scholarly journals The ubiquitous flavonoid quercetin is an atypical KCNQ potassium channel activator

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Kaitlyn E. Redford ◽  
Geoffrey W. Abbott

AbstractMany commonly consumed plants are used as folk medicines, often with unclear molecular mechanisms. Recent studies uncovered the ubiquitous and influential KCNQ family of voltage-gated potassium (Kv) channels as a therapeutic target for several medicinal plant compounds. Capers - immature flower buds of Capparis spinosa - have been consumed for food and medicinal purposes for millennia. Here, we show that caper extract hyperpolarizes cells expressing KCNQ1 or KCNQ2/3 Kv channels. Capers are the richest known natural source of quercetin, the most consumed dietary flavonoid. Quercetin potentiated KCNQ1/KCNE1, KCNQ2/3 and KCNQ4 currents but, unusually, not KCNQ5. Strikingly, quercetin augmented both activation and inactivation of KCNQ1, via a unique KCNQ activation mechanism involving sites atop the voltage sensor and in the pore. The findings uncover a novel potential molecular basis for therapeutic effects of quercetin-rich foods and a new chemical space for atypical modes of KCNQ channel modulation.

2020 ◽  
Vol 28 (2) ◽  
pp. 360-376 ◽  
Author(s):  
Atefeh Amiri ◽  
Maryam Mahjoubin-Tehran ◽  
Zatollah Asemi ◽  
Alimohammad Shafiee ◽  
Sarah Hajighadimi ◽  
...  

: Cancer and inflammatory disorders are two important public health issues worldwide with significant socio.economic impacts. Despite several efforts, the current therapeutic platforms are associated with severe limitations. Therefore, developing new therapeutic strategies for the treatment of these diseases is a top priority. Besides current therapies, the utilization of natural compounds has emerged as a new horizon for the treatment of cancer and inflammatory disorders as well. Such natural compounds could be used either alone or in combination with the standard cancer therapeutic modalities such as chemotherapy, radiotherapy, and immunotherapy. Resveratrol is a polyphenolic compound that is found in grapes as well as other foods. It has been found that this medicinal agent displays a wide pharmacological spectrum, including anti-cancer, anti-inflammatory, anti-microbial, and antioxidant activities. Recently, clinical and pre-clinical studies have highlighted the anti-cancer and anti-inflammatory effects of resveratrol. Increasing evidence revealed that resveratrol exerts its therapeutic effects by targeting various cellular and molecular mechanisms. Among cellular and molecular targets that are modulated by resveratrol, microRNAs (miRNAs) have appeared as key targets. MiRNAs are short non-coding RNAs that act as epigenetic regulators. These molecules are involved in many processes that are involved in the initiation and progression of cancer and inflammatory disorders. Herein, we summarized various miRNAs that are directly/indirectly influenced by resveratrol in cancer and inflammatory disorders.


2021 ◽  
Vol 7 (22) ◽  
pp. eabg3362
Author(s):  
Hamidreza Shaye ◽  
Benjamin Stauch ◽  
Cornelius Gati ◽  
Vadim Cherezov

Metabotropic γ-aminobutyric acid G protein–coupled receptors (GABAB) represent one of the two main types of inhibitory neurotransmitter receptors in the brain. These receptors act both pre- and postsynaptically by modulating the transmission of neuronal signals and are involved in a range of neurological diseases, from alcohol addiction to epilepsy. A series of recent cryo-EM studies revealed critical details of the activation mechanism of GABAB. Structures are now available for the receptor bound to ligands with different modes of action, including antagonists, agonists, and positive allosteric modulators, and captured in different conformational states from the inactive apo to the fully active state bound to a G protein. These discoveries provide comprehensive insights into the activation of the GABAB receptor, which not only broaden our understanding of its structure, pharmacology, and physiological effects but also will ultimately facilitate the discovery of new therapeutic drugs and neuromodulators.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Fan Xia ◽  
Yonju Ha ◽  
Shuizhen Shi ◽  
Yi Li ◽  
Shengguo Li ◽  
...  

AbstractThe retina, as the only visually accessible tissue in the central nervous system, has attracted significant attention for evaluating it as a biomarker for neurodegenerative diseases. Yet, most of studies focus on characterizing the loss of retinal ganglion cells (RGCs) and degeneration of their axons. There is no integrated analysis addressing temporal alterations of different retinal cells in the neurovascular unit (NVU) in particular retinal vessels. Here we assessed NVU changes in two mouse models of tauopathy, P301S and P301L transgenic mice overexpressing the human tau mutated gene, and evaluated the therapeutic effects of a tau oligomer monoclonal antibody (TOMA). We found that retinal edema and breakdown of blood–retina barrier were observed at the very early stage of tauopathy. Leukocyte adhesion/infiltration, and microglial recruitment/activation were constantly increased in the retinal ganglion cell layer of tau transgenic mice at different ages, while Müller cell gliosis was only detected in relatively older tau mice. Concomitantly, the number and function of RGCs progressively decreased during aging although they were not considerably altered in the very early stage of tauopathy. Moreover, intrinsically photosensitive RGCs appeared more sensitive to tauopathy. Remarkably, TOMA treatment in young tau transgenic mice significantly attenuated vascular leakage, inflammation and RGC loss. Our data provide compelling evidence that abnormal tau accumulation can lead to pathology in the retinal NVU, and vascular alterations occur more manifest and earlier than neurodegeneration in the retina. Oligomeric tau-targeted immunotherapy has the potential to treat tau-induced retinopathies. These data suggest that retinal NVU may serve as a potential biomarker for diagnosis and staging of tauopathy as well as a platform to study the molecular mechanisms of neurodegeneration.


2019 ◽  
Vol 11 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Nobue Kitanaka ◽  
Frank Scott Hall ◽  
George Richard Uhl ◽  
Junichi Kitanaka

Background:The effectiveness of lithium salts in neuropsychiatric disorders such as bipolar disorder, Alzheimer’s disease, and treatment-resistant depression has been documented in an extensive scientific literature. Lithium inhibits inositol monophosphatase, inositol polyphosphate 1- phosphatase, and glycogen synthase kinase-3 and decreases expression level of tryptophan hydroxylase 2, conceivably underlying the mood stabilizing effects of lithium, as well as procognitive and neuroprotective effects. However, the exact molecular mechanisms of action of lithium on mood stabilizing and pro-cognitive effects in humans are still largely unknown.Objective:On the basis of the known aspects of lithium pharmacology, this review will discuss the possible mechanisms underlying the therapeutic effects of lithium on positive symptoms of methamphetamine abuse and dependence.Conclusion:It is possible that lithium treatment reduces the amount of newly synthesized phosphatidylinositol, potentially preventing or reversing neuroadaptations contributing to behavioral sensitization induced by methamphetamine. In addition, it is suggested that exposure to repeated doses of methamphetamine induces hyperactivation of glycogen synthase kinase-3β in the nucleus accumbens and in dorsal hippocampus, resulting in a long-term alterations in synaptic plasticity underlying behavioral sensitization as well as other behavioral deficits in memory-related behavior. Therefore it is clear that glycogen synthase kinase-3β inhibitors can be considered as a potential candidate for the treatment of methamphetamine abuse and dependence.


2021 ◽  
Vol 22 (15) ◽  
pp. 7844
Author(s):  
Jason S. Holsapple ◽  
Ben Cooper ◽  
Susan H. Berry ◽  
Aleksandra Staniszewska ◽  
Bruce M. Dickson ◽  
...  

Extracorporeal Shock Wave Therapy (ESWT) is used clinically in various disorders including chronic wounds for its pro-angiogenic, proliferative, and anti-inflammatory effects. However, the underlying cellular and molecular mechanisms driving therapeutic effects are not well characterized. Macrophages play a key role in all aspects of healing and their dysfunction results in failure to resolve chronic wounds. We investigated the role of ESWT on macrophage activity in chronic wound punch biopsies from patients with non-healing venous ulcers prior to, and two weeks post-ESWT, and in macrophage cultures treated with clinical shockwave intensities (150–500 impulses, 5 Hz, 0.1 mJ/mm2). Using wound area measurements and histological/immunohistochemical analysis of wound biopsies, we show ESWT enhanced healing of chronic ulcers associated with improved wound angiogenesis (CD31 staining), significantly decreased CD68-positive macrophages per biopsy area and generally increased macrophage activation. Shockwave treatment of macrophages in culture significantly boosted uptake of apoptotic cells, healing-associated cytokine and growth factor gene expressions and modulated macrophage morphology suggestive of macrophage activation, all of which contribute to wound resolution. Macrophage ERK activity was enhanced, suggesting one mechanotransduction pathway driving events. Collectively, these in vitro and in vivo findings reveal shockwaves as important regulators of macrophage functions linked with wound healing. This immunomodulation represents an underappreciated role of clinically applied shockwaves, which could be exploited for other macrophage-mediated disorders.


2015 ◽  
Vol 35 (6) ◽  
pp. 2349-2359 ◽  
Author(s):  
Youli Xi ◽  
Miaozong Wu ◽  
Hongxia Li ◽  
Siqi Dong ◽  
Erfei Luo ◽  
...  

Background/Aims: Obesity-associated fatty liver disease affects millions of individuals. This study aimed to evaluate the therapeutic effects of baicalin to treat obesity and fatty liver in high fat diet-induced obese mice, and to study the potential molecular mechanisms. Methods: High fat diet-induced obese animals were treated with different doses of baicalin (100, 200 and 400 mg/kg/d). Whole body, fat pad and liver were weighed. Hyperlipidemia, liver steatosis, liver function, and hepatic Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ) / AMP-activated protein kinase (AMPK) / acetyl-CoA carboxylase (ACC) were further evaluated. Results: Baicalin significantly decreased liver, epididymal fat and body weights in high fat diet-fed mice, which were associated with decreased serum levels of triglycerides, total cholesterol, LDL, alanine transaminase and aspartate transaminase, but increased serum HDL level. Pathological analysis revealed baicalin dose-dependently decreased the degree of hepatic steatosis, with predominantly diminished macrovesicular steatosis at lower dose but both macrovesicular and microvesicular steatoses at higher dose of baicalin. Baicalin dose-dependently inhibited hepatic CaMKKβ/AMPK/ACC pathway. Conclusion: These data suggest that baicalin up to 400 mg/kg/d is safe and able to decrease the degree of obesity and fatty liver diseases. Hepatic CaMKKβ/AMPK/ACC pathway may mediate the therapeutic effects of baicalin in high fat diet animal model.


2021 ◽  
Author(s):  
Termeh Shakery ◽  
Fatemeh Safari

Breast cancer (BC) is one of the most causes of cancer-related death among women worldwide. Cancer therapy based on stem cells was considered as a novel and promising platform. In present study, we explored the therapeutic effects of human amniotic mesenchymal stromal cells (hAMSCs) through Pinkbar (planar intestinal-and kidney-specific BAR domain protein), pAKT, and matrix metalloproteinases including MMP2, MMP9 on MDA-MB-231 breast cancer cells. To do so, we employed a co-culture system using 6 well plates transwell with a diameter of 0.4 μm pore sized. After 72h hAMSCs-treated MDA-MB-231 breast cancer cells, the expression of Epidermal growth factor receptor (EGFR), and c-Src (a key mediator in EGFR signaling pathway), Pinkbar, pAKT, MMP2, and MMP9 was analyzed by using quantitative real time PCR (qRT-PCR) and western blot methods. Based on using 2D and 3D cell culture models, the significant reduction of tumor cell growth and motility through down regulation of EGFR, c-Src, Pinkbar, pAKT, MMP2, and MMP9 in MDA-MB-231 breast cancer cells was shown. Also, the induction of cellular apoptosis also found. Our finding indicates that the hAMSCS secretome has therapeutic effects on cancer cells. To identify the details of the molecular mechanisms, more experiments will be required.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wenna Liang ◽  
Xihai Li ◽  
Guanhui Li ◽  
Liu Hu ◽  
Shanshan Ding ◽  
...  

Background. Erzhi pill (EZP), a traditional Chinese herbal formula, has been widely used to treat postmenopausal osteoporosis (PMOP) in China. However, its molecular mechanisms remain unclear. The aim of the present study is to investigate the antiosteoporotic effect of EZP on an ovariectomized rat model of PMOP. We performed the biomarkers of bone metabolism disorder, bone morphology, bone mineral density (BMD), and bone biomechanics to confirm the successful establishment of the PMOP model. We then investigated the expression of biomarkers related to the Sirt1/Foxo axis. We also examined microRNA-132 (miR-132), a regulator in the Sirtuin1 (Sirt1) expression. The bone metabolism disorder, bone morphology, BMD, and bone biomechanics in ovariectomized rats were improved by EZP administration. The antiosteoporotic effect of EZP was confirmed. We also found that the expressions of Sirt1, Runx2, Foxo1, and Foxo3a were downregulated in ovariectomized rats, while being then upregulated by EZP administration. And the expression of PPAR-γ and miR-132 was upregulated in ovariectomized rats and then downregulated by EZP administration. These results provided evidence that Sirt1/Foxo axis related mechanism may play a crucial role in the therapeutic effects of EZP, indicating that Sirt1/Foxo axis can be considered as a potential therapeutic target for PMOP in the future.


2010 ◽  
Vol 26 (3) ◽  
pp. 302-317 ◽  
Author(s):  
Arif Tasleem Jan ◽  
Majid Rasool Kamli ◽  
Imtiyaz Murtaza ◽  
Jang Bahadur Singh ◽  
Arif Ali ◽  
...  

2021 ◽  
Vol 22 (18) ◽  
pp. 10045
Author(s):  
Phuong Thao Do ◽  
Chung-Che Wu ◽  
Yung-Hsiao Chiang ◽  
Chaur-Jong Hu ◽  
Kai-Yun Chen

Ischemic stroke is the leading cause of mortality and long-term disability worldwide. Disruption of the blood–brain barrier (BBB) is a prominent pathophysiological mechanism, responsible for a series of subsequent inflammatory cascades that exacerbate the damage to brain tissue. However, the benefit of recanalization is limited in most patients because of the narrow therapeutic time window. Recently, mesenchymal stem cells (MSCs) have been assessed as excellent candidates for cell-based therapy in cerebral ischemia, including neuroinflammatory alleviation, angiogenesis and neurogenesis promotion through their paracrine actions. In addition, accumulating evidence on how MSC therapy preserves BBB integrity after stroke may open up novel therapeutic targets for treating cerebrovascular diseases. In this review, we focus on the molecular mechanisms of MSC-based therapy in the ischemia-induced prevention of BBB compromise. Currently, therapeutic effects of MSCs for stroke are primarily based on the fundamental pathogenesis of BBB breakdown, such as attenuating leukocyte infiltration, matrix metalloproteinase (MMP) regulation, antioxidant, anti-inflammation, stabilizing morphology and crosstalk between cellular components of the BBB. We also discuss prospective studies to improve the effectiveness of MSC therapy through enhanced migration into defined brain regions of stem cells. Targeted therapy is a promising new direction and is being prioritized for extensive research.


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