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2.
Nature ; 629(8011): 474-480, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38600384

RESUMEN

The µ-opioid receptor (µOR) is an important target for pain management1 and molecular understanding of drug action on µOR will facilitate the development of better therapeutics. Here we show, using double electron-electron resonance and single-molecule fluorescence resonance energy transfer, how ligand-specific conformational changes of µOR translate into a broad range of intrinsic efficacies at the transducer level. We identify several conformations of the cytoplasmic face of the receptor that interconvert on different timescales, including a pre-activated conformation that is capable of G-protein binding, and a fully activated conformation that markedly reduces GDP affinity within the ternary complex. Interaction of ß-arrestin-1 with the µOR core binding site appears less specific and occurs with much lower affinity than binding of Gi.


Asunto(s)
Ligandos , Conformación Proteica , Receptores Opioides mu , Humanos , beta-Arrestina 1/química , beta-Arrestina 1/metabolismo , Sitios de Unión , Transferencia Resonante de Energía de Fluorescencia , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/química , Guanosina Difosfato/metabolismo , Guanosina Difosfato/química , Modelos Moleculares , Unión Proteica , Receptores Opioides mu/metabolismo , Receptores Opioides mu/química , Imagen Individual de Molécula
3.
Nat Prod Res ; : 1-7, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38148164

RESUMEN

A new depsidone derivative botryorhodine J (1), along with six known compounds (2-7) were obtained from solid rice cultures of Alternaria alternata Pas11 that was isolated from leaves of Phragmites australis. The structure of the new compound was elucidated on the basis of combination of NMR spectroscopic data and high resolution mass spectrometry (HRMS). All the isolated compounds were evaluated for their antibacterial activities against a panel of Gram-positive bacterial strains (methicillin-resistant Staphylococcus aureus [MRSA], Bacillus subtilis and S. aureus). Compounds 1 and 6 displayed antibacterial activity against the three bacterial strains with the minimum inhibitory concentration values (MICs) of 14 - 32 µg/mL, while compound 5 showed good antibacterial activity against above bacterial strains with MIC values of 5 - 8 µg/mL.

4.
Sci Rep ; 13(1): 18079, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37872222

RESUMEN

We present numerical results for three-dimensional (3D) solitons with symmetries of the semi-vortex (SV) and mixed-mode (MM) types, which can be created in spinor Bose-Einstein condensates of Rydberg atoms under the action of the spin-orbit coupling (SOC). By means of systematic numerical computations, we demonstrate that the interplay of SOC and long-range spherically symmetric Rydberg interactions stabilize the 3D solitons, improving their resistance to collapse. We find how the stability range depends on the strengths of the SOC and Rydberg interactions and the soft-core atomic radius.

5.
Heliyon ; 9(7): e17851, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37456012

RESUMEN

Aims: Upregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) contributes to the pathogenesis of cardiovascular disease, including hypertension. Transgenic rats expressing the human angiotensinogen gene [TGR (hAGT)L1623] are a new novel humanized model of hypertension that associates with declines in cardiac contractile function and ß-adrenergic receptor (AR) reserve. The molecular mechanisms are unclear. We tested the hypothesis that in TGR (hAGT)L1623 rats, left ventricular (LV) myocyte CaMKIIδ and ß3-AR are upregulated, but ß1-AR is down-regulated, which are important causes of cardiac dysfunction and ß-AR desensitization. Main methods: We compared LV myocyte CaMKIIδ, CaMKIIδ phosphorylation (at Thr287) (pCaMKIIδ), and ß1-and ß3-AR expressions and determined myocyte functional and [Ca2+]I transient ([Ca2+]iT) responses to ß-AR stimulation with and without pretreatment of myocytes using an inhibitor of CaMKII, KN-93 (10-6 M, 30 min) in male Sprague Dawley (SD; N = 10) control and TGR (hAGT)L1623 (N = 10) adult rats. Key findings: Hypertension in TGR (hAGT)L1623 rats was accompanied by significantly increased LV myocyte ß3-AR protein levels and reduced ß1-AR protein levels. CaMKIIδ phosphorylation (at Thr287), pCaMKIIδ was significantly increased by 35%. These changes were followed by significantly reduced basal cell contraction (dL/dtmax), relaxation (dR/dtmax), and [Ca2+]iT. Isoproterenol (10-8 M) produced significantly smaller increases in dL/dtmax, dR/dtmax, and [Ca2+]iT. Moreover, only in TGR (hAGT)L1623 rats, pretreatment of LV myocytes with KN-93 (10-6 M, 30 min) fully restored normal basal and isoproterenol-stimulated myocyte contraction, relaxation, and [Ca2+]iT. Significance: LV myocyte CaMKIIδ overactivation with associated contrast changes in ß3-AR and ß1-AR may be the key molecular mechanism for the abnormal contractile phenotype and ß-AR desensitization in this humanized model of hypertension.

6.
bioRxiv ; 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37163120

RESUMEN

The µ-opioid receptor (µOR) is an important target for pain management and the molecular understanding of drug action will facilitate the development of better therapeutics. Here we show, using double electron-electron resonance (DEER) and single-molecule fluorescence resonance energy transfer (smFRET), how ligand-specific conformational changes of the µOR translate into a broad range of intrinsic efficacies at the transducer level. We identify several cytoplasmic receptor conformations interconverting on different timescales, including a pre-activated receptor conformation which is capable of G protein binding, and a fully activated conformation which dramatically lowers GDP affinity within the ternary complex. Interaction of ß-arrestin-1 with the µOR core binding site appears less specific and occurs with much lower affinity than binding of G protein Gi.

7.
Entropy (Basel) ; 25(5)2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37238561

RESUMEN

The quantification of causality is vital for understanding various important phenomena in nature and laboratories, such as brain networks, environmental dynamics, and pathologies. The two most widely used methods for measuring causality are Granger Causality (GC) and Transfer Entropy (TE), which rely on measuring the improvement in the prediction of one process based on the knowledge of another process at an earlier time. However, they have their own limitations, e.g., in applications to nonlinear, non-stationary data, or non-parametric models. In this study, we propose an alternative approach to quantify causality through information geometry that overcomes such limitations. Specifically, based on the information rate that measures the rate of change of the time-dependent distribution, we develop a model-free approach called information rate causality that captures the occurrence of the causality based on the change in the distribution of one process caused by another. This measurement is suitable for analyzing numerically generated non-stationary, nonlinear data. The latter are generated by simulating different types of discrete autoregressive models which contain linear and nonlinear interactions in unidirectional and bidirectional time-series signals. Our results show that information rate causalitycan capture the coupling of both linear and nonlinear data better than GC and TE in the several examples explored in the paper.

8.
Nat Commun ; 14(1): 2005, 2023 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-37037825

RESUMEN

Advances in structural biology have provided important mechanistic insights into signaling by the transmembrane core of G-protein coupled receptors (GPCRs); however, much less is known about intrinsically disordered regions such as the carboxyl terminus (CT), which is highly flexible and not visible in GPCR structures. The ß2 adrenergic receptor's (ß2AR) 71 amino acid CT is a substrate for GPCR kinases and binds ß-arrestins to regulate signaling. Here we show that the ß2AR CT directly inhibits basal and agonist-stimulated signaling in cell lines lacking ß-arrestins. Combining single-molecule fluorescence resonance energy transfer (FRET), NMR spectroscopy, and molecular dynamics simulations, we reveal that the negatively charged ß2AR-CT serves as an autoinhibitory factor via interacting with the positively charged cytoplasmic surface of the receptor to limit access to G-proteins. The stability of this interaction is influenced by agonists and allosteric modulators, emphasizing that the CT plays important role in allosterically regulating GPCR activation.


Asunto(s)
Receptores Acoplados a Proteínas G , Transducción de Señal , beta-Arrestinas/metabolismo , Línea Celular , Receptores Acoplados a Proteínas G/metabolismo , Receptores Adrenérgicos/metabolismo , Receptores Adrenérgicos beta 2/metabolismo
9.
Neoplasma ; 70(1): 82-93, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36660797

RESUMEN

HOXA5, as a transcription factor, plays an important role in a variety of malignant tumors. Nevertheless, its biological role in cervical squamous cell carcinoma (CSCC) is largely unknown. In our study, we aimed to explore the function of HOXA5 in CSCC and its molecular mechanism. Immunohistochemistry showed that HOXA5 expression was downregulated in human CSCC tissues and HOXA5 staining was negatively correlated with tumor size and histological grade of CSCC. Ectopic expression of HOXA5 inhibited proliferative and metastatic abilities of CSCC cells in vitro and in vivo. Furthermore, overexpression of HOXA5 inhibited the cell cycle by arresting the S/G2 phase by flow cytometry and that was related to the downregulation of Cyclin A. Further study showed that HOXA5 suppressed EMT by inhibiting the ß-catenin/Snail signaling resulting in reduced metastasis of CSCC cells. Altogether, our results suggested that HOXA5 inhibited the proliferation and metastasis via repression of the ß-catenin/Snail pathway, proposing the potential role of HOXA5 in the prevention and treatment of CSCC.


Asunto(s)
Carcinoma de Células Escamosas , Proteínas de Homeodominio , Neoplasias del Cuello Uterino , Femenino , Humanos , beta Catenina/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Proliferación Celular , Proteínas de Homeodominio/genética , Transducción de Señal , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/patología
10.
Heliyon ; 8(11): e11653, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36411910

RESUMEN

Calcium-calmodulin-dependent protein kinase II (CaMKII) is upregulated in diabetes mellitus (DM), leading to the overproduction of collagen in the myocardium. We hypothesized that CaMKII plays a role in the development of diabetic nephropathy (DN). Streptozotocin (STZ) injection into FVB wild-type mice led to mild mesangial matrix expansion, reproducing an essential feature of early human DN. Mesangial matrix measurements were performed on trichrome-stained paraffin sections using a trainable segmentation method based on WEKA (Waikato Environment for Knowledge Analysis) Image J-Fiji plugin (TWS plugin), and the electron micrographs of the whole glomeruli stitched from individual 4800x partial glomerular images. Both methods demonstrated that the statistically significant mesangial matrix expansion seen in the diabetic mice was prevented by chronic pretreatment with KN-93, a small molecule CaMKII inhibitor. This study indicates a role for CaMKII in the development of mesangial alterations in diabetes and suggests a possible new therapeutic target.

11.
Comput Intell Neurosci ; 2022: 4699471, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36148421

RESUMEN

In this study, while aiming at the prevention of fire accidents in underground commercial streets, an underground commercial street is selected as a research object, and the building fire is numerically simulated using the PyroSim software. Fire simulation scenarios are divided according to different fire zones by analyzing the temperature, carbon monoxide (CO) concentration, and visibility in the smoke layer inside a building. The available safe evacuation time is calculated according to the critical fire hazard judgment conditions. We found that the time when the flue gas temperature and CO concentration reached the critical value in the fire site was longer than the time when the visibility reached the critical value reducing or even avoiding the spread of smoke from the fire area to the evacuation stairs can provide effective help for crowd evacuation. Finally, the safety of the building is evaluated, and fire prevention countermeasures are defined based on the actual situation and fire numerical simulation results to reduce fire incidence, casualties, and economic losses.


Asunto(s)
Monóxido de Carbono , Incendios , Accidentes , Monóxido de Carbono/análisis , Simulación por Computador , Incendios/prevención & control , Humo/análisis
12.
Exp Brain Res ; 240(9): 2459-2470, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35933646

RESUMEN

Electrical stimulation of the right median nerve can aid coma arousal after traumatic brain injury (TBI). This study aimed to confirm the efficacy further and explore possible mechanisms of right median nerve electrical stimulation (RMNS). Five comatose patients after severe TBI from May to September 2020 in the Tianjin Medical University General Hospital received RMNS for 2 weeks besides standard management. After the 2-week treatment, the mean Glasgow Coma Scale (GCS) and neurophysiological examination were used. We then investigated the alterations in microRNA (miRNA) expression in cerebrospinal fluid (CSF) by high-throughput whole transcriptome sequencing, analyzed the data by Gene Ontology (GO) and pathway analysis, and constructed the miRNA-target gene network. Patient awareness and brain function showed a more rapid increase after treatment. We also found 38 differently expressed miRNAs, 34 of which were upregulated and 4 downregulated. GO analysis showed a relation of these differentially expressed miRNAs with neuronal growth, repair, and neural signal transmission. The most highly correlated pathways were primarily associated with the tumor necrosis factor (TNF) signaling pathway and dopaminergic synapse. The application of RMNS effectively promoted early awakening in comatose patients with severe TBI. Moreover, differentially expressed miRNAs might reduce neuronal apoptosis and increase dopamine levels by regulating target gene expression, thus participating in the specific biological process after arousal therapy. Our study provided novel targets for further research on the molecular mechanisms of RMNS arousal treatment and a new way to treat neurotraumatic diseases.


Asunto(s)
Lesiones Traumáticas del Encéfalo , MicroARNs , Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/genética , Lesiones Traumáticas del Encéfalo/metabolismo , Coma/etiología , Coma/terapia , Escala de Coma de Glasgow , Humanos , Nervio Mediano
13.
Front Med (Lausanne) ; 9: 1024762, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36698817

RESUMEN

Background: Agitation is very common in the intensive care unit (ICU). The causes include pain, delirium, underlying disease, withdrawal syndrome, and some drug treatments. The practical goal of ICU treatment is to find an appropriate sedation regimen to reduce pain, restlessness, and delirium. Previous trials have examined the use of dexmedetomidine, but no trials have evaluated the efficacy and safety of ciprofol, a new sedative drug. Methods: This study was a multicenter, single-blind, 3-arm parallel randomized controlled trial. ICU patients aged ≥ 18 years with agitation and delirium who met the eligibility criteria were included. The main outcome was the proportion of patients who needed additional study medication or midazolam due to agitation within 4 h after the first intravenous injection of the study medication. The secondary outcomes included the pass rate as indicated by a Richmond Agitation-Sedation Scale (RASS) score < +1, the effectiveness rate of improving delirium symptoms, the number of recurrences of agitation within 24 h, the incidence of rescue treatment, the dose and cost of analgesic and sedative drugs, the length and cost of ICU stay, and the 30-day survival period. The safety evaluation included the incidence of adverse events (hypotension, bradycardia, hypoxia, etc.) and the rate of endotracheal intubation. The subjects were randomly assigned to receive ciprofol, dexmedetomidine, or normal saline at a ratio of 1:1:1. The rates of additional drug administration within 4 h after the first injection of the study drug in the three groups were 40, 50, and 90%, respectively. A total sample size of 81 subjects was required to reach 90% power and an α of 0.05. Considering a 20% loss rate, 102 patients were enrolled and randomly assigned to the three groups in equal proportions. Ethics and communication: This trial was approved by the Ethics Committee of Dalian Municipal Central Hospital. The communication plan includes presentations at scientific conferences, scientific publications, and presentations to the public through non-professional media. Clinical trial registration: www.ClinicalTrials.gov, identifier ChiCTR220006 2799.

14.
J Am Chem Soc ; 143(42): 17566-17576, 2021 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-34663067

RESUMEN

The ß2-adrenergic receptor (ß2AR) is a G-protein-coupled receptor (GPCR) that responds to the hormone adrenaline and is an important drug target in the context of respiratory diseases, including asthma. ß2AR function can be regulated by post-translational modifications such as phosphorylation and ubiquitination at the C-terminus, but access to the full-length ß2AR with well-defined and homogeneous modification patterns critical for biochemical and biophysical studies remains challenging. Here, we report a practical synthesis of differentially modified, full-length ß2AR based on a combined native chemical ligation (NCL) and sortase ligation strategy. An array of homogeneous samples of full-length ß2ARs with distinct modification patterns, including a full-length ß2AR bearing both monoubiquitination and octaphosphorylation modifications, were successfully prepared for the first time. Using these homogeneously modified full-length ß2AR receptors, we found that different phosphorylation patterns mediate different interactions with ß-arrestin1 as reflected in different agonist binding affinities. Our experiments also indicated that ubiquitination can further modulate interactions between ß2AR and ß-arrestin1. Access to full-length ß2AR with well-defined and homogeneous modification patterns at the C-terminus opens a door to further in-depth mechanistic studies into the structure and dynamics of ß2AR complexes with downstream transducer proteins, including G proteins, arrestins, and GPCR kinases.


Asunto(s)
Procesamiento Proteico-Postraduccional , Receptores Adrenérgicos beta 2/química , Regulación Alostérica , Aminoaciltransferasas/química , Proteínas Bacterianas/química , Cisteína Endopeptidasas/química , Humanos , Fosforilación , Receptores Adrenérgicos beta 2/metabolismo , Staphylococcus aureus/enzimología , Ubiquitinación , beta-Arrestina 1/metabolismo
15.
Life Sci ; 285: 119955, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34520767

RESUMEN

AIMS: G protein-coupled estrogen receptor 30 (GPR30) activation by its agonist, G1, exhibits beneficial actions in female with heart failure (HF). Recent evidence indicates its cardiovascular benefits may also include male as well. However, whether and how GPR30 activation may limit HF progression and have a salutary role in males is unknown. We hypothesized that chronic G1 treatment improves LV and cardiomyocyte function, [Ca2+]i regulation and ß-adrenergic reserve, thus limiting HF progression in male. MAIN METHODS: We compared left ventricle (LV) and myocyte function, [Ca2+]i transient ([Ca2+]iT) and ß-AR modulation in control male mice (12/group) and isoproterenol-induced HF (150 mg/kg s.c. for 2 days). Two weeks after isoproterenol injection, HF mice received placebo, or G1 (150 µg/kg/day s.c. mini-pump) for 2 weeks. KEY FINDINGS: Isoproterenol-treated mice exhibited HF with preserved ejection fraction (HFpEF) at 2-weeks and progressed to HF with reduced EF (HFrEF) at 4-weeks, manifested by significantly increased LV time constant of relaxation (τ), decreased EF and mitral flow (dV/dtmax), which were accompanied by reduced myocyte contraction (dL/dtmax), relaxation (dR/dtmax) and [Ca2+]iT. Acute isoproterenol-superfusion caused significantly smaller increases in dL/dtmax, dR/dtmax and [Ca2+]iT. G1 treatment in HF increased basal and isoproterenol-stimulated increases in EF and LV contractility of EES. Importantly, G1 improved basal and isoproterenol-stimulated dL/dtmax, dR/dtmax and [Ca2+]iT to control levels and restored normal cardiac ß-AR subtypes modulation. SIGNIFICANCE: Chronic G1 treatment restores normal myocyte basal and ß-AR-stimulated contraction, relaxation, and [Ca2+]iT, thereby reversing LV dysfunction and playing a rescue role in a male mouse model of HF.


Asunto(s)
Insuficiencia Cardíaca/tratamiento farmacológico , Ventrículos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Quinolinas/uso terapéutico , Animales , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/fisiopatología , Ventrículos Cardíacos/fisiopatología , Isoproterenol , Masculino , Ratones , Ratones Endogámicos C57BL , Contracción Miocárdica/efectos de los fármacos , Miocitos Cardíacos/fisiología , Quinolinas/farmacología
16.
BMC Cardiovasc Disord ; 21(1): 215, 2021 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-33906602

RESUMEN

BACKGROUND: Myocardial ischemia-reperfusion injury (MIRI) is the main pathological manifestation of cardiovascular diseases such as myocardial infarction. The potential therapeutic effects of bone marrow-derived mesenchymal stem cells (BM-MSCs) and the participation of regulatory T cells (Tregs) in MIRI remains to be defined. METHODS: We used the experimental acute MIRI that was induced in mice by left ascending coronary ischemia, which were subsequently randomized to receive immunoglobulin G (IgG) or anti-CD25 antibody PC61 with or without intravenously injected BM-MSCs. The splenectomized mice underwent prior to experimental MIRI followed by intravenous administration of BM-MSCs. At 72 h post-MIRI, the hearts and spleens were harvested and subjected to cytometric and histologic analyses. RESULTS: CD25+Foxp3+ regulatory T cells were significantly elevated after MIRI in the hearts and spleens of mice receiving IgG + BM-MSCs and PC61 + BM-MSCs compared to the respective control mice (all p < 0.01). This was accompanied by upregulation of interleukin 10 and transforming growth factor ß1 and downregulation of creatinine kinase and lactate dehydrogenase in the serum. The post-MIRI mice receiving BM-MSCs showed attenuated inflammation and cellular apoptosis in the heart. Meanwhile, splenectomy compromised all therapeutic effects of BM-MSCs. CONCLUSION: Administration of BM-MSCs effectively alleviates MIRI in mice through inducing Treg activation, particularly in the spleen.


Asunto(s)
Trasplante de Células Madre Mesenquimatosas , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/inmunología , Bazo/inmunología , Linfocitos T Reguladores/inmunología , Animales , Anticuerpos Monoclonales/farmacología , Apoptosis , Creatina Quinasa/sangre , Modelos Animales de Enfermedad , Inmunoglobulina G/farmacología , Interleucina-10/sangre , L-Lactato Deshidrogenasa/sangre , Masculino , Ratones Endogámicos C57BL , Daño por Reperfusión Miocárdica/inmunología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Miocardio/metabolismo , Miocardio/patología , Necrosis , Fenotipo , Bazo/efectos de los fármacos , Bazo/metabolismo , Esplenectomía , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/metabolismo , Factor de Crecimiento Transformador beta1/sangre
17.
J Pharmacol Exp Ther ; 377(3): 316-325, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33722881

RESUMEN

Ca2+/calmodulin-dependent protein kinase II (CaMKII) is upregulated in congestive heart failure (CHF), contributing to electrical, structural, and functional remodeling. CaMKII inhibition is known to improve CHF, but its direct cardiac effects in CHF remain unclear. We hypothesized that CaMKII inhibition improves cardiomyocyte function, [Ca2+]i regulation, and ß-adrenergic reserve, thus improving advanced CHF. In a 16-week study, we compared plasma neurohormonal levels and left ventricular (LV)- and myocyte-functional and calcium transient ([Ca2+]iT) responses in male Sprague-Dawley rats (10/group) with CHF induced by isoproterenol (170 mg/kg sq for 2 days). In rats with CHF, we studied the effects of the CaMKII inhibitor KN-93 or its inactive analog KN-92 (n = 4) (70 µg/kg per day, mini-pump) for 4 weeks. Compared with controls, isoproterenol-treated rats had severe CHF with 5-fold-increased plasma norepinephrine and about 50% decreases in ejection fraction (EF) and LV contractility [slope of LV end-systolic pressure-LV end-systolic volume relation (EES)] but increased time constant of LV relaxation (τ). They also showed significantly reduced myocyte contraction [maximum rate of myocyte shortening (dL/dtmax)], relaxation (dL/dtmax), and [Ca2+]iT Isoproterenol superfusion caused significantly fewer increases in dL/dtmax and [Ca2+]iT KN-93 treatment prevented plasma norepinephrine elevation, with increased basal and acute isoproterenol-stimulated increases in EF and EES and decreased τ in CHF. KN-93 treatment preserved normal myocyte contraction, relaxation, [Ca2+]iT, and ß-adrenergic reserve, whereas KN-92 treatment failed to improve LV and myocyte function, and plasma norepinephrine remained high in CHF. Thus, chronic CaMKII inhibition prevented CHF-induced activation of the sympathetic nervous system, restoring normal LV and cardiomyocyte basal and ß-adrenergic-stimulated contraction, relaxation, and [Ca2+]iT, thereby playing a rescue role in advanced CHF. SIGNIFICANCE STATEMENT: We investigated the therapeutic efficacy of late initiation of chronic Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibition on progression of advanced congestive heart failure (CHF). Chronic CaMKII inhibition prevented CHF-induced activation of the sympathetic nervous system and restored normal intrinsic cardiomyocyte basal and ß-adrenergic receptor-stimulated relaxation, contraction, and [Ca2+]i regulation, leading to reversal of CHF progression. These data provide new evidence that CaMKII inhibition is able and sufficient to rescue a failing heart, and thus cardiac CaMKII inhibition is a promising target for improving CHF treatment.


Asunto(s)
Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Animales , Insuficiencia Cardíaca , Ratas , Ratas Sprague-Dawley
18.
Proc Natl Acad Sci U S A ; 117(37): 23096-23105, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32868434

RESUMEN

The ß2-adrenergic receptor (ß2AR) is a prototypical G protein-coupled receptor (GPCR) that preferentially couples to the stimulatory G protein Gs and stimulates cAMP formation. Functional studies have shown that the ß2AR also couples to inhibitory G protein Gi, activation of which inhibits cAMP formation [R. P. Xiao, Sci. STKE 2001, re15 (2001)]. A crystal structure of the ß2AR-Gs complex revealed the interaction interface of ß2AR-Gs and structural changes upon complex formation [S. G. Rasmussen et al., Nature 477, 549-555 (2011)], yet, the dynamic process of the ß2AR signaling through Gs and its preferential coupling to Gs over Gi is still not fully understood. Here, we utilize solution nuclear magnetic resonance (NMR) spectroscopy and supporting molecular dynamics (MD) simulations to monitor the conformational changes in the G protein coupling interface of the ß2AR in response to the full agonist BI-167107 and Gs and Gi1 These results show that BI-167107 stabilizes conformational changes in four transmembrane segments (TM4, TM5, TM6, and TM7) prior to coupling to a G protein, and that the agonist-bound receptor conformation is different from the G protein coupled state. While most of the conformational changes observed in the ß2AR are qualitatively the same for Gs and Gi1, we detected distinct differences between the ß2AR-Gs and the ß2AR-Gi1 complex in intracellular loop 2 (ICL2). Interactions with ICL2 are essential for activation of Gs These differences between the ß2AR-Gs and ß2AR-Gi1 complexes in ICL2 may be key determinants for G protein coupling selectivity.


Asunto(s)
Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gs/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Benzoxazinas/farmacología , Sitios de Unión/fisiología , Proteínas de Unión al GTP/metabolismo , Humanos , Espectroscopía de Resonancia Magnética/métodos , Simulación de Dinámica Molecular , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología
19.
Int J Cardiol ; 301: 135-141, 2020 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-31521437

RESUMEN

BACKGROUND: Angiotensin-(1-12) [Ang-(1-12)] is a renin-independent precursor for direct angiotensin-II production by chymase. Substantial evidence suggests that heart failure (HF) may alter cardiac Ang-(1-12) expression and activity; this novel Ang-(1-12)/chymase axis may be the main source for angiotensin-II deleterious actions in HF. We hypothesized that HF alters cardiac response to Ang-(1-12). Its stimulation may produce cardiac negative modulation and exacerbate left ventricle (LV) systolic and diastolic dysfunction. METHODS AND RESULTS: We assessed the effects of Ang-(1-12) (2 nmol/kg/min, iv, 10 min) on LV contractility, LV diastolic filling, and LV-arterial coupling (AVC) in 16 SD male rats with HF-induced by isoproterenol (3 mo after 170 mg/kg sq. for 2 consecutive days) and 10 age-matched male controls. In normal controls, versus baseline, Ang-(1-12) increased LV end-systolic pressure, without altering heart rate, arterial elastance (EA), LV end-diastolic pressure (PED), the time constant of LV relaxation (τ) and ejection fraction (EF). Ang-(1-12) significantly increased the slopes (EES) of LV end-systolic pressure (P)-volume (V) relations and the slopes (MSW) of LV stroke wok-end-diastolic V relations, indicating increased LV contractility. AVC (quantified as EES/EA) improved. In contrast, in HF, versus HF baseline, Ang-(1-12) produced a similar increase in PES, but significantly increased τ, EA, and PED. The early diastolic portion of LV PV loop was shifted upward with reduced in EF. Moreover, Ang-(1-12) significantly decreased EES and MSW, demonstrating decreased LV contractility. AVC was decreased by 43%. CONCLUSIONS: In both normal and HF rats, Ang-(1-12) causes similar vasoconstriction. In normal, Ang-(1-12) increases LV contractile function. In HF, Ang-(1-12) has adverse effects and depresses LV systolic and diastolic functional performance.


Asunto(s)
Angiotensinógeno/farmacología , Insuficiencia Cardíaca/fisiopatología , Contracción Miocárdica/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Función Ventricular Izquierda/efectos de los fármacos , Animales , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/etiología , Isoproterenol , Masculino , Ratas , Ratas Sprague-Dawley , Volumen Sistólico/efectos de los fármacos , Presión Ventricular/efectos de los fármacos
20.
Clin Chim Acta ; 500: 208-212, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31678572

RESUMEN

BACKGROUND: Osteopontin (OPN), a matricellular protein, is greatly generated from brain tissues after acute brain injury. We determine the relationship between plasma OPN concentrations and outcome after acute intracerebral hemorrhage (ICH) in a clinical setting. METHODS: In this prospective, observational study enrolling 162 ICH patients and 162 healthy controls, hemorrhagic severity was assessed using National Institutes of Health Stroke Scale (NIHSS) scores and hematoma volumes, a poor outcome was defined as modified Rankin Scale >2 at poststroke 90 days, and early neurologic deterioration (END) was defined as an increase of ≥4 points in the NIHSS score or death at 24 h from symptoms onset. RESULTS: Plasma OPN concentrations were significantly higher in patients than in controls (median value, 1287.6 vs. 405.7 pmol/l; P < 0.001). OPN concentrations were strongly correlated with admission NIHSS scores (r value = 0.520) and hematoma volumes (r value = 0.468). Areas under receiver operating characteristic curve for poor outcome and END were 0.811 and 0.753 respectively. Plasma OPN emerged as an independent predictor of functional outcome and END, with odds ratio values of 3.897 and 6.004 respectively. CONCLUSIONS: Plasma OPN could serve as a useful prognostic biomarker in ICH.


Asunto(s)
Hemorragia Cerebral/sangre , Hemorragia Cerebral/diagnóstico , Osteopontina/sangre , Adulto , Anciano , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Curva ROC
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