RESUMEN

Somatosensory neurons can sense external temperature by converting sensation of temperature information to neural activity via afferent input to the central nervous system. Various populations of somatosensory neurons have specialized gene expression, including expression of thermosensitive transient receptor potential (TRP) ion channels. Thermosensitive TRP channels are responsible for thermal transduction at the peripheral ends of somatosensory neurons and can sense a wide range of temperatures. Here we focus on several thermosensitive TRP channels including TRPV1, TRPV4, TRPM2, TRPM3, TRPM8, TRPC5, and TRPA1 in sensory neurons. TRPV3, TRPV4, and TRPC5 are also involved in somatosensation in nonneuronal cells and tissues. In particular, we discuss whether skin senses ambient temperatures through TRPV3 and TRPV4 activation in skin keratinocytes and the involvement of TRPM2 expressed by hypothalamic neurons in thermosensation in the brain.

Asunto(s)

Sensación Térmica , Canales de Potencial de Receptor Transitorio , Humanos , Sensación Térmica/fisiología , Sensación Térmica/genética , Animales , Canales de Potencial de Receptor Transitorio/metabolismo , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/fisiología , Células Receptoras Sensoriales/metabolismo , Células Receptoras Sensoriales/fisiología , Canales Catiónicos TRPV/metabolismo , Canales Catiónicos TRPV/genética , Piel/metabolismo , Piel/inervación , Canales Catiónicos TRPM/metabolismo , Canales Catiónicos TRPM/genética , Queratinocitos/metabolismo

RESUMEN

Ovarian cancer (OC) becomes a fatal gynecologic malignant cancer in females worldwide. Target therapy is a promising therapeutical choice for patients with OC, and identifying biomarkers and exploring molecular mechanisms are necessary. In this study, the functions and mechanism of long noncoding RNA transient receptor potential cation channel subfamily M member 2 antisense RNA (TRPM2-AS) in OC were explored. TRPM2-AS expression in OC cells was analyzed utilizing reverse transcription quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) and colony forming assays were carried out to explore the influence of TRPM2-AS on OC cell viability and proliferation. Cell apoptosis was detected using TdT-mediated dUTP Nick-End labeling (TUNEL) and flow cytometry analysis. Protein expression of apoptotic markers was subjected to western blotting. RNA pulldown or luciferase reporter assays were applied to explore the interaction between TRPM2-AS and miR-6764-5p or the binding of miR-6764-5p and TRPM2. The results showed that TRPM2-AS is highly expressed in OC cells and was mainly localized in cytoplasm. TRPM2-AS depletion suppressed OC cell viability and proliferation while increasing cell apoptotic rate. TRPM2 displayed a high level in OC cells and was positively regulated by TRPM2-AS. TRPM2-AS interacted with miR-6764-5p and thereby upregulated TRPM2 expression. In addition, TRPM2 overexpression reversed the repressive impact of TRPM2-AS depletion on malignant OC cellular process. In conclusion, TRPM2-AS promotes OC cell viability and proliferation while enhancing cell apoptosis through interaction with miR-6764-5p to regulate TRPM2 level.

RESUMEN

OBJECTIVE: Delayed fracture healing increases the suffering of patients. An in-depth investigation of the pathogenesis of delayed fracture healing may offer new direction for the prevention and treatment. METHODS: The study included 63 normal healing tibial fractures and 58 delayed healing tibial fractures patients. Long non-coding RNA (lncRNA)TRPM2-AS, microRNA-545-3p (miR-545-3p), bone morphogenetic protein 2 (Bmp2) mRNA and osteogenic differentiation markers, including runt-related transcription factor 2 (Runx2), osteocalcin (Ocn), and alkaline phosphatase (Alp) mRNA expression were determined by Real-time quantitative reverse transcription-polymerase chain reaction in serum and MC3T3-E1 cells. The prediction potential of TRPM2-AS in delayed healing fracture patients was verified by receiver operating characteristic curves. The binding relationship of TRPM2-AS/miR-545-3p/Bmp2 was evaluated by dual luciferase reporter gene assay. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry. RESULTS: TRPM2-AS was remarkably down-regulated in patients with delayed fracture healing and could better predict the fracture healing status. TRPM2-AS downregulation inhibited osteogenic markers mRNA expression, restrained proliferation, and promoted apoptosis of MC3T3-E1 cells (p < 0.05). In delayed fracture healing, miR-545-3p was dramatically up-regulated and was negatively regulated by TRPM2-AS. Reducing miR-545-3p eliminate the negative effect of TRPM2-AS down-regulation on osteoblast proliferation and differentiation (p < 0.05). miR-545-3p targets Bmp2, which plays a positive role in osteoblast differentiation (p < 0.05). CONCLUSION: This study found that TRPM2-AS has the potential to be a diagnostic marker for delayed fracture healing and revealed that the TRPM2-AS/miR-545-3p/Bmp2 axis affects fracture healing by regulating osteoblast.

Asunto(s)

Proteína Morfogenética Ósea 2 , Curación de Fractura , MicroARNs , Adulto , Animales , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Apoptosis/genética , Proteína Morfogenética Ósea 2/genética , Proteína Morfogenética Ósea 2/metabolismo , Diferenciación Celular/genética , Proliferación Celular/genética , Curación de Fractura/genética , Curación de Fractura/fisiología , MicroARNs/genética , Osteoblastos/metabolismo , Osteogénesis/genética , Osteogénesis/fisiología , ARN Largo no Codificante/genética , Fracturas de la Tibia/genética , Canales Catiónicos TRPM/genética

RESUMEN

There is an urgent need to fully understand the biology of third generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs), particularly osimertinib, and to develop mechanism-driven strategies to manage their acquired resistance. Transient receptor potential melastatin-2 (TRPM2) functions as an important regulator of Ca2+ influx, but its role in mediating therapeutic efficacies of EGFR-TKIs and acquired resistance to EGFR-TKIs has been rarely studied. This study has demonstrated a previously undiscovered role of suppression of TRPM2 and subsequent inhibition of Ca2+ influx and induction of ROS and DNA damage in mediating apoptosis induction and the therapeutic efficacy of osimertinib against EGFR mutant NSCLC. The rebound elevation represents a key mechanism accounting for the emergence of acquired resistance to osimertinib and other third generation EGFR-TKIs. Accordingly, targeting TRPM2 is a potentially promising strategy for overcoming and preventing acquired resistance to osimertinib, warranting further study in this direction including the development of cancer therapy-optimized TRPM2 inhibitors.

RESUMEN

Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that exhibits Ca2+ permeability. The TRPM2 channel is expressed in various tissues and cells and can be activated by multiple factors, including endogenous ligands, Ca2+, reactive oxygen species (ROS) and temperature. This article reviews the multiple roles of the TRPM2 channel in physiological and pathological processes, particularly on oxidative stress, inflammation and ischemia-reperfusion (I/R) injury. In oxidative stress, the excessive influx of Ca2+ caused by the activation of the TRPM2 channel may exacerbate cellular damage. However, under specific conditions, activating the TRPM2 channel can have a protective effect on cells. In inflammation, the activation of the TRPM2 channel may not only promote inflammatory response but also inhibit inflammation by regulating ROS production and bactericidal ability of macrophages and neutrophils. In I/R, the activation of the TRPM2 channel may worsen I/R injury to various organs, including the brain, heart, kidney and liver. However, activating the TRPM2 channel may protect the myocardium from I/R injury by regulating calcium influx and phosphorylating proline-rich tyrosine kinase 2 (Pyk2). A thorough investigation of the bidirectional role and regulatory mechanism of the TRPM2 channel in these physiological and pathological processes will aid in identifying new targets and strategies for treatment of related diseases.

Asunto(s)

Inflamación , Estrés Oxidativo , Daño por Reperfusión , Canales Catiónicos TRPM , Canales Catiónicos TRPM/metabolismo , Humanos , Daño por Reperfusión/metabolismo , Daño por Reperfusión/inmunología , Inflamación/metabolismo , Inflamación/inmunología , Animales , Especies Reactivas de Oxígeno/metabolismo , Calcio/metabolismo

RESUMEN

Cyclophosphamide (CYP) is widely used to treat various types of cancer. In addition to the therapeutic properties of this drug, unfortunately, its side effects are still not fully understood. This study investigated the protective effect of curcumin (CURC) and berberine (BER) on CYP-induced cardiac damage. Thirty-six male rats were equally divided into the control, dimethyl sulfoxide (DMSO), CYP, CYP + CURC, CYP + BER and CYP + BER + CURC groups. Troponin-I, Creatine kinase-myocardial band (CK-MB), total cholesterol, triglyceride levels in serum samples, and reactive oxygen species (ROS), poly(ADP-ribose) polymerase-1 (PARP-1), and transient receptor potential melastatin 2 (TRPM2) channel levels in heart tissue were measured using an enzyme-linked immunoassay (ELISA) kit. In addition, histopathological examination and immunohistochemical investigation of the TRPM2 channel, fibroblast specific protein-1 (FSP1), transforming growth factor-beta- 1 (TGF-ß1) and α-smooth muscle actin (α-SMA) expressions were determined in heart tissue. The CYP group's troponin-I, total cholesterol, triglyceride, CK-MB, ROS, PARP-1 and TRPM2 channel levels were higher than in the other groups in the ELISA measurements (p < 0.05). In contrast, these parameters in the group treated with CURC and BER together with CYP were lower than in the CYP group (p < 0.05). Additionally, CUR and BER reduced CYP-induced pathological damage, TRPM2, FSP1, TGF-ß1 and α-SMA expressions. The data showed that CYP administration can cause cardiac damage by increasing the TRPM2 channel, TGF-ß1, FSP1 and α-SMA expression levels. Therefore, we concluded that CURC and BER administration following CYP application may be used as therapeutic agents to prevent CYP-induced cardiac damage.

Asunto(s)

Berberina , Curcumina , Ciclofosfamida , Fibrosis , Miocardio , Canales Catiónicos TRPM , Animales , Canales Catiónicos TRPM/metabolismo , Ciclofosfamida/toxicidad , Ciclofosfamida/efectos adversos , Masculino , Ratas , Curcumina/farmacología , Berberina/farmacología , Miocardio/metabolismo , Miocardio/patología , Biomarcadores/metabolismo , Biomarcadores/sangre , Lípidos/sangre , Ratas Wistar , Cardiopatías/inducido químicamente , Cardiopatías/metabolismo , Cardiopatías/patología , Cardiopatías/prevención & control , Cardiopatías/tratamiento farmacológico

RESUMEN

BACKGROUND: Anti-angiogenic therapy has become one of the effective treatment methods for tumors. Long noncoding RNAs (lncRNAs) are emerging as important regulators of tumorigenesis and angiogenesis in EC. However, the underlying mechanisms of lncRNA TRPM2-AS in EC are still not clear. METHODS: We screened the differently expressed lncRNAs that were highly associated with poor prognosis and angiogenesis of EC by bioinformatics analysis, and constructed a ceRNA network based on the prognostic lncRNAs. The subcellular localization of TRPM2-AS was determined by fluorescence in situ hybridization (FISH) and nuclear cytoplasmic fractionation assay. CCK-8, EdU, transwell, western blot, qRT-PCR and endothelial tube formation assay were used to evaluate the effects of TRPM2-AS on the proliferation, invasion, migration of EC cells and angiogenesis. The targeted microRNA (miRNA) of TRPM2-AS was predicted by bioinformatic methods. The interaction between TRPM2-AS and miR497-5p, miR497-5p and SPP1 were analyzed by RNA immunoprecipitation and dual-luciferase reporter assay. A subcutaneous tumor model was used to explore TRPM2-AS's function in vivo. CIBERSORT was used to analyze the correlation between TRPM2-AS and immune cell immersion in EC. RESULTS: We found that the expression of TRPM2-AS and SPP1 was aberrantly upregulated, while miR-497-5p expression was significantly downregulated in EC tissues and cells. TRPM2-AS was closely correlated with the angiogenesis and poor prognosis in EC patients. Mechanistically, TRPM2-AS could sponge miR-497-5p to release SPP1, thus promoting the proliferation, invasion and migration of EC cells and angiogenesis of HUVECs. Knockdown of TRPM2-AS in xenograft mouse model inhibited tumor proliferation and angiogenesis in vivo. In addition, TRPM2-AS plays a vital role in regulating the tumor immune microenvironment of EC, overexpression of TRPM2-AS in EC cells stimulated the polarization of M2 macrophages and angiogenesis through secreting SPP1 enriched exosomes. CONCLUSION: The depletion of TRPM2-AS inhibits the oncogenicity of EC by targeting the miR-497-5p/SPP1 axis. This study offers a better understanding of TRPM2-AS's role in regulating angiogenesis and provides a novel target for EC treatment.

Asunto(s)

Movimiento Celular , Proliferación Celular , Neoplasias Endometriales , Regulación Neoplásica de la Expresión Génica , MicroARNs , Neovascularización Patológica , ARN Largo no Codificante , Humanos , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Neovascularización Patológica/genética , Femenino , Animales , Proliferación Celular/genética , Línea Celular Tumoral , Neoplasias Endometriales/genética , Neoplasias Endometriales/patología , Neoplasias Endometriales/metabolismo , Movimiento Celular/genética , Ratones , Progresión de la Enfermedad , Ratones Desnudos , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Ratones Endogámicos BALB C , Pronóstico , Angiogénesis

RESUMEN

Although various anti-inflammatory medications, such as ephedrine, are employed to manage cough-variant asthma, their underlying mechanisms are yet to be fully understood. Recent studies suggest that exosomes derived from airway epithelial cells (AECs) contain components like messenger RNAs (mRNAs), micro-RNAs (miRNAs), and long noncoding RNA (lncRNA), which play roles in the occurrence and progression of airway inflammation. This study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant asthma. We established a mouse model of asthma and measured airway resistance and serum inflammatory cell levels. Real-time polymerase chain reaction (RT-qPCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA) analyses were used to assess gene and protein expression levels. Exosomes were isolated and characterized. RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and lnc-TRPM2-AS1. In the ovalbumin (OVA)-challenged mouse model, ephedrine treatment reduced inflammatory responses, airway resistance, and Th1/Th2 cell imbalance. Exosomes from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1, which were diminished following ephedrine treatment. The exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4+ T cells, with its packaging into exosomes being facilitated by hnRNPA2B1. This study unveils a novel mechanism by which ephedrine ameliorates OVA-induced CD4+ T cell imbalance by suppressing AEC-derived exosomal lnc-TRPM2-AS1. These findings could provide a theoretical framework for using ephedrine in asthma treatment.

Asunto(s)

Asma , Efedrina , Células Epiteliales , Exosomas , Ratones Endogámicos BALB C , Ovalbúmina , Células Th2 , Animales , Asma/tratamiento farmacológico , Asma/inmunología , Efedrina/farmacología , Exosomas/metabolismo , Ratones , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Th2/inmunología , Células Th2/efectos de los fármacos , Femenino , ARN Largo no Codificante/genética , Humanos , Células TH1/efectos de los fármacos , Células TH1/inmunología , Modelos Animales de Enfermedad

RESUMEN

Interstitial macrophages (IMs) are essential for organ homeostasis, inflammation, and autonomous immune response in lung tissues, which are achieved through polarization to a pro-inflammatory M1 and an M2 state for tissue repair. Their remote parenchymal localization and low counts, however, are limiting factors for their isolation and molecular characterization of their specific role during tissue inflammation. We isolated viable murine IMs in sufficient quantities by coculturing them with stromal cells and analyzed mRNA expression patterns of transient receptor potential (TRP) channels in naïve and M1 polarized IMs after application of lipopolysaccharide (LPS) and interferon γ. M-RNAs for the second member of the melastatin family of TRP channels, TRPM2, were upregulated in the M1 state and functional channels were identified by their characteristic currents induced by ADP-ribose, its specific activator. Most interestingly, cytokine production and secretion of interleukin-1α (IL-1α), IL-6 and tumor necrosis factor-α in M1 polarized but TRPM2-deficient IMs was significantly enhanced compared to WT cells. Activation of TRPM2 channels by ADP-ribose (ADPR) released from mitochondria by ROS-produced H2O2 significantly increases plasma membrane depolarization, which inhibits production of reactive oxygen species by NADPH oxidases and reduces cytokine production and secretion in a negative feedback loop. Therefore, TRPM2 channels are essential for the regulation of cytokine production in M1-polarized murine IMs. Specific activation of these channels may promote an anti-inflammatory phenotype and prevent a harmful cytokine storm often observed in COVID-19 patients.

RESUMEN

Ion channel activation upon ligand gating triggers a myriad of biological events and, therefore, evolution of ligand gating mechanism is of fundamental importance. TRPM2, a typical ancient ion channel, is activated by adenosine diphosphate ribose (ADPR) and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates, but the evolutionary process is still unknown. Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that, the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation, while the N-terminal MHR domain maintains a conserved ligand binding site. Calcium gating pattern has also evolved, from one Ca2+-binding site as in sea anemones to three sites as in human. Importantly, we identified a new group represented by olTRPM2, which has a novel gating mode and fills the missing link of the channel gating evolution. We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated. Such findings benefit the evolutionary investigations of other channels and proteins.

RESUMEN

Glutamate excitotoxicity is a central mechanism contributing to cellular dysfunction and death in various neurological disorders and diseases, such as stroke, traumatic brain injury, epilepsy, schizophrenia, addiction, mood disorders, Huntington's disease, Alzheimer's disease, Parkinson's disease, multiple sclerosis, pathologic pain, and even normal aging-related changes. This detrimental effect emerges from glutamate binding to glutamate receptors, including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, N-methyl-d-aspartate receptors, kainate receptors, and GluD receptors. Thus, excitotoxicity could be prevented by targeting glutamate receptors and their downstream signaling pathways. However, almost all the glutamate receptor antagonists failed to attenuate excitotoxicity in human patients, mainly due to the limited understanding of the underlying mechanisms regulating excitotoxicity. Transient receptor potential (TRP) channels serve as ancient cellular sensors capable of detecting and responding to both external and internal stimuli. The study of human TRP channels has flourished in recent decades since the initial discovery of mammalian TRP in 1995. These channels have been found to play pivotal roles in numerous pathologic conditions, including excitotoxicity. In this review, our focus centers on exploring the intricate interactions between TRP channels and glutamate receptors in excitotoxicity.

RESUMEN

Excitotoxicity and the concurrent loss of inhibition are well-defined mechanisms driving acute elevation in excitatory/inhibitory (E/I) balance and neuronal cell death following an ischemic insult to the brain. Despite the high prevalence of long-term disability in survivors of global cerebral ischemia (GCI) as a consequence of cardiac arrest, it remains unclear whether E/I imbalance persists beyond the acute phase and negatively affects functional recovery. We previously demonstrated sustained impairment of long-term potentiation (LTP) in hippocampal CA1 neurons correlating with deficits in learning and memory tasks in a murine model of cardiac arrest/cardiopulmonary resuscitation (CA/CPR). Here, we use CA/CPR and an in vitro ischemia model to elucidate mechanisms by which E/I imbalance contributes to ongoing hippocampal dysfunction in male mice. We reveal increased postsynaptic GABAA receptor (GABAAR) clustering and function in the CA1 region of the hippocampus that reduces the E/I ratio. Importantly, reduced GABAAR clustering observed in the first 24 h rebounds to an elevation of GABAergic clustering by 3 d postischemia. This increase in GABAergic inhibition required activation of the Ca2+-permeable ion channel transient receptor potential melastatin-2 (TRPM2), previously implicated in persistent LTP and memory deficits following CA/CPR. Furthermore, we find Ca2+-signaling, likely downstream of TRPM2 activation, upregulates Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity, thereby driving the elevation of postsynaptic inhibitory function. Thus, we propose a novel mechanism by which inhibitory synaptic strength is upregulated in the context of ischemia and identify TRPM2 and CaMKII as potential pharmacological targets to restore perturbed synaptic plasticity and ameliorate cognitive function.

Asunto(s)

Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Transducción de Señal , Canales Catiónicos TRPM , Animales , Masculino , Ratones , Isquemia Encefálica/metabolismo , Región CA1 Hipocampal/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Neuronas GABAérgicas/metabolismo , Paro Cardíaco/complicaciones , Paro Cardíaco/metabolismo , Hipocampo/metabolismo , Ratones Endogámicos C57BL , Inhibición Neural/fisiología , Receptores de GABA-A/metabolismo , Canales Catiónicos TRPM/metabolismo

RESUMEN

The transient receptor potential melastatin 2 (TRPM2) channel plays a central role in connecting redox state with calcium signaling in living cells. This coupling makes TRPM2 essential for physiological functions such as pancreatic insulin secretion or cytokine production, but also allows it to contribute to pathological processes, including neuronal cell death or ischemia-reperfusion injury. Genetic deletion of the channel, albeit not lethal, alters physiological functions in mice. In humans, population genetic studies and whole-exome sequencing have identified several common and rare genetic variants associated with mental disorders and neurodegenerative diseases, including single nucleotide variants (SNVs) in exonic regions. In this review, we summarize available information on the four best-documented SNVs: one common (rs1556314) and three rare genetic variants (rs139554968, rs35288229, and rs145947009), manifested in amino acid substitutions D543E, R707C, R755C, and P1018L respectively. We discuss existing evidence supporting or refuting the associations between SNVs and disease. Furthermore, we aim to interpret the molecular impacts of these amino acid substitutions based on recently published structures of human TRPM2. Finally, we formulate testable hypotheses and suggest means to investigate them. Studying the function of proteins with rare mutations might provide insight into disease etiology and delineate new drug targets.

Asunto(s)

Enfermedades Neurodegenerativas , Canales Catiónicos TRPM , Humanos , Ratones , Animales , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Insulina/metabolismo , Secreción de Insulina , Oxidación-Reducción , Calcio/metabolismo

RESUMEN

BACKGROUND: Abnormal angiogenesis is crucial for gallbladder cancer (GBC) tumor growth and invasion, highlighting the importance of elucidating the mechanisms underlying this process. LncRNA (long non-coding RNA) is widely involved in the malignancy of GBC. However, conclusive evidence confirming the correlation between lncRNAs and angiogenesis in GBC is lacking. METHODS: LncRNA sequencing was performed to identify the differentially expressed lncRNAs. RT-qPCR, western blot, FISH, and immunofluorescence were used to measure TRPM2-AS and NOTCH1 signaling pathway expression in vitro. Mouse xenograft and lung metastasis models were used to evaluate the biological function of TRPM2-AS during angiogenesis in vivo. EDU, transwell, and tube formation assays were used to detect the angiogenic ability of HUVECs. RIP, RAP, RNA pull-down, dual-luciferase reporter system, and mass spectrometry were used to confirm the interaction between TRPM2-AS, IGF2BP2, NUMB, and PABPC1. RESULTS: TRPM2-AS was upregulated in GBC tissues and was closely related to angiogenesis and poor prognosis in patients with GBC. The high expression level and stability of TRPM2-AS benefited from m6A modification, which is recognized by IGF2BP2. In terms of exerting pro-angiogenic effects, TRPM2-AS loaded with exosomes transported from GBC cells to HUVECs enhanced PABPC1-mediated NUMB expression inhibition, ultimately promoting the activation of the NOTCH1 signaling pathway. PABPC1 inhibited NUMB mRNA expression through interacting with AGO2 and promoted miR-31-5p and miR-146a-5p-mediated the degradation of NUMB mRNA. The NOTCH signaling pathway inhibitor DAPT inhibited GBC tumor angiogenesis, and TRPM2-AS knockdown enhanced this effect. CONCLUSIONS: TRPM2-AS is a novel and promising biomarker for GBC angiogenesis that promotes angiogenesis by facilitating the activation of the NOTCH1 signaling pathway. Targeting TRPM2-AS opens further opportunities for future GBC treatments.

Asunto(s)

Carcinoma in Situ , Neoplasias de la Vesícula Biliar , MicroARNs , ARN Largo no Codificante , Canales Catiónicos TRPM , Humanos , Animales , Ratones , Neoplasias de la Vesícula Biliar/genética , ARN Largo no Codificante/genética , MicroARNs/genética , Canales Catiónicos TRPM/metabolismo , Angiogénesis , Línea Celular Tumoral , Transducción de Señal , ARN Mensajero , Proliferación Celular , Receptor Notch1/metabolismo , Proteínas de Unión al ARN/metabolismo

RESUMEN

BACKGROUND: The pathogenesis of vascular dementia (VD) is complex, and currently, no effective treatments have been recommended. Floralozone is a colorless liquid first discovered in Lagotis Gaertn. Recently, its medicinal value has been increasingly recognized. Our previous study has demonstrated that Floralozone can improve cognitive dysfunction in rats with VD by regulating the transient receptor potential melastatin 2 (TRPM2) and N-methyl-D-aspartate receptor (NMDAR) signaling pathways. However, the mechanism by which Floralozone regulates TRPM2 and NMDAR to improve VD remains unclear. AMP-activated protein kinase (AMPK) is an energy regulator in vivo; however, its role of AMPK activation in stroke remains controversial. MiR-7a-5p has been identified to be closely related to neuronal function. PURPOSE: To explore whether Floralozone can regulate the miR-7a-5p level in vivo through AMPKα2 activation, affect the TRPM2 and NR2B expression levels, and improve VD symptoms. METHODS: The VD model was established by a modified bilateral occlusion of the common carotid arteries (2-VO) of Sprague-Dawley (SD) rats and AMPKα2 KO transgenic (AMPKα2-/-) mice. Primary hippocampal neurons were modeled using oxygen and glucose deprivation (OGD). Morris water maze (MWM) test, hematoxylin-eosin staining (HE staining), and TUNEL staining were used to investigate the effects of Floralozone on behavior and hippocampal morphology in rats. Minichromosome maintenance complex component 2(MCM2) positive cells were used to investigate the effect of Floralozone on neurogenesis. Immunofluorescence staining, qRT-PCR, and western blot analysis were used to investigate the effect of Floralozone on the expression levels of AMPKα2, miR-7a-5p, TRPM2, and NR2B. RESULTS: The SD rat experiment revealed that Floralozone improved spatial learning and memory, improved the morphology and structure of hippocampal neurons, reduced apoptosis of hippocampal neurons and promoted neurogenesis in VD rats. Floralozone could increase the miR-7a-5p expression level, activate AMPKα2 and NR2B expressions, and inhibit TRPM2 expression in hippocampal neurons of VD rats. The AMPKα2 KO transgenic (AMPKα2-/-) mice experiment demonstrated that Floralozone could regulate miR-7a-5p, TRPM2, and NR2B expression levels through AMPKα2 activation. The cell experiment revealed that the TRPM2 and NR2B expression levels were regulated by miR-7a-5p, whereas the AMPKα2 expression level was not. CONCLUSION: Floralozone could regulate miR-7a-5p expression level by activating the protein expression of AMPKα2, control the protein expression of TRPM2 and NR2B, improve the morphology and structure of hippocampus neurons, reduce the apoptosis of hippocampus neurons, promote neurogenesis and improve the cognitive dysfunction.

Asunto(s)

Proteínas Quinasas Activadas por AMP , Disfunción Cognitiva , Demencia Vascular , MicroARNs , Animales , Masculino , Ratones , Ratas , Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/etiología , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/genética , Demencia Vascular/genética , Demencia Vascular/tratamiento farmacológico , Demencia Vascular/metabolismo , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , MicroARNs/metabolismo , MicroARNs/genética , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Ratas Sprague-Dawley , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo

RESUMEN

N-methyl-D-aspartate receptor (NMDAR)-mediated glutamate excitotoxicity significantly contributes to ischemic neuronal death and post-recanalization infarction expansion. Despite tremendous efforts, targeting NMDARs has proven unsuccessful in clinical trials for mitigating brain injury. Here, we show the discovery of an interaction motif for transient receptor potential melastatin 2 (TRPM2) and protein kinase Cγ (PKCγ) association and demonstrate that TRPM2-PKCγ uncoupling is an effective therapeutic strategy for attenuating NMDAR-mediated excitotoxicity in ischemic stroke. We demonstrate that the TRPM2-PKCγ interaction allows TRPM2-mediated Ca2+ influx to promote PKCγ activation, which subsequently enhances TRPM2-induced potentiation of extrasynaptic NMDAR (esNMDAR) activity. By identifying the PKCγ binding motif on TRPM2 (M2PBM), which directly associates with the C2 domain of PKCγ, an interfering peptide (TAT-M2PBM) is developed to disrupt TRPM2-PKCγ interaction without compromising PKCγ function. M2PBM deletion or TRPM2-PKCγ dissociation abolishes both TRPM2-PKCγ and TRPM2-esNMDAR couplings, resulting in reduced excitotoxic neuronal death and attenuated ischemic brain injury.

Asunto(s)

Lesiones Encefálicas , Canales Catiónicos TRPM , Humanos , Proteínas Quinasas/metabolismo , Canales Catiónicos TRPM/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Péptidos/metabolismo

RESUMEN

Botulinum neurotoxin A (BoNT) is being shown to have anticancer action as a potential adjuvant treatment. The transient receptor potential (TRP) melastatin 2 (TRPM2) stimulator action of BoNT was reported in glioblastoma cells, but not in colorectal cancer (HT29) cells. By activating TRPM2, we evaluated the impacts of BoNT and oxaliplatin (OXA) incubations on oxidant and apoptotic values within the HT29 cells. Control, BoNT (5 IU for 24 h), OXA (50 µM for 24 h) and their combinations were induced. We found that TRPM2 protein is upregulated and mediates enhanced BoNT and OXA-induced Ca2+ entry in cells as compared to control cells. The increase of free reactive oxygen species (ROS), but the decrease of glutathione is the main ROS responsible for TRPM2 activation on H29 exposure to oxidative stress. BoNT and OXA-mediated Ca2+ entry through TRPM2 stimulation in response to H2 O2 results in mitochondrial Ca2+ overload, followed by mitochondrial membrane depolarization, apoptosis and caspase-3/-8/-9, although they were diminished in the TRPM2 antagonist groups (N-(p-amylcinnamoyl)anthranilic acid and carvacrol). In conclusion, by increasing the susceptibility of HT29 tumour cells to oxidative stress and apoptosis, the combined administration of BoNT and OXA via the targeting of TRPM2 may offer a different approach to kill the tumour cells.

Asunto(s)

Toxinas Botulínicas Tipo A , Neoplasias Colorrectales , Canales Catiónicos TRPM , Humanos , Oxaliplatino/farmacología , Especies Reactivas de Oxígeno/metabolismo , Toxinas Botulínicas Tipo A/metabolismo , Regulación hacia Arriba , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Muerte Celular , Estrés Oxidativo/fisiología , Apoptosis/fisiología , Neoplasias Colorrectales/tratamiento farmacológico , Calcio/metabolismo

RESUMEN

Introduction: During thermogenesis, adipose tissue (AT) becomes more active and enhances oxidative metabolism. The promotion of this process in white AT (WAT) is called "browning" and, together with the brown AT (BAT) activation, is considered as a promising approach to counteract obesity and metabolic diseases. Transient receptor potential cation channel, subfamily M, member 2 (TRPM2), is an ion channel that allows extracellular Ca2+ influx into the cytosol, and is gated by adenosine diphosphate ribose (ADPR), produced from NAD+ degradation. The aim of this study was to investigate the relevance of TRPM2 in the regulation of energy metabolism in BAT, WAT, and liver during thermogenesis. Methods: Wild type (WT) and Trpm2-/- mice were exposed to 6°C and BAT, WAT and liver were collected to evaluate mRNA, protein levels and ADPR content. Furthermore, O2 consumption, CO2 production and energy expenditure were measured in these mice upon thermogenic stimulation. Finally, the effect of the pharmacological inhibition of TRPM2 was assessed in primary adipocytes, evaluating the response upon stimulation with the ß-adrenergic receptor agonist CL316,243. Results: Trpm2-/- mice displayed lower expression of browning markers in AT and lower energy expenditure in response to thermogenic stimulus, compared to WT animals. Trpm2 gene overexpression was observed in WAT, BAT and liver upon cold exposure. In addition, ADPR levels and mono/poly-ADPR hydrolases expression were higher in mice exposed to cold, compared to control mice, likely mediating ADPR generation. Discussion: Our data indicate TRPM2 as a fundamental player in BAT activation and WAT browning. TRPM2 agonists may represent new pharmacological strategies to fight obesity.

Asunto(s)

Canales Catiónicos TRPM , Ratones , Animales , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Obesidad/genética , Obesidad/metabolismo , Termogénesis/genética

RESUMEN

TRPM2 is a Ca2+ permeable, non-selective cation channel in the plasma membrane that is involved in the innate immune response regulating, for example, chemotaxis in neutrophils and cytokine secretion in monocytes and macrophages. The intracellular adenine nucleotides ADP-ribose (ADPR) and 2'-deoxy-ADPR (2dADPR) activate the channel, in combination with their co-agonist Ca2+. Interestingly, activation of human TRPM2 (hsTRPM2) by 2dADPR is much more effective than activation by ADPR. However, the underlying mechanism of the nucleotides' differential effect on the channel is not yet fully understood. In this study, we performed whole-cell patch clamp experiments with HEK293 cells heterologously expressing hsTRPM2. We show that 2dADPR has an approx. 4-fold higher Ca2+ sensitivity than ADPR (EC50 = 190 and 690 nM). This allows 2dADPR to activate the channel at lower and thus physiological intracellular Ca2+ concentrations. Kinetic analysis of our data reveals that activation by 2dADPR is faster than activation by ADPR. Mutation in a calmodulin binding N-terminal IQ-like motif in hsTRPM2 completely abrogated channel activation by both agonists. However, mutation of a single amino acid residue (W1355A) in the C-terminus of hsTRPM2, at a site of extensive inter-domain interaction, resulted in slower activation by 2dADPR and neutralized the difference in rate of activation between the two agonists. Taken together, we propose a mechanism by which 2dADPR induces higher hsTRPM2 currents than ADPR by means of faster channel activation. The finding that 2dADPR has a higher Ca2+ sensitivity than ADPR may indicate that 2dADPR rather than ADPR activates hsTRPM2 in physiological contexts such as the innate immune response.

Asunto(s)

Adenosina Difosfato Ribosa , Canales Catiónicos TRPM , Humanos , Adenosina Difosfato Ribosa/química , Adenosina Difosfato Ribosa/farmacología , Señalización del Calcio , Células HEK293 , Cinética , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo

RESUMEN

Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, nonselective cation channel with a widespread distribution throughout the body. It is involved in many pathological and physiological processes, making it a potential therapeutic target for various diseases, including Alzheimer's disease, Parkinson's disease, and cancers. New analytical techniques are beneficial for gaining a deeper understanding of its involvement in disease pathogenesis and for advancing the drug discovery for TRPM2-related diseases. In this work, we present the application of collision-induced affinity selection mass spectrometry (CIAS-MS) for the direct identification of ligands binding to TRPM2. CIAS-MS circumvents the need for high mass detection typically associated with mass spectrometry of large membrane proteins. Instead, it focuses on the detection of small molecules dissociated from the ligand-protein-detergent complexes. This affinity selection approach consolidates all affinity selection steps within the mass spectrometer, resulting in a streamlined process. We showed the direct identification of a known TRPM2 ligand dissociated from the protein-ligand complex. We demonstrated that CIAS-MS can identify binding ligands from complex mixtures of compounds and screened a compound library against TRPM2. We investigated the impact of voltage increments and ligand concentrations on the dissociation behavior of the binding ligand, revealing a dose-dependent relationship.

Asunto(s)

Enfermedad de Alzheimer , Canales Catiónicos TRPM , Humanos , Ligandos , Descubrimiento de Drogas , Biblioteca de Genes