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1.
Am J Hum Genet ; 111(5): 896-912, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38653249

RESUMO

Porokeratosis is a clonal keratinization disorder characterized by solitary, linearly arranged, or generally distributed multiple skin lesions. Previous studies showed that genetic alterations in MVK, PMVK, MVD, or FDPS-genes in the mevalonate pathway-cause hereditary porokeratosis, with skin lesions harboring germline and lesion-specific somatic variants on opposite alleles. Here, we identified non-hereditary porokeratosis associated with epigenetic silencing of FDFT1, another gene in the mevalonate pathway. Skin lesions of the generalized form had germline and lesion-specific somatic variants on opposite alleles in FDFT1, representing FDFT1-associated hereditary porokeratosis identified in this study. Conversely, lesions of the solitary or linearly arranged localized form had somatic bi-allelic promoter hypermethylation or mono-allelic promoter hypermethylation with somatic genetic alterations on opposite alleles in FDFT1, indicating non-hereditary porokeratosis. FDFT1 localization was uniformly diminished within the lesions, and lesion-derived keratinocytes showed cholesterol dependence for cell growth and altered expression of genes related to cell-cycle and epidermal development, confirming that lesions form by clonal expansion of FDFT1-deficient keratinocytes. In some individuals with the localized form, gene-specific promoter hypermethylation of FDFT1 was detected in morphologically normal epidermis adjacent to methylation-related lesions but not distal to these lesions, suggesting that asymptomatic somatic epigenetic mosaicism of FDFT1 predisposes certain skin areas to the disease. Finally, consistent with its genetic etiology, topical statin treatment ameliorated lesions in FDFT1-deficient porokeratosis. In conclusion, we identified bi-allelic genetic and/or epigenetic alterations of FDFT1 as a cause of porokeratosis and shed light on the pathogenesis of skin mosaicism involving clonal expansion of epigenetically altered cells.


Assuntos
Metilação de DNA , Epigênese Genética , Queratinócitos , Mosaicismo , Poroceratose , Regiões Promotoras Genéticas , Poroceratose/genética , Poroceratose/patologia , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Regiões Promotoras Genéticas/genética , Masculino , Alelos , Feminino
2.
Genes Cells ; 28(4): 288-306, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36788710

RESUMO

Ionizing radiation damages DNA and may lead to the development of cancer. Irradiation also generates reactive oxygen species (ROS) which cause damage to various biological molecules. Relatively low dose-rate irradiation causes less damage. However, the damage and its effects on cell fate are difficult to evaluate. To develop a method to analyze the damage and accompanying changes in physiology in cells irradiated by γ-rays at a relatively low dose-rate, we used the protein array technique to quantify marker proteins involved in the stress response and the regulation of cell growth and death. This method enabled efficient analyses of many replicates of experimental data on cell lysate samples. We detected relatively small changes in the levels of these proteins in the irradiated cells. Changes in protein levels suggested ROS production and DNA damage as well as cell cycle retardation and the progression of cellular senescence. Thus, our approach shows promise for analyzing the biological effects of relatively low dose-rate irradiation.


Assuntos
Senescência Celular , Dano ao DNA , Espécies Reativas de Oxigênio/metabolismo , Raios gama , Senescência Celular/genética , Diferenciação Celular
3.
Clin Exp Dermatol ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38722089

RESUMO

BACKGROUND: Cutaneous polyarteritis nodosa (cPN) is a necrotizing arteritis of medium-sized vessels limited to the skin. Because of its rarity and the diversity of its clinical manifestations, there is no consensus treatment. Moreover, there are no established indicators that predict disease severity or its outcome. OBJECTIVES: To investigate clinico-laboratory features that predict patients requiring systemic therapy, including corticosteroids, to control the disease activity. METHODS: Thirty-six cPN patients who had not received systemic corticosteroids at the initial visit were retrospectively analysed by correlating the treatment and its response with clinico-laboratory findings. RESULTS: The major medications administered were antiplatelet agents (63.9%), vasodilators (38.9%), and prednisolone (PSL) (36.1%). In all, 23 cases achieved remission without PSL; 5 were managed with compression therapy alone or even observation; 18 received antiplatelet monotherapy or combined with vasodilator/dapsone; 13 required PSL; 10 achieved remission with PSL monotherapy or PSL and single/multiple medications and 3 with PSL and multiple drugs failed to achieve remission and underwent limb amputation. There were more skin ulcers and an elevated peripheral white blood cell (WBC) count and erythrocyte sedimentation rate (ESR) before corticosteroid induction in patients requiring PSL. Three cases with treatment failure had a markedly elevated ESR (>50). CONCLUSIONS: More than half of cPN can achieve remission without corticosteroids; an elevated WBC and the presence of skin ulcers predict the need for PSL; a high ESR before corticosteroid induction predicts treatment resistance, even with PSL.

4.
J Am Chem Soc ; 145(31): 16973-16977, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37427843

RESUMO

Toward renewable energy for global leveling, compounds that can store ammonia (NH3), a carbon-free energy carrier of hydrogen, will be of great value. Here, we report an organic-inorganic halide perovskite compound that can chemically store NH3 through dynamic structural transformation. Upon NH3 uptake, a chemical structure change occurs from a one-dimensional columnar structure to a two-dimensional layered structure by addition reaction. NH3 uptake is estimated to be 10.2 mmol g-1 at 1 bar and 25 °C. In addition, NH3 extraction can be performed by a condensation reaction at 50 °C under vacuum. X-ray diffraction analysis reveals that reversible NH3 uptake/extraction originates from a cation/anion exchange reaction. This structural transformation shows the potential to integrate efficient uptake and extraction in a hybrid perovskite compound through chemical reaction. These findings will pave the way for further exploration of dynamic, reversible, and functionally useful compounds for chemical storage of NH3.

5.
Anal Chem ; 95(19): 7503-7511, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37130068

RESUMO

Accurate discrimination and classification of unknown species are the basis to predict its characteristics or applications to make correct decisions. However, for biogenic solutions that are ubiquitous in nature and our daily lives, direct determination of their similarities and disparities by their molecular compositions remains a scientific challenge. Here, we explore a standard and visualizable ontology, termed "biogenic solution map", that organizes multifarious classes of biogenic solutions into a map of hierarchical structures. To build the map, a novel 4-dimensional (4D) fingerprinting method based on data-independent acquisition data sets of untargeted metabolomics is developed, enabling accurate characterization of complex biogenic solutions. A generic parameter of metabolic correlation distance, calculated based on averaged similarities between 4D fingerprints of sample groups, is able to define "species", "genus", and "family" of each solution in the map. With the help of the "biogenic solution map", species of unknown biogenic solutions can be explicitly defined. Simultaneously, intrinsic correlations and subtle variations among biogenic solutions in the map are accurately illustrated. Moreover, it is worth mentioning that samples of the same analyte but prepared by alternative protocols may have significantly different metabolic compositions and could be classified into different "genera".


Assuntos
Metabolômica , Metabolômica/métodos
6.
Biochem Biophys Res Commun ; 668: 1-7, 2023 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-37230045

RESUMO

The ability to monitor levels of endogenous markers and clearance profiles of drugs and their metabolites can improve the quality of biomedical research and precision with which therapies are individualized. Towards this end, electrochemical aptamer-based (EAB) sensors have been developed that support the real-time monitoring of specific analytes in vivo with clinically relevant specificity and sensitivity. A challenge associated with the in vivo deployment of EAB sensors, however, is how to manage the signal drift which, although correctable, ultimately leads to unacceptably low signal-to-noise ratios, limiting the measurement duration. Motivated by the correction of signal drift, in this paper, we have explored the use of oligoethylene glycol (OEG), a widely employed antifouling coating, to reduce the signal drift in EAB sensors. Counter to expectations, however, when challenged in 37 °C whole blood in vitro, EAB sensors employing OEG-modified self-assembled monolayers exhibit both greater drift and reduced signal gain, compared with those employ a simple, hydroxyl-terminated monolayer. On the other hand, when EAB sensor was prepared with a mix monolayer using MCH and lipoamido OEG 2 alcohol, reduced signal noise was observed compared to the same sensor prepared with MCH presumably due to improved SAM construction. These results suggest broader exploration of antifouling materials will be required to improve the signal drift of EAB sensors.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Técnicas Biossensoriais/métodos , Oligonucleotídeos , Glicóis , Técnicas Eletroquímicas
7.
Small ; 19(34): e2207943, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37093208

RESUMO

Microbial secretory protein expression is widely used for biopharmaceutical protein production. However, establishing genetically modified industrial strains that secrete large amounts of a protein of interest is time-consuming. In this study, a simple and versatile high-throughput screening method for protein-secreting bacterial strains is developed. Different genotype variants induced by mutagens are encapsulated in microemulsions and cultured to secrete proteins inside the emulsions. The secreted protein of interest is detected as a fluorescence signal by the fluorescent immunosensor quenchbody (Q-body), and a cell sorter is used to select emulsions containing improved protein-secreting strains based on the fluorescence intensity. The concept of the screening method is demonstrated by culturing Corynebacterium glutamicum in emulsions and detecting the secreted proteins. Finally, productive strains of fibroblast growth factor 9 (FGF9) are screened, and the FGF9 secretion increased threefold compared to that of parent strain. This screening method can be applied to a wide range of proteins by fusing a small detection tag. This is a highly simple process that requires only the addition of a Q-body to the medium and does not require the addition of any substrates or chemical treatments. Furthermore, this method shortens the development period of industrial strains for biopharmaceutical protein production.


Assuntos
Técnicas Biossensoriais , Microfluídica , Microfluídica/métodos , Emulsões , Imunoensaio , Proteínas Recombinantes/metabolismo
8.
Exp Cell Res ; 418(1): 113233, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35659971

RESUMO

Mitochondrial cloning is a promising approach to achieve homoplasmic mitochondrial DNA (mtDNA) mutations. We previously developed a microfluidic device that performs single mitochondrion transfer from a mtDNA-intact cell to a mtDNA-less (ρ0) cell by promoting cytoplasmic connection through a microtunnel between them. In the present study, we described a method for generating transmitochondrial cybrids using the microfluidic device. After achieving mitochondrial transfer between HeLa cells and thymidine kinase-deficient ρ0143B cells using the microfluidic device, selective culture was carried out using a pyruvate and uridine (PU)-absent and 5-bromo-2'-deoxyuridine-supplemented culture medium. The resulting cells contained HeLa mtDNA and 143B nuclei, but both 143B mtDNA and HeLa nuclei were absent in these cells. Additionally, these cells showed lower lactate production than parent ρ0143B cells and disappearance of PU auxotrophy for cell growth. These results suggest successful generation of transmitochondrial cybrids using the microfluidic device. Furthermore, we succeeded in selective harvest of generated transmitochondrial cybrids under a PU-supplemented condition by removing unfused ρ0 cells with puromycin-based selection in the microfluidic device.


Assuntos
DNA Mitocondrial , Dispositivos Lab-On-A-Chip , Citoplasma/metabolismo , DNA Mitocondrial/genética , Células HeLa , Humanos , Células Híbridas , Mitocôndrias/genética
9.
Cell Mol Life Sci ; 79(10): 516, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36102977

RESUMO

Diabetic nephropathy (DN) is a significant complication of diabetes and the leading cause of end-stage renal disease. Hyperglycemia-induced dysfunction of the glomerular podocytes is a major contributor to the deterioration of renal function in DN. Previously, we demonstrated that podocyte-specific disruption of the Src homology phosphatase 2 (Shp2) ameliorated lipopolysaccharide-induced renal injury. This study aims to evaluate the contribution of Shp2 to podocyte function under hyperglycemia and explore the molecular underpinnings. We report elevated Shp2 in the E11 podocyte cell line under high glucose and the kidney under streptozotocin- and high-fat diet-induced hyperglycemia. Consistently, Shp2 disruption in podocytes was associated with partial renoprotective effects under hyperglycemia, as evidenced by the preserved renal function. At the molecular level, Shp2 deficiency was associated with altered renal insulin signaling and diminished hyperglycemia-induced renal endoplasmic reticulum stress, inflammation, and fibrosis. Additionally, Shp2 knockdown in E11 podocytes mimicked the in vivo deficiency of this phosphatase and ameliorated the deleterious impact of high glucose, whereas Shp2 reconstitution reversed these effects. Moreover, Shp2 deficiency attenuated high glucose-induced E11 podocyte migration. Further, we identified the protein tyrosine kinase FYN as a putative mediator of Shp2 signaling in podocytes under high glucose. Collectively, these findings suggest that Shp2 inactivation may afford protection to podocytes under hyperglycemia and highlight this phosphatase as a potential target to ameliorate glomerular dysfunction in DN.


Assuntos
Nefropatias Diabéticas , Hiperglicemia , Podócitos , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Animais , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/metabolismo , Glucose/metabolismo , Hiperglicemia/complicações , Hiperglicemia/genética , Hiperglicemia/metabolismo , Camundongos , Monoéster Fosfórico Hidrolases/metabolismo , Podócitos/metabolismo
10.
Mod Pathol ; 35(5): 640-648, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34785767

RESUMO

In rare cases, giant cell tumor of bone (GCTB) can undergo primary or secondary malignant transformation to malignant giant cell tumor of bone (MGCTB), but the details of the molecular alterations are still unclear. The present study aimed to elucidate the clinicopathologic and molecular features of MGCTBs based on immunohistochemistry, fluorescence in situ hybridization (FISH) and next generation sequencing (NGS) of nine MGCTBs (five primary and four secondary). Seven (78%) of 9 MGCTBs were immunohistochemically positive for H3.3 G34W. In two (22%) patients, although GCTB components were focally or diffusely positive for H3.3 G34W, their malignant components were entirely negative for H3.3 G34W, which was associated with heterozygous loss of H3F3A by FISH. NGS on four MGCTBs revealed pathogenic mutations in TP53 (n = 3), EZH2 (n = 1) and several other genes. Immunohistochemical analysis of the nine MGCTBs confirmed the p53 nuclear accumulation (n = 5) and loss of H3K27me3 expression (n = 3) and showed that they were mutually exclusive. In addition, four (80%) of five cases of pleomorphic or epithelioid cell-predominant MGCTBs were positive for p53, while three (75%) of four cases of spindle cell-predominant MGCTBs were negative for trimethylation at lysine 27 of histone 3 (H3K27me3). The results suggested that p53 alteration and dysfunction of histone methylation as evidenced by H3K27me3 loss may play an important role in the malignant progression of GCTB, and might contribute to the phenotype-genotype correlation in MGCTB. The combined histologic, immunohistochemical and molecular information may be helpful in part for the diagnosis of challenging cases.


Assuntos
Neoplasias Ósseas , Tumor de Células Gigantes do Osso , Histonas , Sarcoma , Proteína Supressora de Tumor p53 , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/genética , Tumor de Células Gigantes do Osso/diagnóstico , Tumor de Células Gigantes do Osso/genética , Histonas/genética , Histonas/metabolismo , Humanos , Hibridização in Situ Fluorescente , Metilação , Mutação , Sarcoma/diagnóstico , Sarcoma/genética , Proteína Supressora de Tumor p53/genética
11.
Histopathology ; 80(3): 538-557, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34699612

RESUMO

AIMS: Dedifferentiated liposarcoma (DDLS) has varying histopathological features, but their significance for the biological behaviour of this disease has not been fully clarified. The aim of this study was to elucidate the prognostic factors for DDLS by clinicopathologically reviewing a large case series. METHODS AND RESULTS: We clinicopathologically reviewed 123 cases of primary de-novo DDLS without preoperative treatment, including 81 in the internal trunk (internal DDLS) and 42 in peripheral sites (peripheral DDLS). Univariate and multivariate analyses of their features were also performed for all cases, the internal DDLS group, and the peripheral DDLS group. The results showed that, in all three groups, distant metastasis was significantly associated with shorter overall survival (OS) (univariate analysis, P < 0.0001, P = 0.0011, and P = 0.0101, respectively), whereas local recurrence showed no significant effect on prognosis. Histopathologically, a high mitotic count and the presence of round tumour cells were significantly associated with shorter OS in multivariate analysis of the internal DDLS group [respectively: P = 0.0022, hazard ratio (HR) 4.39, 95% confidence interval (CI) 1.71-11.28; and P = 0.0014, HR 7.19, 95% CI 2.14-24.16]. In the peripheral DDLS group, necrosis and high-grade histological components were significantly associated with shorter OS (univariate analysis, P = 0.0068 and P = 0.0174, respectively). CONCLUSIONS: The presence of round tumour cells may be one of the histological factors associated with a worse prognosis of DDLS patients, as previous studies indicated. This study also suggests that distant metastasis may be predictive of prognosis for both internal and peripheral DDLS, rather than local recurrence.


Assuntos
Histologia , Lipossarcoma/patologia , Metástase Neoplásica , Patologia , Prognóstico , Taxa de Sobrevida , Idoso , Feminino , Humanos , Lipossarcoma/classificação , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo
12.
Biomacromolecules ; 23(7): 2785-2792, 2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35700101

RESUMO

One strategy to prepare phase-separated co-assembly is to use the existing assembly as a platform to architect structures. For this purpose, the edge of a sheet or tube-shaped molecular assembly, which is less hydrophilic than the bulk region can become a starting point to build assembly units to realize more complex structures. In this study, we succeeded in preparing rod-shaped nanocapsules with previously unachieved sealing efficiency (>99%) by fine-tuning the properties of cationic amphiphilic polypeptides to seal the ends of neutral charge nanotubes. In addition, we demonstrated the nanocapsule's reversible responsiveness to salt. In high salt concentrations, a decrease in electrostatic repulsion between cationic polypeptides caused tearing and shrinking of the nanocapsule's sealing dome, which resulted in an opened nanotube. On the other hand, when salt was removed, the electrostatic repulsion among the cationic peptides localizing on the edge of opened nanocapsules was recovered, and the sealing membrane swelled up like an accordion to create a distance between the peptides, resulting in the restoration of the seal.


Assuntos
Nanocápsulas , Nanotubos de Peptídeos , Nanotubos , Cátions , Interações Hidrofóbicas e Hidrofílicas , Nanotubos/química , Peptídeos/química , Cloreto de Sódio
13.
J Phys Ther Sci ; 34(3): 225-229, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35291468

RESUMO

[Purpose] In April 2014, an additional health insurance system aiming to maintain or improve activities of daily living levels was newly established by the Japanese government. The purpose of this study was to determine the influence of this new medical system for rehabilitation on patient management (e.g., activities of daily living level and length of hospital stay) in an acute-phase stroke patient ward. [Participants and Methods] All patients were admitted to the stroke patient ward in our hospital and were registered between January 2012 and December 2019. We assessed the differences in the time to initiation of rehabilitation, length of hospitalization, implementation rate of rehabilitation, and Barthel Index between the period before the start of the new medical system (Prior period) and after this system was started (Post period). [Results] Significant improvements were observed in the initiation of rehabilitation and the difference in the Barthel Index scores after the start of the new medical system. Although the length of hospitalization and implementation rate of rehabilitation did not differ significantly, both indicators gradually improved after the start of the new system. [Conclusion] Our results suggest that the new medical system for rehabilitation is beneficial for patient management in the acute-phase stroke patient ward.

14.
J Pharmacol Sci ; 147(4): 340-347, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34663516

RESUMO

We investigated whether peripheral combination treatment of a sodium-glucose cotransporter 2 (SGLT2) inhibitor and leptin improves glucose metabolism in insulin-dependent diabetes mellitus (IDDM) model mice. Twelve-week-old male C57BL6 mice were intraperitoneally administered a high dose of streptozotocin to produce IDDM. IDDM mice were then divided into five groups: SGLT2 inhibitor treatment alone, leptin treatment alone, leptin and SGLT2 inhibitor co-treatment, untreated IDDM mice, and healthy mice groups. The blood glucose (BG) level at the end of the dark cycle was measured, and a glucose tolerance test (GTT) was performed and compared between the five groups. Leptin was peripherally administered at 20 µg/day using an osmotic pump, and an SGLT2 inhibitor, ipragliflozin, was orally administered at 3 mg/kg/day. Monotherapy with SGLT2 inhibitor or leptin significantly improved glucose metabolism in mice as evaluated by BG and GTT compared with the untreated group, whereas the co-treatment group with SGLT2 inhibitor and leptin further improved glucose metabolism as compared with the monotherapy group. Notably, glucose metabolism in the co-treatment group improved to the same level as that in the healthy mice group. Thus, peripheral combination treatment with leptin and SGLT2 inhibitor improved glucose metabolism in IDDM mice without the use of insulin.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Glucose/metabolismo , Glucosídeos/administração & dosagem , Leptina/administração & dosagem , Inibidores do Transportador 2 de Sódio-Glicose/administração & dosagem , Tiofenos/administração & dosagem , Administração Oral , Animais , Modelos Animais de Doenças , Quimioterapia Combinada , Infusões Intravenosas , Masculino , Camundongos Endogâmicos C57BL
15.
Pituitary ; 24(4): 582-588, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33666833

RESUMO

Wolfram syndrome (WS) is mainly caused by mutations in the WFS1 gene and characterized by diabetes mellitus, optic atrophy, hearing loss, and central diabetes insipidus (CDI). WFS1 is an endoplasmic reticulum (ER)-resident transmembrane protein, and Wfs1 knockout (Wfs1-/-) mice, which have been used as a mouse model for WS, reportedly manifested impairment of glucose tolerance due to pancreatic ß-cell loss. In the present study, we examined water balance, arginine vasopressin (AVP) secretion, and ER stress in AVP neurons of the hypothalamus in Wfs1-/- mice. There were no differences in urine volumes between Wfs1-/- and wild-type mice with free access to water. Conversely, when mice were subjected to intermittent water deprivation (WD) for 20 weeks, during which water was unavailable for 2 days a week, urine volumes were larger in Wfs1-/- mice, accompanied by lower urine AVP concentrations and urine osmolality, compared to wild-type mice. The mRNA expression of immunoglobulin heavy chain binding protein, a marker of ER stress, was significantly increased in the supraoptic nucleus and paraventricular nuclei in Wfs1-/- mice compared to wild-type mice after WD. Our results thus showed that Wfs1 knockout leads to a decrease in AVP secretion during dehydration, which could explain in part the mechanisms by which Wfs1 mutations cause CDI in humans.


Assuntos
Síndrome de Wolfram , Animais , Desidratação , Diabetes Insípido Neurogênico , Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Masculino , Proteínas de Membrana , Camundongos , Água , Síndrome de Wolfram/genética
16.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445471

RESUMO

The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is activated by the small G-protein, Ras homolog enriched in brain (RHEB-GTPase). On lysosome, RHEB activates mTORC1 by binding the domains of N-heat, M-heat, and the focal adhesion targeting (FAT) domain, which allosterically regulates ATP binding in the active site for further phosphorylation. The crucial role of RHEB in regulating growth and survival through mTORC1 makes it a targetable site for anti-cancer therapeutics. However, the binding kinetics of RHEB to mTORC1 is still unknown at the molecular level. Therefore, we studied the kinetics by in vitro and in-cell protein-protein interaction (PPI) assays. To this end, we used the split-luciferase system (NanoBiT®) for in-cell studies and prepared proteins for the in vitro measurements. Consequently, we demonstrated that RHEB binds to the whole mTOR both in the presence or absence of GTPγS, with five-fold weaker affinity in the presence of GTPγS. In addition, RHEB bound to the truncated mTOR fragments of N-heat domain (∆N, aa 60-167) or M-heat domain (∆M, aa 967-1023) with the same affinity in the absence of GTP. The reconstructed binding site of RHEB, ∆N-FAT-M, however, bound to RHEB with the same affinity as ∆N-M, indicating that the FAT domain (∆FAT, aa 1240-1360) is dispensable for RHEB binding. Furthermore, RHEB bound to the truncated kinase domain (∆ATP, aa 2148-2300) with higher affinity than to ∆N-FAT-M. In conclusion, RHEB engages two different binding sites of mTOR, ∆N-FAT-M and ∆ATP, with higher affinity for ∆ATP, which likely regulates the kinase activity of mTOR through multiple different biding modes.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Sítios de Ligação , Células HEK293 , Humanos , Técnicas In Vitro , Cinética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Fosforilação , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genética
17.
Int J Mol Sci ; 22(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34769498

RESUMO

The introduction of α-helical structure with a specific helix-helix interaction into an amphipathic molecule enables the determination of the molecular packing in the assembly and the morphological control of peptide assemblies. We previously reported that the amphiphilic polypeptide SL12 with a polysarcosine (PSar) hydrophilic chain and hydrophobic α-helix (l-Leu-Aib)6 involving the LxxxLxxxL sequence, which induces homo-dimerization due to the concave-convex interaction, formed a nanotube with a uniform 80 nm diameter. In this study, we investigated the importance of the LxxxLxxxL sequence for tube formation by comparing amphiphilic polypeptide SL4A4L4 with hydrophobic α-helix (l-Leu-Aib)2-(l-Ala-Aib)2-(l-Leu-Aib)2 and SL12. SL4A4L4 formed spherical vesicles and micelles. The effect of the LxxxLxxxL sequence elongation on tube formation was demonstrated by studying assemblies of PSar-b-(l-Ala-Aib)-(l-Leu-Aib)6-(l-Ala-Aib) (SA2L12A2) and PSar-b-(l-Leu-Aib)8 (SL16). SA2L12A2 formed nanotubes with a uniform 123 nm diameter, while SL16 assembled into vesicles. These results showed that LxxxLxxxL is a necessary and sufficient sequence for the self-assembly of nanotubes. Furthermore, we fabricated a double-layer nanotube by combining two kinds of nanotubes with 80 and 120 nm diameters-SL12 and SA2L12A2. When SA2L12A2 self-assembled in SL12 nanotube dispersion, SA2L12A2 initially formed a rolled sheet, the sheet then wrapped the SL12 nanotube, and a double-layer nanotube was obtained.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Leucina/química , Nanotubos/química , Peptídeos/química , Sarcosina/análogos & derivados , Modelos Moleculares , Conformação Proteica , Sarcosina/química
18.
J Am Chem Soc ; 142(50): 20994-21003, 2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33272014

RESUMO

The self-assembly of biological molecules is an important pathway to understanding the molecular basis of complex metabolic events. The presence of a cosolvent in an aqueous solution during the self-assembly process can promote the formation of kinetically trapped metastable intermediates. In nature, a category of cosolvents termed osmolytes can work to strengthen the hydrogen-bond network of water such that the native states of certain proteins are favored, thus modulating their function and stability. However, identifying cosolvents that act as osmolytes in biomimetic applications, such as the self-assembly of soft materials, remains challenging. The present work examined the effects of ethanol (EtOH) and acetonitrile (ACN) as cosolvents on the self-assembly of the amphiphilic polypeptide PSar30-(l-Leu-Aib)6 (S30L12), which incorporates α-helical hydrophobic blocks, in aqueous solution. The results provided a direct observation of morphological behavior of S30L12 as a function of solvent composition. Morphological transitions were investigated using transmission electron microscopy, while the packing of peptide molecules was assessed using circular dichroism analyses and evaluations of membrane fluidity. In the EtOH/H2O mixtures, the EtOH strengthened the hydrogen-bond network of the water, thus limiting the hydrophobic hydration of S30L12 assemblies and enhancing hydrophobic interactions between assemblies. In contrast, ACN formed self-associated nanoclusters in water and at the hydrophobic cores of peptide assemblies to stabilize the edges exposed to bulk water and enhance the assembly kinetics. Fourier transform infrared (FT-IR) analysis indicated that both EtOH and ACN can modify the self-assembly of biomaterials in the same manner as osmolyte protectants or denaturants.

19.
Br J Cancer ; 122(6): 771-777, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32009131

RESUMO

BACKGROUND: Anti-programmed cell death-1 (PD-1) antibodies can cause thyroid dysfunction. However, no predictive biomarkers enabling stratification of thyroid dysfunction risk have been identified. METHODS: A total of 209 patients treated with an anti-PD-1 antibody were evaluated for anti-thyroid antibodies at baseline and prospectively for thyroid function every 6 weeks for 24 weeks after treatment initiation, and then observed until the visits stopped. Thyroid ultrasonography was performed if the patient was positive for anti-thyroid antibodies at baseline. RESULTS: Of the 209 patients, 19 (9.1%) developed thyroid dysfunction (destructive thyroiditis or hypothyroidism). The cumulative incidence of thyroid dysfunction was significantly higher in patients who were positive vs. negative for anti-thyroid antibodies (15/44 [34.1%] vs. 4/165 [2.4%], p < 0.001). Forty-two patients positive for anti-thyroid antibodies at baseline were divided into two groups according to the presence of an irregular echo pattern. The cumulative incidence of thyroid dysfunction was significantly higher in those with an irregular vs. a regular echo pattern (13/23 [56.5%] vs. 1/19 [5.3%], p = 0.001). None of the patients developed thyroid dysfunction after the initial 24-week period. CONCLUSIONS: The risk of thyroid dysfunction induced by anti-PD-1 antibodies can be predicted by evaluation of anti-thyroid antibodies and the thyroid echo pattern at baseline. TRIAL REGISTRATION: UMIN000019024.


Assuntos
Receptor de Morte Celular Programada 1/metabolismo , Glândula Tireoide/fisiopatologia , Tireoidite/induzido quimicamente , Ultrassonografia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
20.
Anal Chem ; 92(16): 11260-11267, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32506902

RESUMO

In this study, we demonstrated an electrochemical aptasensor for calmodulin (CaM) detection and the peptide sequence (YWDKIKDFIGG) is obtained from in vitro ribosome display selection. To immobilize this peptide probe on the electrode surface, cystine was incorporated at the end of this peptide sequence. After a maleimide-functionalized poly(3,4-ethylenedioxythiophene), poly(EODT-MI), film was electropolymerized on the electrode, the peptide probe was immobilized through thiol-ene conjugation with the cystine end. Four peptides with different linkers were used for the binding test of bovine serum albumin and CaM using a quartz crystal microbalance. The zwitterionic linker EKEKEKEKEKEK provided good antifouling properties and the highest CaM binding. Furthermore, the immobilization of the peptide with this zwitterionic linker resulted in a minimal increase in the electrochemical impedance. By immobilizing the peptide with the selected zwitterionic linker, we successfully demonstrated an electrochemical aptasensor with a linear detection range for CaM from 0.01 to 10 mg/L and a detection limit of 0.001 mg/L.


Assuntos
Aptâmeros de Peptídeos/química , Calmodulina/análise , Proteínas Imobilizadas/química , Sequência de Aminoácidos , Aptâmeros de Peptídeos/genética , Técnicas Biossensoriais/métodos , Espectroscopia Dielétrica , Evolução Molecular Direcionada , Proteínas Imobilizadas/genética , Limite de Detecção , Polímeros/química , Engenharia de Proteínas
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