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1.
Insects ; 15(4)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38667396

RESUMO

Parasite growth in hosts depends on their hosts' nutritional status. This study examined whether the body size of the strepsipteran parasite Xenos oxyodontes, which parasitizes the eusocial wasp Vespa analis, is affected by several key factors, including host body size. We collected V. analis using bait traps for three years in Niigata, Japan, and evaluated the number of male and female X. oxyodontes parasites throughout the seasons. A total of 185 female parasites were collected, and their cephalothorax widths were measured. The widths of female parasites did not statistically vary among seasons and were positively correlated with the head widths of female host wasps but negatively correlated with the number of parasites per host wasp. In addition, we examined whether the reproductive conditions of post-hibernation solitary queens affected the cephalothorax width of female parasites. The widths of the female parasites were greater when the queens had less-developed ovaries. These results suggested that nutrient availability by female parasites depends on the host wasp and competition with conspecific individuals.

2.
Anal Chem ; 96(2): 642-651, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38165078

RESUMO

Adeno-associated virus (AAV) vectors are produced as a mixture of the desired particle (full particle, FP), which is filled with the designed DNA, product-related impurities such as particle without DNA (empty particle, EP), and aggregates. Cesium chloride or iodixanol equilibrium density gradient ultracentrifugation (DGE-UC) has been used for the purification of AAV vectors. DGE-UC can separate FP from impurities based on the difference in their buoyant densities. Here, we report the applications and limitations of equilibrium density gradient analytical ultracentrifugation (DGE-AUC) using a modern AUC instrument that employs DGE-UC principles for the characterization and quantitation of AAV vectors. We evaluated the quantitative ability of DGE-AUC in comparison with sedimentation velocity AUC (SV-AUC) or band sedimentation AUC (BS-AUC) using AAVs with different DNA lengths and different serotypes. DGE-AUC enabled the accurate quantification of the ratio of FP to EP when the AAV vector primarily contains these particles. Furthermore, we developed a new workflow to identify the components of separated peaks in addition to FP and EP. Ultraviolet absorption spectra obtained by multiwavelength detection can also support peak assignment following component identification. DGE-AUC experiments for AAV vectors have limitations with regard to minor components with low absorption at the detected wavelength or those with a density similar to that of major components of AAV vectors. DGE-AUC is the only analytical method that can evaluate particle density heterogeneity; therefore, SV-AUC or BS-AUC and DGE-AUC are complementary methods for reliable assessment of the purity of AAV vectors.


Assuntos
Dependovirus , Vetores Genéticos , Dependovirus/genética , Ultracentrifugação/métodos , DNA
3.
Pediatr Transplant ; 28(1): e14653, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37990976

RESUMO

BACKGROUND: New-onset allergic diseases, such as food allergy or atopic dermatitis, can develop after allogeneic transplantation. There are limited reports of new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation in children and adolescents, and its treatment is yet to be established. The pathogenesis may differ from typical atopic dermatitis in terms of alloimmunity including graft-versus-host disease. METHODS: We present five children and adolescents with new-onset atopic dermatitis after allogeneic hematopoietic stem cell transplantation. The characteristics and clinical profiles of skin treatment after hematopoietic stem cell transplantation are summarized. RESULTS: Graft-versus-host disease prophylaxis included systemic tacrolimus for all patients. After hematopoietic stem cell transplantation, all patients achieved complete donor chimerism of the bone marrow and had acute graft-versus-host disease of the skin. After engraftment, all patients had skin lesions that met the international consensus diagnostic criteria for atopic dermatitis. None of the patients met the diagnostic criteria for chronic graft-versus-host disease. Topical therapy and skin care based on atopic dermatitis guidelines improved skin condition and atopic dermatitis severity scores in all patients. In addition, type 2 inflammatory markers improved accordingly. CONCLUSION: Topical therapy and skin care may be effective for transplant-related atopic dermatitis after hematopoietic stem cell transplantation. When extensive dermatitis is observed after hematopoietic stem cell transplantation, this treatment may avoid excessive immunosuppressive therapy if it meets the diagnostic criteria for atopic dermatitis.


Assuntos
Dermatite Atópica , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Criança , Humanos , Adolescente , Dermatite Atópica/terapia , Dermatite Atópica/complicações , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante Homólogo/efeitos adversos , Higiene da Pele/efeitos adversos , Condicionamento Pré-Transplante/efeitos adversos
4.
Sci Adv ; 9(45): eadi0487, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37948523

RESUMO

Combinatorial optimization is a broadly attractive area for potential quantum advantage, but no quantum algorithm has yet made the leap. Noise in quantum hardware remains a challenge, and more sophisticated quantum-classical algorithms are required to bolster their performance. Here, we introduce an iterative quantum heuristic optimization algorithm to solve combinatorial optimization problems. The quantum algorithm reduces to a classical greedy algorithm in the presence of strong noise. We implement the quantum algorithm on a programmable superconducting quantum system using up to 72 qubits for solving paradigmatic Sherrington-Kirkpatrick Ising spin glass problems. We find the quantum algorithm systematically outperforms its classical greedy counterpart, signaling a quantum enhancement. Moreover, we observe an absolute performance comparable with a state-of-the-art semidefinite programming method. Classical simulations of the algorithm illustrate that a key challenge to reaching quantum advantage remains improving the quantum device characteristics.

5.
Mol Ther Methods Clin Dev ; 31: 101142, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38027055

RESUMO

Studies of recombinant adeno-associated virus (rAAV) revealed the mixture of full particles with different densities in rAAV. There are no conclusive results because of the lack of quantitative stoichiometric viral proteins, encapsidated DNA, and particle level analyses. We report the first comprehensive characterization of low- and high-density rAAV serotype 2 particles. Capillary gel electrophoresis showed high-density particles possessing a designed DNA encapsidated in the capsid composed of (VP1 + VP2)/VP3 = 0.27, whereas low-density particles have the same DNA but with a different capsid composition of (VP1 + VP2)/VP3 = 0.31, supported by sedimentation velocity-analytical ultracentrifugation and charge detection-mass spectrometry. In vitro analysis demonstrated that the low-density particles had 8.9% higher transduction efficacy than that of the particles before fractionation. Further, based on our recent findings of VP3 clip, we created rAAV2 single amino acid variants of the transcription start methionine of VP3 (M203V) and VP3 clip (M211V). The rAAV2-M203V variant had homogeneous particles with higher (VP1+VP2)/VP3 values (0.35) and demonstrated 24.7% higher transduction efficacy compared with the wild type. This study successfully provided highly functional rAAV by the extensive fractionation from the mixture of rAAV2 full particles or by the single amino acid replacement.

6.
Gait Posture ; 103: 203-209, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37245334

RESUMO

BACKGROUND: Stroke patients have difficulty walking in outdoor environments, including uneven surfaces, reducing their opportunities for social participation. Changes in stroke patients' gait while walking on even surfaces have been reported; however, gait alterations on uneven surfaces remain unclear. RESEARCH QUESTION: To what extent do biomechanical parameters and muscle activity during even and uneven surface walking differ between stroke patients and healthy people? METHODS: Twenty stroke patients and 20 age-matched healthy people walked on a 6 m even and uneven surfaces. Data on gait speed, root mean square (RMS) of trunk acceleration as a measure of gait stability, maximum joint angle, average muscle activity, and muscle activity time were quantified using accelerometers attached to the trunk, video camera images, and electromyography of lower extremities. A two-factor mixed-model analysis of variance was used to test the effects of group, surface, and group × surface interactions. RESULTS: Gait speed decreased (p < 0.001) on the uneven surface in stroke patients and healthy people. RMS showed an interaction (p < 0.001), and the post-hoc test revealed an increase in stroke patients in the mediolateral direction during the swing phase on the uneven surface. The hip extension angle during the stance phase showed an interaction (p = 0.023), and the post-hoc test revealed a decrease in stroke patients on the uneven surface. The soleus muscle activity time showed an interaction during the swing phase (p = 0.041), and the post-hoc test revealed an increase in stroke patients compared to healthy people only on the uneven surface. SIGNIFICANCE: While walking on an uneven surface, stroke patients showed decreased gait stability, decreased hip extension angle during stance phase, and increased ankle plantar flexor activity time during swing phase. These changes may result from impaired motor control and compensatory strategies used by stroke patients on uneven surfaces.


Assuntos
Acidente Vascular Cerebral , Caminhada , Humanos , Fenômenos Biomecânicos/fisiologia , Caminhada/fisiologia , Marcha/fisiologia , Músculo Esquelético/fisiologia , Eletromiografia , Acidente Vascular Cerebral/complicações
7.
Anticancer Res ; 43(6): 2859-2864, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37247919

RESUMO

BACKGROUND/AIM: Maxillary sinus cancer is a relatively rare disease, and treatment is still evolving. We compared the efficacy of superselective intra-arterial infusion of high-dose cisplatin (CDDP) with concomitant radiotherapy (RADPLAT) using three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) and analyzed the relationship between the total radiation dose and the treatment outcome in localized maxillary sinus cancer. PATIENTS AND METHODS: We reviewed the cases of 58 patients with localized maxillary sinus cancer treated with RADPLAT at our institution from March 2004 to November 2020. These 58 patients included 34 who received 3DCRT and 24 who received IMRT. RESULTS: The median follow-up period was 38.4 months. The median prescribed dose to the local lesion was 66 Gy in the 3DCRT group and 70 Gy in the IMRT group. CDDP (100-120 mg/m2) was administered once a week for a median of 6 cycles. The 5-year local control rate and overall survival rate were 69.9% and 72.2%, respectively. The patients treated with 70 Gy had a significantly higher local control rate (87.7%) than those treated with 60 Gy or less (41.0%) (p=0.011). No late grade 3 or higher eye disorders except for cataracts developed in the IMRT group, while grade 4 eye disorders occurred in four patients receiving 3DCRT. CONCLUSION: IMRT can escalate radiation dose safely with acceptable toxicities. The total dose may have an impact on the local control rate in RADPLAT.


Assuntos
Neoplasias do Seio Maxilar , Radioterapia Conformacional , Radioterapia de Intensidade Modulada , Humanos , Cisplatino/efeitos adversos , Neoplasias do Seio Maxilar/tratamento farmacológico , Neoplasias do Seio Maxilar/radioterapia , Radioterapia Conformacional/efeitos adversos , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Resultado do Tratamento , Dosagem Radioterapêutica , Doses de Radiação , Planejamento da Radioterapia Assistida por Computador
8.
Bioorg Med Chem Lett ; 86: 129206, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-36889653

RESUMO

Cytochrome P450 2A6 (CYP2A6) inhibitors are expected to be suitable as smoking cessation aids and for cancer prevention. Because the typical coumarin-based CYP2A6 inhibitor methoxsalen also inhibits CYP3A4, unintended drug-drug interactions are still a concern. Therefore, the development of selective CYP2A6 inhibitors is desirable. In this study, we synthesized coumarin-based molecules, determined the IC50 values for CYP2A6 inhibition, verified the possibility of mechanism-based inhibition, and compared the selectivity for CYP2A6 versus CYP3A4. The results demonstrated that we developed CYP2A6 inhibitors that were more potent and selective than methoxsalen.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Inibidores das Enzimas do Citocromo P-450/farmacologia , Citocromo P-450 CYP3A , Metoxaleno/farmacologia , Cumarínicos/farmacologia , Citocromo P-450 CYP2A6 , Microssomos Hepáticos
9.
Front Immunol ; 14: 1090898, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36761774

RESUMO

Although interactions of small molecular drugs with serum proteins have been widely studied from pharmacokinetic and pharmacodynamic perspectives, there have been few reports on the effects of serum components on therapeutic antibody functions. This study reports the effect of abundant serum proteins on antibody-dependent cellular cytotoxicity (ADCC) mediated by rituximab and Fcγ receptor III (FcγRIII). Human serum albumin (HSA) and the Fab fragment from the pooled serum polyclonal IgG were found to compromise ADCC as non-competitive inhibitors. Our nuclear magnetic resonance data provided direct evidence for the interactions of HSA with both the Fab and Fc regions of rituximab and also with the extracellular region of FcγRIII (sFcγRIII). The degree of involvement in the interaction decreased in the order of rituximab-Fab > rituximab-Fc > sFcγRIII, suggesting preferential binding of HSA to net positively charged proteins. Although much less pronounced than the effect of HSA, polyclonal IgG-Fab specifically interacted with rituximab-Fc. The NMR data also showed that the serum protein interactions cover the Fc surface extensively, suggesting that they can act as pan-inhibitors against various Fc receptor-mediated functions and pharmacokinetics. Our findings highlight the importance of considering serum-protein interactions in the design and application of antibody-based drugs with increased efficacy and safety.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos , Imunoglobulina G , Humanos , Rituximab , Receptores Fc , Fagocitose
10.
Hum Mol Genet ; 32(12): 2032-2045, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36851842

RESUMO

The eye and brain are composed of elaborately organized tissues, development of which is supported by spatiotemporally precise expression of a number of transcription factors and developmental regulators. Here we report the molecular and genetic characterization of Integrator complex subunit 15 (INTS15). INTS15 was identified in search for the causative gene(s) for an autosomal-dominant eye disease with variable individual manifestation found in a large pedigree. While homozygous Ints15 knockout mice are embryonic lethal, mutant mice lacking a small C-terminal region of Ints15 show ocular malformations similar to the human patients. INTS15 is highly expressed in the eye and brain during embryogenesis and stably interacts with the Integrator complex to support small nuclear RNA 3' end processing. Its knockdown resulted in missplicing of a large number of genes, probably as a secondary consequence, and substantially affected genes associated with eye and brain development. Moreover, studies using human iPS cells-derived neural progenitor cells showed that INTS15 is critical for axonal outgrowth in retinal ganglion cells. This study suggests a new link between general transcription machinery and a highly specific hereditary disease.


Assuntos
Anormalidades do Olho , Olho , Peptídeos e Proteínas de Sinalização Intracelular , Olho/crescimento & desenvolvimento , Anormalidades do Olho/genética , Linhagem , Humanos , Masculino , Feminino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células-Tronco/metabolismo , Animais , Camundongos , Camundongos Knockout , Sobrevivência Celular , RNA Nuclear Pequeno/metabolismo , Processamento Pós-Transcricional do RNA , Encéfalo/crescimento & desenvolvimento
11.
J Med Invest ; 69(3.4): 287-293, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36244782

RESUMO

Objective : To examine diagnostic performance of corticotropin-releasing hormone (CRH) test combined with baseline dehydroepiandrosterone sulfate (DHEA-S) in patients with a suspect of central adrenal insufficiency. Methods : Patients (n=215) requiring daily or intermittent hydrocortisone replacement, or no replacement were retrospectively checked with their peak cortisol after CRH test and baseline DHEA-S. Results :  None of 106 patients with the peak cortisol ≥ 17.5 µg / dL after CRH test required replacement, and all 64 patients with the peak cortisol < 10.0 µg / dL required daily replacement. Among 8 patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL and baseline DHEA-S below the reference range, 6 patients required daily replacement and 1 patient was under intermittent replacement. Among 37 patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL and baseline DHEA-S within the reference range, 10 and 6 patients were under intermittent and daily replacement, respectively. Conclusions : No patients with the peak cortisol ≥ 17.5 µg / dL required hydrocortisone replacement, and all patients with the peak cortisol below 10.0 µg / dL required daily replacement. Careful clinical evaluation was required to determine requirement for replacement in patients with 10.0 µg / dL ≤ the peak cortisol < 17.5 µg / dL even in combination with baseline DHEA-S. J. Med. Invest. 69 : 287-293, August, 2022.


Assuntos
Insuficiência Adrenal , Hidrocortisona , Insuficiência Adrenal/diagnóstico , Insuficiência Adrenal/tratamento farmacológico , Hormônio Adrenocorticotrópico , Algoritmos , Hormônio Liberador da Corticotropina , Sulfato de Desidroepiandrosterona , Humanos , Estudos Retrospectivos
12.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 78(10): 1176-1186, 2022 Oct 20.
Artigo em Japonês | MEDLINE | ID: mdl-36058849

RESUMO

PURPOSE: The purpose of this study was to evaluate the differences in the organ doses and the effective doses using three types of automated organ dose estimation software for low-dose computed tomography (CT) screening for lung cancer and to evaluate the correlations between each dose and size-specific dose estimates (SSDEs). METHODS: Seventy-two adults who underwent low-dose CT screening for lung cancer were included, and the organ doses and the effective doses were calculated using each of automated organ dose estimation software. We evaluated differences between software for the organ doses and the effective doses and the correlations between each dose and SSDEs. RESULTS: Differences in organ doses and effective doses were observed among the software. The organ doses showed a strong correlation (r=0.833-0.995) with SSDEs for organs within the scan range. The effective doses showed a strong correlation (r=0.830-0.970) with SSDEs, although there were significant differences among the software. CONCLUSION: Although the organ doses and the effective doses differed between software, it may be possible to estimate them from SSDEs by using linear regression equations.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Adulto , Humanos , Doses de Radiação , Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Software , Automação , Imagens de Fantasmas , Método de Monte Carlo
13.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 78(10): 1149-1157, 2022 Oct 20.
Artigo em Japonês | MEDLINE | ID: mdl-36031372

RESUMO

PURPOSE: There are problems with dose management in X-ray computed tomography (CT) because the protocol used for any examination is not always in the same scan range. The purpose of this study was to investigate the usefulness of setting the CT protocol based on the scan range. METHODS: We evaluated the examination data of patients who underwent plain CT based on a scan range of chest to pelvis and abdomen to pelvis. The previous protocol [Chest-Abdomen Routine] was changed to the current protocols [Chest_Abdomen] and [Chest_Pelvis], and the previous protocol of [Abdomen Routine] was changed to the current protocols [Abdomen] and [Abdomen_Pelvis]. Examination data of height, scan length, volume CT dose index (CTDIvol), and dose length product (DLP) were obtained from digital imaging and communications in medicine, and radiation dose structured report using Radimetrics. The relationship between patient height and scan range, and CTDIvol and DLP was indicated in a scatter plot. Standard deviation (SD) of scan length and DLP were compared between current and previous protocols. Outliers were defined as the data exceeding average ±2SD. RESULTS: The SD of scan length decreased by 77.1% on abdomen to pelvis, and the SD of DLP decreased by 65.2% on abdomen to pelvis. The causes of the outliers were CT scan range, scan parameter, arm position, metal implants, and body thickness of patients. CONCLUSION: Setting CT protocols based on the scan range reduced SD of scan length and DLP. It was helpful for reducing the number of scan range outliers and analyzing the cause of outliers.


Assuntos
Pelve , Tomografia Computadorizada por Raios X , Humanos , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Pelve/diagnóstico por imagem , Tórax , Abdome/diagnóstico por imagem
14.
Chem Soc Rev ; 51(15): 6234-6250, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35796627

RESUMO

Progress in strategies aimed at breaking down therapeutic target proteins has led to a paradigm shift in drug discovery. Thalidomide and its derivatives are the only protein degraders currently used in clinical practice. Our understanding of the molecular mechanism of action of thalidomide and its derivatives has advanced dramatically since the identification of cereblon (CRBN) as their direct target. The binding of thalidomide derivatives to CRBN, a substrate recognition receptor for Cullin 4 RING E3 ubiquitin ligase (CRL4), induces the recruitment of non-native substrates to CRL4CRBN and their subsequent degradation. This discovery was a breakthrough in the current rapid development of protein-degrading agents because clarification of the mechanism of action of thalidomide derivatives has demonstrated the clinical value of these compounds. This review provides an overview of the mechanism of action of thalidomide and its derivatives and describes perspectives for protein degraders.


Assuntos
Peptídeo Hidrolases , Talidomida , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Peptídeo Hidrolases/metabolismo , Talidomida/química , Talidomida/farmacologia , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo
15.
Nat Commun ; 13(1): 2905, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614107

RESUMO

Non-polyadenylated mRNAs of replication-dependent histones (RDHs) are synthesized by RNA polymerase II (Pol II) at histone locus bodies (HLBs). HLBs frequently associate with Cajal bodies (CBs), in which 3'-end processing factors for RDH genes are enriched; however, this association's role in transcription termination of RDH genes remains unclear. Here, we show that Pol II pauses immediately upstream of transcript end sites of RDH genes and Mediator plays a role in this Pol II pausing through CBs' association with HLBs. Disruption of the Mediator docking site for Little elongation complex (LEC)-Cap binding complex (CBC)-Negative elongation factor (NELF), components of CBs, interferes with CBs' association with HLBs and 3' Pol II pausing, resulting in increased aberrant unprocessed RDH gene transcripts. Our findings suggest Mediator's involvement in CBs' association with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing of RDH genes by supplying 3'-end processing factors.


Assuntos
Corpos Enovelados , Histonas , Corpos Enovelados/metabolismo , Histonas/metabolismo , Corpos Nucleares , RNA Polimerase II/metabolismo , Transcrição Gênica
16.
Membranes (Basel) ; 12(3)2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35323766

RESUMO

Hydrogen gas is a promising, clean, and highly efficient energy source. However, to use combustible H2 gas safety, high-performance and safe gas leakage sensors are required. In this study, transparent and flexible platinum-catalyst-loaded tungsten trioxide (Pt/WO3) nanoparticle-dispersed membranes were prepared as H2 gas leakage sensors. The nanoparticle-dispersed membrane with a Pt:W compositional ratio of 1:13 was transparent and exhibited a sufficient color change in response to H2 gas. The membrane containing 0.75 wt.% of Pt/WO3 nanoparticles exhibited high transparency over a wide wavelength range and the largest transmittance change in response to H2 gas among the others. The heat treatment of the particles at 573 K provided sufficient crystallinity and an accessible area for a gasochromic reaction, resulting in a rapid and sensitive response to the presence of H2 gas. The lower limit of detection of the optimized Pt/WO3 nanoparticle-dispersed membrane by naked eye was 0.4%, which was one-tenth of the minimum explosive concentration. This novel membrane was transparent as well as flexible and exhibited a clear and rapid color response to H2. Therefore, it is an ideal candidate sensor for the safe and easy detection of H2 gas leakage.

17.
MAbs ; 14(1): 2038531, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35291930

RESUMO

The interaction between IgG and Fc gamma receptor IIIa (FcγRIIIa) is essential for mediating immune responses. Recent studies have shown that the antigen binding fragment (Fab) and Fc are involved in IgG-FcγRIII interactions. Here, we conducted bio-layer interferometry (BLI) and isothermal titration calorimetry to measure the kinetic and thermodynamic parameters that define the role of Fab in forming the IgG-FcγRIII complex using several marketed therapeutic antibodies. Moreover, hydrogen/deuterium exchange mass spectrometry (HDX-MS) and crosslinking mass spectrometry (XL-MS) were used to clarify the interaction sites and structural changes upon formation of these IgG-FcγRIII complexes. The results showed that Fab in IgG facilitates the interaction via slower dissociation and a larger enthalpy gain. However, a larger entropy loss led to only a marginal change in the equilibrium dissociation constant. Combined HDX-MS and XL-MS analysis revealed that the CL domain of Fab in IgG was in close proximity to FcγRIIIa, indicating that this domain specifically interacts with the extracellular membrane-distal domain (D1) and membrane-proximal domain (D2) of FcγRIIIa. Together with previous studies, these results demonstrate that IgG-FcγRIII interactions are predominantly mediated by the binding of Fc to D2, and the Fab-FcγRIII interaction stabilizes complex formation. These interaction schemes were essentially fucosylation-independent, with Fc-D2 interactions enhanced by afucosylation and the contribution of Fab slightly reduced. Furthermore, the influence of antigen binding on IgG-FcγRIII interactions was also investigated. Combined BLI and HDX-MS results indicate that structural alterations in Fab caused by antigen binding facilitate stabilization of IgG-FcγRIII interactions. This report provides a comprehensive understanding of the interaction between IgG and FcγRIII.


Assuntos
Imunoglobulina G , Receptores de IgG , Glicosilação , Espectrometria de Massa com Troca Hidrogênio-Deutério , Fragmentos Fab das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/química , Imunoglobulina G/química , Receptores de IgG/metabolismo
18.
Nucleic Acids Res ; 50(1): 1-16, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34268577

RESUMO

In eukaryotes, three RNA polymerases (RNAPs) play essential roles in the synthesis of various types of RNA: namely, RNAPI for rRNA; RNAPII for mRNA and most snRNAs; and RNAPIII for tRNA and other small RNAs. All three RNAPs possess a short flexible tail derived from their common subunit RPB6. However, the function of this shared N-terminal tail (NTT) is not clear. Here we show that NTT interacts with the PH domain (PH-D) of the p62 subunit of the general transcription/repair factor TFIIH, and present the structures of RPB6 unbound and bound to PH-D by nuclear magnetic resonance (NMR). Using available cryo-EM structures, we modelled the activated elongation complex of RNAPII bound to TFIIH. We also provide evidence that the recruitment of TFIIH to transcription sites through the p62-RPB6 interaction is a common mechanism for transcription-coupled nucleotide excision repair (TC-NER) of RNAPI- and RNAPII-transcribed genes. Moreover, point mutations in the RPB6 NTT cause a significant reduction in transcription of RNAPI-, RNAPII- and RNAPIII-transcribed genes. These and other results show that the p62-RPB6 interaction plays multiple roles in transcription, TC-NER, and cell proliferation, suggesting that TFIIH is engaged in all RNAP systems.


Assuntos
RNA Polimerase II/química , Fator de Transcrição TFIIH/química , Sítios de Ligação , Células HeLa , Humanos , Simulação de Acoplamento Molecular , Domínios de Homologia à Plecstrina , Ligação Proteica , RNA Polimerase II/metabolismo , Fator de Transcrição TFIIH/metabolismo
19.
Commun Biol ; 4(1): 1277, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34764413

RESUMO

Pomalidomide and lenalidomide are immunomodulatory agents that were derived from thalidomide. Cereblon (CRBN) is a common direct target of thalidomide and related compounds and works as a Cullin Ring 4 E3 ubiquitin ligase (CRL4) with DDB1, CUL4, and ROC1. The substrate specificity of CRL4CRBN is modulated by thalidomide-related compounds. While lenalidomide is approved for the treatment of several diseases including multiple myeloma, 5q- syndrome, mantle cell lymphoma, and follicular lymphoma, pomalidomide is approved only for the treatment of lenalidomide-resistant multiple myeloma. Here we show that PLZF/ZBTB16 and its fusion proteins are pomalidomide-dependent neosubstrates of CRL4CRBN. PLZF joins to RARα or potentially other partner genes, and the translocation causes leukemias, such as acute promyelocytic leukemia and T-cell acute lymphoblastic leukemia. We demonstrate that pomalidomide treatment induces PLZF-RARα degradation, resulting in antiproliferation of leukemic cells expressing PLZF-RARα. This study highlights a potential therapeutic role of pomalidomide as a degrader of leukemogenic fusion proteins.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteína com Dedos de Zinco da Leucemia Promielocítica/genética , Talidomida/análogos & derivados , Ubiquitina-Proteína Ligases/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Células HEK293 , Humanos , Proteína com Dedos de Zinco da Leucemia Promielocítica/metabolismo , Alinhamento de Sequência , Talidomida/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
20.
Materials (Basel) ; 14(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34443259

RESUMO

A NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) electrolyte sheet for all-solid-state batteries was fabricated by a cold sintering process (CSP). The microstructure of the LATP sheet was controlled to improve the wettability which is an essential factor in CSP. The porous sheets of LATP were prepared by calcination the green sheets to remove the organic components and form the porous structure. By the CSP using the porous sheets, the densification of grain boundary was observed and further densified with increasing reaction time. The total conductivity of the prepared LATP sheet was improved from 3.0 × 10-6 S/cm to 3.0 × 10-4 S/cm due to the formation of necks between the particles at the grain boundary.

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