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1.
Article in English | MEDLINE | ID: mdl-38819714

ABSTRACT

PURPOSE: This study aimed to evaluate the effectiveness of a random forest (RF) model in predicting clinical pregnancy outcomes from intrauterine insemination (IUI) and identifying significant factors affecting IUI pregnancy in a large Chinese population. METHODS: RESULTS: A total of 11 variables, including eight from female (age, body mass index, duration of infertility, prior miscarriage, and spontaneous abortion), hormone levels (anti-Müllerian hormone, follicle-stimulating hormone, luteinizing hormone), and three from male (smoking, semen volume, and sperm concentration), were identified as the significant variables associated with IUI clinical pregnancy in our Chinese dataset. The RF-based prediction model presents an area under the receiver operating characteristic curve (AUC) of 0.716 (95% confidence interval, 0.6914-0.7406), an accuracy rate of 0.6081, a sensitivity rate of 0.7113, and a specificity rate of 0.505. Importance analysis indicated that semen volume was the most vital variable in predicting IUI clinical pregnancy. CONCLUSIONS: The machine learning-based IUI clinical pregnancy prediction model showed a promising predictive efficacy that could provide a potent tool to guide selecting targeted infertile couples beneficial from IUI treatment, and also identify which parameters are most relevant in IUI clinical pregnancy.

2.
J Immunol ; 207(9): 2325-2336, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34588221

ABSTRACT

Ubiquitination regulates immune signaling, and multiple E3 ubiquitin ligases have been studied in the context of their role in immunity. Despite this progress, the physiological roles of the Pellino E3 ubiquitin ligases, especially Pellino2, in immune regulation remain largely unknown. Accordingly, this study aimed to elucidate the role of Pellino2 in murine dendritic cells (DCs). In this study, we reveal a critical role of Pellino2 in regulation of the proinflammatory response following TLR9 stimulation. Pellino2-deficient murine DCs show impaired secretion of IL-6 and IL-12. Loss of Pellino2 does not affect TLR9-induced activation of NF-κB or MAPKs, pathways that drive expression of IL-6 and IL-12. Furthermore, DCs from Pellino2-deficient mice show impaired production of type I IFN following endosomal TLR9 activation, and it partly mediates a feed-forward loop of IFN-ß that promotes IL-12 production in DCs. We also observe that Pellino2 in murine DCs is downregulated following TLR9 stimulation, and its overexpression induces upregulation of both IFN-ß and IL-12, demonstrating the sufficiency of Pellino2 in driving these responses. This suggests that Pellino2 is critical for executing TLR9 signaling, with its expression being tightly regulated to prevent excessive inflammatory response. Overall, this study highlights a (to our knowledge) novel role for Pellino2 in regulating DC functions and further supports important roles for Pellino proteins in mediating and controlling immunity.


Subject(s)
Dendritic Cells/immunology , Inflammation/immunology , Nuclear Proteins/metabolism , Toll-Like Receptor 9/metabolism , Animals , Gene Expression Regulation , Immunity , Interferon-beta/metabolism , Interleukin-12/metabolism , Interleukin-6/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Nuclear Proteins/genetics , Signal Transduction , Ubiquitination
3.
BMC Health Serv Res ; 23(1): 1454, 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38129826

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is a leading cause of death in Canada and early detection can prevent deaths through screening. However, CRC screening in Alberta, Canada remains suboptimal and varies by sociodemographic and health system characteristics, as well as geographic location. This study aimed to further the understanding of these participant and health system characteristics associated with CRC screening in Alberta and identify clusters of regions with higher rates of overdue or unscreened individuals. METHODS: We included Albertans aged 52 to 74 as of December 31, 2019 (index date) and we used data from administrative health data sources and linked to the Alberta Colorectal Cancer Screening Program database to determine colorectal cancer screening rates. We used multivariable multinomial logistic regression analysis to investigate the relationship between sociodemographic, health system characteristics and participation in CRC screening. We used optimized Getis-Ord Gi* hot-spot analysis to identify hot and cold-spots in overdue for and no record of CRC screening. RESULTS: We included 919,939 Albertans, of which 65% were currently up to date on their CRC screening, 21% were overdue, and 14% had no record of CRC screening. Compared to Albertans who were currently up to date, those who were in older age groups, those without a usual provider of care, those who were health system non-users, and those living in more deprived areas were more likely to have no record of screening. Areas with high number of Albertans with no record of screening were concentrated in the North and Central zones. CONCLUSIONS: Our study showed important variation in colorectal cancer screening participation across sociodemographic, health system and geographical characteristics and identified areas with higher proportions of individuals who have no record of screening or are under-screened in Alberta, Canada.


Subject(s)
Colorectal Neoplasms , Early Detection of Cancer , Humans , Aged , Alberta/epidemiology , Cross-Sectional Studies , Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/prevention & control , Mass Screening
4.
J Acoust Soc Am ; 154(5): 3188-3200, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37971215

ABSTRACT

We present compact reverse time migration (CRTM), a real-time ultrasound imaging method that can exploit the full waveform information of ultrasonic wave records for imaging breast tissue. Conventional reverse time migration (RTM) computes the gradient of the reflective ultrasound data with respect to the perturbation of the velocity model of the soft tissues and the gradient can indicate the interface between different types of body tissue. In contrast to conventional reflection ultrasound (B-mode), which is based on the high-frequency approximation to the wave equation, the RTM algorithm is based on the complete wave equation, and can thus exploit the full waveform (wide-spectrum) information of the data and provide an image with higher resolution. Unfortunately, the computational burden of RTM is noticeably higher than the ray-based B-mode. This precludes real-time applications, one of the most important features of ultrasound imaging. The proposed CRTM algorithm can significantly reduce the computational costs of RTM, such that it can be applied for real-time imaging. We demonstrate the performance of CRTM through a synthetic experiment of ultrasound breast imaging. CRTM can be potentially adapted to related signal-processing fields, such as seismic imaging, acoustic camera systems, and radar imaging.


Subject(s)
Algorithms , Ultrasonic Waves , Ultrasonography/methods , Signal Processing, Computer-Assisted
5.
Mol Microbiol ; 115(6): 1262-1276, 2021 06.
Article in English | MEDLINE | ID: mdl-33341991

ABSTRACT

Hsp70 is an evolutionarily conserved chaperone involved in maintaining protein homeostasis during normal growth and upon exposure to stresses. Mutations in the ß6/ß7 region of the substrate-binding domain (SBD) disrupt the SBD hydrophobic core resulting in impairment of the heat-shock response and prion propagation in yeast. To elucidate the mechanisms behind Hsp70 loss of function due to disruption of the SBD, we undertook targeted mutational analysis of key residues in the ß6/ß7 region. We demonstrate the critical functional role of the F475 residue across yeast cytosolic Hsp70-Ssa family. We identify the size of the hydrophobic side chain at 475 as the key factor in maintaining SBD stability and functionality. The introduction of amino acid variants to either residue 475, or close neighbor 483, caused instability and cleavage of the Hsp70 SBD and subsequent degradation. Interestingly, we found that Hsp70-Ssa cleavage may occur through a vacuolar carboxypeptidase (Pep4)-dependent mechanism rather than proteasomal. Mutations at 475 and 483 result in compromised ATPase function, which reduces protein re-folding activity and contributes to depletion of cytosolic Hsp70 in vivo. The combination of reduced functionality and stability of Hsp70-Ssa results in yeast cells that are compromised in their stress response and cannot propagate the [PSI+ ] prion.


Subject(s)
HSP70 Heat-Shock Proteins/metabolism , Protein Domains/genetics , Protein Folding , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Adenosine Triphosphatases/genetics , Aspartic Acid Endopeptidases/metabolism , Binding Sites/genetics , HSP70 Heat-Shock Proteins/genetics , Hydrophobic and Hydrophilic Interactions , Loss of Function Mutation/genetics , Protein Binding/genetics , Saccharomyces cerevisiae Proteins/metabolism
6.
Reprod Biomed Online ; 45(6): 1176-1181, 2022 12.
Article in English | MEDLINE | ID: mdl-36207251

ABSTRACT

RESEARCH QUESTION: Is there any difference in clinical outcomes between a human chorionic gonadotrophin (HCG)-only trigger and a dual trigger combining gonadotrophin-releasing hormone agonist (GnRHa) and HCG in a progestin-primed ovarian stimulation (PPOS) protocol? DESIGN: This retrospective cohort study included women younger than 40 years old with a normal ovarian reserve who underwent IVF/intracytoplasmic sperm injection treatment with a PPOS protocol. Participants were allocated to two groups according to the triggering medicines. The clinical outcomes were compared, with cumulative live birth rate (CLBR) being the primary outcome. RESULTS: In total, 1066 women were included, 565 in the HCG-only group and 501 in the dual trigger group. Demographic parameters were comparable between the groups. Fewer oocytes were retrieved in the HCG-only trigger group (dual trigger 12.56 ± 7.12 versus HCG-only trigger 11.62 ± 6.02, P = 0.020). No significant difference was observed in the numbers of two-pronuclear embryos (7.12 ± 4.90 versus 6.76 ± 4.45, P = 0.208) and high-quality embryos (4.01 ± 3.70 versus 3.96 ± 3.32, P = 0.815). The CLBR after one complete cycle was also similar (40.72% versus 43.72%, P = 0.354). Multivariate logistic analysis confirmed that the trigger method had no association with CLBR (odds ratio [OR] 0.763, 95% confidence interval [CI] 0.578-1.005, P = 0.055) in the PPOS-treated patients. CONCLUSIONS: Compared with the HCG-only trigger group, comparable embryological and clinical outcomes were achieved, although more oocytes were retrieved in the dual trigger group. This suggests that there may be no extra benefit from dual triggering, and that it should not be recommended for routine use in the general population undergoing PPOS protocols.


Subject(s)
Fertilization in Vitro , Progestins , Adult , Female , Humans , Pregnancy , Chorionic Gonadotropin/pharmacology , Chorionic Gonadotropin/therapeutic use , Fertilization in Vitro/methods , Gonadotropin-Releasing Hormone , Oocytes , Ovulation Induction/methods , Pregnancy Rate , Progestins/pharmacology , Retrospective Studies
7.
Anal Biochem ; 632: 114384, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34543643

ABSTRACT

Invasive pulmonary aspergillosis (IPA) is a severe life-threatening condition. Diagnosis of fungal disease in general, and especially that caused by Aspergillus fumigatus is problematic. A. fumigatus secretes siderophores to acquire iron during infection, which are also essential for virulence. We describe the chemoacetylation of ferrated fusarinine C to diacetylated fusarinine C (DAFC), followed by protein conjugation, which facilitated triacetylfusarinine C (TAFC)-specific monoclonal antibody production with specific recognition of the ferrated form of TAFC. A single monoclonal antibody sequence was ultimately elucidated by a combinatorial strategy involving protein LC-MS/MS, cDNA sequencing and RNAseq. The resultant murine IgG2a monoclonal antibody was secreted in, and purified from, mammalian cell culture (5 mg) and demonstrated to be highly specific for TAFC detection by competitive ELISA (detection limit: 15 nM) and in a lateral flow test system (detection limit: 3 ng), using gold nanoparticle conjugated- DAFC-bovine serum albumin for competition. Overall, this work reveals for the first time a recombinant TAFC-specific monoclonal antibody with diagnostic potential for IPA diagnosis in traditional and emerging patient groups (e.g., COVID-19) and presents a useful strategy for murine Ig sequence determination, and expression in HEK293 cells, to overcome unexpected limitations associated with aberrant or deficient murine monoclonal antibody production.


Subject(s)
Antibodies, Monoclonal/immunology , Aspergillosis/diagnosis , Ferric Compounds/immunology , Hydroxamic Acids/immunology , Immunoconjugates/chemistry , Siderophores/chemistry , Animals , Aspergillosis/microbiology , Aspergillus fumigatus/chemistry , Aspergillus fumigatus/pathogenicity , Enzyme-Linked Immunosorbent Assay , Ferric Compounds/analysis , HEK293 Cells , Humans , Hydroxamic Acids/analysis , Mice , Recombinant Proteins/immunology
8.
Biol Chem ; 401(4): 505-515, 2020 03 26.
Article in English | MEDLINE | ID: mdl-31527287

ABSTRACT

The present study aimed at evaluating the mechanism by which functionality of hepatic stellate cells (HSCs) is modulated by bone marrow stromal cells (BMSCs). Induction of apoptosis in HSCs was found to be caused by directly co-culturing HSCs with BMSCs, where the expression of α-smooth muscle actin (α-SMA) increased significantly in HSCs, along with an increase in their proliferation rate. Additionally, expression of Hes1 and Notch1 in HSCs co-cultured with BMSCs increased significantly at both protein and mRNA levels. Blocking of the notch signaling pathway (NSP) either by Notch1 siRNA or by DAPT treatment increased the proliferation rate while decreasing apoptosis and led to activation of the NF-κB signaling pathway in HSCs co-cultured with BMSCs. These effects were found to be reversed in HSCs overexpressing IκB S32/S36 mutants. The Notch signaling-mediated cell-cell contact was partially involved in the significant inhibition of proliferation of HSCs by BMSCs. Additionally, the NF-κB pathway was found to be responsible for NSP-mediated inhibition of growth of HSCs in the co-culture system. Thus, BMSCs might have a potential therapeutic significance in treating hepatic fibrosis.


Subject(s)
Apoptosis , Bone Marrow/metabolism , Hepatic Stellate Cells/metabolism , Mesenchymal Stem Cells/metabolism , NF-kappa B/metabolism , Receptors, Notch/metabolism , Cells, Cultured , Coculture Techniques , Humans , Signal Transduction
9.
J Biol Chem ; 293(46): 17663-17675, 2018 11 16.
Article in English | MEDLINE | ID: mdl-30228181

ABSTRACT

The allosteric coupling of the highly conserved nucleotide- and substrate-binding domains of Hsp70 has been studied intensively. In contrast, the role of the disordered, highly variable C-terminal region of Hsp70 remains unclear. In many eukaryotic Hsp70s, the extreme C-terminal EEVD motif binds to the tetratricopeptide-repeat domains of Hsp70 co-chaperones. Here, we discovered that the TVEEVD sequence of Saccharomyces cerevisiae cytoplasmic Hsp70 (Ssa1) functions as a SUMO-interacting motif. A second C-terminal motif of ∼15 amino acids between the α-helical lid and the extreme C terminus, previously identified in bacterial and eukaryotic organellar Hsp70s, is known to enhance chaperone function by transiently interacting with folding clients. Using structural analysis, interaction studies, fibril formation assays, and in vivo functional assays, we investigated the individual contributions of the α-helical bundle and the C-terminal disordered region of Ssa1 in the inhibition of fibril formation of the prion protein Ure2. Our results revealed that although the α-helical bundle of the Ssa1 substrate-binding domain (SBDα) does not directly bind to Ure2, the SBDα enhances the ability of Hsp70 to inhibit fibril formation. We found that a 20-residue C-terminal motif in Ssa1, containing GGAP and GGAP-like tetrapeptide repeats, can directly bind to Ure2, the Hsp40 co-chaperone Ydj1, and α-synuclein, but not to the SUMO-like protein SMT3 or BSA. Deletion or substitution of the Ssa1 GGAP motif impaired yeast cell tolerance to temperature and cell-wall damage stress. This study highlights that the C-terminal GGAP motif of Hsp70 is important for substrate recognition and mediation of the heat shock response.


Subject(s)
Adenosine Triphosphatases/metabolism , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Response/physiology , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/chemistry , Adenosine Triphosphatases/chemistry , Amino Acid Motifs , Amyloid/metabolism , Glutathione Peroxidase/metabolism , HSP40 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/chemistry , Prions/metabolism , Protein Binding , Protein Domains , Protein Multimerization , Saccharomyces cerevisiae Proteins/chemistry , alpha-Synuclein/metabolism
10.
Cell Mol Life Sci ; 75(8): 1445-1459, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29124308

ABSTRACT

Hsp70 is a highly conserved chaperone that in addition to providing essential cellular functions and aiding in cell survival following exposure to a variety of stresses is also a key modulator of prion propagation. Hsp70 is composed of a nucleotide-binding domain (NBD) and substrate-binding domain (SBD). The key functions of Hsp70 are tightly regulated through an allosteric communication network that coordinates ATPase activity with substrate-binding activity. How Hsp70 conformational changes relate to functional change that results in heat shock and prion-related phenotypes is poorly understood. Here, we utilised the yeast [PSI +] system, coupled with SBD-targeted mutagenesis, to investigate how allosteric changes within key structural regions of the Hsp70 SBD result in functional changes in the protein that translate to phenotypic defects in prion propagation and ability to grow at elevated temperatures. We find that variants mutated within the ß6 and ß7 region of the SBD are defective in prion propagation and heat-shock phenotypes, due to conformational changes within the SBD. Structural analysis of the mutants identifies a potential NBD:SBD interface and key residues that may play important roles in signal transduction between domains. As a consequence of disrupting the ß6/ß7 region and the SBD overall, Hsp70 exhibits a variety of functional changes including dysregulation of ATPase activity, reduction in ability to refold proteins and changes to interaction affinity with specific co-chaperones and protein substrates. Our findings relate specific structural changes in Hsp70 to specific changes in functional properties that underpin important phenotypic changes in vivo. A thorough understanding of the molecular mechanisms of Hsp70 regulation and how specific modifications result in phenotypic change is essential for the development of new drugs targeting Hsp70 for therapeutic purposes.


Subject(s)
HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Response/physiology , Prions/metabolism , Adenosine Triphosphatases/metabolism , Allosteric Regulation/physiology , Binding Sites/physiology , Molecular Chaperones/metabolism , Protein Binding/physiology , Protein Domains/physiology , Yeasts/metabolism
11.
J Reprod Med ; 62(3-4): 179-83, 2017.
Article in English | MEDLINE | ID: mdl-30230791

ABSTRACT

Objective: To evaluate the association between leptin level, adiponectin level, gestational weight gain, maternal constitutional factors, and the weights at birth and at 1 year of age in infants born to women with gestational diabetes mellitus (GDM). Study Design: Fifty-one women with GDM were recruited from June 2011 to September 2011. Leptin and adiponectin levels in maternal and cord blood were measured and their correlations with infant's birth weight and weight after 1 year were evaluated using Pearson correlation analysis. The weight correlations were also determined with maternal constitutional factors. Results: The neonatal birth weight positively correlates with cord blood leptin (r=0.316, p=0.024) and adiponectin (r=0.855, p=0.026) levels. One-year-old infant's weight correlates only with the cord blood adiponectin level (r=0.753, p=0.036). The infant's birth weight had positive correlations with maternal constitutional factors such as prepregnancy weight (r=0.340, p=0.015), prepregnancy BMI (r=0.289, p=0.040), prepartum weight (r=0.404, p=0.003), prepartum BMI (r=0.348, p=0.012), and gestational weight gain (r= 0.280, p=0.047). Conclusion: The infant's birth weight is closely associated with cord blood levels of both leptin and adiponectin and with pregravid and prepartum maternal obesity. The 1-year weight of infants born to GDM mothers is only associated with levels of adiponectin in cord blood.


Subject(s)
Adiponectin/blood , Birth Weight , Diabetes, Gestational/blood , Fetal Blood/metabolism , Leptin/blood , Adult , Body Mass Index , Female , Humans , Infant , Infant, Newborn , Obesity/blood , Pregnancy , Receptors, Leptin/blood , Young Adult
12.
J Low Genit Tract Dis ; 21(1): 17-20, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27824788

ABSTRACT

OBJECTIVE: To examine the screening history of invasive cervical cancer (ICC) cases in Alberta, Canada to identify areas for improvement of the population-based cervical cancer screening program. METHODS: Retrospective review of ICC cases diagnosed in 2 cities in Alberta between 2007 and 2012. Cancer morphology and staging were elicited from the Alberta Cancer Registry; cancer screening history and Pap test results were extracted from the Provincial Cervical Cancer Screening database. Women were classified as adequately screened, underscreened, and unscreened depending on time from last screening Pap test to diagnosis. RESULTS: Of the 280 cases that occurred in women eligible for screening, 125 (44.6%) were adequately screened, 18 (6.4%) were underscreened, and 137 (49%) were unscreened. Among the adequately screened, 71 (56.8%) had normal Pap test results, but 48 (38%) had less than 3 previous Pap tests (p = .003). Cancer stages I to II were diagnosed in 48.8% and 44.1% of adequately screened and unscreened women and cancer stages III to IV in 30.6% and 66.1% in each group, respectively (p = .0058). Squamous cell carcinoma (SCC) was diagnosed in 189 women (67.5%). The proportion of SCCs was similar in adequately screened and unscreened women. CONCLUSIONS: The proportion of SCCs and advanced stages of ICC seems to be decreased. The results of quality improvement initiatives such as enhanced surveillance of high-grade Pap test results and histology-cytology correlation will be monitored and are expected to result in better outcomes for adequately screened women.


Subject(s)
Carcinoma, Squamous Cell/diagnosis , Early Detection of Cancer/statistics & numerical data , Papanicolaou Test/statistics & numerical data , Uterine Cervical Neoplasms/diagnosis , Adult , Aged , Alberta , Carcinoma, Squamous Cell/pathology , Cities , Female , Humans , Middle Aged , Retrospective Studies , Uterine Cervical Neoplasms/pathology , Young Adult
13.
CMAJ ; 188(12): E281-E288, 2016 Sep 06.
Article in English | MEDLINE | ID: mdl-27378467

ABSTRACT

BACKGROUND: A school-based program with quadrivalent human papillomavirus (HPV) vaccination was implemented in Alberta in 2008. We assessed the impact of this program on Pap test cytology results using databases of province-wide vaccination and cervical cancer screening. METHODS: We conducted a nested case-control study involving a cohort of women in Alberta born between 1994 and 1997 who had at least 1 Pap test between 2012 and 2015. Women with negative cytology results were controls. Women with low-grade (atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion) and high-grade (atypical squamous cells, cannot rule out a high-grade lesion; or high-grade squamous intraepithelial lesion) cervical abnormalities were cases. Exposure status was assigned according to records of HPV vaccination. Odds ratios (ORs) for abnormal cytology results by vaccination status were adjusted for neighbourhood income, laboratory service, rural versus urban residency, and age. RESULTS: The total study population was 10 204. Adjusting for age, vaccinated women had a higher screening rate than unvaccinated women (13.0% v. 11.4%, p < 0.001). Among women who received full vaccination (≥ 3 doses), the adjusted OR for cervical abnormalities was 0.72 (95% confidence interval [CI] 0.63-0.82). For high-grade lesions, the adjusted OR was 0.50 (95% CI 0.30-0.85). With 2-dose HPV vaccination, the adjusted OR for cervical abnormalities was 1.08 (95% CI 0.84-1.38). INTERPRETATION: Quadrivalent HPV vaccination significantly reduced high-grade cervical abnormalities but required 3 doses. Vaccination against HPV was associated with screening uptake. Population-based vaccination and screening programs should work together to optimize cervical cancer prevention.


Subject(s)
Early Detection of Cancer/statistics & numerical data , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines/therapeutic use , Uterine Cervical Neoplasms/diagnosis , Vaccination/statistics & numerical data , Adolescent , Alberta , Case-Control Studies , Databases, Factual , Female , Humans , Logistic Models , Mass Screening/statistics & numerical data , Papanicolaou Test , Uterine Cervical Neoplasms/virology , Vaginal Smears , Young Adult
14.
PLoS Comput Biol ; 9(1): e1002896, 2013.
Article in English | MEDLINE | ID: mdl-23382668

ABSTRACT

Genetic screens using Saccharomyces cerevisiae have identified an array of cytosolic Hsp70 mutants that are impaired in the ability to propagate the yeast [PSI(+)] prion. The best characterized of these mutants is the Ssa1 L483W mutant (so-called SSA1-21), which is located in the substrate-binding domain of the protein. However, biochemical analysis of some of these Hsp70 mutants has so far failed to provide major insight into the specific functional changes in Hsp70 that cause prion impairment. In order to gain a better understanding of the mechanism of Hsp70 impairment of prions we have taken an in silico approach and focused on the Escherichia coli Hsp70 ortholog DnaK. Using steered molecular dynamics simulations (SMD) we demonstrate that DnaK variant L484W (analogous to SSA1-21) is predicted to bind substrate more avidly than wild-type DnaK due to an increase in numbers of hydrogen bonds and hydrophobic interactions between chaperone and peptide. Additionally the presence of the larger tryptophan side chain is predicted to cause a conformational change in the peptide-binding domain that physically impairs substrate dissociation. The DnaK L484W variant in combination with some SSA1-21 phenotypic second-site suppressor mutations exhibits chaperone-substrate interactions that are similar to wild-type protein and this provides a rationale for the phenotypic suppression that is observed. Our computational analysis fits well with previous yeast genetics studies regarding the functionality of the Ssa1-21 protein and provides further evidence suggesting that manipulation of the Hsp70 ATPase cycle to favor the ADP/substrate-bound form impairs prion propagation. Furthermore, we demonstrate how SMD can be used as a computational tool for predicting Hsp70 peptide-binding domain mutants that impair prion propagation.


Subject(s)
HSP70 Heat-Shock Proteins/metabolism , Molecular Dynamics Simulation , Mutation , Prions/metabolism , HSP70 Heat-Shock Proteins/chemistry , HSP70 Heat-Shock Proteins/genetics , Hydrogen Bonding , Models, Molecular , Protein Binding
15.
J Med Screen ; : 9691413241239023, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38486492

ABSTRACT

OBJECTIVE: To quantify the associations between time to colonoscopy after a positive fecal immunochemical test (FIT+) and colorectal cancer (CRC)-related outcomes in the context of a provincial, population-based CRC screening program. SETTING: Population-based, retrospective cohort study in Alberta, Canada, including Albertans aged 50-74 with at least one FIT+ in 2014-2017. METHODS: Study outcomes were CRC diagnosis after a FIT+ and a diagnostic follow-up colonoscopy in 2014-2019 and CRC stage at diagnosis. Multivariable logistic regression models were used to evaluate the relative risk of any CRC or advanced-stage CRC. Results were presented as crude odds ratio (OR) and adjusted OR (aOR) with 95% confidence intervals (CIs). RESULTS: Of the 787,967 participants who had a FIT, 63,232 (8%) had a FIT+ and met the study's eligibility criteria. The risk of any CRC or advanced-stage CRC stayed high and was relatively consistent for follow-up colonoscopies performed within 1-12 months of the FIT+. After 12 months, the risk of CRC was considerably higher, particularly for advanced-stage CRC. The OR and aOR for any CRC were 1.40 (95% CI: 1.13-1.73; p < 0.05) and 1.20 (95% CI: 0.96-1.49), respectively, and the OR and aOR for advanced-stage CRC were 1.42 (95% CI: 0.98-2.08) and 0.88 (95% CI: 0.59-1.32), respectively, for colonoscopy follow-up within 12-18 months versus 1-2 months. CONCLUSIONS: For Albertans who used FIT for CRC screening, a longer time interval between a FIT+ and follow-up colonoscopy, particularly over 12 months, increases the risk of having CRC and decreases the effectiveness of CRC screening programs.

16.
Int J Biol Macromol ; 260(Pt 1): 129455, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38232876

ABSTRACT

Plumbago zeylanica L., a traditional Chinese medicine, has anti-bacterial and anti-inflammatory effects, and it is critical important to explore the chemical compounds and evaluate their biological actions from the medicinal plant. However, the chemical structure and biological activities of polysaccharides from P. zeylanica. were still poorly understood. In this study, two water-soluble polysaccharides named WPZP-2-1 and WPZP-2-2 were purified from P. zeylanica L. Chemical and spectroscopic tests showed that the main chain of WPZP-2-1 was →4)-α-D-GalpA-(1 â†’ 2)-α-L-Rhap-(1→, and the branch chain was galactose or arabinose. The main chain of WPZP-2-2 was composed of →4)-α-D-GalpA-(1 â†’ 2)-α-L-Rhap-(1→, and the O-2 and O-3 of →4)-α-D-GalpA had a small amount of acetylation. In addition, in vitro test showed that WPZP-2-1 and WPZP-2-2 significantly improved the inflammatory damage of LPS + IFN-γ-induced THP-1 cells via reducing the protein levels of CD14, TLR4 and MyD88, thereby promoting IL-10 expression and inhibiting the mRNA levels of TNF-α and IL-1ß. Those findings indicated that WPZP-2-1 and WPZP-2-2 from the plant should be served as the potential anti-inflammatory agents.


Subject(s)
Plants, Medicinal , Plumbaginaceae , Plumbaginaceae/chemistry , Polysaccharides/chemistry , Anti-Inflammatory Agents/pharmacology , Plant Extracts/chemistry
17.
Article in English | MEDLINE | ID: mdl-38706410

ABSTRACT

OBJECTIVE: To investigate associations between hysteroscopic surgery for patients with varying cesarean scar diverticulum (CSD) severity and in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) embryo transfer (ET) pregnancy outcomes, focusing also on the correlation between the CSD size with its severity, and pregnancy outcomes. METHODS: A retrospective study was conducted on patients with CSD who underwent IVF/ICSI-ET at a university-based hospital between January 2017 and July 2023. Patients were categorized into four groups based on CSD severity and whether they received hysteroscopic surgery: a mild surgical group (Group A, n = 86), a mild non-surgical group (Group B, n = 30), a moderate-to-severe surgical group (Group C, n = 173), and a moderate-to-severe non-surgical group (Group D, n = 96). Baseline characteristics and pregnancy outcomes were compared among these groups. Correlation assessments were conducted to explore relationships between CSD size with its severity, and pregnancy outcomes. RESULTS: Compared with Group D, Group C exhibited significantly increased rates of biochemical pregnancy (odds ratio [OR] 1.90; 95% confidence interval [CI] 1.03-3.51, P = 0.041), clinical pregnancy (OR 2.30; 95% CI1.18-4.45; P = 0.014), and live birth (OR 2.77; 95% CI 1.10-7.00, P = 0.031). However, no differences in pregnancy outcomes were observed between Groups A and B. Correlation analyses revealed significant positive associations between CSD severity and its depth, length, width, and volume. CONCLUSIONS: Patients with moderate-to-severe CSD achieved favorable IVF/ICSI pregnancy outcomes following hysteroscopic surgery. The CSD size was significantly related to its severity.

18.
Gut Microbes ; 16(1): 2359665, 2024.
Article in English | MEDLINE | ID: mdl-38831611

ABSTRACT

The facultative anaerobic Gram-positive bacterium Enterococcus faecium is a ubiquitous member of the human gut microbiota. However, it has gradually evolved into a pathogenic and multidrug resistant lineage that causes nosocomial infections. The establishment of high-level intestinal colonization by enterococci represents a critical step of infection. The majority of current research on Enterococcus has been conducted under aerobic conditions, while limited attention has been given to its physiological characteristics in anaerobic environments, which reflects its natural colonization niche in the gut. In this study, a high-density transposon mutant library containing 26,620 distinct insertion sites was constructed. Tn-seq analysis identified six genes that significantly contribute to growth under anaerobic conditions. Under anaerobic conditions, deletion of sufB (encoding Fe-S cluster assembly protein B) results in more extensive and significant impairments on carbohydrate metabolism compared to aerobic conditions. Consistently, the pathways involved in this utilization-restricted carbohydrates were mostly expressed at significantly lower levels in mutant compared to wild-type under anaerobic conditions. Moreover, deletion of sufB or pflA (encoding pyruvate formate lyase-activating protein A) led to failure of gastrointestinal colonization in mice. These findings contribute to our understanding of the mechanisms by which E. faecium maintains proliferation under anaerobic conditions and establishes colonization in the gut.


Subject(s)
Bacterial Proteins , Enterococcus faecium , Iron-Sulfur Proteins , Enterococcus faecium/genetics , Enterococcus faecium/metabolism , Enterococcus faecium/growth & development , Animals , Mice , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Anaerobiosis , Iron-Sulfur Proteins/genetics , Iron-Sulfur Proteins/metabolism , Gastrointestinal Tract/microbiology , Gastrointestinal Microbiome , Gram-Positive Bacterial Infections/microbiology , Humans , DNA Transposable Elements , Carbohydrate Metabolism , Female , Acetyltransferases
19.
BMC Cancer ; 13: 167, 2013 Mar 28.
Article in English | MEDLINE | ID: mdl-23537372

ABSTRACT

BACKGROUND: UCN-01 (7-hydroxystaurosporine), a protein kinase inhibitor, has attracted a great deal of attention as a potent antitumour agent. Several clinical trials of UCN-01 alone or in combination with other agents for different tumour types are currently underway, and some of these trials have had positive results. Hepatocellular carcinoma has high incidence rates and is associated with poor prognosis and high mortality rates. METHODS: Three different hepatoma cell lines (Huh7, HepG2, and Hep3B) were treated with different concentrations of UCN-01, and the anti-tumour effects of UCN-01 were evaluated. Following UCN-01 treatment, cell growth was measured using an MTT assay, cell cycle arrest was assayed using flow cytometry, and the mechanisms of cell cycle arrest and invasion inhibition were investigated through western blotting and a Matrigel invasion assay. RESULTS: After a 72-h UCN-01 treatment, the growth of different hepatoma cell lines was significantly inhibited in a dose-dependent manner, with IC50 values ranging from 69.76 to 222.74 nM. Flow cytometry results suggested that UCN-01 inhibits proliferation in the hepatoma cells by inducing S and G2/M phase arrest, but not G1/S arrest, which differs from previous reports that used other tumour cell lines. Western blot results illustrated that UCN-01 induces a G2/M phase arrest, regardless of the status of the p53/P21(waf1) pathway, whereas the CHK2/CDC25C pathway and the p53/p21(waf1)pathway were involved in the UCN-01-induced S phase arrest. UCN-01 remarkably inhibited Huh7 cell invasion in a time-dependent manner. Suppression of Huh7 cell invasion may be due to the down-regulation of phosphorylated ß-catenin by UCN-01. CONCLUSIONS: These findings suggest that UCN-01 induces hepatoma cell growth inhibition by regulating the p53/p21(waf1) and CHK2/CDC25 pathways. Suppression of Huh7 cell invasion by UCN-01 may be due to the down-regulation of phosphorylated ß-catenin. These data lend support for further studies on UCN-01 as a promising anti-HCC candidate.


Subject(s)
Cell Cycle Checkpoints/drug effects , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Protein Serine-Threonine Kinases/metabolism , Signal Transduction/drug effects , Staurosporine/analogs & derivatives , Tumor Suppressor Protein p53/metabolism , cdc25 Phosphatases/metabolism , Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Checkpoint Kinase 2 , Humans , Inhibitory Concentration 50 , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Protein Kinase Inhibitors/pharmacology , Staurosporine/pharmacology , Tumor Suppressor Protein p53/genetics
20.
Microbiol Spectr ; 11(1): e0275022, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36541787

ABSTRACT

Listeria monocytogenes is a foodborne pathogen that can tolerate a variety of extreme environments. In particular, its acid resistance (AR) capability is considered one of the key factors threating food safety. Here, we employed a microbial functional genomic technology termed transposon sequencing (Tn-seq), leading to the identification of two genes involved in cell wall peptidoglycan biosynthesis (murF) and phosphate transport (lmo2248) that play key roles in lactic acid resistance (LAR) of L. monocytogenes. Deletion of lmo2248 significantly impaired the ability of LAR in L. monocytogenes, demonstrating the accuracy of the Tn-seq results. Transcriptome analysis revealed that 31.7% of the L. monocytogenes genes on the genome were differentially expressed under lactic acid (LA) treatment, in which genes involved in phosphate transport were influenced most significantly. These findings shed light on the LAR mechanisms of L. monocytogenes, which may contribute to the development of novel strategies against foodborne pathogens. IMPORTANCE Listeria monocytogenes is a Gram-positive foodborne pathogen with high lethality and strong stress resistance, and its strong acid tolerance leads to many foodborne illnesses occurring in low-pH foods. Lactic acid is a generally recognized as safe (GRAS) food additive approved for use by the FDA. However, the genetic determinants of lactic acid resistance in L. monocytogenes have not been fully identified. In this study, the lactic acid resistance determinants of L. monocytogenes were comprehensively identified by Tn-seq on a genome-wide scale. Two genes, murF (cell wall peptidoglycan biosynthesis) and lmo2248 (phosphate transport), were identified to play an important role in the lactic acid resistance. Moreover, genome-wide transcriptomic analysis showed that phosphotransferase system (PTS)-related genes play a key role at the transcriptional level. These findings contribute to a better understanding of the lactic acid resistance mechanism of L. monocytogenes and may provide unique targets for the development of other novel antimicrobial agents.


Subject(s)
Listeria monocytogenes , Listeria monocytogenes/genetics , Transcriptome , Lactic Acid , Peptidoglycan , Food Microbiology , Gene Expression Profiling , Phosphates
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