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1.
Nat Commun ; 15(1): 3901, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724505

RESUMO

Activation of the NF-κB pathway is strictly regulated to prevent excessive inflammatory and immune responses. In a well-known negative feedback model, IκBα-dependent NF-κB termination is a delayed response pattern in the later stage of activation, and the mechanisms mediating the rapid termination of active NF-κB remain unclear. Here, we showed IκBα-independent rapid termination of nuclear NF-κB mediated by CLK2, which negatively regulated active NF-κB by phosphorylating the RelA/p65 subunit of NF-κB at Ser180 in the nucleus to limit its transcriptional activation through degradation and nuclear export. Depletion of CLK2 increased the production of inflammatory cytokines, reduced viral replication and increased the survival of the mice. Mechanistically, CLK2 phosphorylated RelA/p65 at Ser180 in the nucleus, leading to ubiquitin‒proteasome-mediated degradation and cytoplasmic redistribution. Importantly, a CLK2 inhibitor promoted cytokine production, reduced viral replication, and accelerated murine psoriasis. This study revealed an IκBα-independent mechanism of early-stage termination of NF-κB in which phosphorylated Ser180 RelA/p65 turned off posttranslational modifications associated with transcriptional activation, ultimately resulting in the degradation and nuclear export of RelA/p65 to inhibit excessive inflammatory activation. Our findings showed that the phosphorylation of RelA/p65 at Ser180 in the nucleus inhibits early-stage NF-κB activation, thereby mediating the negative regulation of NF-κB.


Assuntos
Citoplasma , Inibidor de NF-kappaB alfa , NF-kappa B , Proteínas Tirosina Quinases , Fator de Transcrição RelA , Animais , Fosforilação , Inibidor de NF-kappaB alfa/metabolismo , Inibidor de NF-kappaB alfa/genética , Camundongos , Fator de Transcrição RelA/metabolismo , Humanos , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , NF-kappa B/metabolismo , Citoplasma/metabolismo , Proteólise , Núcleo Celular/metabolismo , Replicação Viral , Células HEK293 , Transdução de Sinais , Camundongos Endogâmicos C57BL , Citocinas/metabolismo , Transporte Ativo do Núcleo Celular , Proteínas Serina-Treonina Quinases
2.
bioRxiv ; 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38746433

RESUMO

Islet transplantation can cure type 1 diabetes, but peri-transplant beta cell death limits this procedure to those with low insulin requirements. Improving human beta cell survival or proliferation may make islet transplantation a possibility for more type 1 patients. To identify novel regulators of beta cell survival and proliferation, we conducted a pooled small hairpin RNA (shRNA) screen in primary human beta cells transplanted into immunocompromised mice. shRNAs targeting several cyclin dependent kinase inhibitors were enriched after transplant. Here, we focused on the Gi/o-coupled GPCR, serotonin 1F receptor ( HTR1F, 5-HT 1F ) which our screen identified as a negative regulator of beta cell numbers after transplant. In vitro , 5-HT 1F knockdown induced human beta cell proliferation but only when combined with harmine and exendin-4. In vivo , knockdown of 5-HT 1F reduced beta cell death during transplant. To demonstrate the feasibility of targeting 5-HT 1F in islet transplant, we identified and validated a small molecule 5-HT 1F antagonist. This antagonist increased glucose stimulated insulin secretion from primary human islets and cAMP accumulation in primary human beta cells. Finally, the 5-HT 1F antagonist improved glycemia in marginal mass, human islet transplants into immunocompromised mice. We identify 5-HT 1F as a novel druggable target to improve human beta cell survival in the setting of islet transplantation. One Sentence Summary: Serotonin 1F receptor (5-HT 1F ) negatively regulates insulin secretion and beta cell survival during transplant.

3.
Front Neurosci ; 18: 1368552, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38716255

RESUMO

Probucol has been utilized as a cholesterol-lowering drug with antioxidative properties. However, the impact and fundamental mechanisms of probucol in obesity-related cognitive decline are unclear. In this study, male C57BL/6J mice were allocated to a normal chow diet (NCD) group or a high-fat diet (HFD) group, followed by administration of probucol to half of the mice on the HFD regimen. Subsequently, the mice were subjected to a series of behavioral assessments, alongside the measurement of metabolic and redox parameters. Notably, probucol treatment effectively alleviates cognitive and social impairments induced by HFD in mice, while exhibiting no discernible influence on mood-related behaviors. Notably, the beneficial effects of probucol arise independently of rectifying obesity or restoring systemic glucose and lipid homeostasis, as evidenced by the lack of changes in body weight, serum cholesterol levels, blood glucose, hyperinsulinemia, systemic insulin resistance, and oxidative stress. Instead, probucol could regulate the levels of nitric oxide and superoxide-generating proteins, and it could specifically alleviate HFD-induced hippocampal insulin resistance. These findings shed light on the potential role of probucol in modulating obesity-related cognitive decline and urge reevaluation of the underlying mechanisms by which probucol exerts its beneficial effects.

4.
Trials ; 25(1): 306, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38715042

RESUMO

BACKGROUND: Premature infants commonly encounter difficulties with oral feeding, a complication that extends hospital stays, affects infants' quality of life, and imposes substantial burdens on families and society. Enhancing preterm infants' oral feeding skills and facilitating their transition from parenteral or nasal feeding to full oral feeding pose challenges for neonatal intensive care unit (NICU) healthcare professionals. Research indicates that oral motor interventions (OMIs) can enhance preterm infants' oral feeding capabilities and expedite the transition from feeding initiation to full oral feeding. Nonetheless, the most suitable timing for commencing these interventions remains uncertain. METHODS: This is a single-blind, randomized controlled trial. Preterm with a gestational age between 29+0 to 34+6 weeks will be eligible for the study. These infants will be randomized and allocated to one of two groups, both of which will receive the OMIs. The intervention commences once the infant begins milk intake during the early OMIs. Additionally, in the late OMIs group, the intervention will initiate 48 h after discontinuing nasal continuous positive airway pressure. DISCUSSION: OMIs encompass non-nutritive sucking and artificial oral stimulation techniques. These techniques target the lips, jaw, muscles, or tongue of premature infants, aiming to facilitate the shift from tube feeding to oral feeding. The primary objective is to determine the ideal intervention timing that fosters the development of oral feeding skills and ensures a seamless transition from parenteral or nasal feeding to full oral feeding among preterm infants. Furthermore, this study might yield insights into the long-term effects of OMIs on the growth and neurodevelopmental outcomes of preterm infants. Such insights could bear substantial significance for the quality of survival among preterm infants and the societal burden imposed by preterm birth. TRIAL REGISTRATION: chictr.org.cn ChiCTR2300076721. Registered on October 17, 2023.


Assuntos
Recém-Nascido Prematuro , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento de Sucção , Humanos , Recém-Nascido , Método Simples-Cego , Fatores de Tempo , Idade Gestacional , Resultado do Tratamento , Unidades de Terapia Intensiva Neonatal , Comportamento Alimentar , Feminino , Desenvolvimento Infantil
6.
Brain Imaging Behav ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717573

RESUMO

BACKGROUND: Impaired visual mental imagery is an important symptom of depression and has gradually become an intervention target for cognitive behavioral therapy. METHODS: Our study involved a total of 25 healthy controls (HC) and 23 individuals with moderate depressive symptoms (MD). This study explored the attentional mechanism supporting visual mental imagery impairments in depression using the Vividness of Visual Imagery Questionnaire (VVIQ), attentional network test (ANT), and resting-state functional magnetic resonance imaging (rs-fMRI). The intrinsic activity of attention-related regions relative to those supporting visual mental imagery was identified in depression patients. In addition, a meta-analysis was used to describe the cognitive function related to this intrinsic activity. RESULTS: The global correlation (GCOR) of the right anterior fusiform gyrus (FG) was decreased in depression patients. Attention-related areas were concentrated in the right posterior FG; the anterior and posterior functional connectivity (FC) of the FG was decreased in depression patients. Graph theoretic analysis showed that the degree of the right anterior FG was decreased, the degree of the anterior insula was increased, and the negative connection between these two regions was strengthened in depression patients. In addition, the degree of the right anterior FG, the FC between the subregions of the right FG, and the FC between the right anterior FG and insula were correlated with VVIQ scores; however, this correlation was not significant in depression patients. The meta-analysis suggested that the changes in the anterior FG in depressed patients may stem from difficulties of semantic memory retrieval. CONCLUSION: The changed intrinsic activity of subregions of the FG relative to the semantic memory retrieval may be associated with visual mental imagery impairments in depression.

7.
Chem Commun (Camb) ; 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38690680

RESUMO

Hydrogen peroxide (H2O2), an environmentally friendly strong oxidant and energy carrier, has attracted widespread attention in photocatalysis. Artificial photosynthesis of H2O2 using water and oxygen as raw materials, solar energy as an energy source, and semiconductor materials as catalysts is considered a promising technology. In the past few decades, encouraging progress has been made in the photocatalytic production of H2O2. Therefore, we summarize the research achievements in this field in recent years. This review first briefly introduces the reaction pathway, detection techniques and evaluation metrics. Then, the recent advances in photocatalysts are highlighted. Furthermore, the existing challenges and possible solutions in this field are presented. At last, we look forward to the future development direction of this field. This review provides valuable insights and guidance for efficient photocatalytic H2O2 production.

8.
Food Chem ; 449: 139158, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38608602

RESUMO

This work presents a novel use of fibrous egg white protein (FEWP) in food preservation and nutraceutical applications. In this study, food-grade FEWP was used as an encapsulating material, along with chitosan (CS), to stabilize emulsions. The emulsion system was then used as a delivery system to improve the stability of retinyl acetate (RA). The structural and functional properties, as well as the stability and rheological behavior of the FEWP/CS copolymer, was investigated. The stability of RA-enriched emulsions was also evaluated. FEWP and CS stabilized emulsions exhibited smaller particle size and enhanced stability against different ionic strengths and storage periods. Additionally, RA-encapsulated emulsions stabilized by FEWP:CS (25:1 w/w) effectively inhibited apple browning. This study provides a promising strategy for delivering antioxidant components, highlighting its potential in food preservation and nutraceutical applications.


Assuntos
Diterpenos , Clara de Ovo , Emulsões , Ésteres de Retinil , Vitamina A , Emulsões/química , Diterpenos/química , Ésteres de Retinil/química , Clara de Ovo/química , Vitamina A/química , Tamanho da Partícula , Conservação de Alimentos/métodos , Proteínas do Ovo/química , Malus/química , Quitosana/química , Reologia , Galinhas
9.
iScience ; 27(5): 109698, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38655198

RESUMO

Mounting evidence supports the role of neuroinflammation in radiation-induced brain injury (RIBI), a chronic disease characterized by delayed and progressive neurological impairment. Asparagine endopeptidase (AEP), also known as legumain (LGMN), participates in multiple malignancies and neurodegenerative diseases and may potentially be involved in RIBI. Here, we found AEP expression was substantially elevated in the cortex and hippocampus of wild-type (Lgmn+/+) mice following whole-brain irradiation. Lgmn knockout (Lgmn-/-) alleviated neurological impairment caused by whole-brain irradiation by suppressing neuronal senescence. Bulk RNA and metabolomic sequencing revealed AEP's involvement in the antigen processing and presentation pathway and neuroinflammation. This was further confirmed by co-culturing Lgmn+/+ primary neurons with the conditioned media derived from irradiated Lgmn+/+ or Lgmn-/- primary microglia. Furthermore, esomeprazole inhibited the enzymatic activity of AEP and RIBI. These findings identified AEP as a critical factor of neuroinflammation in RIBI, highlighting the prospect of targeting AEP as a therapeutic approach.

10.
Angew Chem Int Ed Engl ; : e202405399, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570193

RESUMO

Through a coordination-driven self-assembly method, four 4 1 2 ${4_1^2 }$ metalla-links and one tetranuclear monocycle were constructed with high selectivity and yield by adjusting the substituent species of the building blocks, as evidenced using X-ray crystallographic analysis, electrospray ionization-time-of-flight/mass spectrometry (ESI-TOF/MS), elemental analysis and detailed solution-state nuclear magnetic resonance (NMR) spectroscopy. Based on X-ray crystallographic analysis and independent gradient model analysis, a significant factor leading to the formation of 4 1 2 ${4_1^2 }$ metalla-links was the introduction of F, Cl, Br and I atoms, which generated additional weak C-H⋅⋅⋅X (X=F, Cl, Br and I) interactions. Furthermore, the dynamic conversion of 4 1 2 ${4_1^2 }$ metalla-links to monocyclic rings in methanol solution was systematically investigated using quantitative 1H NMR techniques.

11.
Mitochondrial DNA B Resour ; 9(4): 506-511, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38623176

RESUMO

Zanthoxylum ailanthoides is a deciduous tree, with important medicinal and economic values. The complete chloroplast genome sequence of Z. ailanthoides was assembled and the phylogenetic relationship to other species was inferred in this study. The chloroplast genome is 157,209 bp in length, including two inverted repeats of 26,408 bp, a large single-copy of 86,099 bp and a small single copy of 18,294 bp. Moreover, the chloroplast genome contains 129 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The overall GC content of the chloroplast genome is 38.4%. The phylogenetic analysis indicated that Z. ailanthoides was grouped with a clade containing the species of Z. multijugum, Z. calcicola, Z. oxyphyllum, Z. stenophyllum, and the genus was closely related to Phellodendron. This study contributes to a better understanding of the phylogenetic relationships among Zanthoxylum species.

12.
Langmuir ; 40(16): 8427-8439, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38607689

RESUMO

This work aims to enhance the adsorption performance of Laponite @diatomite for organic pollutants by modifying it with cetyltrimethylammonium bromide (CTAB). The microstructure and morphology of the CTAB-modified Laponite @diatomite material were characterized using SEM, XRD, FTIR, BET, and TG. Furthermore, the influences of key parameters, containing pH, adsorbent dosage, reaction time, and reaction temperature, on the adsorption process were investigated. The kinetics, thermodynamics, and isotherm models of the adsorption process were analyzed. Finally, potential adsorption mechanisms were given based on the characterization. The research findings indicate that CTAB-La@D exhibits good adsorption performance toward Congo red (CR) over a broad pH range. The maximum adsorption capacity of CR was 451.1 mg/g under the optimum conditions (dosage = 10 mg, contact time = 240 min, initial CR concentration = 100 mg/L, temperature = 25 °C, and pH = 7). The adsorption process conformed to the pseudo-second-order kinetic model, and the adsorption isotherms indicated that the adsorption process of CR was more in line with the Langmuir model, and it was physical adsorption. Thermodynamic analysis illustrates that the adsorption process is exothermic and spontaneous. Additionally, the mechanisms of electrostatic adsorption and hydrophobic effect adsorption of CR were investigated through XPS and FTIR analysis. This work provides an effective pathway for designing high-performance adsorbents for the removal of organic dye, and the synthesized materials hold great capability for practical utilization in the treatment of wastewater.

13.
Vaccine ; 42(12): 3075-3083, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38584060

RESUMO

As the major outer membrane protein (OMP) presents in the Pasteurella multocida envelope, OmpH was frequently expressed for laboratory assessments of its immunogenicity against P. multocida infections, but the results are not good. In this study, we modified OmpH with dendritic cell targeting peptide (Depeps) and/or Salmonella FliCd flagellin, and expressed three types of recombinant proteins with the MBP tag (rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, rFliC-OmpH-MBP). Assessments in mouse models revealed that vaccination with rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, or rFliC-OmpH-MBP induced significant higher level of antibodies as well as IFN-γ and IL-4 in murine sera than vaccination with rOmpH-MBP (P < 0.5). Vaccination with the three modified proteins also provided increased protection (rDepeps-FliC-OmpH-MBP, 70 %; rDepeps-OmpH-MBP, 50 %; rFliC-OmpH-MBP, 60 %) against P. multocida serotype D compared to vaccination with rOmpH-MBP (30 %). In mice vaccinated with different types of modified OmpHs, a significantly decreased bacterial strains were recovered from bloods, lungs, and spleens compared to rOmpH-MBP-vaccinated mice (P < 0.5). Notably, our assessments also demonstrated that vaccination with rDepeps-FliC-OmpH-MBP provided good protection against infections caused by a heterogeneous group of P. multocida serotypes (A, B, D). Our above findings indicate that modification with DCpep and Salmonella flagellin could be used as a promising strategy to improve vaccine effectiveness.


Assuntos
Infecções por Pasteurella , Pasteurella multocida , Animais , Camundongos , Sorogrupo , Infecções por Pasteurella/prevenção & controle , Flagelina/metabolismo , Proteínas da Membrana Bacteriana Externa , Peptídeos/metabolismo , Células Dendríticas , Vacinas Bacterianas
14.
J Biochem Mol Toxicol ; 38(4): e23676, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38561971

RESUMO

Although the treatment of ovarian cancer has made great progress, there are still many patients who are not timely detected and given targeted therapy due to unknown pathogenesis. Recent studies have found that hsa_circ_0015326 is upregulated in ovarian cancer and is involved in the proliferation, invasion, and migration of ovarian cancer cells. However, whether hsa_circ_0015326 can be used as a new target of ovarian cancer needs further investigation. Therefore, the effect of hsa_circ_0015326 on epithelial ovarian cancer was investigated in this study. At first, si-hsa_circ_0015326 lentivirus was transfected into epithelial ovarian cancer cells. Then real-time fluorescence quantitative PCR (qRT-PCR) was used to detect hsa_circ_0015326 level. The proliferation of ovarian cancer cells was detected by CCK-8 assay. The horizontal and vertical migration abilities of the cells were detected by wound-healing assay and Transwell assay, respectively. Transwell assay was also used to determine the invasion rate. As for the apoptosis rate, it was assessed by flow cytometry. As a result, the expression level of hsa_circ_0015326 in A2780 and SKOV3 was found to be higher than that in IOSE-80. However, after transfecting si-hsa_circ_0015326 and si-NC into the cells, the proliferation, migration, and invasion abilities of A2780 and SKOV3 cells in the si-hsa_circ_0015326 group were significantly reduced in comparison to those in the si-NC and mock groups, while their apoptosis rates were elevated. Collectively, silencing hsa_circ_0015326 bears the capability of inhibiting the proliferation, migration, and invasion of ovarian cancer cells while increasing apoptosis rate. It can be concluded that hsa_circ_0015326 promotes the malignant biological activities of epithelial ovarian cancer cells.


Assuntos
MicroRNAs , Neoplasias Ovarianas , Humanos , Feminino , RNA/metabolismo , Carcinoma Epitelial do Ovário/genética , RNA Circular/genética , RNA Circular/metabolismo , Linhagem Celular Tumoral , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proliferação de Células , Apoptose , MicroRNAs/metabolismo , Movimento Celular
15.
Mitochondrial DNA B Resour ; 9(3): 411-414, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38562438

RESUMO

Hemiboea pterocaulis is a unique species only found in Guilin, Guangxi, China. In this study, we sequenced and assembled the complete chloroplast genome of H. pterocaulis and revealed its phylogenetic relationship with other Hemiboea species. The chloroplast genome sequence of H. pterocaulis is 153,159 bp in length and comprises a large single-copy (LSC) region of 84,178 bp, a small single-copy (SSC) region of 18,087 bp, and a pair of inverted repeat (IR) regions, each with a length of 25,447 bp. It has a total GC content of 37.6% and encodes 132 genes, including 87 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The phylogenetic relationships based on the complete chloroplast genome sequences of Hemiboea taxa indicate that H. pterocaulis is most closely related to H. suiyangensis, indicating that H. pterocaulis is an independent species and is separated from the H. subcapitata complex. These results provide valuable insights into the phylogeny, species divergence, and delimitation of the Hemiboea genus.

16.
Front Pharmacol ; 15: 1365911, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567353

RESUMO

Lung diseases have become a major threat to human health worldwide. Despite advances in treatment and intervention in recent years, effective drugs are still lacking for many lung diseases. As a traditional natural medicine, Tibetan medicine has had a long history of medicinal use in ethnic minority areas, and from ancient times to the present, it has a good effect on the treatment of lung diseases and has attracted more and more attention. In this review, a total of 586 Tibetan medicines were compiled through literature research of 25 classical works on Tibetan medicine, drug standards, and some Chinese and English databases. Among them, 33 Tibetan medicines have been studied to show their effectiveness in treating lung diseases. To investigate the uses of these Tibetan medicines in greater depth, we have reviewed the ethnomedicinal, phytochemical and pharmacological properties of the four commonly used Tibetan medicines for lung diseases (rhodiola, gentian, sea buckthorn, liexiang dujuan) and the five most frequently used Tibetan medicines (safflower, licorice, sandalwood, costus, myrobalan). It is expected to provide some reference for the development of new drugs of lung diseases in the future.

17.
J Agric Food Chem ; 72(17): 9856-9866, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38635925

RESUMO

The purpose of this study was to identify ovalbumin-derived immunomodulatory peptides by in vitro cell experiments, de novo sequencing, and molecular docking. Ovalbumin hydrolysates were prepared by two enzymes (alkaline protease and papain) individually, sequentially, or simultaneously, respectively. The simultaneous enzymatic hydrolysate (OVAH) had a high degree of hydrolysis (38.12 ± 0.48%) and exhibited immune-enhancing and anti-inflammatory activities. A total of 160 peptides were identified by LC-MS/MS in OVAH. Three novel peptides NVMEERKIK, ADQARELINS, and WEKAFKDE bound to TLR4-MD2 through hydrogen bonds and hydrophobic interactions with high binding affinity and binding energies of -181.40, -178.03, and -168.12 kcal/mol, respectively. These three peptides were synthesized and validated for two-way immunomodulatory activity. NVMEERKIK exhibiting the strongest immunomodulatory activity, increased NO and TNF-α levels by 128.69 and 38.01%, respectively, in normal RAW264.7 cells and reduced NO and TNF-α levels by 27.31 and 39.13%, respectively, in lipopolysaccharide-induced inflammatory RAW264.7 cells. Overall, this study first revealed that ovalbumin could be used as an immunomodulatory source for controlling inflammatory factor secretion.


Assuntos
Simulação de Acoplamento Molecular , Ovalbumina , Peptídeos , Ovalbumina/imunologia , Ovalbumina/química , Camundongos , Animais , Células RAW 264.7 , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/imunologia , Receptor 4 Toll-Like/química , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Agentes de Imunomodulação/química , Agentes de Imunomodulação/farmacologia , Sequência de Aminoácidos , Espectrometria de Massas em Tandem , Óxido Nítrico/metabolismo , Óxido Nítrico/imunologia , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia
18.
Brain Res ; 1838: 148947, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38657887

RESUMO

Perceived stress is an acknowledged risk factor for subthreshold depression (StD), and fluctuations in perceived stress are thought to disrupt the harmony of brain networks essential for emotional and cognitive functioning. This study aimed to elucidate the relationship between eye-open (EO) and eye-closed (EC) states, perceived stress, and StD. We recruited 27 individuals with StD and 33 healthy controls, collecting resting state fMRI data under both EC and EO conditions. We combined intrinsic connectivity and seed-based functional connectivity analyses to construct the functional network and explore differences between EC and EO conditions. Graph theory analysis revealed weakened connectivity strength in the right superior frontal gyrus (SFG) and right median cingulate and paracingulate gyrus (MCC) among participants with StD, suggesting an important role for these regions in the stress-related emotions dysregulation. Notably, altered SFG connectivity was observed to significantly relate to perceived stress levels in StD, and the SFG connection emerges as a neural mediator potentially influencing the relationship between perceived stress and StD. These findings highlight the role of SFG and MCC in perceived stress and suggest that understanding EC and EO states in relation to these regions is important in the neurobiological framework of StD. This may offer valuable perspectives for early prevention and intervention strategies in mental health disorders.

19.
bioRxiv ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38659943

RESUMO

Three proton-sensing G protein-coupled receptors (GPCRs), GPR4, GPR65, and GPR68, respond to changes in extracellular pH to regulate diverse physiology and are implicated in a wide range of diseases. A central challenge in determining how protons activate these receptors is identifying the set of residues that bind protons. Here, we determine structures of each receptor to understand the spatial arrangement of putative proton sensing residues in the active state. With a newly developed deep mutational scanning approach, we determined the functional importance of every residue in proton activation for GPR68 by generating ~9,500 mutants and measuring effects on signaling and surface expression. This unbiased screen revealed that, unlike other proton-sensitive cell surface channels and receptors, no single site is critical for proton recognition in GPR68. Instead, a network of titratable residues extend from the extracellular surface to the transmembrane region and converge on canonical class A GPCR activation motifs to activate proton-sensing GPCRs. More broadly, our approach integrating structure and unbiased functional interrogation defines a new framework for understanding the rich complexity of GPCR signaling.

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