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1.
Commun Biol ; 7(1): 655, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38806706

ABSTRACT

The gut microbiota influences human health and the development of chronic diseases. However, our understanding of potentially protective or harmful microbe-host interactions at the molecular level is still in its infancy. To gain further insights into the hidden gut metabolome and its impact, we identified a cryptic non-ribosomal peptide BGC in the genome of Bacillus cereus DSM 28590 from the mouse intestine ( www.dsmz.de/miBC ), which was predicted to encode a thiazol(in)e substructure. Cloning and heterologous expression of this BGC revealed that it produces bacillamide D. In-depth functional evaluation showed potent cytotoxicity and inhibition of cell migration using the human cell lines HCT116 and HEK293, which was validated using primary mouse organoids. This work establishes the bacillamides as selective cytotoxins from a bacterial gut isolate that affect mammalian cells. Our targeted structure-function-predictive approach is demonstrated to be a streamlined method to discover deleterious gut microbial metabolites with potential effects on human health.


Subject(s)
Bacillus cereus , Gastrointestinal Microbiome , Bacillus cereus/metabolism , Bacillus cereus/genetics , Animals , Mice , Humans , HEK293 Cells , Cytotoxins/metabolism , Cytotoxins/genetics , HCT116 Cells , Intestines/microbiology , Cell Movement , Organoids/metabolism
2.
Proc Natl Acad Sci U S A ; 121(19): e2314704121, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38691589

ABSTRACT

Amine modification through nucleophilic attack of the amine functionality is a very common chemical transformation. Under biorelevant conditions using acidic-to-neutral pH buffer, however, the nucleophilic reaction of alkyl amines (pKa ≈ 10) is not facile due to the generation of ammonium ions lacking nucleophilicity. Here, we disclose a unique molecular transformation system, catalysis driven by amyloid-substrate complex (CASL), that promotes amine modifications in acidic buffer. Ammonium ions attached to molecules with amyloid-binding capability were activated through deprotonation due to the close proximity to the amyloid catalyst formed by Ac-Asn-Phe-Gly-Ala-Ile-Leu-NH2 (NL6), derived from islet amyloid polypeptide (IAPP). Under the CASL conditions, alkyl amines underwent various modifications, i.e., acylation, arylation, cyclization, and alkylation, in acidic buffer. Crystallographic analysis and chemical modification studies of the amyloid catalysts suggested that the carbonyl oxygen of the Phe-Gly amide bond of NL6 plays a key role in activating the substrate amine by forming a hydrogen bond. Using CASL, selective conversion of substrates possessing equivalently reactive amine functionalities was achieved in catalytic reactions using amyloids. CASL provides a unique method for applying nucleophilic conversion reactions of amines in diverse fields of chemistry and biology.


Subject(s)
Amyloid , Catalysis , Amyloid/chemistry , Amyloid/metabolism , Amines/chemistry , Amines/metabolism , Hydrogen Bonding , Islet Amyloid Polypeptide/chemistry , Islet Amyloid Polypeptide/metabolism , Hydrogen-Ion Concentration , Humans
3.
J Med Virol ; 96(5): e29653, 2024 May.
Article in English | MEDLINE | ID: mdl-38712746

ABSTRACT

The magnitude of the effect of human T-lymphotropic virus 1 (HTLV-1) infection on uveitis remains unclear. We conducted a cross-sectional study in a highly endemic area of HTLV-1 in Japan. The study included 4265 residents (men, 39.2%), mostly middle-aged and older individuals with a mean age of 69.9 years, who participated in our surveys between April 2016 and September 2022. We identified HTLV-1 carriers by screening using chemiluminescent enzyme immunoassays and confirmatory tests, and the proportion of carriers was 16.1%. Participants with uveitis were determined from the medical records of all hospitals and clinics where certified ophthalmologists practiced. We conducted logistic regression analyses in an age- and sex-adjusted model to compute the odds ratio (OR) and 95% confidence interval (CI) of uveitis according to HTLV-1 infection status. Thirty-two (0.8%) participants had uveitis. For HTLV-1 carriers, the age- and sex-adjusted OR (95% CI) of uveitis was 3.27 (1.57-6.72) compared with noncarriers. In conclusion, HTLV-1 infection was associated with a higher risk of uveitis among mostly middle-aged and older Japanese residents in a highly endemic HTLV-1 area. Our findings suggest that physicians who treat HTLV-1 carriers should assess ocular symptoms, and those who diagnose patients with uveitis should consider HTLV-1 infection.


Subject(s)
Carrier State , HTLV-I Infections , Human T-lymphotropic virus 1 , Uveitis , Humans , Female , Male , Japan/epidemiology , Uveitis/epidemiology , Uveitis/virology , HTLV-I Infections/epidemiology , Cross-Sectional Studies , Aged , Middle Aged , Prevalence , Human T-lymphotropic virus 1/isolation & purification , Carrier State/epidemiology , Carrier State/virology , Adult , Aged, 80 and over , Endemic Diseases , Young Adult
4.
Membranes (Basel) ; 14(4)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38668103

ABSTRACT

Protein dynamics play important roles in biological functions, which accompany allosteric structure changes. Diffracted X-ray blinking (DXB) uses monochromatic X-rays and nanocrystal probes. The intramolecular motion of target proteins is analyzed from the intensity changes in detector signals at the diffraction rings. In contrast, diffracted X-ray tracking (DXT) elucidates molecular dynamics by analyzing the trajectories of Laue spots. In this study, we have developed a dual-labeling technique for DXB and DXT, allowing the simultaneous observation of motions at different domains in proteins. We identified zinc oxide (ZnO) crystals as promising candidates for the second labeling probes due to their excellent diffraction patterns, high chemical stability, and favorable binding properties with proteins. The diffraction spots from the ZnO crystals are sufficiently separated from those of gold, enabling independent motion analysis at different domains. Dual-labeling DXB was employed for the motion analysis of the 5-HT2A receptor in living cells. Simultaneous motion recording of the N-terminus and the second extracellular loop demonstrated ligand-induced motion suppression at both domains. The dual-labeling DXT technique demonstrated a capsaicin-induced peak shift in the two-dimensional motion maps at the N-terminus of the TRPV1 protein, but the peak shift was not obvious in the C-terminus. The capsaicin-induced motion modulation was recovered by the addition of the competitive inhibitor AMG9810.

5.
Clin Nucl Med ; 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38651784

ABSTRACT

ABSTRACT: 99mTc-3,3-diphosphono-1,2-propanedicarboxylic acid (DPD) scintigraphy and 99mTc-pyrophosphate (PYP) scintigraphy are highly sensitive modalities for imaging both myocardial and extracardiac amyloid transthyretin in patients with wild-type transthyretin (ATTRwt) amyloidosis. "Loss of bone signal" on planar imaging of 99mTc-DPD scintigraphy, in which the tracer uptake in bone is obscured by marked tracer uptake in the overlying skeletal muscles, is reported. However, this phenomenon has not yet been documented on 99mTc-PYP scintigraphy. We describe an 89-year-old woman with ATTRwt amyloidosis in whom "loss of bone signal" together with marked tracer uptake into the skeletal muscles was clearly demonstrated on 99mTc-PYP scan.

6.
Environ Microbiol Rep ; 16(2): e13243, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38425145

ABSTRACT

We developed a simulation model of human oral microbiota using Bio Palette oral medium (BPOM) containing 0.02% glucose and lower bacterial nitrogen sources, derived from saliva and dental plaque. By decreasing the concentration of Gifu anaerobic medium (GAM) from 30 to 10 g L-1 , we observed increased ratios of target pathogenic genera, Porphyromonas and Fusobacterium from 0.5% and 1.7% to 1.2% and 3.5%, respectively, in the biofilm on hydroxyapatite (HA) discs. BPOM exhibited the higher ratios of Porphyromonas and Fusobacterium, and amplicon sequence variant number on HA, compared with GAM, modified GAM and basal medium mucin. Mixing glycerol stocks of BPOM culture solutions from four human subjects resulted in comparable ratios of these bacteria to the original saliva. In this simulation model, sitafloxacin showed higher inhibitory effects on P. gingivalis than minocycline hydrochloride at a low dosage of 0.1 µg mL-1 . Probiotics such as Streptococcus salivarius and Limosilactobacillus fermentum also showed significant decreases in Porphyromonas and Fusobacterium ratios on HA, respectively. Overall, the study suggests that BPOM with low carbon and nutrients could be a versatile platform for assessing the efficacy of antibiotics and live biotherapeutics in treating oral diseases caused by Porphyromonas and Fusobacterium.


Subject(s)
Fusobacterium nucleatum , Microbiota , Humans , Porphyromonas gingivalis/genetics , Saliva/microbiology , Biofilms
7.
J Nanobiotechnology ; 22(1): 114, 2024 Mar 16.
Article in English | MEDLINE | ID: mdl-38493106

ABSTRACT

BACKGROUND: Rice bran a by-product of the rice milling process is currently underutilized. Recent studies have shown that plant-derived nanoparticles (pdNPs) can be mass-produced at a low cost and exhibit biological and therapeutic activities. Rice bran contains various anti-cancer compounds, including γ-oryzanol and γ-tocotrienol, and rice bran-derived nanoparticles (rbNPs) can be employed as novel therapeutic agents for cancer treatment. RESULTS: Koshihikari rice bran was suspended in water, and the suspension was centrifuged and filtered through a 0.45-µm-pore size syringe filter. The filtrate was ultracentrifuged, and the precipitates were suspended to obtain rbNPs. The rbNPs were negatively charged exosome-like nanoparticles with an average diameter of approximately 130 nm. The rbNPs exhibited cytotoxic activities against cancer cells but not against normal cells. The cytotoxic activity of rbNPs to murine colon adenocarcinoma colon26 cells was significantly greater than DOXIL® or other pdNPs. The rbNPs induced cell cycle arrest and apoptosis, and reduced the expression of proliferative proteins, including ß-catenin and cyclin D1. Intraperitoneal injections of rbNPs into mice bearing peritoneal dissemination of colon26 cells significantly suppressed tumor growth with no significant adverse effects. CONCLUSION: These results indicated that rbNPs are promising nanoparticles, hold significant potential for anti-cancer applications, and are expected to play a vital role in cancer treatment.


Subject(s)
Adenocarcinoma , Antineoplastic Agents , Colonic Neoplasms , Oryza , Animals , Mice , Colonic Neoplasms/drug therapy , Antioxidants/pharmacology , Antineoplastic Agents/pharmacology
8.
Sci Rep ; 14(1): 2649, 2024 02 01.
Article in English | MEDLINE | ID: mdl-38302478

ABSTRACT

"Yips" are involuntary movements that interfere with the automatic execution of sports movements. However, how the coordination among the various muscles necessary for sports movements is impaired in athletes with yips remains to be fully understood. This study aimed to assess whether muscle synergy analysis through non-negative matrix factorization (NMF) could identify impaired spatiotemporal muscle coordination in baseball players with throwing yips. Twenty-two college baseball players, including 12 with and 10 without yips symptoms participated in the study. Electromyographic activity was recorded from 13 ipsilateral upper extremity muscles during full-effort throwing. Muscle synergies were extracted through NMF. Cluster analysis was conducted to identify any common spatiotemporal patterns of muscle synergies in players with yips. Whether individual players with yips showed deviations in spatiotemporal patterns of muscle synergies compared with control players was also investigated. Four muscle synergies were extracted for each player, but none were specific to the yips group. However, a more detailed analysis of individual players revealed that two of the three players who presented dystonic symptoms during the experiment exhibited specific patterns that differed from those in control players. By contrast, each player whose symptoms were not reproduced during the experiment presented spatiotemporal patterns of muscle synergies similar to those of the control group. The results of this study indicate no common spatiotemporal pattern of muscle synergies specific to the yips group. Furthermore, these results suggest that the spatiotemporal pattern of muscle synergies in baseball throwing motion is not impaired in situations where symptoms are not reproduced even if the players have yips symptoms. However, muscle synergy analysis can identify the characteristics of muscle coordination of players who exhibit dystonic movements. These findings can be useful in developing personalized therapeutic strategies based on individual characteristics of yips symptoms.


Subject(s)
Baseball , Sports , Humans , Baseball/physiology , Sports/physiology , Muscle, Skeletal , Movement , Upper Extremity
9.
Eur Biophys J ; 53(1-2): 15-25, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38233601

ABSTRACT

The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response. Ivermectin was reported as one of the positive allosteric modulators, since the binding of Ivermectin to the channel enhances acetylcholine-evoked α7 currents. One research has suggested that tilting motions of the nicotinic acetylcholine receptor are responsible for channel opening and activation. To verify this hypothesis applies to α7 nicotinic acetylcholine receptor, we utilized a diffracted X-ray tracking method to monitor the stable twisting and tilting motion of nAChR α7 without a ligand, with acetylcholine, with Ivermectin, and with both of them. The results show that the α7 nicotinic acetylcholine receptor twists counterclockwise with the channel transiently opening, transitioning to a desensitized state in the presence of acetylcholine and clockwise without the channel opening in the presence of Ivermectin. We propose that the conformational transition of ACh-bound nAChR α7 may be due to the collective twisting of the five α7 subunits, resulting in the compression and movement, either downward or upward, of one or more subunits, thus manifesting tilting motions. These tilting motions possibly represent the transition from the resting state to channel opening and potentially to the desensitized state.


Subject(s)
Receptors, Nicotinic , alpha7 Nicotinic Acetylcholine Receptor , alpha7 Nicotinic Acetylcholine Receptor/chemistry , alpha7 Nicotinic Acetylcholine Receptor/metabolism , Acetylcholine/chemistry , Acetylcholine/metabolism , Ligands , Ivermectin/pharmacology , Receptors, Nicotinic/chemistry , Receptors, Nicotinic/metabolism , Allosteric Regulation
10.
J Control Release ; 367: 486-499, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38295995

ABSTRACT

Cell transplantation is a promising therapeutic strategy for myocardial regeneration therapy. To improve therapeutic effects, we developed a culture medium additive that enhances the mitochondrial function of cardiomyocytes for transplantation. A mitochondrial targeting drug delivery system (MITO-Porter system) was used to deliver mitochondrial activation molecules to mouse-derived cardiac progenitor cells. In this study, we investigated whether the mitochondrial function of human-derived myocardial precursor cells could be enhanced using MITO-Porter. Human cardiosphere-derived cells (CDCs) were isolated from myocardium which was excised during surgery for congenital heart disease. MITO-Porter was added to the cell culture medium to generate mitochondrial activated CDCs (human MITO cells). The human MITO cells were transplanted into myocardial ischemia-reperfusion model rat, and the effect was investigated. The transplanted human MITO cells improved the cardiac function and suppressed myocardial fibrosis compared to conventional cell transplantation methods. These effects were observed not only with myocardial administration but also by intravenous administration of human MITO cells. This study is the first study that assessed whether the mitochondrial delivery of functional compounds improved the outcome of human-derived myocardial cell transplantation therapy.


Subject(s)
Cardiomyopathies , Myocardium , Mice , Humans , Rats , Animals , Myocardium/metabolism , Myocytes, Cardiac , Drug Delivery Systems , Mitochondria , Cardiomyopathies/metabolism
11.
Amyloid ; 31(1): 12-21, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37486102

ABSTRACT

BACKGROUND: Technetium-99m-pyrophosphate (99mTc-PYP) uptake in the internal oblique muscle (IOM), which is often observed in patients with wild-type transthyretin cardiac amyloidosis (ATTR-CA), indicates amyloid transthyretin (ATTR) deposition. OBJECTIVE: This study aimed to assess the safety and efficacy of 99mTc-PYP imaging-based computed tomography (CT)-guided core-needle biopsy of the IOM as a new extracardiac screening biopsy for confirming the presence of ATTR deposits. METHODS: Patients with suspected ATTR-CA in whom myocardial tracer uptake was detected on chest- and abdomen-centered images of 99mTc-PYP scintigraphy underwent CT-guided core-needle biopsy at the site with the highest tracer uptake in the IOM between September 2021 and November 2022. RESULTS: All 18 consecutive patients (mean age, 86.3 years ± 6.5; 61.1% male) enrolled in the study showed 99mTc-PYP uptake into the IOM. Adequate tissue samples were obtained from all patients except one without serious complications. Immunohistochemical analysis confirmed ATTR deposits in 16/18 (88.9%) patients. In the remaining two patients, ATTR deposits were observed via endomyocardial biopsy. All patients were diagnosed with wild-type ATTR-CA based on transthyretin gene sequence testing results. CONCLUSION: In wild-type ATTR-CA, 99mTc-PYP imaging-based CT-guided core-needle biopsy of the IOM could be used as an extracardiac screening biopsy to confirm the presence of ATTR deposits.


Subject(s)
Amyloidosis , Cardiomyopathies , Humans , Male , Aged, 80 and over , Female , Technetium Tc 99m Pyrophosphate , Diphosphates , Technetium , Prealbumin/genetics , Abdominal Oblique Muscles , Amyloidosis/genetics , Tomography, X-Ray Computed , Biopsy , Biopsy, Needle , Cardiomyopathies/diagnostic imaging , Radiopharmaceuticals
13.
Virus Res ; 339: 199294, 2024 01 02.
Article in English | MEDLINE | ID: mdl-38056502

ABSTRACT

Saliva is a key component of mucosal immunity, which protects the oral cavity from viral infections. However, salivary immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in terms of immunoglobulin dynamics and recognition, have not been investigated sufficiently. In this study, saliva samples were collected from individuals that received SARS-CoV-2 vaccine, and immunoglobulin G (IgG), IgM, and IgA against whole spike protein and S1 protein were measured. IgA against whole spike protein increased significantly following vaccination, while IgA against S1 protein did not. Of note, the IgA response was evident two weeks after the first vaccine dose and continued to rise thereafter. On the contrary, IgG antibodies against S1 increased significantly at four weeks after vaccination. These results reveal the dynamics and recognition antigens of immunoglobulins in saliva, indicating the function of IgA in the mucosal immune system. These findings may pave the way for further studies on mucosal immune response induced by vaccination.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , COVID-19/prevention & control , Vaccination , Immunoglobulin G , Immunoglobulin A , Antibodies, Viral
14.
Int J Mol Sci ; 24(24)2023 Dec 14.
Article in English | MEDLINE | ID: mdl-38139291

ABSTRACT

The photoinduced crawling motion of crystals is a continuous motion that azobenzene molecular crystals exhibit under light irradiation. Such motion enables object manipulation at the microscale with a simple setup of fixed LED light sources. Transportation of nano-/micromaterials using photoinduced crawling motion has recently been reported. However, the details of the motion mechanism have not been revealed so far. Herein, we report visualization of the dynamics of fine particles in 4-(methylamino)azobenzene (4-MAAB) crystals under light irradiation via diffracted X-ray tracking (DXT). Continuously repeated melting and recrystallization of 4-MAAB crystals under light irradiation results in the flow of liquid 4-MAAB. Zinc oxide (ZnO) particles were introduced inside the 4-MAAB crystals to detect diffracted X-rays. The ZnO particles rotate with the flow of liquid 4-MAAB. By using white X-rays with a wide energy width, the rotation of each zinc oxide nanoparticle was detected as the movement of a bright spot in the X-ray diffraction pattern. It was clearly shown that the ZnO particles rotated increasingly as the irradiation light intensity increased. Furthermore, we also found anisotropy in the rotational direction of ZnO particles that occurred during the crawling motion of 4-MAAB crystals. It has become clear that the flow perpendicular to the supporting film of 4-MAAB crystals is enhanced inside the crystal during the crawling motion. DXT provides a unique means to elucidate the mechanism of photoinduced crawling motion of crystals.


Subject(s)
Zinc Oxide , X-Rays , Azo Compounds/chemistry , Rotation
15.
Microbiol Spectr ; 11(6): e0207823, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-37966220

ABSTRACT

IMPORTANCE: The World Health Organization estimated that 5-10 million people are infected with human T-cell leukemia virus type 1 (HTLV-1). This number is likely to be underestimated because reliable endemic data are available for only approximately 1.5 billion people worldwide. The point-of-care test is a powerful tool for the easy and quick detection of infections without the requirement for expensive instruments and laboratory equipment. Espline HTLV-I/II, a newly developed rapid immunochromatographic antibody test that was evaluated in this study, might significantly advance our understanding of the global epidemiology of HTLV-1 infection.


Subject(s)
HTLV-I Infections , Human T-lymphotropic virus 1 , Humans , HTLV-I Infections/diagnosis , HTLV-I Infections/epidemiology
16.
BMC Infect Dis ; 23(1): 823, 2023 Nov 23.
Article in English | MEDLINE | ID: mdl-37996783

ABSTRACT

BACKGROUND: A test-based strategy against coronavirus disease 2019 (COVID-19) is one of the measures to assess the need for isolation and prevention of infection. However, testing with high sensitivity methods, such as quantitative RT-PCR, leads to unnecessary isolation, whereas the lateral flow antigen test shows low sensitivity and false negative results. The purpose of this study was to evaluate the performance of the LumiraDx SARS-CoV-2 Ag test (Lumira Ag), a rapid microfluidic immunofluorescence method, in assessing infectivity. METHODS: This study was performed from March 2022 to July 2022. A pair of nasopharyngeal swab samples were obtained from each patient with mild COVID-19. One swab was used for Lumira Ag testing, and the other for quantitative RT-PCR testing and virus culture. RESULTS: A total of 84 patients were included in the study. Among them, PCR, Lumira Ag test, and virus culture indicated positivity for 82, 66, and 24 patients, respectively. When comparing the Lumira Ag test to virus culture, its sensitivity was 100.0% (24/24), specificity, 30.0% (18/60); positive predictive value, 36.3% (24/66); and negative predictive value (NPV), 100.0% (18/18). The positive sample for virus culture was observed until the ninth day from the onset of symptoms, while the Lumira Ag test was observed until day 11. CONCLUSIONS: The Lumira Ag test showed high sensitivity and NPV (100% each) compared to virus culture. A test-based strategy using the Lumira Ag test can effectively exclude COVID-19 infectiousness.


Subject(s)
COVID-19 , Microfluidics , Humans , COVID-19/diagnosis , SARS-CoV-2 , Fluorescent Antibody Technique , Immunologic Tests , Sensitivity and Specificity , Antigens, Viral
17.
Int J Mol Sci ; 24(19)2023 Oct 03.
Article in English | MEDLINE | ID: mdl-37834298

ABSTRACT

The CCT/TRiC complex is a type II chaperonin that undergoes ATP-driven conformational changes during its functional cycle. Structural studies have provided valuable insights into the mechanism of this process, but real-time dynamics analyses of mammalian type II chaperonins are still scarce. We used diffracted X-ray tracking (DXT) to investigate the intramolecular dynamics of the CCT complex. We focused on three surface-exposed loop regions of the CCT1 subunit: the loop regions of the equatorial domain (E domain), the E and intermediate domain (I domain) juncture near the ATP-binding region, and the apical domain (A domain). Our results showed that the CCT1 subunit predominantly displayed rotational motion, with larger mean square displacement (MSD) values for twist (χ) angles compared with tilt (θ) angles. Nucleotide binding had a significant impact on the dynamics. In the absence of nucleotides, the region between the E and I domain juncture could act as a pivotal axis, allowing for greater motion of the E domain and A domain. In the presence of nucleotides, the nucleotides could wedge into the ATP-binding region, weakening the role of the region between the E and I domain juncture as the rotational axis and causing the CCT complex to adopt a more compact structure. This led to less expanded MSD curves for the E domain and A domain compared with nucleotide-absent conditions. This change may help to stabilize the functional conformation during substrate binding. This study is the first to use DXT to probe the real-time molecular dynamics of mammalian type II chaperonins at the millisecond level. Our findings provide new insights into the complex dynamics of chaperonins and their role in the functional folding cycle.


Subject(s)
Molecular Dynamics Simulation , Protein Folding , Animals , X-Rays , Group II Chaperonins/chemistry , Group II Chaperonins/metabolism , Chaperonins/metabolism , Adenosine Triphosphate/metabolism , Nucleotides , Chaperonin Containing TCP-1/chemistry , Protein Conformation , Mammals/metabolism
18.
Biochem Biophys Res Commun ; 682: 381-385, 2023 11 19.
Article in English | MEDLINE | ID: mdl-37844447

ABSTRACT

The measurement of serum IgG4 levels is mandatory for the diagnosis of IgG4-related disease, but no widely accepted reference material exists due to a lack of consensus on the standard assay. Therefore, we developed here an LC-MS/MS method for absolute quantification of IgG4 in a purified IgG sample, addressing a concern over the reliability depending on the proteolytic digestion efficiency. Our method uses internal calibrator sets containing unique amino acid sequences within IgG4, each of which comprises non-cleavable and dually-cleavable peptides labeled with different numbers of isotopes for mass separation, to determine digestion efficiency. Surrogate peptides generated by trypsin or lysyl endopeptidase digestion were selected based on selectivity, stability, and identifiability. IgG4 quantification using synthetic calibrator peptides showed high precision across the two conditions with different peptidases (relative differences ≤6.1%), even with low digestion efficiencies (<20%), which was within the interday precision under an established condition (% coefficient of variation ≤6.9%, digestion efficiencies >90%, n = 5). These results indicate that the LC-MS/MS method for quantifying IgG4 is robust against digestion efficiency variations and is applicable to validating an IgG4 reference material.


Subject(s)
Immunoglobulin G , Tandem Mass Spectrometry , Chromatography, Liquid/methods , Reproducibility of Results , Tandem Mass Spectrometry/methods , Peptides/chemistry , Digestion
19.
Intern Med ; 2023 Oct 27.
Article in English | MEDLINE | ID: mdl-37899242

ABSTRACT

In patients with wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), the uptake of the tracer on technetium-99m-labeled pyrophosphate (99mTc-PYP) scintigraphy, which indicates amyloid transthyretin (ATTR) per se, is often observed in skeletal muscles, such as the abdominal oblique and gluteal muscles. Among extracardiac biopsies for confirming ATTR deposition in ATTRwt-CA, a 99mTc-PYP imaging-based computed tomography (CT)-guided core needle biopsy of the internal oblique muscle has relatively high sensitivity. In some patients, the 99mTc-PYP uptake is more pronounced in the gluteal muscles than in oblique muscles. We herein report two cases of ATTRwt-CA in which a CT-guided biopsy of the gluteus medius muscle with 99mTc-PYP uptake confirmed the presence of ATTR deposits.

20.
Geriatr Gerontol Int ; 23(10): 744-749, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37694453

ABSTRACT

AIM: Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial infection-causing pathogen. The clonal shift from staphylococcal cassette chromosome mec (SCCmec) type II MRSA to SCCmec type IV MRSA has occurred rapidly in acute-care hospitals. However, the epidemiology and clinical impacts of MRSA in geriatric hospitals are poorly documented. We performed a molecular epidemiological analysis of the clinical isolates and retrospectively investigated the clinical characteristics of SCCmec type IV MRSA in elderly individuals. METHODS: MRSA isolates were grouped according to the SCCmec type and virulence genes (tst, sea, seb, sec, and lukS/F-PV), and multi-locus sequence typing (MLST) was performed. RESULTS: Of the 145 MRSA isolates obtained from patients with a median age of 85 years, 100 (69.0%) were obtained from sputum samples, 22 (15.2%) from skin and soft tissues, and seven (4.8%) from blood samples. The most prevalent clone was SCCmec type IV/clonal complex (CC)1/sea+ (59.3%), followed by SCCmec type I/sequence type (ST) 8 (17.3%). Of the 17 (11.7%) strains to which an anti-MRSA drug was administered by a physician, only three were SCCmec type IV/CC1/sea+ (17.6%) and five were SCCmec type I/ST8 (29.4%). SCCmec type IV/CC1/sea+ MRSA was more frequently isolated in long-term care wards than were SCCmec type I/ST8 strains (odds ratio: 2.85, 95% confidence interval: 1.08-7.54) and was less frequently treated as the cause of MRSA infections (odds ratio: 0.15, 95% confidence interval: 0.03-0.73). CONCLUSIONS: SCCmec type IV/CC1/sea+ MRSA was the predominant clone and could be easily transmissible and be capable of colonization. Geriatr Gerontol Int 2023; 23: 744-749.

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