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BACKGROUND & AIMS: Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer and is highly lethal. Clonorchis sinensis (C. sinensis) infection is an important risk factor for iCCA. Here we investigated the clinical impact and underlying molecular characteristics of C. sinensis infection-related iCCA. METHODS: We performed single-cell RNA sequencing, whole-exome sequencing, RNA sequencing, metabolomics and spatial transcriptomics in 251 patients with iCCA from three medical centers. Alterations in metabolism and the immune microenvironment of C. sinensis-related iCCAs were validated through an in vitro co-culture system and in a mouse model of iCCA. RESULTS: We revealed that C. sinensis infection was significantly associated with iCCA patients' overall survival and response to immunotherapy. Fatty acid biosynthesis and the expression of fatty acid synthase (FASN), a key enzyme catalyzing long-chain fatty acid synthesis, were significantly enriched in C. sinensis-related iCCAs. iCCA cell lines treated with excretory/secretory products of C. sinensis displayed elevated FASN and free fatty acids. The metabolic alteration of tumor cells was closely correlated with the enrichment of tumor-associated macrophage (TAM)-like macrophages and the impaired function of T cells, which led to formation of an immunosuppressive microenvironment and tumor progression. Spatial transcriptomics analysis revealed that malignant cells were in closer juxtaposition with TAM-like macrophages in C. sinensis-related iCCAs than non-C. sinensis-related iCCAs. Importantly, treatment with a FASN inhibitor significantly reversed the immunosuppressive microenvironment and enhanced anti-PD-1 efficacy in iCCA mouse models treated with excretory/secretory products from C. sinensis. CONCLUSIONS: We provide novel insights into metabolic alterations and the immune microenvironment in C. sinensis infection-related iCCAs. We also demonstrate that the combination of a FASN inhibitor with immunotherapy could be a promising strategy for the treatment of C. sinensis-related iCCAs. IMPACT AND IMPLICATIONS: Clonorchis sinensis (C. sinensis)-infected patients with intrahepatic cholangiocarcinoma (iCCA) have a worse prognosis and response to immunotherapy than non-C. sinensis-infected patients with iCCA. The underlying molecular characteristics of C. sinensis infection-related iCCAs remain unclear. Herein, we demonstrate that upregulation of FASN (fatty acid synthase) and free fatty acids in C. sinensis-related iCCAs leads to formation of an immunosuppressive microenvironment and tumor progression. Thus, administration of FASN inhibitors could significantly reverse the immunosuppressive microenvironment and further enhance the efficacy of anti-PD-1 against C. sinensis-related iCCAs.
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Neoplasias de los Conductos Biliares , Colangiocarcinoma , Clonorquiasis , Clonorchis sinensis , Ácidos Grasos , Microambiente Tumoral , Colangiocarcinoma/inmunología , Colangiocarcinoma/parasitología , Animales , Clonorchis sinensis/inmunología , Clonorchis sinensis/fisiología , Clonorquiasis/inmunología , Neoplasias de los Conductos Biliares/inmunología , Neoplasias de los Conductos Biliares/parasitología , Ratones , Microambiente Tumoral/inmunología , Humanos , Ácidos Grasos/metabolismo , Acido Graso Sintasa Tipo I/genética , Acido Graso Sintasa Tipo I/antagonistas & inhibidores , Acido Graso Sintasa Tipo I/metabolismo , Masculino , Femenino , Línea Celular Tumoral , Modelos Animales de Enfermedad , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismoRESUMEN
Although multiple forms of dimers have been described for GPCR, their dynamics and function are still controversially discussed field. Fluorescence microscopy allows GPCR to be imaged within their native context; however, a key challenge is to site-specifically incorporate reporter moieties that can produce high-quality signals upon formation of GPCR dimers. To this end, we propose a supramolecular sensor approach to detect agonist-induced dimer formation of µ-opioid receptors (µORs) at the surface of intact cells. With the macrocyclic host cucurbit[7]uril and its guest hemicyanine dye tethered to aptamer strands directed against the histidine residues, the sensing module is assembled by host-guest complexation once the histidine-tagged µORs dimerize and bring the discrete supramolecular units into close proximity. With the enhanced sensitivity attributed by the "turn-on" fluorescence emission and high specificity afforded by the intermolecular recognition, in situ visualization of dynamic GPCR dimerization was realized with high precision, thereby validating the supramolecular sensing entity as a sophisticated and versatile strategy to investigate GPCR dimers, which represent an obvious therapeutic target.
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Hidrocarburos Aromáticos con Puentes , Carbocianinas , Colorantes Fluorescentes , Colorantes Fluorescentes/química , Hidrocarburos Aromáticos con Puentes/química , Dimerización , HistidinaRESUMEN
Type 2 diabetes (T2D) is on a notable rise worldwide, which leads to unfavorable outcomes during implant treatments. Surface modification of implants and exosome treatment have been utilized to enhance osseointegration. However, there has been insufficient approach to improve adverse osseointegration in T2D conditions. In this study, we successfully loaded TNF-α-treated mesenchymal stem cell (MSC)-derived exosomes onto micro/nano-network titanium (Ti) surfaces. TNF-α-licensed exosome-integrated titanium (TNF-exo-Ti) effectively enhanced M2 macrophage polarization in hyperglycemic conditions, with increased secretion of anti-inflammatory cytokines and decreased secretion of pro-inflammatory cytokines. In addition, TNF-exo-Ti pretreated macrophage further enhanced angiogenesis and osteogenesis of endothelial cells and bone marrow MSCs. More importantly, TNF-exo-Ti markedly promoted osseointegration in T2D mice. Mechanistically, TNF-exo-Ti activated macrophage autophagy to promote M2 polarization through inhibition of the PI3K/AKT/mTOR pathway, which could be abolished by PI3K agonist. Thus, this study established TNF-α-licensed exosome-immobilized titanium surfaces that could rectify macrophage immune states and accelerate osseointegration in T2D conditions.
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Autofagia , Diabetes Mellitus Tipo 2 , Exosomas , Macrófagos , Ratones Endogámicos C57BL , Oseointegración , Titanio , Factor de Necrosis Tumoral alfa , Titanio/química , Titanio/farmacología , Animales , Exosomas/metabolismo , Autofagia/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Oseointegración/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Ratones , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Polaridad Celular/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Activación de Macrófagos/efectos de los fármacos , Diabetes Mellitus Experimental/metabolismoRESUMEN
The development of a natural pyrite/peroxymonosulfate (PMS) system for the removal of antibiotic contamination from water represented an economic and green sustainable strategy. Yet, a noteworthy knowledge gap remained considering the underlying reaction mechanism of the system, particularly in relation to its pH sensitivity. Herein, this paper investigated the impacts of critical reaction parameters and initial pH levels on the degradation of sulfadiazine (SDZ, 3 mg/L) in the pyrite/PMS system, and elucidated the pH dependence of the reaction mechanism. Results showed that under optimal conditions, SDZ could be completely degraded within 5 min at a broad pH range of 3.0-9.0, with a pseudo-first-order reaction rate of >1.0 min-1. The low or high PMS doses could lower degradation rates of SDZ through the decreased levels of active species, while the amount of pyrite was positively correlated with the removal rate of SDZ. The diminutive concentrations of anions exerted minor impacts on the decomposition of SDZ within the pyrite PMS system. Mechanistic results demonstrated that the augmentation of pH levels facilitated the transition from the non-radical to the radical pathway within the natural pyrite/PMS system, while concurrently amplifying the role of â¢OH in the degradation process of SDZ. This could be attributed to the change in interface electrostatic repulsion induced by pH fluctuations, as well as the mutual transformation between active species. The stable presence of the relative content of Fe(II) in the used pyrite was ensured owing to the reduced sulfur species acting as electron donors, providing the pyrite/PMS system excellent reusability. This paper sheds light on the mechanism regulation of efficient removal of organic pollutants through pyrite PMS systems, contributing to practical application.
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Sulfadiazina , Sulfadiazina/química , Concentración de Iones de Hidrógeno , Hierro/química , Sulfuros/química , Contaminantes Químicos del Agua/química , Peróxido de Hidrógeno/química , PeróxidosRESUMEN
Trace analysis of lipophilic substances in complex environmental, food, or biological matrices has proven to be a challenge, on account of their high susceptibility to adsorption by particulate matter and liquid-solid interfaces. For this purpose, liquid-liquid extraction (LLE) is often employed as the separation method, which uses water-immiscible organic solvents. As an alternative, magnetic solid-phase extraction (MSPE) allows for adsorption, separation, and recovery of analytes from large volumes of aqueous samples with minimum usage of organic solvents. However, the poor selectivity hampers its performance in various scenarios, especially in sewage samples where complicated and unpredictable interference exists, resulting in block of the active adsorption sites of the sorbent. To this end, we propose receptor-affinity MSPE employing magnetic liposomes decorated with cell membranes expressing G-protein-coupled receptor as the sorbents. Application of the novel sorbent CM@Lip@Fe infused with CB1 cannabinoid receptors was demonstrated for the targeted extraction and enrichment of tetrahydrocannabinol from sewage matrix. Thanks to the high affinity and molecular selectivity of the ligand-receptor interactions, a limit of quantitation of 5.17 ng/L was achieved coupled with HPLC-MS/MS in unfiltered raw sewage, featuring minimum usage of organic solvents, fivefold enhanced sensitivity, low sorbent dosage (75 mg/L of sewage), and high efficiency as major advantages over conventional LLE. This work establishes a framework for efficient separation of specific molecules from complex media, thus promising to extend and refine standard LLE as the clean-up procedure for trace analysis.
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Liposomas , Aguas del Alcantarillado , Espectrometría de Masas en Tándem/métodos , Solventes , Extracción en Fase Sólida/métodos , Agua , Membrana Celular , Fenómenos Magnéticos , Cromatografía Líquida de Alta Presión/métodosRESUMEN
BACKGROUND: Apoptosis resistance of myofibroblasts is critical in pathology of irradiation-induced fibrosis and osteoradionecrosis of the jaw (ORNJ). However, molecular mechanism of apoptosis resistance induced by irradiation in oral myofibroblasts remains largely obscure. METHODS: Matched ORNJ fibroblasts and normal fibroblasts pairs from gingival were primarily cultured, and myofibroblast markers of α-SMA and FAP were evaluated by qRT-PCR and western blot. CCK8 assay and flow cytometric analysis were performed to investigate the cell viability and apoptosis under irradiation treatment. Autophagy-related protein LC3 and ATG7, and punctate distribution of LC3 localization were further detected. After inhibition of autophagy with inhibitor CQ and 3-MA, as well as transfected ATG7-siRNA, cell viability and apoptosis of ORNJ and normal fibroblasts were further assessed. RESULTS: Compared with normal fibroblasts, ORNJ fibroblasts exhibited significantly higher α-SMA and FAP expression, increased cell, viability and decreased apoptosis under irradiation treatment. LC3-II and ATG7 were up-regulated in ORNJ fibroblasts with irradiation stimulation. After inhibition of irradiation-induced autophagic flux with lysosome inhibitor CQ, LC3-II protein was accumulated and punctate distribution of LC3 localization was increased in ORNJ fibroblasts. Moreover, autophagy inhibitor CQ and 3-MA enhanced the irradiation-induced apoptosis but inhibited viability of ORNJ fibroblasts. Silencing ATG7 with siRNA could obviously weaken irradiation-induced LC3-II expression, and promoted irradiation-induced apoptosis of ORNJ fibroblasts. After knockdown of ATG7, finally, p-AKT(Ser473) and p-mTOR(Ser2448) levels of ORNJ fibroblasts were significantly increased under irradiation. CONCLUSION: Compared with normal fibroblasts, human gingival myofibroblasts are resistant to irradiation-induced apoptosis via autophagy activation. Silencing ATG7 may evidently inhibit activation of autophagy, and promote apoptosis of gingival myofibroblasts via Akt/mTOR pathway.
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Miofibroblastos , Proteínas Proto-Oncogénicas c-akt , Humanos , Apoptosis , Autofagia , Miofibroblastos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Interferente Pequeño/genética , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
BACKGROUND: Conventional approach to myocardial strain analysis relies on a software designed for the left ventricle (LV) which is complex and time-consuming and is not specific for right ventricular (RV) and left atrial (LA) assessment. This study compared this conventional manual approach to strain evaluation with a novel semi-automatic analysis of myocardial strain, which is also chamber-specific. METHODS: Two experienced observers used the AutoStrain software and manual QLab analysis to measure the LV, RV and LA strains in 152 healthy volunteers. Fifty cases were randomly selected for timing evaluation. RESULTS: No significant differences in LV global longitudinal strain (LVGLS) were observed between the two methods (-21.0% ± 2.5% vs. -20.8% ± 2.4%, p = 0.230). Conversely, RV longitudinal free wall strain (RVFWS) and LA longitudinal strain during the reservoir phase (LASr) measured by the semi-automatic software differed from the manual analysis (RVFWS: -26.4% ± 4.8% vs. -31.3% ± 5.8%, p < 0.001; LAS: 48.0% ± 10.0% vs. 37.6% ± 9.9%, p < 0.001). Bland-Altman analysis showed a mean error of 0.1%, 4.9%, and 10.5% for LVGLS, RVFWS, and LASr, respectively, with limits of agreement of -2.9,2.6%, -8.1,17.9%, and -12.3,33.3%, respectively. The semi-automatic method had a significantly shorter strain analysis time compared with the manual method. CONCLUSIONS: The novel semi-automatic strain analysis has the potential to improve efficiency in measurement of longitudinal myocardial strain. It shows good agreement with manual analysis for LV strain measurement.
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Ventrículos Cardíacos , Programas Informáticos , Humanos , Reproducibilidad de los Resultados , Estudios de Factibilidad , Ventrículos Cardíacos/diagnóstico por imagen , Atrios Cardíacos , Función Ventricular IzquierdaRESUMEN
Natural transformation is one of the major mechanisms of horizontal gene transfer in bacterial populations and has been demonstrated in numerous species of bacteria. Despite the prevalence of natural transformation, much of the molecular mechanism remains unexplored. One major outstanding question is how the cell powers DNA import, which is rapid and highly processive. ComFA is one of a few proteins required for natural transformation in Gram-positive bacteria. Its structural resemblance to the DEAD box helicase family has led to a long-held hypothesis that ComFA acts as a motor to help drive DNA import into the cytosol. Here, we explored the helicase and translocase activity of ComFA to address this hypothesis. We followed the DNA-dependent ATPase activity of ComFA and, combined with mathematical modeling, demonstrated that ComFA likely translocates on single-stranded DNA from 5' to 3'. However, this translocase activity does not lead to DNA unwinding under the conditions we tested. Further, we analyzed the ATPase cycle of ComFA and found that ATP hydrolysis stimulates the release of DNA, providing a potential mechanism for translocation. These findings help define the molecular contribution of ComFA to natural transformation and support the conclusion that ComFA plays a key role in powering DNA uptake. IMPORTANCE Competence, or the ability of bacteria to take up and incorporate foreign DNA in a process called natural transformation, is common in the bacterial kingdom. Research in several bacterial species suggests that long, contiguous stretches of DNA are imported into cells in a processive manner, but how bacteria power transformation remains unclear. Our finding that ComFA, a DEAD box helicase required for competence in Gram-positive bacteria, translocates on single-stranded DNA from 5' to 3', supports the long-held hypothesis that ComFA may be the motor powering DNA transport during natural transformation. Moreover, ComFA may be a previously unidentified type of DEAD box helicase-one with the capability of extended translocation on single-stranded DNA.
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Adenosina Trifosfatasas , ADN de Cadena Simple , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/metabolismo , ARN Helicasas DEAD-box/metabolismo , ADN , ADN Helicasas/metabolismo , ADN de Cadena Simple/genéticaRESUMEN
Oral diseases, such as periapical periodontitis and periodontitis, are characterized by inflammation-induced bone loss. LL-37, a human antimicrobial peptide (AMP), has multiple biological functions and the potential to promote osteogenesis. Therefore, this study aimed to investigate the regulatory effects of LL-37 within normal and inflammatory microenvironments. The roles of P2X7 receptor (P2X7R) and mitogen-activated protein kinase (MAPK) signaling pathway were also demonstrated. The results showed that LL-37 promoted bone marrow stromal cell (BMSC) proliferation, migration and osteogenic differentiation. LL-37 inhibited the expression of the inflammatory cytokines interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and receptor activator of nuclear factor kappa-B ligand (RANKL) at both protein and gene levels, and attenuated the lipopolysaccharide (LPS)-induced inhibition of osteogenesis. Immunofluorescence (IF) confirmed P2X7R expression in BMSCs. BBG, a P2X7R antagonist, significantly attenuated LL-37-promoted osteogenesis. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase (JNK) increased after LL-37 stimulation, which did not affect p38 phosphorylation. The effects of LL-37 on osteogenesis-related gene expression were markedly attenuated by selective inhibitors of ERK1/2 and JNK. Furthermore, a mouse model of LPS-stimulated calvarial osteolysis was established, and results showed that LL-37 markedly inhibited osteoclastic bone resorption. In conclusion, we speculate that LL-37 inhibits inflammation and promotes BMSC osteogenesis via P2X7R and MAPK signaling pathway.
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Péptidos Catiónicos Antimicrobianos/administración & dosificación , Inflamación/tratamiento farmacológico , Células Madre Mesenquimatosas/efectos de los fármacos , Osteogénesis/genética , Receptores Purinérgicos P2X7/efectos de los fármacos , Pérdida de Hueso Alveolar/tratamiento farmacológico , Pérdida de Hueso Alveolar/genética , Pérdida de Hueso Alveolar/patología , Animales , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Microambiente Celular/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Humanos , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/patología , Lipopolisacáridos/toxicidad , Células Madre Mesenquimatosas/metabolismo , Ratones , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , FN-kappa B/genética , Osteogénesis/efectos de los fármacos , Fosforilación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , CatelicidinasRESUMEN
When edentulism is accompanied by an impacted tooth, conventional treatment usually involves traumatic tooth extraction, which would inevitably destroy the surrounding alveolar bone and cause unfavorable esthetics, especially for anterior teeth. Recently, implant placement through the impacted tooth or residual root has been proposed as an alternative to invasive extraction. A particular type of integration has been observed between dentin/cementum and titanium implant, while enamel-implant contact has not been reported. In this article, an implant was placed through the impacted maxillary central incisor, thereby avoiding an invasive extraction surgery. The buccal section of the tooth, including crown enamel, was retained in situ for buccal alveolar ridge preservation. The follow-up results were satisfactory, and a stable enamel-implant contact was observed. Combining with previous similar studies, this technique opens intriguing possibilities and brings fresh insight for the concept of dentointegration. More histological and clinical studies with long-term follow-up are warranted before endorsing this technique in routine application.
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Implantación Dental Endoósea , Dentina , Incisivo , Maxilar , Diente Impactado , Humanos , Esmalte Dental/lesiones , Implantación Dental Endoósea/métodos , Implantes Dentales de Diente Único , Incisivo/lesiones , Maxilar/cirugía , Oseointegración/fisiología , Diente Impactado/cirugíaRESUMEN
OBJECTIVES: This study aimed to evaluate the impact of prefabricated auxiliary devices (PAD) and scanning patterns on the accuracy of complete-arch implant digital impressions. METHODS: An edentulous maxillary model was inserted with four parallel implant analogs and four PAD. The model was scanned with D2000 dental laboratory scanner as the reference scans. Test scans were obtained by 8 different scanning patterns (SP), which including SPA, SPB, SPC, SPD, SPE, SPF, SPG and SPH, with (test group) or without (control group) using the PAD by an intraoral scanner (Aoralscan 3, 3DShining). SPA was the scanning pattern recommended by the manufacturer. Each scanning time was recorded. The related files were imported into inspection software for assessment. Aligned Ranks Transformation ANOVA, Kruskal-Wallis and Mann-Whitney tests were used to evaluate the values. The level of significance was set at α = 0.05. RESULTS: The scanning patterns significantly influenced the linear accuracy in the test group and the scanning time for both groups. Lower linear trueness in the test group was found in SPF (p<0.05) and SPG (p<0.05). Longer scanning time was found in SPB and SPG for both groups. The test group demonstrated linear accuracy enhancement in all the scanning patterns; angular trueness enhancement was seen in SPA (p<0.05), SPC (p<0.01) and SPH (p<0.01). Significant longer scanning time was found in SPB (p<0.05), SPF (p<0.05), SPG (p<0.05) and SPH (p<0.05) when using PAD. CONCLUSION: The scanning patterns impact the accuracy differently depending on the PAD's existence. The scanning time can be significantly influenced by the scanning patterns and the PAD. CLINICAL SIGNIFICANCE: In daily clinical practice, selecting a suitable scanning pattern is significant in achieving accurate digital impressions. The PAD demonstrated effective linear accuracy enhancement in all the scanning patterns tested.
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Implantes Dentales , Imagenología Tridimensional , Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Maxilar/diagnóstico por imagenRESUMEN
OBJECTIVES: To examine the effect of artificial landmarks of prefabricated auxiliary devices (PAD) located at different arch positions on the accuracy of complete-arch edentulous digital implant scanning. METHODS: A reference model containing four analogs and PAD were fabricated by a 3D printer (AccuFab-C1s, 3DShining). 10 digital scans were performed using an intraoral scanner (Aoralscan 3, 3DShining), sv 1.0.0.3115, with artificial landmarks located at different arch positions: group I, without any artificial landmarks; group II, with artificial landmarks at the anterior region; group III, with artificial landmarks at the posterior region. group IV: with artificial landmarks at both anterior and posterior regions. For group V: Conventional open-tray splinted impressions. The reference file and conventional stone casts were digitalized by using a dental laboratory scanner. The related files were imported into inspection software for trueness and precision assessment. Statistical analysis was performed with One-way ANOVA and Kruskal-Wallis test. The level of significance was set at α=0.05. RESULTS: For the global accuracy assessment, significantly higher global trueness was seen in group II (p < 0.01), III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. Significantly higher global precision was seen in group III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. For the local accuracy assessment, the PAD primarily improved accuracy on the linear deviations. CONCLUSIONS: Artificial landmarks of PAD at different arch positions significantly influenced the scanning accuracy. Applying the PAD in group IV could achieve comparable outcomes to conventional open-tray splinted impressions. Artificial landmarks on the posterior region may be more pivotal than those on the anterior region. CLINICAL SIGNIFICANCE: Group IV could achieve comparable accuracy to conventional open-tray splinted impressions.
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Implantes Dentales , Boca Edéntula , Humanos , Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Imagenología TridimensionalRESUMEN
PURPOSE: Based on a self-controlled case, this study evaluated the finite element analysis (FEA) results of a single missing molar with wide mesiodistal length (MDL) restored by a single or double implant-supported crown. METHODS: A case of a missing bilateral mandibular first molar with wide MDL was restored using a single or double implant-supported crown. The implant survival and peri-implant bone were compared. FEA was conducted in coordination with the case using eight models with different MDLs (12, 13, 14, and 15 mm). Von Mises stress was calculated in the FEA to evaluate the biomechanical responses of the implants under increasing vertical and lateral loading, including the stress values of the implant, abutment, screw, crown, and cortical bone. RESULTS: The restorations on the left and right sides supported by double implants have been used for 6 and 12 years, respectively, and so far have shown excellent osseointegration radiographically.The von Mises stress calculated in the FEA showed that when the MDL was >14 mm, both the bone and prosthetic components bore more stress in the single implant-supported strategy. The strength was 188.62-201.37 MPa and 201.85-215.9 MPa when the MDL was 14 mm and 15 mm, respectively, which significantly exceeded the allowable yield stress (180 MPa). CONCLUSIONS: Compared with the single implant-supported crown, the double implant-supported crown reduced peri-implant bone stress and produced a more appropriate stress transfer model at the implant-bone interface when the MDL of the single missing molar was ≥14 mm.
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Saliva is essential for oral health. The molecular mechanisms leading to physiological fluid secretion are largely established, but factors that underlie secretory hypofunction, specifically related to the autoimmune disease Sjögren's syndrome (SS) are not fully understood. A major conundrum is the lack of association between the severity of inflammatory immune cell infiltration within the salivary glands and glandular hypofunction. In this study, we investigated in a mouse model system, mechanisms of glandular hypofunction caused by the activation of the stimulator of interferon genes (STING) pathway. Glandular hypofunction and SS-like disease were induced by treatment with 5,6-Dimethyl-9-oxo-9H-xanthene-4-acetic acid (DMXAA), a small molecule agonist of murine STING. Contrary to our expectations, despite a significant reduction in fluid secretion in DMXAA-treated mice, in vivo imaging demonstrated that neural stimulation resulted in greatly enhanced spatially averaged cytosolic Ca2+ levels. Notably, however, the spatiotemporal characteristics of the Ca2+ signals were altered to signals that propagated throughout the entire cytoplasm as opposed to largely apically confined Ca2+ rises observed without treatment. Despite the augmented Ca2+ signals, muscarinic stimulation resulted in reduced activation of TMEM16a, although there were no changes in channel abundance or absolute sensitivity to Ca2+. However, super-resolution microscopy revealed a disruption in the intimate colocalization of Inositol 1,4,5-trisphosphate receptor Ca2+ release channels in relation to TMEM16a. TMEM16a channel activation was also reduced when intracellular Ca2+ buffering was increased. These data are consistent with altered local coupling between the channels contributing to the reduced activation of TMEM16a. Appropriate Ca2+ signaling is also pivotal for mitochondrial morphology and bioenergetics and secretion is an energetically expensive process. Disrupted mitochondrial morphology, a depolarized mitochondrial membrane potential, and reduced oxygen consumption rate were observed in DMXAA-treated animals compared to control animals. We report that early in SS disease, dysregulated Ca2+ signals lead to decreased fluid secretion and disrupted mitochondrial function contributing to salivary gland hypofunction and likely the progression of SS disease.
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Periprosthetic osteolysis (PPO) induced by wear particles is considered the primary cause of titanium prosthesis failure and revision surgery. The specific molecular mechanisms involve titanium particles inducing multiple intracellular pathways, which impact disease prevention and the targeted therapy of PPO. Notably, N6methyladenosine (m6A) serves critical roles in epigenetic regulation, particularly in bone metabolism and inflammatory responses. Thus, the present study aimed to determine the role of RNA methylation in titanium particleinduced osteolysis. Results of reverse transcriptionquantitative PCR (RTqPCR), western blotting, ELISA and RNA dot blot assays revealed that titanium particles induced osteogenic inhibition and proinflammatory responses, accompanied by the reduced expression of methyltransferaselike (Mettl) 3, a key component of m6A methyltransferase. Specific lentiviruses vectors were employed for Mettl3 knockdown and overexpression experiments. RTqPCR, western blotting and ELISA revealed that the knockdown of Mettl3 induced osteogenic inhibition and proinflammatory responses comparable with that induced by titanium particle, while Mettl3 overexpression attenuated titanium particleinduced cellular reactions. Methylated RNA immunoprecipitationqPCR results revealed that titanium particles mediated the methylation of two inhibitory molecules, namely Smad7 and SMAD specific E3 ubiquitin protein ligase 1, via Mettl3 in bone morphogenetic protein signaling, leading to osteogenic inhibition. Furthermore, titanium particles induced activation of the nucleotide binding oligomerization domain 1 signaling pathway through methylation regulation, and the subsequent activation of the MAPK and NFκB pathways. Collectively, the results of the present study indicated that titanium particles utilized Mettl3 as an upstream regulatory molecule to induce osteogenic inhibition and inflammatory responses. Thus, the present study may provide novel insights into potential therapeutic targets for aseptic loosening in titanium prostheses.
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Osteólisis , Humanos , Osteólisis/inducido químicamente , Osteólisis/genética , Titanio/toxicidad , Metilación de ARN , Epigénesis Genética , ARN/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismoRESUMEN
Despite the generally accepted role of the hydrophobic effect as the driving force for folding, many intrinsically disordered proteins (IDPs), including those with hydrophobic content typical of foldable proteins, behave nearly as self-avoiding random walks (SARWs) under physiological conditions. Here, we tested how temperature and ionic conditions influence the dimensions of the N-terminal domain of pertactin (PNt), an IDP with an amino acid composition typical of folded proteins. While PNt contracts somewhat with temperature, it nevertheless remains expanded over 10-58°C, with a Flory exponent, ν, >0.50. Both low and high ionic strength also produce contraction in PNt, but this contraction is mitigated by reducing charge segregation. With 46% glycine and low hydrophobicity, the reduced form of snow flea anti-freeze protein (red-sfAFP) is unaffected by temperature and ionic strength and persists as a near-SARW, ν ~ 0.54, arguing that the thermal contraction of PNt is due to stronger interactions between hydrophobic side chains. Additionally, red-sfAFP is a proxy for the polypeptide backbone, which has been thought to collapse in water. Increasing the glycine segregation in red-sfAFP had minimal effect on ν. Water remained a good solvent even with 21 consecutive glycine residues (ν > 0.5), and red-sfAFP variants lacked stable backbone hydrogen bonds according to hydrogen exchange. Similarly, changing glycine segregation has little impact on ν in other glycine-rich proteins. These findings underscore the generality that many disordered states can be expanded and unstructured, and that the hydrophobic effect alone is insufficient to drive significant chain collapse for typical protein sequences.
Asunto(s)
Proteínas Intrínsecamente Desordenadas , Pliegue de Proteína , Agua/química , Cloruro de Sodio , Glicina/química , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Prestin responds to transmembrane voltage fluctuations by changing its cross-sectional area, a process underlying the electromotility of outer hair cells and cochlear amplification. Prestin belongs to the SLC26 family of anion transporters yet is the only member capable of displaying electromotility. Prestin's voltage-dependent conformational changes are driven by the putative displacement of residue R399 and a set of sparse charged residues within the transmembrane domain, following the binding of a Cl - anion at a conserved binding site formed by amino termini of the TM3 and TM10 helices. However, a major conundrum arises as to how an anion that binds in proximity to a positive charge (R399), can promote the voltage sensitivity of prestin. Using hydrogen-deuterium exchange mass spectrometry, we find that prestin displays an unstable anion-binding site, where folding of the amino termini of TM3 and TM10 is coupled to Cl - binding. This event shortens the TM3-TM10 electrostatic gap, thereby connecting the two helices, resulting in reduced cross-sectional area. These folding events upon anion-binding are absent in SLC26A9, a non-electromotile transporter closely related to prestin. Dynamics of prestin embedded in a lipid bilayer closely match that in detergent micelle, except for a destabilized lipid-facing helix TM6 that is critical to prestin's mechanical expansion. We observe helix fraying at prestin's anion-binding site but cooperative unfolding of multiple lipid-facing helices, features that may promote prestin's fast electromechanical rearrangements. These results highlight a novel role of the folding equilibrium of the anion-binding site, and helps define prestin's unique voltage-sensing mechanism and electromotility.
RESUMEN
Prestin responds to transmembrane voltage fluctuations by changing its cross-sectional area, a process underlying the electromotility of outer hair cells and cochlear amplification. Prestin belongs to the SLC26 family of anion transporters yet is the only member capable of displaying electromotility. Prestin's voltage-dependent conformational changes are driven by the putative displacement of residue R399 and a set of sparse charged residues within the transmembrane domain, following the binding of a Cl- anion at a conserved binding site formed by the amino termini of the TM3 and TM10 helices. However, a major conundrum arises as to how an anion that binds in proximity to a positive charge (R399), can promote the voltage sensitivity of prestin. Using hydrogen-deuterium exchange mass spectrometry, we find that prestin displays an unstable anion-binding site, where folding of the amino termini of TM3 and TM10 is coupled to Cl- binding. This event shortens the TM3-TM10 electrostatic gap, thereby connecting the two helices, resulting in reduced cross-sectional area. These folding events upon anion binding are absent in SLC26A9, a non-electromotile transporter closely related to prestin. Dynamics of prestin embedded in a lipid bilayer closely match that in detergent micelle, except for a destabilized lipid-facing helix TM6 that is critical to prestin's mechanical expansion. We observe helix fraying at prestin's anion-binding site but cooperative unfolding of multiple lipid-facing helices, features that may promote prestin's fast electromechanical rearrangements. These results highlight a novel role of the folding equilibrium of the anion-binding site, and help define prestin's unique voltage-sensing mechanism and electromotility.
Asunto(s)
Cóclea , Células Ciliadas Auditivas Externas , Aniones , Sitios de Unión , Membrana Dobles de Lípidos , Proteínas de Transporte de MembranaRESUMEN
Excessive tissue damage or loss has been solved by guided tissue regeneration and guided bone regeneration theories. However, the unfavorable degradation property of the resorbable collagen scaffold brings a big challenge to support soft tissue stabilization and time-consuming osteogenesis. The combined effect for soft tissue and bone of the collagen scaffold with better degradation pattern has not been clearly proven. This study determined whether the double surfaces of crosslinked collagen scaffolds could optimize the combined soft tissue repair and osteogenesis. In this study, we applied the chemically crosslinking treatment to the commercially available collagen scaffolds. Surface characterization, mechanical property and cell proliferation in vitro were evaluated. Combined bilateral skin and bone defects were established with the smooth surface of scaffold facing the skin defect and the rough surface facing the bone defect on the calvaria of rat. Micro-CT and histological evaluation were applied to determine the scaffold degradation pattern, soft tissue repair and osteogenesis. The crosslinked collagen scaffolds showed comparably favorable surface porosity, structure intactness, superhydrophilicity and mechanical properties. Compared to the native scaffolds, the crosslinked scaffolds could optimize the combined soft tissue repair and osteogenesis by preferably prolonged degradation time. Early pro-angiogenesis facilitated soft tissue repair and osteogenesis by upregulated soft tissue matrix degradation and balanced pro-osteogenesis with limited osteoclast-mediated bone resorption. Taken together, this study offers a promising repair strategy for the combined soft tissue and bone defects. Further, the possible mechanism of controllable scaffold degradation should be conducted.
Asunto(s)
Osteogénesis , Andamios del Tejido , Ratas , Animales , Andamios del Tejido/química , Regeneración Ósea , Colágeno/química , Cráneo , Ingeniería de TejidosRESUMEN
Intestinal fibrosis associated stricture is a common complication of inflammatory bowel disease usually requiring endoscopic or surgical intervention. Effective anti-fibrotic agents aiming to control or reverse intestinal fibrosis are still unavailable. Thus, clarifying the mechanism underpinning intestinal fibrosis is imperative. Fibrosis is characterized by an excessive accumulation of extracellular matrix (ECM) proteins at the injured sites. Multiple cellular types are implicated in fibrosis development. Among these cells, mesenchymal cells are major compartments that are activated and then enhance the production of ECM. Additionally, immune cells contribute to the persistent activation of mesenchymal cells and perpetuation of inflammation. Molecules are messengers of crosstalk between these cellular compartments. Although inflammation is necessary for fibrosis development, purely controlling intestinal inflammation cannot halt the development of fibrosis, suggesting that chronic inflammation is not the unique contributor to fibrogenesis. Several inflammation-independent mechanisms including gut microbiota, creeping fat, ECM interaction, and metabolic reprogramming are involved in the pathogenesis of fibrosis. In the past decades, substantial progress has been made in elucidating the cellular and molecular mechanisms of intestinal fibrosis. Here, we summarized new discoveries and advances of cellular components and major molecular mediators that are associated with intestinal fibrosis, aiming to provide a basis for exploring effective anti-fibrotic therapies in this field.