductance.
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9
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Gao K, Lin Z, Wen S, Jiang Y. Potassium channels and epilepsy. Acta Neurol Scand 2022; 146:699-707. [PMID: 36225112 DOI: 10.1111/ane.13695] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 08/16/2022] [Indexed: 01/10/2023]
Abstract
With the development and application of next-generation sequencing technology, the aetiological diagnosis of genetic epilepsy is rapidly becoming easier and less expensive. Additionally, there is a growing body of research into precision therapy based on genetic diagnosis. The numerous genes in the potassium ion channel family constitute the largest family of ion channels: this family is divided into different subtypes. Potassium ion channels play a crucial role in the electrical activity of neurons and are directly involved in the mechanism of epileptic seizures. In China, scientific research on genetic diagnosis and studies of precision therapy for genetic epilepsy are progressing rapidly. Many cases of epilepsy caused by mutation of potassium channel genes have been identified, and several potassium channel gene targets and drug candidates have been discovered. The purpose of this review is to briefly summarize the progress of research on the precise diagnosis and treatment of potassium ion channel-related genetic epilepsy, especially the research conducted in China. Here in, we review several large cohort studies on the genetic diagnosis of epilepsy in China in recent years, summarized the proportion of potassium channel genes. We focus on the progress of precison therapy on some hot epilepsy related potassium channel genes: KCNA1, KCNA2, KCNB1, KCNC1, KCND2, KCNQ2, KCNQ3, KCNMA1, and KCNT1.
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Affiliation(s)
- Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Zehong Lin
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Sijia Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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10
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Slayden AV, Dyer CL, Ma D, Li W, Bukiya AN, Parrill AL, Dopico AM. Discovery of agonist-antagonist pairs for the modulation of Ca [2]+ and voltage-gated K + channels of large conductance that contain beta1 subunits. Bioorg Med Chem 2022; 68:116876. [PMID: 35716586 PMCID: PMC10464842 DOI: 10.1016/j.bmc.2022.116876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/31/2022] [Accepted: 06/03/2022] [Indexed: 11/02/2022]
Abstract
Large conductance, calcium/voltage-gated potassium channels (BK) regulate critical body processes, including neuronal, secretory and smooth muscle (SM) function. While BK-forming alpha subunits are ubiquitous, accessory beta1 subunits are highly expressed in SM. This makes beta1 an attractive target for pharmaceutical development to treat SM disorders, such as hypertension or cerebrovascular spasm. Compounds activating BK via beta1 have been identified, yet they exhibit low potency and off-target effects while antagonists that limit agonist activity via beta 1 remain unexplored. Beta1-dependent BK ligand-based pharmacophore modeling and ZINC database searches identified 15 commercially available hits. Concentration-response curves on BK alpha + beta1 subunit-mediated currents were obtained in CHO cells. One potent (EC50 = 20 nM) and highly efficacious activator (maximal activation = ×10.3 of control) was identified along with a potent antagonist (KB = 3.02 nM), both of which were dependent on beta1. Our study provides the first proof-of-principle that an agonist/antagonist pair can be used to control beta1-containing BK activity.
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Affiliation(s)
- Alexandria V Slayden
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis TN, 38103, USA
| | - Christy L Dyer
- Department of Chemistry, The University of Memphis, Memphis TN, 38152, USA
| | - Dejian Ma
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis TN, 38163, USA
| | - Wei Li
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis TN, 38163, USA
| | - Anna N Bukiya
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis TN, 38103, USA
| | - Abby L Parrill
- Department of Chemistry, The University of Memphis, Memphis TN, 38152, USA
| | - Alex M Dopico
- Department of Pharmacology, Addiction Science and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis TN, 38103, USA.
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11
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Neonatal Diabetes in Patients Affected by Liang-Wang Syndrome Carrying KCNMA1 Variant p.(Gly375Arg) Suggest a Potential Role of Ca 2+ and Voltage-Activated K + Channel Activity in Human Insulin Secretion. Curr Issues Mol Biol 2021; 43:1036-1042. [PMID: 34563042 PMCID: PMC8928946 DOI: 10.3390/cimb43020073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 12/22/2022] Open
Abstract
Liang-Wang syndrome (LIWAS) is a polymalformative syndrome first described in 2019 caused by heterozygous mutation of the KCNMA1 gene encoding the Ca2+ and voltage-activated K+ channel (BKC). The KCNMA1 variant p.(Gly356Arg) abolishes the function of BKC and blocks the generation of K+ current. The phenotype of this variant includes developmental delay, and visceral and connective tissue malformations. So far, only three cases of LWAS have been described, one of which also had neonatal diabetes (ND). We present the case of a newborn affected by LIWAS carrying the p.(Gly375Arg) variant who manifested diabetes in the first week of life. The description of our case strongly increases the frequency of ND in LIWAS patients and suggests a role of BK inactivation in human insulin secretion. The knowledge on the role of BKC in insulin secretion is very poor. Analyzing the possible mechanisms that could explain the association of LIWAS with ND, we speculate that BK inactivation might impair insulin secretion through the alteration of ion-dependent membrane activities and mitochondrial functions in β-cells, as well as the impaired intra-islet vessel reactivity.
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12
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Huang S, Chen T, Suo Q, Shi R, Khan H, Ma Y, Tang Y, Yang GY, Zhang Z. BK Channel-Mediated Microglial Phagocytosis Alleviates Neurological Deficit After Ischemic Stroke. Front Cell Neurosci 2021; 15:683769. [PMID: 34276309 PMCID: PMC8281043 DOI: 10.3389/fncel.2021.683769] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
Microglial phagocytosis benefits neurological recovery after stroke. Large-conductance Ca2+-activated K+ currents are expressed in activated microglia, and BK channel knockout aggravates cerebral ischemic injury. However, the effect of BK channels on microglial phagocytosis after ischemic stroke remains unknown. Here, we explored whether BK channel activation is beneficial for neurological outcomes through microglial phagocytosis after ischemic stroke. ICR mice after transient middle cerebral artery occlusion (tMCAO) were treated with dimethyl sulfoxide (DMSO), BK channel activator NS19504, and inhibitor Paxilline. The results showed a decrease in BK channel expression after tMCAO. BK channel activator NS19504 alleviates neurological deficit after experimental modeling of tMCAO in mice compared to the control. Furthermore, we treated primary microglia with DMSO, NS19504, and Paxilline after oxygen glucose deprivation (OGD). NS19504 promoted primary microglial phagocytosing fluorescent beads and neuronal debris, which reduced neuronal apoptosis after stroke. These effects could be reversed by BK channel inhibitor Paxilline. Finally, NS19504 increased relative phosphorylated extracellular signal-regulated kinase 1/2 expression compared to the Paxilline group at the third day after stroke. Our findings indicate that microglial BK channels are a potential target for acute stage of ischemic stroke therapy.
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Affiliation(s)
- Shuxian Huang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Tingting Chen
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qian Suo
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Rubing Shi
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Haroon Khan
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yuanyuan Ma
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yaohui Tang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhijun Zhang
- Shanghai Jiao Tong University Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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13
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Raupach A, Karakurt E, Torregroza C, Bunte S, Feige K, Stroethoff M, Brandenburger T, Heinen A, Hollmann MW, Huhn R. Dexmedetomidine Provides Cardioprotection During Early or Late Reperfusion Mediated by Different Mitochondrial K+-Channels. Anesth Analg 2021; 132:253-260. [PMID: 32889843 DOI: 10.1213/ane.0000000000005148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Cardioprotective interventions-such as pharmacological postconditioning-are a promising strategy to reduce deleterious consequences of ischemia and reperfusion injury (I/RI) in the heart, especially as timing and onset of myocardial infarction are unpredictable. Pharmacological postconditioning by treatment with dexmedetomidine (Dex), an α2-adrenoreceptor agonist, during reperfusion protects hearts from I/RI, independently of time point and duration of application during the reperfusion phase. The mitochondrial ATP-sensitive K (mKATP) and mitochondrial large-conductance calcium-sensitive potassium channel (mBKCa) play a pivotal role in mediating this cardioprotective effect. Therefore, we investigated whether Dex-induced cardioprotection during early or late reperfusion is mediated variously by these mitochondrial K-channels. METHODS Hearts of male Wistar rats were randomized into 8 groups and underwent a protocol of 15 minutes adaption, 33 minutes ischemia, and 60 minutes reperfusion in an in vitro Langendorff-system. A 10-minute treatment phase was started directly (first subgroup, early reperfusion) or 30 minutes (second subgroup, late reperfusion) after the onset of reperfusion. Control (Con) hearts received vehicle only. In the first subgroup, hearts were treated with 3 nM Dex, 100 µM mKATP-channel blocker 5-hydroxydecanoate (5HD) or 1 µM mBKCa-channel blocker Paxilline (Pax) alone or with respective combinations (5HD + Dex, Pax + Dex). Hearts of the second subgroup received Dex alone (Dex30') or in combination with the respective blockers (5HD + Dex30', Pax + Dex30'). Infarct size was determined with triphenyltetrazoliumchloride staining. Hemodynamic variables were recorded during the whole experiment. RESULTS During early reperfusion (first subgroup), the infarct size reducing effect of Dex (Con: 57% ± 9%, Dex: 31% ± 7%; P< .0001 versus Con) was completely abolished by 5HD and Pax (52% ± 6%; Pax + Dex: 53% ± 4%; each P< .0001 versus Dex), while both blockers alone had no effect on infarct size (5HD: 54% ± 8%, Pax: 53% ± 11%). During late reperfusion (second subgroup) the protective effect of Dex (Dex30': 33% ± 10%, P< .0001 versus Con) was fully abrogated by Pax (Pax + Dex30': 58% ± 7%, P < .0001 versus Dex30'), whereas 5HD did not block cardioprotection (5HD + Dex30': 36% ± 7%). Between groups and within each group throughout reperfusion no significant differences in hemodynamic variables were detected. CONCLUSIONS Cardioprotection by treatment with Dex during early reperfusion seems to be mediated by both mitochondrial K-channels, whereas during late reperfusion only mBKCa-channels are involved.
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Affiliation(s)
- Annika Raupach
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Elif Karakurt
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Carolin Torregroza
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Sebastian Bunte
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany.,Department of Internal Medicine, Elbe Clinics Stade-Buxtehude, Stade, Germany
| | - Katharina Feige
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Martin Stroethoff
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - Timo Brandenburger
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
| | - André Heinen
- Institute of Cardiovascular Physiology, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Markus W Hollmann
- Department of Anesthesiology, Amsterdam University Medical Center (AUMC), Amsterdam, the Netherlands
| | - Ragnar Huhn
- From the Department of Anesthesiology, University Hospital Duesseldorf, Duesseldorf, Germany
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14
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Alves QL, Moraes RDA, Froes TQ, Castilho MS, Aquino de Araújo RS, Barbosa-Filho JM, Meira CS, Pereira Soares MB, Silva DF. Inhibition of intracellular Ca 2+ mobilization and potassium channels activation are involved in the vasorelaxation induced by 7-hydroxycoumarin. Eur J Pharmacol 2020; 887:173525. [PMID: 32889064 DOI: 10.1016/j.ejphar.2020.173525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/24/2020] [Accepted: 08/28/2020] [Indexed: 11/30/2022]
Abstract
Coumarins exhibit a wide variety of biological effects, including activities in the cardiovascular system and the aim of this study was to evaluate the vascular therapeutic potential of 7-Hydroxicoumarin (7-HC). The vascular effects induced by 7-HC (0.001 μM-300 μM), were investigated by in vitro approaches using isometric tension measurements in rat superior mesenteric arteries and by in silico assays using Ligand-based analysis. Our results suggest that the vasorelaxant effect of 7-HC seems to rely on potassium channels, notably through large conductance Ca2+-activated K+ (BKCa) channels activation. In fact, 7-HC (300 μM) significantly reduced CaCl2-induced contraction as well as the reduction of intracellular calcium mobilization. However, the relaxation induced by 7-HC was independent of store-operated calcium entry (SOCE). Moreover, in silico analysis suggests that potassium channels have a common binding pocket, where 7-HC may bind and hint that its binding profile is more similar to quinine's than verapamil's. These results are compatible with the inhibition of Ca2+ release from intracellular stores, which is prompted by phenylephrine and caffeine. Taken together, these results demonstrate a therapeutic potential of 7-HC on the cardiovascular system, making it a promising lead compound for the development of drugs useful in the treatment of cardiovascular diseases.
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Affiliation(s)
- Quiara Lovatti Alves
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, BA, 40110-902, Brazil; Gonçalo Moniz Institute, Oswaldo Cruz Foundation, FIOCRUZ, Bahia, Brazil
| | - Raiana Dos Anjos Moraes
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, BA, 40110-902, Brazil; Gonçalo Moniz Institute, Oswaldo Cruz Foundation, FIOCRUZ, Bahia, Brazil
| | - Thamires Quadros Froes
- Laboratory of Bioinformatics and Molecular Modeling, Faculty of Pharmacy, Federal University of Bahia, Salvador, BA, 40170-115, Brazil
| | - Marcelo Santos Castilho
- Laboratory of Bioinformatics and Molecular Modeling, Faculty of Pharmacy, Federal University of Bahia, Salvador, BA, 40170-115, Brazil
| | - Rodrigo Santos Aquino de Araújo
- Laboratory of Pharmaceutical Technology, Department of Physiology and Pathology, Federal University of Paraíba, João Pessoa, PB, 58051-970, Brazil
| | - José Maria Barbosa-Filho
- Laboratory of Pharmaceutical Technology, Department of Physiology and Pathology, Federal University of Paraíba, João Pessoa, PB, 58051-970, Brazil
| | | | | | - Darízy Flávia Silva
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, BA, 40110-902, Brazil; Gonçalo Moniz Institute, Oswaldo Cruz Foundation, FIOCRUZ, Bahia, Brazil.
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15
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Housley DM, Pinyon JL, von Jonquieres G, Perera CJ, Smout M, Liddell MJ, Jennings EA, Wilson D, Housley GD. Australian Scorpion Hormurus waigiensis Venom Fractions Show Broad Bioactivity Through Modulation of Bio-Impedance and Cytosolic Calcium. Biomolecules 2020; 10:E617. [PMID: 32316246 PMCID: PMC7226344 DOI: 10.3390/biom10040617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/06/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Scorpion venoms are a rich source of bioactive molecules, but characterisation of toxin peptides affecting cytosolic Ca2+, central to cell signalling and cell death, is limited. We undertook a functional screening of the venom of the Australian scorpion Hormurus waigiensis to determine the breadth of Ca2+ mobilisation. A human embryonic kidney (HEK293) cell line stably expressing the genetically encoded Ca2+ reporter GCaMP5G and the rabbit type 1 ryanodine receptor (RyR1) was developed as a biosensor. Size-exclusion Fast Protein Liquid Chromatography separated the venom into 53 fractions, constituting 12 chromatographic peaks. Liquid chromatography mass spectroscopy identified 182 distinct molecules with 3 to 63 components per peak. The molecular weights varied from 258 Da-13.6 kDa, with 53% under 1 kDa. The majority of the venom chromatographic peaks (tested as six venom pools) were found to reversibly modulate cell monolayer bioimpedance, detected using the xCELLigence platform (ACEA Biosciences). Confocal Ca2+ imaging showed 9/14 peak samples, with molecules spanning the molecular size range, increased cytosolic Ca2+ mobilization. H. waigiensis venom Ca2+ activity was correlated with changes in bio-impedance, reflecting multi-modal toxin actions on cell physiology across the venom proteome.
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Affiliation(s)
- David M. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; (D.M.H.); (J.L.P.); (G.v.J.); (C.J.P.)
- Department of Otolaryngology, Sunshine Coast University Hospital, Sunshine Coast, QLD 4575, Australia
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, QLD 4878, Australia;
| | - Jeremy L. Pinyon
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; (D.M.H.); (J.L.P.); (G.v.J.); (C.J.P.)
| | - Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; (D.M.H.); (J.L.P.); (G.v.J.); (C.J.P.)
| | - Chamini J. Perera
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; (D.M.H.); (J.L.P.); (G.v.J.); (C.J.P.)
| | - Michael Smout
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia; (M.S.); (D.W.)
- Centre for Molecular Therapeutics, James Cook University, Cairns, QLD 4878, Australia
| | - Michael J. Liddell
- Centre for Tropical Environmental and Sustainability Science, College of Science & Engineering, Cairns Campus, James Cook University, Cairns, QLD 4878, Australia;
| | - Ernest A. Jennings
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, QLD 4878, Australia;
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia; (M.S.); (D.W.)
- Centre for Molecular Therapeutics, James Cook University, Cairns, QLD 4878, Australia
| | - David Wilson
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia; (M.S.); (D.W.)
- Centre for Molecular Therapeutics, James Cook University, Cairns, QLD 4878, Australia
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; (D.M.H.); (J.L.P.); (G.v.J.); (C.J.P.)
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16
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Miłaczewska A, Borowski T. On the reaction mechanism of an endoperoxide ring formation by fumitremorgin B endoperoxidase. The right arrangement makes a difference. Dalton Trans 2019; 48:16211-16221. [PMID: 31580360 DOI: 10.1039/c9dt02581b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Fumitremorgin B endoperoxidase (FtmF) belongs to 2-oxoglutarate dependent dioxygenases and catalyzes an unusual oxidative reaction of endoperoxide formation at the final stage of biosynthesis of verruculogen - a mycotoxin produced by Aspergillus and Penicillinum strains. The published crystal structure of FtmF (PDB: ), which is of overall good quality, contains a model of the substrate bound in the active site, which, however, has very low occupancy and its conformation does not comply with the small molecule crystal structure. Moreover, a previous computational study that employed a model based on this crystal structure revealed a substantial reaction barrier, which might indicate that the model of FtmF/substrate complex can have serious errors. The purpose of this work was to model with computational methods the structure of the enzyme-substrate complex and to investigate the mechanisms of the enzymatic reaction. Docking, molecular dynamics simulation and DFT results, all indicate the substrate most likely binds in the active site in a configuration very different from that originally suggested. Moreover, for this newly proposed structure of the enzyme-substrate complex, the reaction energy profile is characterised exclusively by low barriers and it successfully explains the observed regiospecificity of the enzymatic process. Finally, a plausible binding site for ascorbate was found and it is suggested that ascorbate is involved in the final step of the FtmF reaction.
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Affiliation(s)
- Anna Miłaczewska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Kraków, Poland.
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Kraków, Poland.
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17
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Optimization of Scorpion Protein Extraction and Characterization of the Proteins' Functional Properties. Molecules 2019; 24:molecules24224103. [PMID: 31766309 PMCID: PMC6891329 DOI: 10.3390/molecules24224103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 11/17/2022] Open
Abstract
Scorpion has long been used in traditional Chinese medicine, because whole scorpion body extract has anti-cancer, analgesic, anti-thrombotic blood anti-coagulation, immune modulating, anti-epileptic, and other functions. The purpose of this study was to find an efficient extraction method and investigate some of physical and chemical parameters, like water solubility, emulsification, foaming properties, and oil-holding capacity of obtained scorpion proteins. Response surface methodology (RSM) was used for the determination of optimal parameters of ultrasonic extraction (UE). Based on single factor experiments, three factors (ultrasonic power (w), liquid/solid (mL/g) ratio, and extraction time (min)) were used for the determination of scorpion proteins (SPs). The order of the effects of the three factors on the protein content and yield were ultrasonic power > extraction time > liquid/solid ratio, and the optimum conditions of extraction proteins were as follows: extraction time = 50.00 min, ultrasonic power = 400.00 w, and liquid/solid ratio = 18.00 mL/g. For the optimal conditions, the protein content of the ultrasonic extraction and yield were 78.94% and 24.80%, respectively. The solubility, emulsification and foaming properties, and water and oil holding capacity of scorpion proteins were investigated. The results of this study suggest that scorpion proteins can be considered as an important ingredient and raw material for the creation of water-soluble supramolecular complexes for drugs.
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18
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Yang X, Wang G, Cao T, Zhang L, Ma Y, Jiang S, Teng X, Sun X. Large-conductance calcium-activated potassium channels mediate lipopolysaccharide-induced activation of murine microglia. J Biol Chem 2019; 294:12921-12932. [PMID: 31296663 DOI: 10.1074/jbc.ra118.006425] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 07/02/2019] [Indexed: 12/28/2022] Open
Abstract
Large-conductance calcium-activated potassium (BK) channels are ubiquitously expressed in most cell types where they regulate many cellular, organ, and organismal functions. Although BK currents have been recorded specifically in activated murine and human microglia, it is not yet clear whether and how the function of this channel is related to microglia activation. Here, using patch-clamping, Griess reaction, ELISA, immunocytochemistry, and immunoblotting approaches, we show that specific inhibition of the BK channel with paxilline (10 μm) or siRNA-mediated knockdown of its expression significantly suppresses lipopolysaccharide (LPS)-induced (100 ng/ml) BV-2 and primary mouse microglial cell activation. We found that membrane BK current is activated by LPS at a very early stage through Toll-like receptor 4 (TLR4), leading to nuclear translocation of NF-κB and to production of inflammatory cytokines. Furthermore, we noted that BK channels are also expressed intracellularly, and their nuclear expression significantly increases in late stages of LPS-mediated microglia activation, possibly contributing to production of nitric oxide, tumor necrosis factor-α, and interleukin-6. Of note, a specific TLR4 inhibitor suppressed BK channel expression, whereas an NF-κB inhibitor did not. Taken together, our findings indicate that BK channels participate in both the early and the late stages of LPS-stimulated murine microglia activation involving both membrane-associated and nuclear BK channels.
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Affiliation(s)
- Xiaoying Yang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Guiqin Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Ting Cao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Li Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Yunzhi Ma
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Shuhui Jiang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Xinchen Teng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Xiaohui Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Collaborative Innovation Center for Brain Science, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China.
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19
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Raupach A, Reinle J, Stroethoff M, Mathes A, Heinen A, Hollmann MW, Huhn R, Bunte S. Milrinone-Induced Pharmacological Preconditioning in Cardioprotection: Hints for a Role of Mitochondrial Mechanisms. J Clin Med 2019; 8:jcm8040507. [PMID: 31013843 PMCID: PMC6517902 DOI: 10.3390/jcm8040507] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/29/2019] [Accepted: 04/10/2019] [Indexed: 02/06/2023] Open
Abstract
The activation of mitochondrial calcium-sensitive potassium (mBKCa) channels is crucially involved in cardioprotection induced by preconditioning. For milrinone (Mil)-induced preconditioning, the involvement of mBKCa-channels and further mitochondrial signaling is unknown. We hypothesize that (1) Mil-induced preconditioning is concentration-dependent and (2) that the activation of mBKCa-channels, release of reactive oxygen species (ROS), and the mitochondrial permeability transition pore (mPTP) could be involved. Isolated hearts of male Wistar rats were perfused with Krebs-Henseleit buffer and underwent 33 min of ischemia followed by 60 min of reperfusion. For determination of a concentration-dependent effect of Mil, hearts were perfused with different concentrations of Mil (0.3–10 µM) over 10 min before ischemia. In a second set of experiments, in addition to controls, hearts were pretreated with the lowest protective concentration of 1 µM Mil either alone or combined with the mBKCa-channel blocker paxilline (Pax + Mil), or paxilline alone (Pax). In additional groups, Mil was administered with and without the ROS scavenger N-2-mercaptopropionylglycine (MPG + Mil, MPG) or the mPTP inhibitor cyclosporine A (MPG + Mil + CsA, CsA + Mil), respectively. Infarct sizes were determined by triphenyltetrazolium chloride (TTC) staining. The lowest and most cardioprotective concentration was 1 µM Mil (Mil 1: 32 ± 6%; p < 0.05 vs. Con: 63 ± 8% and Mil 0.3: 49 ± 6%). Pax and MPG blocked the infarct size reduction of Mil (Pax + Mil: 53 ± 6%, MPG + Mil: 59 ± 7%; p < 0.05 vs. Mil: 34 ± 6%) without having an effect on infarct size when administered alone (Pax: 53 ± 7%, MPG: 58 ± 5%; ns vs. Con). The combined administration of CsA completely restored the MPG-inhibited cardioprotection of Mil (MPG + Mil + CsA: 35 ± 7%, p < 0.05 vs. MPG + Mil). Milrinone concentration-dependently induces preconditioning. Cardioprotection is mediated by the activation of mBKCa-channels, release of ROS and mPTP inhibition.
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Affiliation(s)
- Annika Raupach
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Julia Reinle
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Martin Stroethoff
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Alexander Mathes
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
| | - André Heinen
- Institute of Cardiovascular Physiology, Heinrich-Heine-University Duesseldorf, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
| | - Markus W Hollmann
- Department of Anesthesiology, Amsterdam University Medical Center (AUMC), Location AMC, Meiberdreef 9, 1105 AZ Amsterdam, The Netherlands.
| | - Ragnar Huhn
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | - Sebastian Bunte
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf, Germany.
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20
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Leanza L, Checchetto V, Biasutto L, Rossa A, Costa R, Bachmann M, Zoratti M, Szabo I. Pharmacological modulation of mitochondrial ion channels. Br J Pharmacol 2019; 176:4258-4283. [PMID: 30440086 DOI: 10.1111/bph.14544] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/15/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022] Open
Abstract
The field of mitochondrial ion channels has undergone a rapid development during the last three decades, due to the molecular identification of some of the channels residing in the outer and inner membranes. Relevant information about the function of these channels in physiological and pathological settings was gained thanks to genetic models for a few, mitochondria-specific channels. However, many ion channels have multiple localizations within the cell, hampering a clear-cut determination of their function by pharmacological means. The present review summarizes our current knowledge about the ins and outs of mitochondrial ion channels, with special focus on the channels that have received much attention in recent years, namely, the voltage-dependent anion channels, the permeability transition pore (also called mitochondrial megachannel), the mitochondrial calcium uniporter and some of the inner membrane-located potassium channels. In addition, possible strategies to overcome the difficulties of specifically targeting mitochondrial channels versus their counterparts active in other membranes are discussed, as well as the possibilities of modulating channel function by small peptides that compete for binding with protein interacting partners. Altogether, these promising tools along with large-scale chemical screenings set up to identify new, specific channel modulators will hopefully allow us to pinpoint the actual function of most mitochondrial ion channels in the near future and to pharmacologically affect important pathologies in which they are involved, such as neurodegeneration, ischaemic damage and cancer. LINKED ARTICLES: This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc.
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Affiliation(s)
- Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| | | | - Lucia Biasutto
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Andrea Rossa
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Roberto Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | - Mario Zoratti
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
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21
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Bisen S, Simakova MN, Dopico AM, Bukiya AN. Large conductance voltage- and calcium-gated potassium channels (BK) in cerebral artery myocytes of perinatal fetal primates share several major characteristics with the adult phenotype. PLoS One 2018; 13:e0203199. [PMID: 30212531 PMCID: PMC6136719 DOI: 10.1371/journal.pone.0203199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 06/19/2018] [Indexed: 12/30/2022] Open
Abstract
Large conductance voltage- and calcium-gated channels (BK) control fundamental processes, including smooth muscle contractility and artery diameter. We used a baboon (Papio spp) model of pregnancy that is similar to that of humans to characterize BK channels in the middle cerebral artery and its branches in near-term (165 dGa) primate fetuses and corresponding pregnant mothers. In cell-attached patches (K+pipette = 135 mM) on freshly isolated fetal cerebral artery myocytes, BK currents were identified by large conductance, and voltage- and paxilline-sensitive effects. Their calcium sensitivity was confirmed by a lower Vhalf (transmembrane voltage needed to reach half-maximal current) in inside-out patches at 30 versus 3 μM [Ca2+]free. Immunostaining against the BK channel-forming alpha subunit revealed qualitatively similar levels of BK alpha protein-corresponding fluorescence in fetal and maternal myocytes. Fetal and maternal BK currents recorded at 3 μM [Ca2+]free from excised membrane patches had similar unitary current amplitude, and Vhalf. However, subtle differences between fetal and maternal BK channel phenotypes were detected in macroscopic current activation kinetics. To assess BK function at the organ level, fetal and maternal artery branches were pressurized in vitro at 30 mmHg and probed with the selective BK channel blocker paxilline (1 μM). The degree of paxilline-induced constriction was similar in fetal and maternal arteries, yet the constriction of maternal arteries was achieved sooner. In conclusion, we present a first identification and characterization of fetal cerebral artery BK channels in myocytes from primates. Although differences in BK channels between fetal and maternal arteries exist, the similarities reported herein advance the idea that vascular myocyte BK channels are functional near-term, and thus may serve as pharmacological targets during the perinatal-neonatal period.
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Affiliation(s)
- Shivantika Bisen
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Maria N. Simakova
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Alex M. Dopico
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Anna N. Bukiya
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
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22
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Scott LL, Iyer S, Philpo AE, Avalos MN, Wu NS, Shi T, Prakash BA, Nguyen TT, Mihic SJ, Aldrich RW, Pierce JT. A Novel Peptide Restricts Ethanol Modulation of the BK Channel In Vitro and In Vivo. J Pharmacol Exp Ther 2018; 367:282-290. [PMID: 30158242 DOI: 10.1124/jpet.118.251918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Alcohol is a widely used and abused substance. A major unresolved issue in the alcohol research field is determining which of the many alcohol target proteins identified to date is responsible for shaping each specific alcohol-related behavior. The large-conductance, calcium- and voltage-activated potassium channel (BK channel) is a conserved target of ethanol. Genetic manipulation of the highly conserved BKα channel influences alcohol-related behaviors across phylogenetically diverse species that include worm, fly, mouse, and man. A pharmacological tool that prevents alcohol's action at a single target, like the BK channel, would complement genetic approaches in the quest to define the behavioral consequences of alcohol at each target. To identify agents that specifically modulate the action of ethanol at the BK channel, we executed a high-throughput phagemid-display screen in combination with a Caenorhabditis elegans behavioral genetics assay. This screen selected a novel nonapeptide, LS10, which moderated acute ethanol intoxication in a BK channel-humanized C. elegans strain without altering basal behavior. LS10's action in vivo was dependent upon BK channel functional activity. Single-channel electrophysiological recordings in vitro showed that preincubation with a submicromolar concentration of LS10 restricted ethanol-induced changes in human BKα channel gating. In contrast, no substantial changes in basal human BKα channel function were observed after LS10 application. The results obtained with the LS10 peptide provide proof-of-concept evidence that a combined phagemid-display/behavioral genetics screening approach can provide novel tools for understanding the action of alcohol at the BK channel and how this, in turn, exerts influence over central nervous system function.
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Affiliation(s)
- Luisa L Scott
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Sangeetha Iyer
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Ashley E Philpo
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Melva N Avalos
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Natalie S Wu
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Ted Shi
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Brooke A Prakash
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Thanh-Tu Nguyen
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - S John Mihic
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Richard W Aldrich
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
| | - Jonathan T Pierce
- Waggoner Center for Alcohol and Addiction Research (L.L.S., S.I., A.E.P., M.N.A., N.S.W., T.S., B.A.P., T.-T.N., S.J.M., R.W.A., J.T.P.), Department of Neuroscience (S.J.M., R.W.A., J.T.P.), and Center for Learning and Memory (R.W.A., J.T.P.), The University of Texas at Austin, Austin, Texas
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23
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Cell Cycle Regulation by Ca 2+-Activated K⁺ (BK) Channels Modulators in SH-SY5Y Neuroblastoma Cells. Int J Mol Sci 2018; 19:ijms19082442. [PMID: 30126198 PMCID: PMC6121591 DOI: 10.3390/ijms19082442] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/02/2018] [Accepted: 08/13/2018] [Indexed: 12/28/2022] Open
Abstract
The effects of Ca2+-activated K+ (BK) channel modulation by Paxilline (PAX) (10−7–10−4 M), Iberiotoxin (IbTX) (0.1–1 × 10−6 M) and Resveratrol (RESV) (1–2 × 10−4 M) on cell cycle and proliferation, AKT1pSer473 phosphorylation, cell diameter, and BK currents were investigated in SH-SY5Y cells using Operetta-high-content-Imaging-System, ELISA-assay, impedentiometric counting method and patch-clamp technique, respectively. IbTX (4 × 10−7 M), PAX (5 × 10−5 M) and RESV (10−4 M) caused a maximal decrease of the outward K+ current at +30 mV (Vm) of −38.3 ± 10%, −31.9 ± 9% and −43 ± 8%, respectively, which was not reversible following washout and cell depolarization. After 6h of incubation, the drugs concentration dependently reduced proliferation. A maximal reduction of cell proliferation, respectively of −60 ± 8% for RESV (2 × 10−4 M) (IC50 = 1.50 × 10−4 M), −65 ± 6% for IbTX (10−6 M) (IC50 = 5 × 10−7 M), −97 ± 6% for PAX (1 × 10−4 M) (IC50 = 1.06 × 10−5 M) and AKT1pser473 dephosphorylation was observed. PAX induced a G1/G2 accumulation and contraction of the S-phase, reducing the nuclear area and cell diameter. IbTX induced G1 contraction and G2 accumulation reducing diameter. RESV induced G2 accumulation and S contraction reducing diameter. These drugs share common actions leading to a block of the surface membrane BK channels with cell depolarization and calcium influx, AKT1pser473 dephosphorylation by calcium-dependent phosphatase, accumulation in the G2 phase, and a reduction of diameter and proliferation. In addition, the PAX action against nuclear membrane BK channels potentiates its antiproliferative effects with early apoptosis.
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24
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Amorim FG, Cordeiro FA, Pinheiro-Júnior EL, Boldrini-França J, Arantes EC. Microbial production of toxins from the scorpion venom: properties and applications. Appl Microbiol Biotechnol 2018; 102:6319-6331. [PMID: 29858954 DOI: 10.1007/s00253-018-9122-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/19/2018] [Accepted: 05/21/2018] [Indexed: 12/14/2022]
Abstract
Scorpion venom are composed mainly of bioactive proteins and peptides that may serve as lead compounds for the design of biotechnological tools and therapeutic drugs. However, exploring the therapeutic potential of scorpion venom components is mainly impaired by the low yield of purified toxins from milked venom. Therefore, production of toxin-derived peptides and proteins by heterologous expression is the strategy of choice for research groups and pharmaceutical industry to overcome this limitation. Recombinant expression in microorganisms is often the first choice, since bacteria and yeast systems combine high level of recombinant protein expression, fast cell growth and multiplication and simple media requirement. Herein, we present a comprehensive revision, which describes the scorpion venom components that were produced in their recombinant forms using microbial systems. In addition, we highlight the pros and cons of performing the heterologous expression of these compounds, regarding the particularities of each microorganism and how these processes can affect the application of these venom components. The most used microbial system in the heterologous expression of scorpion venom components is Escherichia coli (85%), and among all the recombinant venom components produced, 69% were neurotoxins. This review may light up future researchers in the choice of the best expression system to produce scorpion venom components of interest.
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Affiliation(s)
- Fernanda Gobbi Amorim
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil.
| | - Francielle Almeida Cordeiro
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Ernesto Lopes Pinheiro-Júnior
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Johara Boldrini-França
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil
| | - Eliane Candiani Arantes
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Do Café, s/n, Ribeirão Preto, SP, 14040-903, Brazil.
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25
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Tanner MR, Pennington MW, Chamberlain BH, Huq R, Gehrmann EJ, Laragione T, Gulko PS, Beeton C. Targeting KCa1.1 Channels with a Scorpion Venom Peptide for the Therapy of Rat Models of Rheumatoid Arthritis. J Pharmacol Exp Ther 2018; 365:227-236. [PMID: 29453198 DOI: 10.1124/jpet.117.245118] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 02/14/2018] [Indexed: 12/21/2022] Open
Abstract
Fibroblast-like synoviocytes (FLSs) are a key cell type involved in rheumatoid arthritis (RA) progression. We previously identified the KCa1.1 potassium channel (Maxi-K, BK, Slo 1, KCNMA1) as a regulator of FLSs and found that KCa1.1 inhibition reduces disease severity in RA animal models. However, systemic KCa1.1 block causes multiple side effects. In this study, we aimed to determine whether the KCa1.1 β1-3-specific venom peptide blocker iberiotoxin (IbTX) reduces disease severity in animal models of RA without inducing major side effects. We used immunohistochemistry to identify IbTX-sensitive KCa1.1 subunits in joints of rats with a model of RA. Patch-clamp and functional assays were used to determine whether IbTX can regulate FLSs through targeting KCa1.1. We then tested the efficacy of IbTX in ameliorating disease in two rat models of RA. Finally, we determined whether IbTX causes side effects including incontinence or tremors in rats, compared with those treated with the small-molecule KCa1.1 blocker paxilline. IbTX-sensitive subunits of KCa1.1 were expressed by FLSs in joints of rats with experimental arthritis. IbTX inhibited KCa1.1 channels expressed by FLSs from patients with RA and by FLSs from rat models of RA and reduced FLS invasiveness. IbTX significantly reduced disease severity in two rat models of RA. Unlike paxilline, IbTX did not induce tremors or incontinence in rats. Overall, IbTX inhibited KCa1.1 channels on FLSs and treated rat models of RA without inducing side effects associated with nonspecific KCa1.1 blockade and could become the basis for the development of a new treatment of RA.
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Affiliation(s)
- Mark R Tanner
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Michael W Pennington
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Brayden H Chamberlain
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Redwan Huq
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Elizabeth J Gehrmann
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Teresina Laragione
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Pércio S Gulko
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
| | - Christine Beeton
- Department of Molecular Physiology and Biophysics (M.R.T., B.H.C., R.H., E.J.G., C.B.), Interdepartmental Graduate Program in Translational Biology and Molecular Medicine (M.R.T.), and Biology of Inflammation Center and Center for Drug Discovery (C.B.), Baylor College of Medicine, Houston, Texas; Peptides International Inc., Louisville, Kentucky (M.W.P.); and Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York (T.L., P.S.G.)
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26
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Oyrer J, Maljevic S, Scheffer IE, Berkovic SF, Petrou S, Reid CA. Ion Channels in Genetic Epilepsy: From Genes and Mechanisms to Disease-Targeted Therapies. Pharmacol Rev 2018; 70:142-173. [PMID: 29263209 DOI: 10.1124/pr.117.014456] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Epilepsy is a common and serious neurologic disease with a strong genetic component. Genetic studies have identified an increasing collection of disease-causing genes. The impact of these genetic discoveries is wide reaching-from precise diagnosis and classification of syndromes to the discovery and validation of new drug targets and the development of disease-targeted therapeutic strategies. About 25% of genes identified in epilepsy encode ion channels. Much of our understanding of disease mechanisms comes from work focused on this class of protein. In this study, we review the genetic, molecular, and physiologic evidence supporting the pathogenic role of a number of different voltage- and ligand-activated ion channels in genetic epilepsy. We also review proposed disease mechanisms for each ion channel and highlight targeted therapeutic strategies.
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Affiliation(s)
- Julia Oyrer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Ingrid E Scheffer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Samuel F Berkovic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Christopher A Reid
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
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27
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Burke RC, Bardet SM, Carr L, Romanenko S, Arnaud-Cormos D, Leveque P, O'Connor RP. Nanosecond pulsed electric fields depolarize transmembrane potential via voltage-gated K+, Ca2+ and TRPM8 channels in U87 glioblastoma cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2040-2050. [DOI: 10.1016/j.bbamem.2017.07.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/05/2017] [Accepted: 07/05/2017] [Indexed: 12/20/2022]
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28
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BK Channels Mediate Synaptic Plasticity Underlying Habituation in Rats. J Neurosci 2017; 37:4540-4551. [PMID: 28348135 DOI: 10.1523/jneurosci.3699-16.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/17/2017] [Accepted: 03/21/2017] [Indexed: 11/21/2022] Open
Abstract
Habituation is a basic form of implicit learning and represents a sensory filter that is disrupted in autism, schizophrenia, and several other mental disorders. Despite extensive research in the past decades on habituation of startle and other escape responses, the underlying neural mechanisms are still not fully understood. There is evidence from previous studies indicating that BK channels might play a critical role in habituation. We here used a wide array of approaches to test this hypothesis. We show that BK channel activation and subsequent phosphorylation of these channels are essential for synaptic depression presumably underlying startle habituation in rats, using patch-clamp recordings and voltage-sensitive dye imaging in slices. Furthermore, positive modulation of BK channels in vivo can enhance short-term habituation. Although results using different approaches do not always perfectly align, together they provide convincing evidence for a crucial role of BK channel phosphorylation in synaptic depression underlying short-term habituation of startle. We also show that this mechanism can be targeted to enhance short-term habituation and therefore to potentially ameliorate sensory filtering deficits associated with psychiatric disorders.SIGNIFICANCE STATEMENT Short-term habituation is the most fundamental form of implicit learning. Habituation also represents a filter for inundating sensory information, which is disrupted in autism, schizophrenia, and other psychiatric disorders. Habituation has been studied in different organisms and behavioral models and is thought to be caused by synaptic depression in respective pathways. The underlying molecular mechanisms, however, are poorly understood. We here identify, for the first time, a BK channel-dependent molecular synaptic mechanism leading to synaptic depression that is crucial for habituation, and we discuss the significance of our findings for potential treatments enhancing habituation.
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29
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A novel BK channel-targeted peptide suppresses sound evoked activity in the mouse inferior colliculus. Sci Rep 2017; 7:42433. [PMID: 28195225 PMCID: PMC5307958 DOI: 10.1038/srep42433] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/10/2017] [Indexed: 02/06/2023] Open
Abstract
Large conductance calcium-activated (BK) channels are broadly expressed in neurons and muscle where they modulate cellular activity. Decades of research support an interest in pharmaceutical applications for modulating BK channel function. Here we report a novel BK channel-targeted peptide with functional activity in vitro and in vivo. This 9-amino acid peptide, LS3, has a unique action, suppressing channel gating rather than blocking the pore of heterologously expressed human BK channels. With an IC50 in the high picomolar range, the apparent affinity is higher than known high affinity BK channel toxins. LS3 suppresses locomotor activity via a BK channel-specific mechanism in wild-type or BK channel-humanized Caenorhabditis elegans. Topical application on the dural surface of the auditory midbrain in mouse suppresses sound evoked neural activity, similar to a well-characterized pore blocker of the BK channel. Moreover, this novel ion channel-targeted peptide rapidly crosses the BBB after systemic delivery to modulate auditory processing. Thus, a potent BK channel peptide modulator is open to neurological applications, such as preventing audiogenic seizures that originate in the auditory midbrain.
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Giacoppo JDOS, Carregal JB, Junior MC, Cunha EFFD, Ramalho TC. Towards the understanding of tetrahydroquinolines action in Aedes aegypti: larvicide or adulticide? MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2016.1239823] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | - Juliano B. Carregal
- Department of Chemistry, Federal University of São João del Rey, Divinópolis, Brazil
| | - Moacyr C. Junior
- Department of Chemistry, Federal University of São João del Rey, Divinópolis, Brazil
| | | | - Teodorico C. Ramalho
- Department of Chemistry, Federal University of Lavras, Lavras, Brazil
- Center for Basic and Applied Research, University Hradec Kralove, Hradec Kralove, Czech Republic
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Housley DM, Housley GD, Liddell MJ, Jennings EA. Scorpion toxin peptide action at the ion channel subunit level. Neuropharmacology 2016; 127:46-78. [PMID: 27729239 DOI: 10.1016/j.neuropharm.2016.10.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 09/06/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022]
Abstract
This review categorizes functionally validated actions of defined scorpion toxin (SCTX) neuropeptides across ion channel subclasses, highlighting key trends in this rapidly evolving field. Scorpion envenomation is a common event in many tropical and subtropical countries, with neuropharmacological actions, particularly autonomic nervous system modulation, causing significant mortality. The primary active agents within scorpion venoms are a diverse group of small neuropeptides that elicit specific potent actions across a wide range of ion channel classes. The identification and functional characterisation of these SCTX peptides has tremendous potential for development of novel pharmaceuticals that advance knowledge of ion channels and establish lead compounds for treatment of excitable tissue disorders. This review delineates the unique specificities of 320 individual SCTX peptides that collectively act on 41 ion channel subclasses. Thus the SCTX research field has significant translational implications for pathophysiology spanning neurotransmission, neurohumoral signalling, sensori-motor systems and excitation-contraction coupling. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'
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Affiliation(s)
- David M Housley
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Michael J Liddell
- Centre for Tropical Environmental and Sustainability Science and College of Science & Engineering, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia
| | - Ernest A Jennings
- College of Medicine and Dentistry, Cairns Campus, James Cook University, Cairns, Queensland 4878, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Queensland 4878, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns Campus, QLD, Australia
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