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In oxygenic photosynthetic organisms, light energy is captured by antenna systems and transferred to photosystem II (PSII) and photosystem I (PSI) to drive photosynthesis1,2. The antenna systems of red algae consist of soluble phycobilisomes (PBSs) and transmembrane light-harvesting complexes (LHCs)3. Excitation energy transfer pathways from PBS to photosystems remain unclear owing to the lack of structural information. Here we present in situ structures of PBS-PSII-PSI-LHC megacomplexes from the red alga Porphyridium purpureum at near-atomic resolution using cryogenic electron tomography and in situ single-particle analysis4, providing interaction details between PBS, PSII and PSI. The structures reveal several unidentified and incomplete proteins and their roles in the assembly of the megacomplex, as well as a huge and sophisticated pigment network. This work provides a solid structural basis for unravelling the mechanisms of PBS-PSII-PSI-LHC megacomplex assembly, efficient energy transfer from PBS to the two photosystems, and regulation of energy distribution between PSII and PSI.
Assuntos
Complexos de Proteínas Captadores de Luz , Complexo de Proteína do Fotossistema I , Complexo de Proteína do Fotossistema II , Ficobilissomas , Porphyridium , Transferência de Energia , Complexos de Proteínas Captadores de Luz/química , Complexos de Proteínas Captadores de Luz/metabolismo , Complexos de Proteínas Captadores de Luz/ultraestrutura , Fotossíntese , Complexo de Proteína do Fotossistema I/química , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema I/ultraestrutura , Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/metabolismo , Complexo de Proteína do Fotossistema II/ultraestrutura , Ficobilissomas/química , Ficobilissomas/metabolismo , Ficobilissomas/ultraestrutura , Porphyridium/química , Porphyridium/enzimologia , Porphyridium/metabolismo , Porphyridium/ultraestrutura , Microscopia Crioeletrônica , Imagem Individual de MoléculaRESUMO
Photosynthetic organisms have developed various light-harvesting systems to adapt to their environments1. Phycobilisomes are large light-harvesting protein complexes found in cyanobacteria and red algae2-4, although how the energies of the chromophores within these complexes are modulated by their environment is unclear. Here we report the cryo-electron microscopy structure of a 14.7-megadalton phycobilisome with a hemiellipsoidal shape from the red alga Porphyridium purpureum. Within this complex we determine the structures of 706 protein subunits, including 528 phycoerythrin, 72 phycocyanin, 46 allophycocyanin and 60 linker proteins. In addition, 1,598 chromophores are resolved comprising 1,430 phycoerythrobilin, 48 phycourobilin and 120 phycocyanobilin molecules. The markedly improved resolution of our structure compared with that of the phycobilisome of Griffithsia pacifica5 enabled us to build an accurate atomic model of the P. purpureum phycobilisome system. The model reveals how the linker proteins affect the microenvironment of the chromophores, and suggests that interactions of the aromatic amino acids of the linker proteins with the chromophores may be a key factor in fine-tuning the energy states of the chromophores to ensure the efficient unidirectional transfer of energy.
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Microscopia Crioeletrônica , Transferência de Energia , Ficobilissomas/química , Ficobilissomas/ultraestrutura , Porphyridium/química , Porphyridium/ultraestrutura , Proteínas de Algas/química , Proteínas de Algas/metabolismo , Proteínas de Algas/ultraestrutura , Modelos Moleculares , Fotossíntese , Ficobilinas/química , Ficobilinas/metabolismo , Ficobilissomas/metabolismo , Conformação Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Rodófitas/química , Rodófitas/ultraestruturaRESUMO
Grain appearance and nutritional quality are critical traits for rice marketing. However, how to simultaneously improve grain appearance (slender grain and low chalkiness) and nutritional quality (improved protein and amino acid contents) in rice remains a major challenge. Here, we show that knocking out rice isopropylmalate synthase genes OsIPMS1 and OsIPMS2 can improve both grain appearance and nutritional quality. We find that OsIPMS1 directly interacts with OsIPMS2 to form heterodimers. Meanwhile, we observe that OsIPMS1 and OsIPMS2 influence the expression of genes previously reported to be involved in the determination of grain size and nutritional quality in the developing panicles and grains. Furthermore, we show that Osipms1/2 double mutants exhibit significantly improved grain appearance and nutritional quality in polished rice in both the japonica (Wuyungeng 23) and indica (Huanghuazhan) varieties. Our findings indicate that OsIPMS is a useful target gene for breeding of rice varieties appealing for marketing and with health-benefiting properties.
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Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two aging-related neurodegenerative diseases that share common key features, including aggregation of pathogenic proteins, dysfunction of mitochondria, and impairment of autophagy. Mutations in ubiquilin 2 (UBQLN2), a shuttle protein in the ubiquitin-proteasome system (UPS), can cause ALS/FTD, but the mechanism underlying UBQLN2-mediated pathogenesis is still uncertain. Recent studies indicate that mitophagy, a selective form of autophagy which is crucial for mitochondrial quality control, is tightly associated with neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and ALS. In this study, we show that after Parkin-dependent ubiquitination of damaged mitochondria, UBQLN2 is recruited to poly-ubiquitinated mitochondria through the UBA domain. UBQLN2 cooperates with the chaperone HSP70 to promote UPS-driven degradation of outer mitochondrial membrane (OMM) proteins. The resulting rupture of the OMM triggers the autophagosomal recognition of the inner mitochondrial membrane receptor PHB2. UBQLN2 is required for Parkin-mediated mitophagy and neuronal survival upon mitochondrial damage, and the ALS/FTD pathogenic mutations in UBQLN2 impair mitophagy in primary cultured neurons. Taken together, our findings link dysfunctional mitophagy to UBQLN2-mediated neurodegeneration.
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Esclerose Lateral Amiotrófica , Demência Frontotemporal , Doenças Neurodegenerativas , Humanos , Membranas Mitocondriais/metabolismo , Esclerose Lateral Amiotrófica/genética , Mitofagia , Demência Frontotemporal/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Relacionadas à Autofagia/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismo , Doenças Neurodegenerativas/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Mitochondrial preproteins synthesized in cytosol are imported into mitochondria by a multisubunit translocase of the outer membrane (TOM) complex. Functioned as the receptor, the TOM complex components, Tom 20, Tom22, and Tom70, recognize the presequence and further guide the protein translocation. Their deficiency has been linked with neurodegenerative diseases and cardiac pathology. Although several structures of the TOM complex have been reported by cryoelectron microscopy (cryo-EM), how Tom22 and Tom20 function as TOM receptors remains elusive. Here we determined the structure of TOM core complex at 2.53 Å and captured the structure of the TOM complex containing Tom22 and Tom20 cytosolic domains at 3.74 Å. Structural analysis indicates that Tom20 and Tom22 share a similar three-helix bundle structural feature in the cytosolic domain. Further structure-guided biochemical analysis reveals that the Tom22 cytosolic domain is responsible for binding to the presequence, and the helix H1 is critical for this binding. Altogether, our results provide insights into the functional mechanism of the TOM complex recognizing and transferring preproteins across the mitochondrial membrane.
Assuntos
Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Receptores Citoplasmáticos e Nucleares , Microscopia Crioeletrônica , Humanos , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial/química , Domínios Proteicos , Receptores Citoplasmáticos e Nucleares/químicaRESUMO
Iron (Fe) deficiency significantly affects the growth and development, fruit yield and quality of apples. Apple roots respond to Fe deficiency stress by promoting H+ secretion, which acidifies the soil. In this study, the plasma membrane (PM) H+ -ATPase MxHA2 promoted H+ secretion and root acidification of apple rootstocks under Fe deficiency stress. H+ -ATPase MxHA2 is upregulated in Fe-efficient apple rootstock of Malus xiaojinensis at the transcription level. Fe deficiency also induced kinase MxMPK6-2, a positive regulator in Fe absorption that can interact with MxHA2. However, the mechanism involving these two factors under Fe deficiency stress is unclear. MxMPK6-2 overexpression in apple roots positively regulated PM H+ -ATPase activity, thus enhancing root acidification under Fe deficiency stress. Moreover, co-expression of MxMPK6-2 and MxHA2 in apple rootstocks further enhanced PM H+ -ATPase activity under Fe deficiency. MxMPK6-2 phosphorylated MxHA2 at the Ser909 site of C terminus, Thr320 and Thr412 sites of the Central loop region. Phosphorylation at the Ser909 and Thr320 promoted PM H+ -ATPase activity, while phosphorylation at Thr412 inhibited PM H+ -ATPase activity. MxMPK6-2 also phosphorylated the Fe deficiency-induced transcription factor MxbHLH104 at the Ser169 site, which then could bind to the promoter of MxHA2, thus enhancing MxHA2 upregulation. In conclusion, the MAP kinase MxMPK6-2-mediated phosphorylation directly and indirectly regulates PM H+ -ATPase MxHA2 activity at the protein post-translation and transcription levels, thus synergistically enhancing root acidification under Fe deficiency stress.
Assuntos
Malus , Malus/metabolismo , Fosforilação , Ferro/metabolismo , Membrana Celular/metabolismo , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
BACKGROUND: There are little data on changes in insulin sensitivity during the first few years of life following in utero human immunodeficiency virus (HIV) and antiretroviral (ARV) exposure. METHODS: The Tshilo Dikotla study enrolled pregnant persons with HIV (PWH) (receiving tenofovir/emtricitabine or lamivudine plus dolutegravir or efavirenz) and pregnant individuals without HIV, as well as their liveborn children. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was assessed at birth and 1, 18, 24, and 36 months of life. We fit linear mixed-effects models to evaluate the association between in utero HIV/ARV exposure and average HOMA-IR from birth through 36 months of life, adjusting for confounders. RESULTS: A total of 419 children were included (287 with in utero HIV/ARV exposure and uninfected [CHEU] and 132 without in utero HIV/ARV exposure [CHUU]). CHEU were born to older women (29.6 vs 25.3 years of age) with higher gravidity (3 vs 1). HOMA-IR was persistently higher in CHEU versus CHUU in adjusted analyses (mean difference of 0.07 in log10 HOMA-IR, P = .02) from birth through 36 months of life. Among CHEU, no differences in HOMA-IR were observed from birth through 36 months by in utero ARV exposure status or between AZT and NVP infant prophylaxis arms. CONCLUSIONS: In utero HIV/ARV exposure was associated with lower insulin sensitivity throughout the first 36 months of life, indicating persistent early life metabolic disturbances which may raise concern for poorer metabolic health later in life.
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Helicases, classified into six superfamilies, are mechanoenzymes that utilize energy derived from ATP hydrolysis to remodel DNA and RNA substrates. These enzymes have key roles in diverse cellular processes, such as translation, ribosome assembly, and genome maintenance. Helicases with essential functions in certain cancer cells have been identified, and helicases expressed by many viruses are required for their pathogenicity. Therefore, helicases are important targets for chemical probes and therapeutics. However, it has been very challenging to develop chemical inhibitors for helicases, enzymes with high conformational dynamics. We envisioned that electrophilic "scout fragments", which have been used in chemical proteomic studies, could be leveraged to develop covalent inhibitors of helicases. We adopted a function-first approach, combining enzymatic assays with enantiomeric probe pairs and mass spectrometry, to develop a covalent inhibitor that selectively targets an allosteric site in SARS-CoV-2 nsp13, a superfamily-1 helicase. Further, we demonstrate that scout fragments inhibit the activity of two human superfamily-2 helicases, BLM and WRN, involved in genome maintenance. Together, our findings suggest an approach to discover covalent inhibitor starting points and druggable allosteric sites in conformationally dynamic mechanoenzymes.
Assuntos
DNA Helicases , Proteômica , Humanos , DNA Helicases/química , DNA/químicaRESUMO
Diabetic wounds pose a persistent challenge due to their slow healing nature, primarily caused by bacterial infection and excessive reactive oxygen species (ROS)-induced inflammation. In this study, carbon dots with synergistic antibacterial and antioxidant properties, referred to as AA-CDs, are developed specifically for diabetic wound healing using a straightforward solvothermal method. By utilizing cost-effective precursors like citric acid and ascorbic acid, AA-CDs are engineered to possess tailored functions of photothermal sterilization and ROS scavenging. The resulting AA-CDs demonstrats broad-spectrum antibacterial activity, particularly against multidrug-resistant strains, along with efficient ROS scavenging both in solution and within cells. Additionally, AA-CDs exhibits a protective effect against oxidative stress-induced damage. Notably, with a high photothermal conversion efficiency (41.18%), AA-CDs displays heat-enhanced antioxidant performance, providing not only augmented ROS scavenging but also additional protection against oxidative stress, yielding a true "1 + 1 > 2" effect. To facilitate their use in vivo, AA-CDs are incorporated into a thermally responsive hydrogel, which exhibits evident anti-inflammatory properties by modulating inflammatory factors and significantly promots the healing of diabetic wounds. This study underscores the value of integrated platforms for diabetic wound healing and highlights the potential of versatile CDs as promising therapeutic agents in biomedical applications.
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Aberrantly-active signal transducer and activator of transcription (Stat)3 has a causal role in many human cancers and represents a validated anticancer drug target, though it has posed significant challenge to drug development. A new small molecule, JKB887, was identified through virtual library screening and is predicted to interact with Lys591, Arg609 and Pro63 in the phospho-tyrosine (pTyr)-binding pocket of the Stat3 SH2 domain. JKB887 inhibited Stat3 DNA-binding activity in vitro in a time-dependent manner, with IC50 of 2.2-4.5 µM at 30-60-min incubation. It directly disrupted both the Stat3 binding to the cognate, high-affinity pTyr (pY) peptide, GpYLPQTV-NH2 in fluorescent polarization assay with IC50 of 3.5-5.5 µM at 60-90-min incubation, and to the IL-6 receptor/gp130 or Src in treated malignant cells. Treatment with JKB887 selectively blocked constitutive Stat3 phosphorylation, nuclear translocation and transcriptional activity, Stat3-regulated gene expression, and decreased viable cell numbers, cell growth, colony formation, migration, and survival in human or mouse tumor cells. By contrast, JKB887 had minimal effects on Stat1 activity, pErk1/2MAPK, pShc, pJAK2, pSrc induction, or cells that do not harbor aberrantly-active Stat3. Additionally, JKB887 inhibited growth of human breast cancer xenografts in mice. JKB887 is a Stat3-selective inhibitor with demonstrable antitumor effects against Stat3-dependent human cancers.
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Type 1 fimbria, the short hair-like appendage assembled on the bacterial surface, plays a pivotal role in adhesion and invasion in Edwardsiella piscicida. The type III secretion system (T3SS), another bacterial surface appendage, facilitates E. piscicida's replication in vivo by delivering effectors into host cells. Our previous research demonstrated that E. piscicida T3SS protein EseJ inhibits adhesion and invasion of E. piscicida by suppressing type 1 fimbria. However, how EseJ suppresses type 1 fimbria remains elusive. In this study, a lacI-like operator (nt -245 to -1 of fimA) upstream of type 1 fimbrial operon in E. piscicida was identified, and EseJ inhibits type 1 fimbria through the lacI-like operator. Moreover, through DNA pull-down and electrophoretic mobility shift assay, an AraC-type T3SS regulator, EsrC, was screened and verified to bind to nt -145 to -126 and nt -50 to -1 of fimA, suppressing type 1 fimbria. EseJ is almost abolished upon the depletion of EsrC. EsrC and EseJ impede type 1 fimbria expression. Intriguingly, nutrition and microbiota-derived indole activate type 1 fimbria through downregulating T3SS, alleviating EsrC or EseJ's inhibitory effect on lacI-like operator of type 1 fimbrial operon. By this study, it is revealed that upon entering the gastrointestinal tract, rich nutrients and indole downregulate T3SS and thereof upregulate type 1 fimbria, stimulating efficient adhesion and invasion; upon being internalized into epithelium, the limit in indole and nutrition switches on T3SS and thereof switches off type 1 fimbria, facilitating effector delivery to guarantee E. piscicida's survival/replication in vivo.IMPORTANCEIn this work, we identified the lacI-like operator of type 1 fimbrial operon in E. piscicida, which was suppressed by the repressors-T3SS protein EseJ and EsrC. We unveiled that E. piscicida upregulates type 1 fimbria upon sensing rich nutrition and the microbiota-derived indole, thereof promoting the adhesion of E. piscicida. The increase of indole and nutrition promotes type 1 fimbria by downregulating T3SS. The decrease in EseJ and EsrC alleviates their suppression on type 1 fimbria, and vice versa.
Assuntos
Aderência Bacteriana , Proteínas de Bactérias , Edwardsiella , Fímbrias Bacterianas , Óperon , Sistemas de Secreção Tipo III , Edwardsiella/genética , Edwardsiella/fisiologia , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Animais , Regulação Bacteriana da Expressão Gênica , Infecções por Enterobacteriaceae/microbiologiaRESUMO
Seed germination is a critical trait for the success of direct seeding in rice cultivation. However, the underlying mechanism determining seed germination is largely unknown in rice. Here, we report that NAC transcription factor OsNAC3 positively regulates seed germination of rice. OsNAC3 regulates seed germination involving abscisic acid (ABA) pathway and cell elongation. OsNAC3 can directly bind to the promoter of ABA catabolic gene OsABA8ox1 and cell expansion gene OsEXP4, which consequently activates their expressions during seed germination. We also find that the expression of OsEXP4 is reduced by ABA during seed germination in rice. OsNAC3 regulates seed germination by influencing cell elongation of the embryo through directly affecting OsEXP4 expression and indirectly ABA-medicated OsEXP4 expression. The OsNAC3 elite haplotype is useful for genetic improvement of seed germination, and overexpression of OsNAC3 can significantly increase seed germination. We therefore propose that OsNAC3 is a potential target in breeding of rice varieties with high seed germination for direct seeding cultivation.
Assuntos
Ácido Abscísico , Oryza , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Germinação/genética , Oryza/metabolismo , Sementes/genética , Melhoramento Vegetal , Regulação da Expressão Gênica de PlantasRESUMO
Western diet (WD) consumption during early life developmental periods is associated with impaired memory function, particularly for hippocampus (HPC)-dependent processes. We developed an early life WD rodent model associated with long-lasting HPC dysfunction to investigate the neurobiological mechanisms mediating these effects. Rats received either a cafeteria-style WD (ad libitum access to various high-fat/high-sugar foods; CAF) or standard healthy chow (CTL) during the juvenile and adolescent stages (postnatal days 26-56). Behavioral and metabolic assessments were performed both before and after a healthy diet intervention period beginning at early adulthood. Results revealed HPC-dependent contextual episodic memory impairments in CAF rats that persisted despite the healthy diet intervention. Given that dysregulated HPC acetylcholine (ACh) signaling is associated with memory impairments in humans and animal models, we examined protein markers of ACh tone in the dorsal HPC (HPCd) in CAF and CTL rats. Results revealed significantly lower protein levels of vesicular ACh transporter in the HPCd of CAF vs. CTL rats, indicating chronically reduced ACh tone. Using intensity-based ACh sensing fluorescent reporter (iAChSnFr) in vivo fiber photometry targeting the HPCd, we next revealed that ACh release during object-contextual novelty recognition was highly predictive of memory performance and was disrupted in CAF vs. CTL rats. Neuropharmacological results showed that alpha 7 nicotinic ACh receptor agonist infusion in the HPCd during training rescued memory deficits in CAF rats. Overall, these findings reveal a functional connection linking early life WD intake with long-lasting dysregulation of HPC ACh signaling, thereby identifying an underlying mechanism for WD-associated memory impairments.
Assuntos
Acetilcolina , Dieta Ocidental , Humanos , Ratos , Animais , Adolescente , Adulto , Acetilcolina/metabolismo , Memória/fisiologia , Hipocampo/metabolismo , Transdução de Sinais , Transtornos da Memória/metabolismoRESUMO
Few studies have evaluated postpartum depression (PPD) in women living with HIV (WLHIV) in Botswana, a high prevalence HIV setting. The Edinburgh Postnatal Depression Scale (EPDS) was used to evaluate PPD symptoms in WLHIV (n = 300) and women who are HIV-uninfected (n = 131) in the Tshilo Dikotla study, an observational cohort study with a nested randomized trial. The EPDS was administered at 2, 6, and 12 months postpartum. We assessed the association of (1) HIV infection and (2) antiretroviral therapy (ART) with odds of PPD symptoms (EPDS ≥ 10 or thoughts of self-harm) in the first year postpartum using generalized estimating equations. Of WLHIV, 24 (8.00%) had PPD symptoms at one or more follow-up time points, compared to 9 (6.9%) women who were HIV-seronegative. There was no association between HIV status and PPD symptoms (adjusted odds ratio [aOR]:1.69, 95% confidence interval [CI]: 0.73-3.93, p = 0.225); however, WLHIV on efavirenz-based ART regimens had higher odds of experiencing PPD symptoms compared to dolutegravir-based ART (aOR:3.05, 95% CI:1.16-8.03, p = 0.024).
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Acute myeloid leukemia (AML) is the most common type of blood cancer and has been strongly correlated with the overexpression of Fms-like tyrosine kinase 3 (FLT3), a member of the class III receptor tyrosine kinase family. With the emergence of FLT3 internal tandem duplication alteration (ITD) and tyrosine kinase domain (TKD) mutations, the development of FLT3 small molecule inhibitors has become an effective medicinal chemistry strategy for AML. Herein, we have designed and synthesized two series of 1H-pyrrolo[2,3-b]pyridine derivatives CM1-CM24, as FLT3 inhibitors based on F14, which we previously reported, that can target the hydrophobic FLT3 back pocket. Among these derivates, CM5 showed significant inhibition of FLT3 and FLT3-ITD, with inhibitory percentages of 57.72 % and 53.77 % respectively at the concentration of 1 µΜ. Furthermore, CM5 demonstrated potent inhibition against FLT3-dependent human AML cell lines MOLM-13 and MV4-11 (both harboring FLT3-ITD mutant), with IC50 values of 0.75 µM and 0.64 µM respectively. In our cellular mechanistic studies, CM5 also effectively induces apoptosis by arresting cell cycle progression in the G0/G1 phase. In addition, the amide and urea linker function were discussed in detail based on computational simulations studies. CM5 will serve as a novel lead compound for further structural modification and development of FLT3 inhibitors specifically targeting AML with FLT3-ITD mutations.
Assuntos
Leucemia Mieloide Aguda , Tirosina Quinase 3 Semelhante a fms , Humanos , Apoptose , Linhagem Celular Tumoral , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Piridinas/farmacologiaRESUMO
BACKGROUND: The adenoids act as a reservoir of bacterial pathogens and immune molecules, and they are significantly involved in children with otitis media with effusion (OME). As an essential carrier of intercellular substance transfer and signal transduction, exosomes with different biological functions can be secreted by various types of cells. There remains significant uncertainty regarding the clinical relevance of exosomes to OME, especially in its pathophysiologic development. In this study, we will seek to determine the biological functions of exosomes in children with adenoid hypertrophy accompanied by OME (AHOME). METHODS: The diagnostic criteria for OME in children aged 4-10 years include a disease duration of at least 3 months, type B or C acoustic immittance, and varying degrees of conductive hearing loss. Adenoidal hypertrophy is diagnosed when nasal endoscopy shows at least 60% adenoidal occlusion in the nostrils or when nasopharyngeal lateral X-ray shows A/N > 0.6. Children who meet the indications for adenoidectomy surgery undergo adenoidectomy. Peripheral blood, nasopharyngeal swab, and adenoid tissue will be collected from patients, and the exosomes will be isolated from the samples. Following the initial collection, patients will undergo adenoidectomy and peripheral blood and nasopharyngeal swabs will be collected again after 3 months. EXPECTED RESULTS: This study aims to identify differences in exosomes from preoperative adenoid tissue and peripheral blood samples between children with AHOME and those with adenoid hypertrophy alone. Additionally, it seeks to determine changes in microbial diversity in adenoid tissue between these groups. CONCLUSIONS: The findings are expected to provide new insights into the diagnosis and treatment of OME, to identify novel biomarkers, and to enhance our understanding of the pathophysiology of OME, potentially leading to the development of innovative diagnostic and therapeutic approaches.
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Adenoidectomia , Tonsila Faríngea , Exossomos , Hipertrofia , Otite Média com Derrame , Humanos , Tonsila Faríngea/patologia , Otite Média com Derrame/etiologia , Otite Média com Derrame/diagnóstico , Criança , Pré-Escolar , Masculino , FemininoRESUMO
A notable ambiguity persists concerning whether distinct forms of parent-child triangulation (unstable coercive coalition, stable coalition, detouring-attacking, detouring supportive, parentification) might mediate the association between interparental conflict and early adolescent depressive symptoms similarly within the context of Chinese Confucianism. Filling this research gap, this study aimed to examine the mediating role of the five dimensions of parent-child triangulation in the association between interparental conflict and early adolescent depressive symptoms, as well as the moderating effect of grandparent support on this mediating pathway. Data were drawn from a sample of 761 Chinese adolescents (M age = 12.82 ± 0.47, 49.1% girls). Structural equation model analyses indicated that unstable coercive coalition, stable coalition, and detouring-attacking behaviors partially mediated the association between interparental conflict and adolescent depressive symptoms, while detouring-supportive behaviors and parentification did not demonstrate such mediating effects. Unlike Western societies, a negative correlation was observed between interparental conflict and parentification in the context of China. Grandparent support mitigated the adverse effects of both interparental conflict and the unstable coercive coalition on early adolescent depressive symptoms.
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Conflito Familiar , Avós , Feminino , Humanos , Adolescente , Masculino , Depressão , Pais , Relações Pais-FilhoRESUMO
Previous research concerning the interplay between genetics and parenting in the development of the parent-child relationship during adolescence has been extremely scarce, predominantly adopting single-gene designs. This limited body of work has largely overlooked the distinct effects of maternal and paternal roles, as well as potential gender differences. Additionally, existing gene-by-environment (G × E) studies have mainly concentrated on adverse environmental factors and associated negative outcomes, somewhat neglecting positive environments and outcomes. The present study examined the interactions of cumulative genetic scores (CGS, dopamine receptor D2 TaqIA and oxytocin receptor gene rs53576 polymorphisms) with both positive and negative parenting on parent-adolescent cohesion and conflict. Furthermore, this study aimed to ascertain with which gene-environment model the potential G × E interactions would align. A total of 745 Chinese Han adolescents (Mage = 13.36 ± 0.96 years; 46.8% girls) from grades 7 to 9 participated in this study. Results revealed a significant effect of CGS and negative maternal parenting on mother-adolescent conflict among males, consistent with the weak differential susceptibility model. As CGS increased, the effects of negative maternal parenting on mother-son conflict were magnified. These findings have implications for the timing and focus of interventions aimed at improving parent-adolescent relationships.
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Poder Familiar , Pais , Masculino , Feminino , Humanos , Adolescente , Criança , Pai , Relações Pais-Filho , MãesRESUMO
Tuberculosis remains a leading cause of death from a single infection worldwide. Drug resistance to existing and even new antimycobacterials calls for research into novel targets and unexplored mechanisms of action. Recently we reported on the development of tight-binding inhibitors of Mycobacterium tuberculosis (Mtb) lipoamide dehydrogenase (Lpd), which selectively inhibit the bacterial but not the human enzyme based on a differential modality of inhibitor interaction with these targets. Here we report on the striking improvement in inhibitor residence time on the Mtb enzyme associated with scaffold progression from an indazole to 2-cyanoindole. Cryo-EM of Lpd with the bound 2-cyanoindole inhibitor 19 confirmed displacement of the buried water molecule deep in the binding channel with a cyano group. The ensuing hours-long improvement in on-target residence time is associated with enhanced antibacterial activity in axenic culture and in primary mouse macrophages. Resistance to 2-cyanoindole inhibitors involves mutations within the inhibitor binding site that have little effect on inhibitor affinity but change the modality of inhibitor-target interaction, resulting in fast dissociation from Lpd. These findings underscore that on-target residence time is a major determinant of antibacterial activity and in vivo efficacy.
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The autophagic clearance of mitochondria has been defined as mitophagy, which is triggered by mitochondrial damage and serves as a major pathway for mitochondrial homeostasis and cellular quality control. PINK1 and Parkin-mediated mitophagy is the most extensively studied form of mitophagy, which has been linked to the pathogenesis of neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The current paradigm of this particular mitophagy pathway is that the ubiquitination of the outer mitochondrial membrane is the key step to enable the recognition of damaged mitochondria by the core autophagic component autophagosome. However, whether the inner mitochondrial membrane (IMM) is ubiquitinated by Parkin and its contribution to sufficient mitophagy remain unclear. Here, using molecular, cellular, and biochemical approaches, we report that prohibitin 2 (PHB2), an essential IMM receptor for mitophagy, is ubiquitinated by Parkin and thereby gains higher affinity to the autophagosome during mitophagy. Our findings suggest that Parkin directly binds to PHB2 through its RING1 domain and promotes K11- and K33-linked ubiquitination on K142/K200 sites of PHB2, thereby enhancing the interaction between PHB2 and MAP1LC3B/LC3B. Interestingly and importantly, our study allows us to propose a novel model in which IMM protein PHB2 serves as both a receptor and a ubiquitin-mediated base for autophagosome recruitment to ensure efficient mitophagy.