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1.
Adv Sci (Weinh) ; 11(15): e2307237, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38350720

RESUMO

Various disorders are accompanied by histamine-independent itching, which is often resistant to the currently available therapies. Here, it is reported that the pharmacological activation of Slack (Kcnt1, KNa1.1), a potassium channel highly expressed in itch-sensitive sensory neurons, has therapeutic potential for the treatment of itching. Based on the Slack-activating antipsychotic drug, loxapine, a series of new derivatives with improved pharmacodynamic and pharmacokinetic profiles is designed that enables to validate Slack as a pharmacological target in vivo. One of these new Slack activators, compound 6, exhibits negligible dopamine D2 and D3 receptor binding, unlike loxapine. Notably, compound 6 displays potent on-target antipruritic activity in multiple mouse models of acute histamine-independent and chronic itch without motor side effects. These properties make compound 6 a lead molecule for the development of new antipruritic therapies targeting Slack.


Assuntos
Canais de Potássio , Prurido , Animais , Camundongos , Antipruriginosos/uso terapêutico , Histamina/metabolismo , Loxapina/uso terapêutico , Canais de Potássio/metabolismo , Prurido/tratamento farmacológico , Prurido/metabolismo
2.
FASEB J ; 38(2): e23411, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38243766

RESUMO

Autism spectrum disorder is discussed in the context of altered neural oscillations and imbalanced cortical excitation-inhibition of cortical origin. We studied here whether developmental changes in peripheral auditory processing, while preserving basic hearing function, lead to altered cortical oscillations. Local field potentials (LFPs) were recorded from auditory, visual, and prefrontal cortices and the hippocampus of BdnfPax2 KO mice. These mice develop an autism-like behavioral phenotype through deletion of BDNF in Pax2+ interneuron precursors, affecting lower brainstem functions, but not frontal brain regions directly. Evoked LFP responses to behaviorally relevant auditory stimuli were weaker in the auditory cortex of BdnfPax2 KOs, connected to maturation deficits of high-spontaneous rate auditory nerve fibers. This was correlated with enhanced spontaneous and induced LFP power, excitation-inhibition imbalance, and dendritic spine immaturity, mirroring autistic phenotypes. Thus, impairments in peripheral high-spontaneous rate fibers alter spike synchrony and subsequently cortical processing relevant for normal communication and behavior.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Camundongos , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Audição , Fenótipo
3.
Cell Mol Life Sci ; 80(12): 369, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37989805

RESUMO

Mutations of large conductance Ca2+- and voltage-activated K+ channels (BK) are associated with cognitive impairment. Here we report that CA1 pyramidal neuron-specific conditional BK knock-out (cKO) mice display normal locomotor and anxiety behavior. They do, however, exhibit impaired memory acquisition and retrieval in the Morris Water Maze (MWM) when compared to littermate controls (CTRL). In line with cognitive impairment in vivo, electrical and chemical long-term potentiation (LTP) in cKO brain slices were impaired in vitro. We further used a genetically encoded fluorescent K+ biosensor and a Ca2+-sensitive probe to observe cultured hippocampal neurons during chemical LTP (cLTP) induction. cLTP massively reduced intracellular K+ concentration ([K+]i) while elevating L-Type Ca2+ channel- and NMDA receptor-dependent Ca2+ oscillation frequencies. Both, [K+]i decrease and Ca2+ oscillation frequency increase were absent after pharmacological BK inhibition or in cells lacking BK. Our data suggest that L-Type- and NMDAR-dependent BK-mediated K+ outflow significantly contributes to hippocampal LTP, as well as learning and memory.


Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta , Potenciação de Longa Duração , Camundongos , Animais , Potenciação de Longa Duração/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Plasticidade Neuronal/fisiologia , Hipocampo/fisiologia , Neurônios , Camundongos Knockout
4.
Commun Biol ; 6(1): 1029, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37821582

RESUMO

Mutations of the Na+-activated K+ channel Slack (KCNT1) are associated with terrible epilepsy syndromes that already begin in infancy. Here we report increased severity of acute kainic acid-induced seizures in adult and juvenile Slack knockout mice (Slack-/-) in vivo. Fittingly, we find exacerbation of cell death following kainic acid exposure in organotypic hippocampal slices as well as dissociated hippocampal cultures from Slack-/- in vitro. Furthermore, in cultured Slack-/- neurons, kainic acid-triggered Ca2+ influx and K+ efflux as well as depolarization-induced tetrodotoxin-sensitive inward currents are higher compared to the respective controls. This apparent changes in ion homeostasis could possibly explain altered action potential kinetics of Slack-/- neurons: steeper rise slope, decreased threshold, and duration of afterhyperpolarization, which ultimately lead to higher action potential frequencies during kainic acid application or injection of depolarizing currents. Based on our data, we propose Slack as crucial gatekeeper of neuronal excitability to acutely limit seizure severity.


Assuntos
Ácido Caínico , Canais de Potássio , Camundongos , Animais , Canais de Potássio/genética , Canais de Potássio Ativados por Sódio/genética , Canais de Potássio Ativados por Sódio/metabolismo , Ácido Caínico/toxicidade , Ácido Caínico/metabolismo , Neurônios/fisiologia , Convulsões/induzido quimicamente , Convulsões/metabolismo , Camundongos Knockout
5.
Biospektrum (Heidelb) ; 29(2): 145-149, 2023.
Artigo em Alemão | MEDLINE | ID: mdl-37073321

RESUMO

2023 marks the 30th anniversary of the discovery of single-domain antibody fragments in camelids, better known as nanobodies. This was the starting point for their tremendous success story in biomedicine. Here we highlight recent advances in the development of nanobodies for the detection of neutralizing SARS-CoV-2 antibodies, as biosensors for monitoring extracellular metabolites and as tracer molecules for non-invasive imaging of immune cells.

6.
J Thromb Haemost ; 21(7): 1957-1966, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37054918

RESUMO

BACKGROUND: Pathophysiologic platelet activation leads to thrombo-occlusive diseases such as myocardial infarction or ischemic stroke. Niemann-Pick C1 protein (NPC1) is involved in the regulation of lysosomal lipid trafficking and calcium ion (Ca2+) signaling, and its genetic mutation causes a lysosomal storage disorder. Lipids and Ca2+ are key players in the complex orchestration of platelet activation. OBJECTIVES: The present study aimed to determine the impact of NPC1 on Ca2+ mobilization during platelet activation in thrombo-occlusive diseases. METHODS: Using MK/platelet-specific knockout mice of Npc1 (Npc1Pf4∆/Pf4∆), ex vivo and in vitro approaches as well as in vivo models of thrombosis, we investigated the effect of Npc1 on platelet function and thrombus formation. RESULTS: We showed that Npc1Pf4∆/Pf4∆ platelets display increased sphingosine levels and a locally impaired membrane-associated and SERCA3-dependent Ca2+ mobilisation compared to platelets from wildtype littermates (Npc1lox/lox). Further, we observed decreased platelet. CONCLUSION: Our findings highlight that NPC1 regulates membrane-associated and SERCA3-dependent Ca2+ mobilization during platelet activation and that MK/platelet-specific ablation of Npc1 protects against experimental models of arterial thrombosis and myocardial or cerebral ischemia/reperfusion injury.


Assuntos
Proteína C1 de Niemann-Pick , Doença de Niemann-Pick Tipo C , Camundongos , Animais , Cálcio/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/metabolismo , Camundongos Knockout
7.
Front Mol Neurosci ; 16: 1017761, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36873102

RESUMO

The complex mechanism by which stress can affect sensory processes such as hearing is still poorly understood. In a previous study, the mineralocorticoid (MR) and/or glucocorticoid receptor (GR) were deleted in frontal brain regions but not cochlear regions using a CaMKIIα-based tamoxifen-inducible Cre ERT2/loxP approach. These mice exhibit either a diminished (MRTMXcKO) or disinhibited (GRTMXcKO) auditory nerve activity. In the present study, we observed that mice differentially were (MRTMXcKO) or were not (GRTMXcKO) able to compensate for altered auditory nerve activity in the central auditory pathway. As previous findings demonstrated a link between central auditory compensation and memory-dependent adaptation processes, we analyzed hippocampal paired-pulse facilitation (PPF) and long-term potentiation (LTP). To determine which molecular mechanisms may impact differences in synaptic plasticity, we analyzed Arc/Arg3.1, known to control AMPA receptor trafficking, as well as regulators of tissue perfusion and energy consumption (NO-GC and GC-A). We observed that the changes in PPF of MRTMXcKOs mirrored the changes in their auditory nerve activity, whereas changes in the LTP of MRTMXcKOs and GRTMXcKOs mirrored instead the changes in their central compensation capacity. Enhanced GR expression levels in MRTMXcKOs suggest that MRs typically suppress GR expression. We observed that hippocampal LTP, GC-A mRNA expression levels, and ABR wave IV/I ratio were all enhanced in animals with elevated GR (MRTMXcKOs) but were all lower or not mobilized in animals with impaired GR expression levels (GRTMXcKOs and MRGRTMXcKOs). This suggests that GC-A may link LTP and auditory neural gain through GR-dependent processes. In addition, enhanced NO-GC expression levels in MR, GR, and MRGRTMXcKOs suggest that both receptors suppress NO-GC; on the other hand, elevated Arc/Arg3.1 levels in MRTMXcKOs and MRGRTMXcKOs but not GRTMXcKOs suggest that MR suppresses Arc/Arg3.1 expression levels. Conclusively, MR through GR inhibition may define the threshold for hemodynamic responses for LTP and auditory neural gain associated with GC-A.

8.
Cell Death Dis ; 13(12): 1055, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36539400

RESUMO

Ion channels are non-conventional, druggable oncological targets. The intermediate-conductance calcium-dependent potassium channel (KCa3.1) is highly expressed in the plasma membrane and in the inner mitochondrial membrane (mitoKCa3.1) of various cancer cell lines. The role mitoKCa3.1 plays in cancer cells is still undefined. Here we report the synthesis and characterization of two mitochondria-targeted novel derivatives of a high-affinity KCa3.1 antagonist, TRAM-34, which retain the ability to block channel activity. The effects of these drugs were tested in melanoma, pancreatic ductal adenocarcinoma and breast cancer lines, as well as in vivo in two orthotopic models. We show that the mitochondria-targeted TRAM-34 derivatives induce release of mitochondrial reactive oxygen species, rapid depolarization of the mitochondrial membrane, fragmentation of the mitochondrial network. They trigger cancer cell death with an EC50 in the µM range, depending on channel expression. In contrast, inhibition of the plasma membrane KCa3.1 by membrane-impermeant Maurotoxin is without effect, indicating a specific role of mitoKCa3.1 in determining cell fate. At sub-lethal concentrations, pharmacological targeting of mitoKCa3.1 significantly reduced cancer cell migration by enhancing production of mitochondrial reactive oxygen species and nuclear factor-κB (NF-κB) activation, and by downregulating expression of Bcl-2 Nineteen kD-Interacting Protein (BNIP-3) and of Rho GTPase CDC-42. This signaling cascade finally leads to cytoskeletal reorganization and impaired migration. Overexpression of BNIP-3 or pharmacological modulation of NF-κB and CDC-42 prevented the migration-reducing effect of mitoTRAM-34. In orthotopic models of melanoma and pancreatic ductal adenocarcinoma, the tumors at sacrifice were 60% smaller in treated versus untreated animals. Metastasis of melanoma cells to lymph nodes was also drastically reduced. No signs of toxicity were observed. In summary, our results identify mitochondrial KCa3.1 as an unexpected player in cancer cell migration and show that its pharmacological targeting is efficient against both tumor growth and metastatic spread in vivo.


Assuntos
Carcinoma Ductal Pancreático , Melanoma , Neoplasias Pancreáticas , Canais de Potássio Cálcio-Ativados , Animais , NF-kappa B/metabolismo , Cálcio/metabolismo , Canais de Cálcio , Canais de Potássio , Espécies Reativas de Oxigênio/metabolismo , Morte Celular , Mitocôndrias/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Neoplasias Pancreáticas
9.
Cell Death Dis ; 13(10): 902, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-36302750

RESUMO

Ca2+-activated K+ channels of intermediate conductance (IK) are frequently overexpressed in breast cancer (BC) cells, while IK channel depletion reduces BC cell proliferation and tumorigenesis. This raises the question, of whether and mechanistically how IK activity interferes with the metabolic activity and energy consumption rates, which are fundamental for rapidly growing cells. Using BC cells obtained from MMTV-PyMT tumor-bearing mice, we show that both, glycolysis and mitochondrial ATP-production are reduced in cells derived from IK-deficient breast tumors. Loss of IK altered the sub-/cellular K+- and Ca2+- homeostasis and mitochondrial membrane potential, ultimately resulting in reduced ATP-production and metabolic activity. Consequently, we find that BC cells lacking IK upregulate AMP-activated protein kinase activity to induce autophagy compensating the glycolytic and mitochondrial energy shortage. Our results emphasize that IK by modulating cellular Ca2+- and K+-dynamics contributes to the remodeling of metabolic pathways in cancer. Thus, targeting IK channel might disturb the metabolic activity of BC cells and reduce malignancy.


Assuntos
Neoplasias da Mama , Canais de Potássio Ativados por Cálcio de Condutância Intermediária , Animais , Camundongos , Trifosfato de Adenosina/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Glicólise , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Neoplasias da Mama/metabolismo
10.
iScience ; 25(9): 104907, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36046190

RESUMO

Ion and analyte changes in the tumor microenvironment (TME) alter the metabolic activity of cancer cells, promote tumor cell growth, and impair anti-tumor immunity. Consequently, accurate determination and visualization of extracellular changes of analytes in real time is desired. In this study, we genetically combined FRET-based biosensors with nanobodies (Nbs) to specifically visualize and monitor extracellular changes in K+, pH, and glucose on cell surfaces. We demonstrated that these Nb-fused biosensors quantitatively visualized K+ alterations on cancer and non-cancer cell lines and primary neurons. By implementing a HER2-specific Nb, we generated functional K+ and pH sensors, which specifically stained HER2-positive breast cancer cells. Based on the successful development of several Nb-fused biosensor combinations, we anticipate that this approach can be readily extended to other biosensors and will open new opportunities for the study of extracellular analytes in advanced experimental settings.

11.
Front Oncol ; 12: 920211, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36106098

RESUMO

Women after mastectomy may decide to either have a breast reconstruction or use an external breast prosthesis. AIM: The aim of the presented research was to evaluate the influence of external breast prosthesis on postural stability in women after mastectomy. METHODS AND PROCEDURES: In the study 52 women after unilateral mastectomy took part. The study consisted of 4 parts: 1) anthropometric measurements; 2) measurements of upper limb circumference; 3) assessment of weight-bearing (WB); and 4) posturographic tests (PT). OUTCOMES AND RESULTS: Differences in the arm circumferences on the amputated (A) and non-amputated (NA) sides did not confirm the occurrence of lymphedema in limb on amputated side. The results of the WB between the A and NA body sides in both tested conditions, i.e., with open and closed eyes, showed no significant differences between the test with and without an external prosthesis. No statistically differences have been observed between posturometric parameters with and without breast prosthesis during both PT. In comparing the posturometric parameters between the PT with open and closed eyes, the sway path of the center of pressure was statistically significantly longer when eyes were closed in both conditions, i.e., with and without breast prosthesis. CONCLUSION AND IMPLICATIONS: The finding show that 1) external breast prosthesis does not have a significant influence on the symmetry of loading on the A and NA body sides and on the postural stability of women after unilateral mastectomy and 2) exclusion visual control during PT increases postural instability in women after unilateral mastectomy.

12.
Cells ; 11(10)2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35626730

RESUMO

The transient receptor potential (TRP) ankyrin type 1 (TRPA1) channel is highly expressed in a subset of sensory neurons where it acts as an essential detector of painful stimuli. However, the mechanisms that control the activity of sensory neurons upon TRPA1 activation remain poorly understood. Here, using in situ hybridization and immunostaining, we found TRPA1 to be extensively co-localized with the potassium channel Slack (KNa1.1, Slo2.2, or Kcnt1) in sensory neurons. Mice lacking Slack globally (Slack-/-) or conditionally in sensory neurons (SNS-Slack-/-) demonstrated increased pain behavior after intraplantar injection of the TRPA1 activator allyl isothiocyanate. By contrast, pain behavior induced by the TRP vanilloid 1 (TRPV1) activator capsaicin was normal in Slack-deficient mice. Patch-clamp recordings in sensory neurons and in a HEK cell line transfected with TRPA1 and Slack revealed that Slack-dependent potassium currents (IKS) are modulated in a TRPA1-dependent manner. Taken together, our findings highlight Slack as a modulator of TRPA1-mediated, but not TRPV1-mediated, activation of sensory neurons.


Assuntos
Nociceptividade , Canais de Potencial de Receptor Transitório , Animais , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Dor/metabolismo , Canais de Potássio/metabolismo , Canais de Potássio Ativados por Sódio , Células Receptoras Sensoriais/metabolismo , Canal de Cátion TRPA1/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo
13.
Cells ; 11(8)2022 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-35456043

RESUMO

Vascular smooth muscle cells (VSMCs) can switch from their contractile state to a synthetic phenotype resulting in high migratory and proliferative capacity and driving atherosclerotic lesion formation. The cysteine-rich LIM-only protein 4 (CRP4) reportedly modulates VSM-like transcriptional signatures, which are perturbed in VSMCs undergoing phenotypic switching. Thus, we hypothesized that CRP4 contributes to adverse VSMC behaviours and thereby to atherogenesis in vivo. The atherogenic properties of CRP4 were investigated in plaque-prone apolipoprotein E (ApoE) and CRP4 double-knockout (dKO) as well as ApoE-deficient CRP4 wildtype mice. dKO mice exhibited lower plaque numbers and lesion areas as well as a reduced content of α-smooth muscle actin positive cells in the lesion area, while lesion-associated cell proliferation was elevated in vessels lacking CRP4. Reduced plaque volumes in dKO correlated with significantly less intra-plaque oxidized low-density lipoprotein (oxLDL), presumably due to upregulation of the antioxidant factor peroxiredoxin-4 (PRDX4). This study identifies CRP4 as a novel pro-atherogenic factor that facilitates plaque oxLDL deposition and identifies the invasion of atherosclerotic lesions by VSMCs as important determinants of plaque vulnerability. Thus, targeting of VSMC CRP4 should be considered in plaque-stabilizing pharmacological strategies.


Assuntos
Aterosclerose , Placa Aterosclerótica , Animais , Apolipoproteínas E , Aterosclerose/metabolismo , Cisteína/metabolismo , Modelos Animais de Doenças , Camundongos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Placa Aterosclerótica/patologia , alfa-Defensinas
14.
Front Immunol ; 13: 826515, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35251008

RESUMO

Neutrophils are the most numerous cells in the leukocyte population and essential for innate immunity. To limit their effector functions, neutrophils are able to modulate glycolysis and other cellular metabolic pathways. These metabolic pathways are essential not only for energy usage, but also for specialized effector actions, such as the production of reactive oxygen species (ROS), chemotaxis, phagocytosis, degranulation, and the formation of neutrophil extracellular traps (NETs). It has been demonstrated that activated viable neutrophils can produce NETs, which consists of a DNA scaffold able to bind granule proteins and microorganisms. The formation of NETs requires the availability of increased amounts of adenosine triphosphate (ATP) as it is an active cellular and therefore energy-dependent process. In this article, we discuss the glycolytic and other metabolic routes in association with neutrophil functions focusing on their role for building up NETs in the extracellular space. A better understanding of the requirements of metabolic pathways for neutrophil functions may lead to the discovery of molecular targets suitable to develop novel anti-infectious and/or anti-inflammatory drugs.


Assuntos
Armadilhas Extracelulares , Neutrófilos , Imunidade Inata , Redes e Vias Metabólicas , Fagocitose
15.
iScience ; 25(3): 103981, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35281733

RESUMO

The key auditory signature that may associate peripheral hearing with central auditory cognitive defects remains elusive. Suggesting the involvement of stress receptors, we here deleted the mineralocorticoid and glucocorticoid receptors (MR and GR) using a CaMKIIα-based tamoxifen-inducible CreERT2/loxP approach to generate mice with single or double deletion of central but not cochlear MR and GR. Hearing thresholds of MRGRCaMKIIαCreERT2 conditional knockouts (cKO) were unchanged, whereas auditory nerve fiber (ANF) responses were larger and faster and auditory steady state responses were improved. Subsequent analysis of single MR or GR cKO revealed discrete roles for both, central MR and GR on cochlear functions. Limbic MR deletion reduced inner hair cell (IHC) ribbon numbers and ANF responses. In contrast, GR deletion shortened the latency and improved the synchronization to amplitude-modulated tones without affecting IHC ribbon numbers. These findings imply that stress hormone-dependent functions of central MR/GR contribute to "precognitive" sound processing in the cochlea.

16.
Br J Pharmacol ; 179(11): 2321-2327, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35332531

Assuntos
GMP Cíclico
17.
Anesthesiology ; 136(5): 802-822, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35303056

RESUMO

BACKGROUND: Slick, a sodium-activated potassium channel, has been recently identified in somatosensory pathways, but its functional role is poorly understood. The authors of this study hypothesized that Slick is involved in processing sensations of pain and itch. METHODS: Immunostaining, in situ hybridization, Western blot, and real-time quantitative reverse transcription polymerase chain reaction were used to investigate the expression of Slick in dorsal root ganglia and the spinal cord. Mice lacking Slick globally (Slick-/-) or conditionally in neurons of the spinal dorsal horn (Lbx1-Slick-/-) were assessed in behavioral models. RESULTS: The authors found Slick to be enriched in nociceptive Aδ-fibers and in populations of interneurons in the spinal dorsal horn. Slick-/- mice, but not Lbx1-Slick-/- mice, showed enhanced responses to noxious heat in the hot plate and tail-immersion tests. Both Slick-/- and Lbx1-Slick-/- mice demonstrated prolonged paw licking after capsaicin injection (mean ± SD, 45.6 ± 30.1 s [95% CI, 19.8 to 71.4]; and 13.1 ± 16.1 s [95% CI, 1.8 to 28.0]; P = 0.006 [Slick-/- {n = 8} and wild-type {n = 7}, respectively]), which was paralleled by increased phosphorylation of the neuronal activity marker extracellular signal-regulated kinase in the spinal cord. In the spinal dorsal horn, Slick is colocalized with somatostatin receptor 2 (SSTR2), and intrathecal preadministration of the SSTR2 antagonist CYN-154806 prevented increased capsaicin-induced licking in Slick-/- and Lbx1-Slick-/- mice. Moreover, scratching after intrathecal delivery of the somatostatin analog octreotide was considerably reduced in Slick-/- and Lbx1-Slick-/- mice (Slick-/- [n = 8]: 6.1 ± 6.7 bouts [95% CI, 0.6 to 11.7]; wild-type [n =8]: 47.4 ± 51.1 bouts [95% CI, 4.8 to 90.2]; P = 0.039). CONCLUSIONS: Slick expressed in a subset of sensory neurons modulates heat-induced pain, while Slick expressed in spinal cord interneurons inhibits capsaicin-induced pain but facilitates somatostatin-induced itch.


Assuntos
Capsaicina , Células do Corno Posterior , Animais , Capsaicina/efeitos adversos , Capsaicina/metabolismo , Gânglios Espinais/metabolismo , Camundongos , Dor , Células do Corno Posterior/metabolismo , Canais de Potássio , Prurido/induzido quimicamente , Células Receptoras Sensoriais/metabolismo , Canais de Sódio , Somatostatina/efeitos adversos , Somatostatina/metabolismo , Medula Espinal/metabolismo
18.
Free Radic Biol Med ; 181: 43-51, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35091062

RESUMO

Cancer represents a leading cause of death worldwide. Hence, a better understanding of the molecular mechanisms causing and propelling the disease is of utmost importance. Several cancer entities are associated with altered K+ channel expression which is frequently decisive for malignancy and disease outcome. The impact of such oncogenic K+ channels on cell patho-/physiology and homeostasis and their roles in different subcellular compartments is, however, far from being understood. A refined method to simultaneously investigate metabolic and ionic signaling events on the level of individual cells and their organelles represent genetically encoded fluorescent biosensors, that allow a high-resolution investigation of compartmentalized metabolite or ion dynamics in a non-invasive manner. This feature of these probes makes them versatile tools to visualize and understand subcellular consequences of aberrant K+ channel expression and activity in K+ channel related cancer research.


Assuntos
Técnicas Biossensoriais , Neoplasias , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Humanos , Íons , Neoplasias/genética
19.
Br J Pharmacol ; 179(11): 2344-2360, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33991427

RESUMO

The 3',5'-cGMP pathway triggers cytoprotective responses and improves cardiomyocyte survival during myocardial ischaemia and reperfusion (I/R) injury. These beneficial effects were attributed to NO-sensitive GC induced cGMP production leading to activation of cGMP-dependent protein kinase I (cGKI). cGKI in turn phosphorylates many substrates, which eventually facilitate opening of mitochondrial ATP-sensitive potassium channels (mitoKATP ) and Ca2+ -activated potassium channels of the BK type (mitoBK). Accordingly, agents activating mitoKATP or mitoBK provide protection against I/R-induced damages. Here, we provide an up-to-date summary of the infarct-limiting actions exhibited by the GC/cGMP axis and discuss how mitoKATP and mitoBK, which are present at the inner mitochondrial membrane, confer mito- and cytoprotective effects on cardiomyocytes exposed to I/R injury. In view of this, we believe that the functional connection between the cGMP cascade and mitoK+ channels should be exploited further as adjunct to reperfusion therapy in myocardial infarction. LINKED ARTICLES: This article is part of a themed issue on cGMP Signalling in Cell Growth and Survival. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.11/issuetoc.


Assuntos
Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , GMP Cíclico/metabolismo , Humanos , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/metabolismo , Transdução de Sinais
20.
Br J Pharmacol ; 179(12): 2906-2924, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-32468618

RESUMO

BACKGROUND AND PURPOSE: Pore-forming α subunits of the voltage- and Ca2+ -activated K+ channel with large conductance (BKα) promote malignant phenotypes of breast tumour cells. Auxiliary subunits such as the leucine-rich repeat containing 26 (LRRC26) protein, also termed BKγ1, may be required to permit activation of BK currents at a depolarized resting membrane potential that frequently occur in non-excitable tumour cells. EXPERIMENTAL APPROACH: Anti-tumour effects of BKα loss were investigated in breast tumour-bearing MMTV-PyMT transgenic BKα knockout (KO) mice, primary MMTV-PyMT cell cultures, and in a syngeneic transplantation model of breast cancer derived from these cells. The therapeutic relevance of BK channels in the context of endocrine treatment was assessed in human breast cancer cell lines expressing either low (MCF-7) or high (MDA-MB-453) levels of BKα and BKγ1, as well as in BKα-negative MDA-MB-157. KEY RESULTS: BKα promoted breast cancer onset and overall survival in preclinical models. Conversely, lack of BKα and/or knockdown of BKγ1 attenuated proliferation of murine and human breast cancer cells in vitro. At low concentrations, tamoxifen and its major active metabolites stimulated proliferation of BKα/γ1-positive breast cancer cells, independent of the genomic signalling controlled by the oestrogen receptor. Finally, tamoxifen increased the relative survival time of BKα KO but not of wild-type tumour cell recipient mice. CONCLUSION AND IMPLICATIONS: Breast cancer initiation, progression, and tamoxifen sensitivity depend on functional BK channels thereby providing a rationale for the future exploration of the oncogenic actions of BK channels in clinical outcomes with anti-oestrogen therapy. LINKED ARTICLES: This article is part of a themed issue on New avenues in cancer prevention and treatment (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.12/issuetoc.


Assuntos
Neoplasias da Mama , Canais de Potássio Ativados por Cálcio de Condutância Alta , Animais , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Potenciais da Membrana , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Tamoxifeno/farmacologia
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