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1.
Artigo em Inglês | MEDLINE | ID: mdl-38456577

RESUMO

Mechanical forces play a crucial role in diverse physiological processes, such as cell migration, cytokinesis, and morphogenesis. The actin cytoskeleton generates a large fraction of the mechanical forces via molecular interactions between actin filaments (F-actins) and myosin motors. Recent studies have shown that the common tendency of actomyosin networks to contract into a smaller structure deeply involves F-actin buckling induced by motor activities, fragmentation of F-actins, and the force-dependent unbinding of cross-linkers that inter-connect F-actins. The fragmentation of F-actins was shown to originate from either buckling or tensile force from previous single-molecule experiments. While the role of buckling in network contraction has been studied extensively, to date, the role of tension-induced F-actin fragmentation in network contraction has not been investigated. In this study, we employed in vitro experiments and an agent-based computational model to illuminate when and how the tension-induced F-actin fragmentation facilitates network contraction. Our experiments demonstrated that F-actins can be fragmented due to tensile forces, immediately followed by catastrophic rupture and contraction of networks. Using the agent-based model, we showed that F-actin fragmentation by tension results in distinct rupture dynamics different from that observed in networks only with cross-linker unbinding. Moreover, we found that tension-induced F-actin fragmentation is particularly important for the contraction of networks with high connectivity. Results from our study shed light on an important regulator of the contraction of actomyosin networks which has been neglected. In addition, our results provide insights into the rupture mechanisms of polymeric network structures and bio-inspired materials.

2.
Structure ; 32(3): 352-361.e5, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38194963

RESUMO

Orexin neuropeptides have many physiological roles in the sleep-wake cycle, feeding behavior, reward demands, and stress responses by activating cognitive receptors, the orexin receptors (OX1R and OX2R), distributed in the brain. There are only subtle differences between OX1R and OX2R in the orthosteric site, which has hindered the rational development of subtype-selective antagonists. In this study, we utilized solution-state NMR to capture the structural plasticity of OX2R labeled with 13CH3-ε-methionine in complex with antagonists. Mutations in the orthosteric site allosterically affected the intracellular tip of TM6. Ligand exchange experiments with the subtype-selective EMPA and the nonselective suvorexant identified three methionine residues that were substantially perturbed. The NMR spectra suggested that the suvorexant-bound state exhibited more structural plasticity than the EMPA-bound state, which has not been foreseen from the close similarity of their crystal structures, providing insights into dynamic features to be considered in understanding the ligand recognition mode.


Assuntos
Metionina , Humanos , Orexinas , Ligantes , Receptores de Orexina/genética , Receptores de Orexina/química , Espectroscopia de Ressonância Magnética
3.
Intern Med ; 63(3): 419-423, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37344430

RESUMO

Bilateral adrenal infarction is an extremely rare disease, and it has been reported that some coagulation abnormalities, including essential thrombocythemia (ET), exist in the background. We herein report a 76-year-old patient in whom the platelet count had been in the normal range at the onset of adrenal infarction but subsequently increased to 102×104/µL at 7 months later, leading to the diagnosis of JAK2V617F-positive ET. As the presence of the JAK2V617F mutation increases the risk of thrombosis, Janus kinase 2 (JAK2) genetic testing should be considered in some cases of nonspecific unknown thrombosis, even if there are no obvious hematological findings, such as clonal hematopoiesis of indeterminate potential (CHIP).


Assuntos
Doenças das Glândulas Suprarrenais , Trombocitemia Essencial , Trombose , Humanos , Idoso , Trombocitemia Essencial/complicações , Trombocitemia Essencial/diagnóstico , Trombocitemia Essencial/genética , Trombose/genética , Contagem de Plaquetas , Mutação , Infarto/diagnóstico por imagem , Infarto/etiologia , Janus Quinase 2/genética
4.
Sci Rep ; 13(1): 22027, 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38086879

RESUMO

Brain-enriched guanylate kinase-associated protein (BEGAIN) is highly enriched in the post-synaptic density (PSD) fraction and was identified in our previous study as a protein associated with neuropathic pain in the spinal dorsal horn. PSD protein complexes containing N-methyl-D-aspartate receptors are known to be involved in neuropathic pain. Since these PSD proteins also participate in learning and memory, BEGAIN is also expected to play a crucial role in this behavior. To verify this, we first examined the distribution of BEGAIN in the brain. We found that BEGAIN was widely distributed in the brain and highly expressed in the dendritic regions of the hippocampus. Moreover, we found that BEGAIN was concentrated in the PSD fraction of the hippocampus. Furthermore, immunoelectron microscopy confirmed that BEGAIN was localized at the asymmetric synapses. Behavioral tests were performed using BEGAIN-knockout (KO) mice to determine the contribution of BEGAIN toward learning and memory. Spatial reference memory and reversal learning in the Barns circular maze test along with contextual fear and cued fear memory in the contextual and cued fear conditioning test were significantly impaired in BEGAIN-KO mice compared to with those in wild-type mice. Thus, this study reveals that BEGAIN is a component of the post-synaptic compartment of excitatory synapses involved in learning and memory.


Assuntos
Neuralgia , Densidade Pós-Sináptica , Camundongos , Animais , Densidade Pós-Sináptica/metabolismo , Encéfalo/metabolismo , Hipocampo/metabolismo , Camundongos Knockout , Aprendizagem em Labirinto , Guanilato Quinases/metabolismo , Neuralgia/metabolismo
5.
Intern Med ; 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38008447

RESUMO

A 52-year-old man who had been using a proton pump inhibitor (PPI) and a potassium-competitive acid blocker (P-CAB) for 14 years underwent esophagogastroduodenoscopy and was found to have three neuroendocrine tumors (NETs) in the gastric body. Following detailed examinations, parietal cell dysfunction was excluded, and the NETs did not meet the criteria for the Rindi classification types I-III. The lesions were ultimately considered to be associated with the long-term use of the PPI and P-CAB. We performed endoscopic submucosal dissection of the lesions, with no recurrence or new lesions noted after discontinuation of the PPI and P-CAB.

6.
Foods ; 12(20)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37893662

RESUMO

This study exploits quantitative algorithms of Raman spectroscopy to assess, at the molecular scale, the nutritional quality of individual kernels of the Japanese short-grain rice cultivar Koshihikari in terms of amylose-to-amylopectin ratio, fractions of phenylalanine and tryptophan aromatic amino acid residues, protein-to-carbohydrate ratio, and fractions of protein secondary structures. Statistical assessments on a large number of rice kernels reveal wide distributions of the above nutritional parameters over nominally homogeneous kernel batches. This demonstrates that genetic classifications cannot catch omic fluctuations, which are strongly influenced by a number of extrinsic factors, including the location of individual grass plants within the same rice field and the level of kernel maturation. The possibility of collecting nearly real-time Raman "multi-omic snapshots" of individual rice kernels allows for the automatic (low-cost) differentiation of groups of kernels with restricted nutritional characteristics that could be used in the formulation of functional foods for specific diseases and in positively modulating the intestinal microbiota for protection against bacterial infection and cancer prevention.

7.
Biosci Biotechnol Biochem ; 87(12): 1470-1477, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37715303

RESUMO

Neohesperidin dihydrochalcone (NHDC) is a sweetener, which interacts with the transmembrane domain (TMD) of the T1R3 subunit of the human sweet taste receptor. Although NHDC and a sweet taste inhibitor lactisole share similar structural motifs, they have opposite effects on the receptor. This study involved the creation of an NHDC-docked model of T1R3 TMD through mutational analyses followed by in silico simulations. When certain NHDC derivatives were docked to the model, His7345.44 was demonstrated to play a crucial role in activating T1R3 TMD. The NHDC-docked model was then compared with a lactisole-docked inactive form, several residues were characterized as important for the recognition of NHDC; however, most of them were distinct from those of lactisole. Residues such as His6413.33 and Gln7947.38 were found to be oriented differently. This study provides useful information that will facilitate the design of sweeteners and inhibitors that interact with T1R3 TMD.


Assuntos
Chalconas , Receptores Acoplados a Proteínas G , Simulação de Dinâmica Molecular , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Hesperidina/análogos & derivados , Chalconas/química , Simulação de Acoplamento Molecular , Humanos , Edulcorantes/química , Estrutura Molecular
8.
PLoS One ; 18(9): e0285295, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37733805

RESUMO

The spinal dorsal horn comprises heterogeneous neuronal populations, that interconnect with one another to form neural circuits modulating various types of sensory information. Decades of evidence has revealed that transcription factors expressed in each neuronal progenitor subclass play pivotal roles in the cell fate specification of spinal dorsal horn neurons. However, the development of subtypes of these neurons is not fully understood in more detail as yet and warrants the investigation of additional transcription factors. In the present study, we examined the involvement of the POU domain-containing transcription factor Brn3a in the development of spinal dorsal horn neurons. Analyses of Brn3a expression in the developing spinal dorsal horn neurons in mice demonstrated that the majority of the Brn3a-lineage neurons ceased Brn3a expression during embryonic stages (Brn3a-transient neurons), whereas a limited population of them continued to express Brn3a at high levels after E18.5 (Brn3a-persistent neurons). Loss of Brn3a disrupted the localization pattern of Brn3a-persistent neurons, indicating a critical role of this transcription factor in the development of these neurons. In contrast, Brn3a overexpression in Brn3a-transient neurons directed their localization in a manner similar to that in Brn3a-persistent neurons. Moreover, Brn3a-overexpressing neurons exhibited increased axonal extension to the ventral and ventrolateral funiculi, where the axonal tracts of Brn3a-persistent neurons reside. These results suggest that Brn3a controls the soma localization and axonal extension patterns of Brn3a-persistent spinal dorsal horn neurons.


Assuntos
Neurônios , Células do Corno Posterior , Animais , Camundongos , Axônios , Diferenciação Celular , Fatores de Transcrição/genética
9.
Soft Matter ; 19(37): 7109-7121, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37694444

RESUMO

This study presents the application of the smoothed profile (SP) method to perform direct numerical simulations for the motion of both passive and active "squirming" particles in Newtonian and viscoelastic fluids. We found that fluid elasticity has a significant impact on both the transient behavior and the steady-state velocity of the particles. Specifically, we observe that the swirling flow generated by the squirmer's surface velocity significantly enhances their swimming speed as the Weissenberg number increases, regardless of the swimming type. Furthermore, we find that pushers outperform pullers in Oldroyd-B fluids, suggesting that the speed of a squirmer depends on the swimmer type. To understand the physical origin of the phenomenon of swirling flow enhancing the swimming speed, we investigate the velocity field and polymer conformation around non-swirling and swirling neutral squirmers in viscoelastic fluids. Our investigation reveals that the velocity field around the neutral swirling squirmers exhibits pusher-like extensional flow characteristics, as well as an asymmetric polymer conformation distribution, which gives rise to this increased propulsion. This is confirmed by the investigation of the force on a fixed squirmer, which revealed that the polymer stress, particularly its diagonal components, plays a critical role in enhancing the swimming speed of swirling squirmers in viscoelastic fluids. Additionally, our results demonstrate that the maximum swimming speeds of swirling squirmers occur at an intermediate value of the fluid viscosity ratio for all swimmer types. These findings have important implications for understanding the behavior of particles and micro-organisms in complex fluids.

10.
Contemp Clin Trials Commun ; 33: 101125, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37091510

RESUMO

Background: Decreased walking speed in older patients admitted to convalescent rehabilitation wards (CRWs) is one of the factors that inhibit home discharge. Therefore, interventions to improve gait speed in older patients admitted to CRWs are important, and rhythmic auditory stimulation (RAS) may be an effective intervention strategy. However, the effect of RAS on gait speed in older patients admitted to CRWs is not well known. Therefore, this study protocol aims to determine the feasibility of the RAS-based gait practice for older patients admitted to the CRW. Methods: The study is designed as a single-center, open-label, pilot, randomized, parallel-group study. Participants will be 30 patients aged ≥65 years admitted to the CRW and randomly assigned to the experimental group (RAS-based gait practice; n = 15) or the control group (normal gait practice; n = 15). In both groups, interventions will be conducted for 30 min per session, 5 times per week for 3 weeks. The primary outcome is the change in the 10-m walk test 3 weeks after the baseline assessment. Secondary outcome is the change in the score of the Medical Outcome Study 8-Item Short-Form Health Survey and the Japanese version of the modified Gait Efficacy Scale from baseline assessment to 3 weeks later. Discussion: This exploratory RCT was developed using strict scientific standards and is based on defined protocols. Thus, this study will be used to assess the viability of a larger investigation into RAS-based gait practice. If our theory is accurate, this study could serve as a foundation for establishing RAS-based gait practice in CRWs as a common rehabilitation strategy. Trial registration: This study was registered in the University Hospital Medical Information Network (UMIN) clinical trials registry in Japan (UMIN000049089).

11.
Circ Arrhythm Electrophysiol ; 16(3): e011387, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36866681

RESUMO

BACKGROUND: CaM (calmodulin) is a ubiquitously expressed, multifunctional Ca2+ sensor protein that regulates numerous proteins. Recently, CaM missense variants have been identified in patients with malignant inherited arrhythmias, such as long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT). However, the exact mechanism of CaM-related CPVT in human cardiomyocytes remains unclear. In this study, we sought to investigate the arrhythmogenic mechanism of CPVT caused by a novel variant using human induced pluripotent stem cell (iPSC) models and biochemical assays. METHODS: We generated iPSCs from a patient with CPVT bearing CALM2 p.E46K. As comparisons, we used 2 control lines including an isogenic line, and another iPSC line from a patient with long QT syndrome bearing CALM2 p.N98S (also reported in CPVT). Electrophysiological properties were investigated using iPSC-cardiomyocytes. We further examined the RyR2 (ryanodine receptor 2) and Ca2+ affinities of CaM using recombinant proteins. RESULTS: We identified a novel de novo heterozygous variant, CALM2 p.E46K, in 2 unrelated patients with CPVT accompanied by neurodevelopmental disorders. The E46K-cardiomyocytes exhibited more frequent abnormal electrical excitations and Ca2+ waves than the other lines in association with increased Ca2+ leakage from the sarcoplasmic reticulum via RyR2. Furthermore, the [3H]ryanodine binding assay revealed that E46K-CaM facilitated RyR2 function especially by activating at low [Ca2+] levels. The real-time CaM-RyR2 binding analysis demonstrated that E46K-CaM had a 10-fold increased RyR2 binding affinity compared with wild-type CaM which may account for the dominant effect of the mutant CaM. Additionally, the E46K-CaM did not affect CaM-Ca2+ binding or L-type calcium channel function. Finally, antiarrhythmic agents, nadolol and flecainide, suppressed abnormal Ca2+ waves in E46K-cardiomyocytes. CONCLUSIONS: We, for the first time, established a CaM-related CPVT iPSC-CM model which recapitulated severe arrhythmogenic features resulting from E46K-CaM dominantly binding and facilitating RyR2. In addition, the findings in iPSC-based drug testing will contribute to precision medicine.


Assuntos
Células-Tronco Pluripotentes Induzidas , Síndrome do QT Longo , Taquicardia Ventricular , Humanos , Calmodulina/genética , Calmodulina/metabolismo , Miócitos Cardíacos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Taquicardia Ventricular/metabolismo , Arritmias Cardíacas , Síndrome do QT Longo/genética , Síndrome do QT Longo/metabolismo , Cálcio/metabolismo , Mutação
12.
World J Clin Oncol ; 14(12): 620-627, 2023 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-38179403

RESUMO

BACKGROUND: Intraductal tubulopapillary neoplasm (ITPN) is a rare disease accounting for approximately 3% of all intraductal pancreatic tumors, with intraductal papillary mucinous neoplasm (IPMN) being one of the most common differential diagnoses. Both ITPN and IPMN display slow growth. A branched pancreatic duct type is commonly observed in IPMN, whereas ITPN derived from the branched pancreatic duct has been reported in a limited number of cases; hence, its pathogenesis remains unclear. CASE SUMMARY: Here, we present the case of a patient with ITPN localized in a branched pancreatic duct, with poorly controlled irritable bowel syndrome. A contrast-enhanced computed tomography scan of the abdomen incidentally revealed a 5-mm oligemic nodule-like change in the body of the pancreas. Endoscopic ultrasound (EUS) indicated a 10-mm hypoechoic mass without any cystic structures that had grown within 2 mo. EUS-guided fine needle aspiration was performed for definitive diagnosis, and the findings suggested ductal papillary carcinoma. Distal pancreatectomy was performed, and the tumor was pathologically diagnosed as ITPN with an invasive cancerous component, pT3N1aM0, pStage IIB (International Cancer Control, 8th edition). The patient underwent treatment with postoperative adjuvant chemotherapy (S-1 monotherapy); however, relapse was observed 1 year and 10 mo after surgical resection, and subsequent treatment involving a combination of chemotherapy and radiotherapy was administered. Maintenance therapy has since facilitated a stable disease state. CONCLUSION: Regardless of the microscopic size of the neoplasm, early diagnosis of ITPN with EUS-guided fine needle aspiration and surgical resection are crucial.

13.
Front Pain Res (Lausanne) ; 3: 979038, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36570085

RESUMO

The spinal dorsal horn plays a crucial role in the transmission and processing of somatosensory information. Although spinal neural circuits that process several distinct types of somatic sensations have been studied extensively, those responsible for visceral pain transmission remain poorly understood. In the present study, we analyzed dextran sodium sulfate (DSS)-induced inflammatory bowel disease (IBD) mouse models to characterize the spinal dorsal horn neurons involved in visceral pain transmission. Immunostaining for c-fos, a marker of neuronal activity, demonstrated that numerous c-fos-positive cells were found bilaterally in the lumbosacral spinal dorsal horn, and their distribution was particularly abundant in the shallow dorsal horn. Characterization of these neurons by several molecular markers revealed that the percentage of the Pit1-Oct1-Unc86 domain (POU domain)-containing transcription factor Brn3a-positive neurons among the c-fos-positive neurons in the shallow dorsal horn was 30%-40% in DSS-treated mice, which was significantly higher than that in the somatic pain model mice. We further demonstrated by neuronal tracing that, within the shallow dorsal horn, Brn3a-positive neurons were more highly represented in spino-solitary projection neurons than in spino-parabrachial projection neurons. These results raise the possibility that Brn3a-positive spinal dorsal horn neurons make a large contribution to visceral pain transmission, part of which is mediated through the spino-solitary pathway.

14.
Healthcare (Basel) ; 10(11)2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36360513

RESUMO

Japan's universal healthcare insurance is facing economic challenges due to the advanced aging society, however, objective data of dental expenditure has never been introduced. This study aimed to identify the associated factors with dental expenditures using government-provided digitized insurance claims data and calculated the spending in the context of dental cost per person (DCPP). Seven associated factors analyzed were age, demographic, geographic, socioeconomic, regional wealth, the impact of the 8020-national campaign implementation (keep 20 teeth at age 80), and the effect of the home-visit dentistry for the elders. The average DCPP was high in older populations (75+) in all prefectures. The prefectures with the highest and lowest DCPP were significant compared to other states and retained their respective places in the cost hierarchy over the four years. The prefectures with more citizens participating in government assistance programs (GAP) had greater DCPPs. Dental costs were significantly related to geographic regions, age, per capita income, government assistance program prevalence, office complete denture frequency, and home visit care per patient. With a growing aging population, dental care costs will continue to increase, burdening its fiscal future. Associated factors identified should be considered to control the contentious increase of healthcare cost.

15.
J Gen Physiol ; 154(12)2022 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-36318155

RESUMO

In skeletal muscle excitation-contraction (E-C) coupling, depolarization of the plasma membrane triggers Ca2+ release from the sarcoplasmic reticulum (SR), referred to as depolarization-induced Ca2+ release (DICR). DICR occurs through the type 1 ryanodine receptor (RyR1), which physically interacts with the dihydropyridine receptor Cav1.1 subunit in specific machinery formed with additional essential components including ß1a, Stac3 adaptor protein, and junctophilins. Exome sequencing has accelerated the discovery of many novel mutations in genes encoding DICR machinery in various skeletal muscle diseases. However, functional validation is time-consuming because it must be performed in a skeletal muscle environment. In this study, we established a platform of the reconstituted DICR in HEK293 cells. The essential components were effectively transduced into HEK293 cells expressing RyR1 using baculovirus vectors, and Ca2+ release was quantitatively measured with R-CEPIA1er, a fluorescent ER Ca2+ indicator, without contaminant of extracellular Ca2+ influx. In these cells, [K+]-dependent Ca2+ release was triggered by chemical depolarization with the aid of inward rectifying potassium channel, indicating a successful reconstitution of DICR. Using the platform, we evaluated several Cav1.1 mutations that are implicated in malignant hyperthermia and myopathy. We also tested several RyR1 inhibitors; whereas dantrolene and Cpd1 inhibited DICR, procaine had no effect. Furthermore, twitch potentiators such as perchlorate and thiocyanate shifted the voltage dependence of DICR to more negative potentials without affecting Ca2+-induced Ca2+ release. These results well reproduced the findings with the muscle fibers and the cultured myotubes. Since the procedure is simple and reproducible, the reconstituted DICR platform will be highly useful for the validation of mutations and drug discovery for skeletal muscle diseases.


Assuntos
Doenças Musculares , Canal de Liberação de Cálcio do Receptor de Rianodina , Humanos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Cálcio/metabolismo , Células HEK293 , Retículo Sarcoplasmático/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Canais de Cálcio Tipo L/metabolismo , Doenças Musculares/metabolismo , Músculo Esquelético/metabolismo , Mutação , Descoberta de Drogas
16.
Biosci Biotechnol Biochem ; 86(11): 1599-1604, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36085524

RESUMO

Cesium (Cs) in the environment is primarily absorbed by a potassium (K) transporter. OsHAK5 is a KT/HAK/KUP family K-transporter showing a high affinity for K. We created cultured rice cells whose OsHAK5 was knocked down by RNAi (named KD). In the medium containing 1.0 m m and less K, the growth of KD was significantly suppressed, suggesting that OsHAK5 greatly contributed to K absorption under limited K conditions. Although Cs suppressed the growth of KD and WT, stronger inhibition was observed on KD. Both KD and WT accumulated similar amounts of Cs when they were cultured in a medium containing Cs, whereas lower amounts of K were detected in KD. These results suggest that OsHAK5 was less involved in the absorption of Cs, although it was essential to K absorption under limited K conditions. In contrast, this means that another transporter may contribute to cesium uptake in rice.


Assuntos
Proteínas de Transporte de Cátions , Oryza , Oryza/genética , Oryza/metabolismo , Potássio , Césio/metabolismo , Transporte de Íons , Proteínas de Transporte de Cátions/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
17.
Cell Rep ; 40(11): 111323, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36103815

RESUMO

Prostaglandin receptors have been implicated in a wide range of functions, including inflammation, immune response, reproduction, and cancer. Our group has previously determined the crystal structure of the active-like EP3 bound to its endogenous agonist, prostaglandin E2. Here, we present the single-particle cryoelectron microscopy (cryo-EM) structure of the human EP3-Gi signaling complex at a resolution of 3.4 Å. The structure reveals the binding mode of Gi to EP3 and the structural changes induced in EP3 by Gi binding. In addition, we compare the structure of the EP3-Gi complex with other subtypes of prostaglandin receptors (EP2 and EP4) bound to Gs that have been previously reported and examine the differences in amino acid composition at the receptor-G protein interface. Mutational analysis reveals that the selectivity of the G protein depends on specific amino acid residues in the second intracellular loop and TM5.


Assuntos
Dinoprostona , Receptores de Prostaglandina E , Aminoácidos , Microscopia Crioeletrônica , Dinoprostona/farmacologia , Humanos , Receptores de Prostaglandina E/agonistas , Receptores de Prostaglandina E/metabolismo , Receptores de Prostaglandina E Subtipo EP3/metabolismo
18.
Molecules ; 27(15)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35956840

RESUMO

Molecular interaction analysis is an essential technique for the study of biomolecular functions and the development of new drugs. Most current methods generally require manipulation to immobilize or label molecules, and require advance identification of at least one of the two molecules in the reaction. In this study, we succeeded in detecting the interaction of low-molecular-weight (LMW) compounds with a membrane protein mixture derived from cultured cells expressing target membrane proteins by using the size exclusion chromatography-mass spectrometry (SEC-MS) method under the condition of 0.001% lauryl maltose neopentyl glycol as detergent and atmospheric pressure chemical ionization. This method allowed us to analyze the interaction of a mixture of medicinal herbal ingredients with a mixture of membrane proteins to identify the two interacting ingredients. As it does not require specialized equipment (e.g., a two-dimensional liquid chromatography system), this SEC-MS method enables the analysis of interactions between LMW compounds and relatively high-expressed membrane proteins without immobilization or derivatization of the molecules.


Assuntos
Proteínas de Membrana , Cromatografia em Gel , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Peso Molecular
19.
Sci Rep ; 12(1): 14498, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-36008434

RESUMO

The importance of plant chemistry in the host specialization of phytophagous insects has been emphasized. However, only a few chemicals associated with host shifting have been characterized. Herein, we focus on the leaf-mining moth Acrocercops transecta (Gracillariidae) consisting of ancestral Juglans (Juglandaceae)- and derived Lyonia (Ericaceae)-associated host races. The females of the Lyonia race laid eggs on a cover glass treated with an L. ovalifolia leaf extract; the extract was fractionated using silica gel and ODS column chromatography to isolate the oviposition stimulants. From a separated fraction, two analogous Lyonia-specific triterpenoid glycosides were characterized as oviposition stimulants. Furthermore, we observed probable contact chemosensilla on the distal portion of the female antennae. Lyonia race females laid their eggs on the non-host Juglans after the leaves were treated with a Lyonia-specific oviposition stimulant, although they do not lay eggs on Juglans. These results suggest that Lyonia race females do not lay eggs on Juglans leaves because the leaves do not contain specific oviposition stimulant(s). Otherwise, the activity of the oviposition stimulants overcomes oviposition deterrents contained in Juglans leaves. This paper describes the roles of plant chemicals in the different preferences between host races associated with distantly related plant taxa.


Assuntos
Ericaceae , Juglandaceae , Juglans , Mariposas , Animais , Feminino , Oviposição , Folhas de Planta
20.
Diagnostics (Basel) ; 12(6)2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35741232

RESUMO

The accurate diagnosis of individual tooth prognosis has to be determined comprehensively in consideration of the broader treatment plan. The objective of this study was to establish an effective artificial intelligence (AI)-based module for an accurate tooth prognosis decision based on the Harvard School of Dental Medicine (HSDM) comprehensive treatment planning curriculum (CTPC). The tooth prognosis of 2359 teeth from 94 cases was evaluated with 1 to 5 levels (1-Hopeless, 5-Good condition for long term) by two groups (Model-A with 16, and Model-B with 13 examiners) based on 17 clinical determining factors selected from the HSDM-CTPC. Three AI machine-learning methods including gradient boosting classifier, decision tree classifier, and random forest classifier were used to create an algorithm. These three methods were evaluated against the gold standard data determined by consensus of three experienced prosthodontists, and their accuracy was analyzed. The decision tree classifier indicated the highest accuracy at 0.8413 (Model-A) and 0.7523 (Model-B). Accuracy with the gradient boosting classifier and the random forest classifier was 0.6896, 0.6687, and 0.8413, 0.7523, respectively. Overall, the decision tree classifier had the best accuracy among the three methods. The study contributes to the implementation of AI in the decision-making process of tooth prognosis in consideration of the treatment plan.

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