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1.
Can J Neurol Sci ; : 1-12, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-38178730

ABSTRACT

OBJECTIVES: Spinal muscular atrophy (SMA) is a leading genetic cause of infant death and represents a significant burden of care. An improved understanding of the epidemiology of SMA in Canada may help inform strategies to improve the standard of care for individuals living with SMA. METHODS: We employed a multisource approach to estimate the minimal incidence and prevalence of 5q SMA and to gain greater insight into recent clinical practices and treatment trends for the Canadian SMA population. Data sources included the Canadian Paediatric Surveillance Program (CPSP), Canadian Neuromuscular Disease Registry (CNDR), and molecular genetics laboratories in Canada. RESULTS: The estimated annual minimum incidence of 5q SMA was 4.38, 3.44, and 7.99 cases per 100,000 live births in 2020 and 2021, based on CPSP, CNDR, and molecular genetics laboratories data, respectively, representing approximately 1 in 21,472 births (range 12,516-29,070) in Canada. SMA prevalence was estimated to be 0.85 per 100,000 persons aged 0-79 years. Delay in diagnosis exists across all SMA subtypes. Most common presenting symptoms were delayed milestones, hypotonia, and muscle weakness. Nusinersen was the most common disease-modifying treatment received. Most patients utilized multidisciplinary clinics for management of SMA. CONCLUSION: This study provides data on the annual minimum incidence of pediatric 5q SMA in Canada. Recent therapeutic advances and newborn screening have the potential to drastically alter the natural history of SMA. Findings underline the importance of ongoing surveillance of the epidemiology and long-term health outcomes of SMA in the Canadian population.

2.
J Neurol Sci ; 457: 122864, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38185014

ABSTRACT

Congenital myopathy with tremor (MYOTREM) is a recently described disorder characterized by mild myopathy and a postural and intention tremor present since early infancy. MYOTREM is associated with pathogenic variants in MYBPC1 which encodes slow myosin-binding protein C, a sarcomere protein with regulatory and structural roles. Here, we describe a family with three generations of variably affected members exhibiting a novel variant in MYBPC1 (c.656 T > C, p.Leu219Pro). Among the unique features of affected family members is the persistence of tremor in sleep. We also present the first muscle magnetic resonance images for this disorder, and report muscle atrophy and fatty infiltration.


Subject(s)
Muscular Diseases , Tremor , Humans , Family , Mutation/genetics , Tremor/diagnostic imaging , Tremor/genetics
4.
J Infect Dis ; 229(1): 262-272, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-37855446

ABSTRACT

Periodontitis is an exemplar of dysbiosis associated with the coordinated action of multiple members within the microbial consortium. The polymicrobial synergy and dysbiosis hypothesis proposes a dynamic host-microbiome balance, with certain modulators capable of disrupting eubiosis and driving shifts towards dysbiosis within the community. However, these factors remain to be explored. We established a Porphyromonas gingivalis- or Aggregatibacter actinomycetemcomitans-modified subgingival microbiome model and 16S rRNA sequencing revealed that P. gingivalis and A. actinomycetemcomitans altered the microbiome structure and composition indicated by α and ß diversity metrics. P. gingivalis increased the subgingival dysbiosis index (SDI), while A. actinomycetemcomitans resulted in a lower SDI. Furthermore, P. gingivalis-stimulated microbiomes compromised epithelium function and reduced expression of tight junction proteins, whereas A. actinomycetemcomitans yielded mild effects. In conclusion, by inoculating P. gingivalis, we created dysbiotic microcosm biofilms in vitro resembling periodontitis-related subgingival microbiota, exhibiting enhanced dysbiosis and impaired epithelium integrity.


Subject(s)
Microbiota , Periodontitis , Humans , Porphyromonas gingivalis , Aggregatibacter actinomycetemcomitans/genetics , RNA, Ribosomal, 16S/genetics , Dysbiosis
5.
Clin Ther ; 45(8): 702-709, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37453830

ABSTRACT

PURPOSE: Although costly, genome-wide sequencing (GWS) detects an extensive range of variants, enhancing our ability to diagnose and assess risk for an increasing number of diseases. In addition to detecting variants related to the indication for testing, GWS can detect secondary variants in BRCA1, BRCA2, and other genes for which early intervention may improve health. As the list of secondary findings grows, there is increased demand for surveillance and management by multiple specialists, adding pressure to constrained health care budgets. Secondary finding testing is actively debated because some consider it opportunistic screening for future health risks that may not manifest. Given the economic implications of secondary finding testing and follow-up and its unproven clinical utility, the objective is to assess the incremental cost-effectiveness of secondary finding ascertainment per case detected and per unit of improved clinical utility in families of children with unexplained suspected genetic conditions undergoing clinical GWS. METHODS: Those undergoing trio genome or exome sequencing are eligible for the study. Positive secondary finding index cases will be matched to negative controls (1:2) based on age group, primary result(s) type, and clinical indication. During the 2-year study, 71 cases and 142 matched controls are expected. Health service use will be collected in patients and 1 adult family member every 6 months. The per-child and per-dyad total cost will be determined by multiplying use of each resource by a corresponding unit price and summing all cost items. Costs will be estimated from the public and societal payer perspectives. The mean cost per child and per dyad for secondary finding-positive and secondary finding-negative groups will be compared statistically. If important demographic differences are observed between groups, ordinary least-squares regression, log transformation, or other nonparametric technique will be used to compare adjusted mean costs. The ratio of the difference in mean cost to the secondary finding yield will be used to estimate incremental cost-effectiveness. In secondary analyses, effectiveness will be estimated using the number of clinical management changes due to secondary findings or the Clinician-Reported Genetic Testing Utility Index (C-GUIDE) score, a validated measure of clinical utility. Sensitivity analysis will be undertaken to assess the robustness of the findings to variation in key parameters. IMPLICATIONS: This study generates key evidence to inform clinical practice and funding allocation related to secondary finding testing. The inclusion of family members and a new measure of clinical utility represent important advancements in economic evaluation in genomics.

6.
Molecules ; 28(9)2023 May 07.
Article in English | MEDLINE | ID: mdl-37175356

ABSTRACT

Oral health is crucial to daily life, yet many people worldwide suffer from oral diseases. With the development of oral tissue engineering, there is a growing demand for dental biomaterials. Addressing oral diseases often requires a two-fold approach: fighting bacterial infections and promoting tissue growth. Hydrogels are promising tissue engineering biomaterials that show great potential for oral tissue regeneration and drug delivery. In this review, we present a classification of hydrogels commonly used in dental research, including natural and synthetic hydrogels. Furthermore, recent applications of these hydrogels in endodontic restorations, periodontal tissues, mandibular and oral soft tissue restorations, and related clinical studies are also discussed, including various antimicrobial and tissue growth promotion strategies used in the dental applications of hydrogels. While hydrogels have been increasingly studied in oral tissue engineering, there are still some challenges that need to be addressed for satisfactory clinical outcomes. This paper summarizes the current issues in the abovementioned application areas and discusses possible future developments.


Subject(s)
Hydrogels , Tissue Engineering , Humans , Biocompatible Materials/pharmacology , Hydrogels/pharmacology , Periodontium
7.
Zhongguo Gu Shang ; 36(4): 364-70, 2023 Apr 25.
Article in Chinese | MEDLINE | ID: mdl-37087627

ABSTRACT

OBJECTIVE: To explore correlation between imaging classification of knee osteoarthritis (KOA) and axis angle of tibiofemoral and patellofemoral joints. METHODS: A retrospective analysis of 739 middle-aged and elderly patients with KOA (1 026 knee joints) who underwent vertical X-ray examination of both lower limbs and lateral knee joints from September 2018 to December 2020. Among them, 63 patients with K-L 0 grade (95 knee joints), 100 patients with K-L 1 grade (130 knee joints), 161 patients with K-L 2 grade (226 knee joints), 187 patients with K-L 3 grade (256 knee joints), and 228 patients of K-L 4 grade (319 knee joints). According to relative position of knee joint center and line between hip joint center and ankle joint center, the affected knee was divided into varus group(844 knees joints) and valgus group (182 knees joints). According to Install-Salvati method, the affected knee was divided into three groups, such as high patella (patella height>1.2 mm, 347 knees joints), median patella (patella height ranged from 0.8 to 1.2 mm, 561 knees joints), and low patella (patella height<0.8 mm, 118 knees joints). Lower femur angle, upper tibia angle, femoral neck shaft angle, femoral tibial angle, joint gap angle, hip-knee-ankle angle, patella-femoral angle and patella height among different groups were observed and compared. RESULTS: (1) In varus KOA group, there were statistical differnces in hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades (P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle and K-L grade were significantly positively correlated at 0.01(P<0.05);femoral neck shaft angle and K-L grade showed negative correlation at 0.01(P<0.05). (2) In valgus KOA group, hip-knee-ankle angle, there were statistical differences in tibiofemoral angle, inferior femoral angle, superior tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades(P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, and femoral neck shaft angle showed negative correlation with K-L grades at level of 0.01 (P<0.05);joint gap angle and K-L grades showed significantly positive correlation at level of 0.01(P<0.05). (3) In high patella group, there were statistically differences in patellar height and patellar femoral angle of different K-L grades(P<0.05);there were no statistical difference in patella height and patellar femoral angle of different K-L grades in median patella group. There was no significant difference in patella heightin low patella group with different K-L grades(P>0.05), and there was statistical difference in patellofemoral angle(P<0.05). Patellar height and patella-femoral angle of high patella group were significantly positively correlated with K-L grades at the level of 0.01 (P<0.05);patella height and patella-femoral angle were not correlated with K-L grades in median patella group(P>0.05). There was no correlation between height of patella and K-L grade in low patella group (P>0.05). There was significant negative correlation between patella-femoral angle and K-L grade at level of 0.05 (P<0.05). CONCLUSION: Inferior femoral angle, tibiofemoral angle, joint gap angle, hip-knee-ankle angle, femoral neck shaft angle and high patella are related to K-L classification of varus KOA, which could be used for early diagnosis and provide objective data for efficacy analysis of conservative treatment.


Subject(s)
Osteoarthritis, Knee , Patellofemoral Joint , Aged , Middle Aged , Humans , Patellofemoral Joint/diagnostic imaging , Osteoarthritis, Knee/diagnostic imaging , Retrospective Studies , Knee Joint , Femur/diagnostic imaging , Tibia
8.
Int J Mol Sci ; 24(6)2023 Mar 07.
Article in English | MEDLINE | ID: mdl-36982143

ABSTRACT

A large amount of cyanide-containing wastewater is discharged during electrode material synthesis. Among them, cyanides will form metal-cyanide complex ions which possess high stability, making it challenging to separate them from these wastewaters. Therefore, it is imperative to understand the complexation mechanism of cyanide ions and heavy metal ions from wastewater in order to obtain a deep insight into the process of cyanide removal. This study employs Density Functional Theory (DFT) calculations to reveal the complexation mechanism of metal-cyanide complex ions formed by the interaction of Cu+ and CN- in copper cyanide systems and its transformation patterns. Quantum chemical calculations show that the precipitation properties of Cu(CN)43- can assist in the removal of CN-. Therefore, transferring other metal-cyanide complex ions to Cu(CN)43- can achieve deep removal. OLI studio 11.0 analyzed the optimal process parameters of Cu(CN)43- under different conditions and determined the optimal process parameters of the removal depth of CN-. This work has the potential to contribute to the future preparation of related materials such as CN- removal adsorbents and catalysts and provide theoretical foundations for the development of more efficient, stable, and environmentally friendly next-generation energy storage electrode materials.


Subject(s)
Coordination Complexes , Water Pollutants, Chemical , Wastewater , Copper/chemistry , Cyanides/chemistry , Water , Species Specificity , Ions , Water Pollutants, Chemical/chemistry
9.
Am J Med Genet A ; 191(2): 338-347, 2023 02.
Article in English | MEDLINE | ID: mdl-36331261

ABSTRACT

The introduction of clinical exome sequencing (ES) has provided a unique opportunity to decrease the diagnostic odyssey for patients living with a rare genetic disease (RGD). ES has been shown to provide a diagnosis in 29%-57% of patients with a suspected RGD, with as many as 70% remaining undiagnosed. There is a need to advance the clinical model of care by more formally integrating approaches that were previously considered research into an enhanced diagnostic workflow. We developed an Exome Clinic, which set out to evaluate a workflow for improving the diagnostic yield of ES for patients with an undiagnosed RGD. Here, we report the outcomes of 47 families who underwent clinical ES in the first year of the clinic. The diagnostic yield from clinical ES was 40% (19/47). Families who remained undiagnosed after ES had the opportunity for follow-up studies that included phenotyping and candidate variant segregation in relatives, genomic matchmaking, and ES reanalysis. This enhanced diagnostic workflow increased the diagnostic yield to 55% (26/47), predominantly through the resolution of variants and genes of uncertain significance. We advocate that this approach be integrated into mainstream clinical practice and highlight the importance of a coordinated translational approach for patients with RGD.


Subject(s)
Genomics , Rare Diseases , Humans , Exome Sequencing , Canada , Rare Diseases/diagnosis , Rare Diseases/genetics , Oligopeptides/genetics , Genetic Testing
10.
Clin Genet ; 103(3): 288-300, 2023 03.
Article in English | MEDLINE | ID: mdl-36353900

ABSTRACT

We examined the utility of clinical and research processes in the reanalysis of publicly-funded clinical exome sequencing data in Ontario, Canada. In partnership with eight sites, we recruited 287 families with suspected rare genetic diseases tested between 2014 and 2020. Data from seven laboratories was reanalyzed with the referring clinicians. Reanalysis of clinically relevant genes identified diagnoses in 4% (13/287); four were missed by clinical testing. Translational research methods, including analysis of novel candidate genes, identified candidates in 21% (61/287). Of these, 24 families have additional evidence through data sharing to support likely diagnoses (8% of cohort). This study indicates few diagnoses are missed by clinical laboratories, the incremental gain from reanalysis of clinically-relevant genes is modest, and the highest yield comes from validation of novel disease-gene associations. Future implementation of translational research methods, including continued reporting of compelling genes of uncertain significance by clinical laboratories, should be considered to maximize diagnoses.


Subject(s)
Genetic Testing , Humans , Genetic Testing/methods , Ontario/epidemiology , Exome Sequencing
11.
J Phys Chem B ; 126(49): 10374-10383, 2022 12 15.
Article in English | MEDLINE | ID: mdl-36471236

ABSTRACT

One of the key questions in systems biology is to understand the roles of gene regulatory circuits in determining cellular states and their functions. In previous studies, some researchers have inferred large gene networks from genome wide genomics/transcriptomics data using the top-down approach, while others have modeled core gene circuits of small sizes using the bottom-up approach. Despite many existing systems biology studies, there is still no general rule on what sizes of gene networks and what types of circuit motifs a system would need to achieve robust biological functions. Here, we adopt a gene circuit motif analysis to discover four-node circuits responsible for multiplicity (rich in dynamical behavior), flexibility (versatile to alter gene expression), or both. We identify the most reoccurring two-node circuit motifs and the co-occurring motif pairs. Furthermore, we investigate the contributing factors of multiplicity and flexibility for large gene networks of different types and sizes. We find that gene networks of intermediate sizes tend to have combined high levels of multiplicity and flexibility. Our study will contribute to a better understanding of the dynamical mechanisms of gene regulatory circuits and provide insights into rational designs of robust gene circuits in synthetic and systems biology.


Subject(s)
Gene Regulatory Networks , Systems Biology
12.
Front Cell Infect Microbiol ; 12: 1023457, 2022.
Article in English | MEDLINE | ID: mdl-36439223

ABSTRACT

Bacteria in nature are present in different lifestyles with distinct characteristics. Streptococcus mutans is the etiologic pathogen of dental caries and could easily gain access into the bloodstream after oral surgery and adopt a biofilm lifestyle, resulting in infective endocarditis. A growing amount of evidence have revealed that the large web-like structure composed of extracellular DNA and antimicrobial proteins released by neutrophils, named Neutrophil Extracellular Traps (NETs), play an active role in the defense against bacterial invasion. The present study demonstrated that NETs formation was discriminatively affected by S. mutans biofilm and its planktonic counterpart. The free-floating planktonic S. mutans exhibited an active NETs response, whereas the biofilm community exhibited a reverse negative NETs response. Besides, impaired biofilm killing correlated with the decrease in NETs production. Unlike planktonic cells, biofilm avoided the burst of reactive oxygen species (ROS) when co-culture with neutrophils, and the NADPH-oxidase pathway was partially involved. A mice infection model also supported the distinguishing response of neutrophils challenged by different lifestyles of S. mutans. In conclusion, different bacterial physiological states can affect the distinct response of the host-microbe interaction, thus contributing to the anti-pathogen immune response activation and immune surveillance survival.


Subject(s)
Dental Caries , Extracellular Traps , Mice , Animals , Extracellular Traps/metabolism , Neutrophils , Streptococcus mutans , Biofilms
13.
CMAJ Open ; 10(2): E460-E465, 2022.
Article in English | MEDLINE | ID: mdl-35609929

ABSTRACT

BACKGROUND: Genome-wide sequencing has emerged as a promising strategy for the timely diagnosis of rare diseases, but it is not yet available as a clinical test performed in Canadian diagnostic laboratories. We describe the protocol for evaluating a 2-year pilot project, Genome-wide Sequencing Ontario, to offer high-quality clinical genome-wide sequencing in Ontario, Canada. METHODS: The Genome-wide Sequencing Ontario protocol was codesigned by the Ontario Ministry of Health, the Hospital for Sick Children in Toronto and the Children's Hospital of Eastern Ontario in Ottawa. Enrolment of a prospective cohort of patients began on Apr. 1, 2021. Eligible cases with blood samples available for the index case and both parents (i.e., trios) are randomized to receive exome sequencing or genome sequencing. We will collect patient-level data and ascertain costs associated with the laboratory workflow for exome sequencing and genome sequencing. We will compare point estimates for the diagnostic utility and timeliness of exome sequencing and genome sequencing, and we will determine an incremental cost-effectiveness ratio (expressed as the incremental cost of genome sequencing versus exome sequencing per additional patient with a causal variant detected). INTERPRETATION: Findings from this work will provide robust evidence for the diagnostic utility, cost-effectiveness and timeliness of exome sequencing and genome sequencing, and will be disseminated via academic publications and policy briefs. Findings will inform provincial and cross-provincial policy related to the long-term organization, delivery and reimbursement of clinical-grade genome diagnostics for rare disease.


Subject(s)
Rare Diseases , Child , Humans , Ontario/epidemiology , Pilot Projects , Prospective Studies , Randomized Controlled Trials as Topic , Rare Diseases/diagnosis , Rare Diseases/genetics , Exome Sequencing
14.
HGG Adv ; 3(3): 100108, 2022 Jul 14.
Article in English | MEDLINE | ID: mdl-35599849

ABSTRACT

Genome-wide sequencing (GWS) is a standard of care for diagnosis of suspected genetic disorders, but the proportion of patients found to have pathogenic or likely pathogenic variants ranges from less than 30% to more than 60% in reported studies. It has been suggested that the diagnostic rate can be improved by interpreting genomic variants in the context of each affected individual's full clinical picture and by regular follow-up and reinterpretation of GWS laboratory results. Trio exome sequencing was performed in 415 families and trio genome sequencing in 85 families in the CAUSES study. The variants observed were interpreted by a multidisciplinary team including laboratory geneticists, bioinformaticians, clinical geneticists, genetic counselors, pediatric subspecialists, and the referring physician, and independently by a clinical laboratory using standard American College of Medical Genetics and Genomics (ACMG) criteria. Individuals were followed for an average of 5.1 years after testing, with clinical reassessment and reinterpretation of the GWS results as necessary. The multidisciplinary team established a diagnosis of genetic disease in 43.0% of the families at the time of initial GWS interpretation, and longitudinal follow-up and reinterpretation of GWS results produced new diagnoses in 17.2% of families whose initial GWS interpretation was uninformative or uncertain. Reinterpretation also resulted in rescinding a diagnosis in four families (1.9%). Of the families studied, 33.6% had ACMG pathogenic or likely pathogenic variants related to the clinical indication. Close collaboration among clinical geneticists, genetic counselors, laboratory geneticists, bioinformaticians, and individuals' primary physicians, with ongoing follow-up, reanalysis, and reinterpretation over time, can improve the clinical value of GWS.

16.
Sensors (Basel) ; 21(13)2021 Jun 24.
Article in English | MEDLINE | ID: mdl-34202766

ABSTRACT

At present, synthetic aperture radar (SAR) automatic target recognition (ATR) has been deeply researched and widely used in military and civilian fields. SAR images are very sensitive to the azimuth aspect of the imaging geomety; the same target at different aspects differs greatly. Thus, the multi-aspect SAR image sequence contains more information for classification and recognition, which requires the reliable and robust multi-aspect target recognition method. Nowadays, SAR target recognition methods are mostly based on deep learning. However, the SAR dataset is usually expensive to obtain, especially for a certain target. It is difficult to obtain enough samples for deep learning model training. This paper proposes a multi-aspect SAR target recognition method based on a prototypical network. Furthermore, methods such as multi-task learning and multi-level feature fusion are also introduced to enhance the recognition accuracy under the case of a small number of training samples. The experiments by using the MSTAR dataset have proven that the recognition accuracy of our method can be close to the accruacy level by all samples and our method can be applied to other feather extraction models to deal with small sample learning problems.


Subject(s)
Pattern Recognition, Automated , Radar , Algorithms
17.
Hum Genet ; 140(2): 289-297, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32627054

ABSTRACT

Whole exome sequencing (WES)-based assays undergo rigorous validation before being implemented in diagnostic laboratories. This validation process generates experimental evidence that allows laboratories to predict the performance of the intended assay. The NA12878 Genome in a Bottle (GIAB) HapMap reference sample is commonly used for validation in diagnostic laboratories. We investigated what data points should be taken into consideration when validating WES-based assays using the GIAB reference in a diagnostic setting. We delineate specific factors that require special consideration and identify OMIM genes associated with diseases that may 'bypass' validation. Four replicates of the NA12878 sample were sequenced at the CHEO Genetics Diagnostic Laboratory on a NextSeq 500; the data were analyzed using the bcbio_nexgen v1.1.2 pipeline. The hap.py validation engine, Real Time Genomics vcfeval tool, and high confidence (HC) variant calls in HC regions available for the GIAB sample were used to validate the obtained variant calls. The same validation process was then used to evaluate variant calls obtained for the same sample by two other clinical diagnostic laboratories. We showed that variant calls in NA12878 can be confidently measured only in the regions that intersect between the GIAB HC regions and the target regions of exome capture. Of the 4139 (as of October 2019) OMIM genes associated with a phenotype and having a known molecular basis of disease, 84 were fully outside of the GIAB HC regions and many of the remaining OMIM genes were only partially covered by the HC regions. A significant proportion of variants identified in the NA12878 sample outside of the HC regions have unknown (UNK) status due to the absence of HC reference alleles. Verification of such calls is possible either by an alternative truth set or by orthogonal testing. Similarly, many variants outside of exome capture regions, if not accounted for, will be deemed false negatives due to insufficient probe coverage. Our results demonstrate the importance of the intersection between genomic regions of interest, capture regions, and the high confidence regions. If not considered, false and ambiguous variant calls could have a negative impact on diagnostic accuracy of the intended WES-based diagnostic assay and increase the need for confirmatory testing. To enable laboratories to identify 'problematic' regions and optimize validation efforts, we have made our VCF and BED files available in UCSC Genome Browser: NA12878 WES Benchmark. Relevant genes and genome annotations are evolving, we implemented a general purpose algorithm to cross-reference OMIM genes with the genomic regions of interest that can be applied to capture genes/regions outside HC regions (see repository of data material section).


Subject(s)
Exome Sequencing/methods , Genome, Human/genetics , Alleles , Exome/genetics , Genetic Variation/genetics , Genomics/methods , Humans , Molecular Sequence Annotation/methods
18.
Microbiologyopen ; 9(12): e1128, 2020 12.
Article in English | MEDLINE | ID: mdl-33047890

ABSTRACT

The black pigmentation-related genes in Porphyromonas gingivalis are primarily involved in regulating gingipain functions. In this study, we identified a pigmentation-related gene, designated as pgn_0361. To characterize the role of pgn_0361 in regulating P. gingivalis-mediated epithelial cell detachment and inhibition of wound closure, PgΔ0361, an isogenic pgn_0361-defective mutant strain, and PgΔ0361C, a complementation strain, were constructed using P. gingivalis ATCC 33277. The gingipain and hemagglutination activities, as well as biofilm formation, were examined in all three strains. The effect of P. gingivalis strains on epithelial cell detachment was investigated using the HO-1-N-1 and Ca9-22 epithelial cell lines. The inhibition of wound closure by heat-killed P. gingivalis cells and culture supernatant was analyzed using an in vitro wound closure assay. Compared to the wild-type strain, the PgΔ0361 strain did not exhibit gingipain or hemagglutination activity but exhibited enhanced biofilm formation. Additionally, the PgΔ0361 strain exhibited attenuated ability to detach the epithelial cells and to inhibit wound closure in vitro. Contrastingly, the culture supernatant of PgΔ0361 exhibited high gingipain activity and strong inhibition of wound closure. The characteristics of PgΔ0361C and wild-type strains were comparable. In conclusion, the pgn_0361 gene is involved in regulating gingipains. The PGN_0361-defective strain exhibited reduced virulence in terms of epithelial cell detachment and inhibition of wound closure. The culture supernatant of the mutant strain highly inhibited wound closure, which may be due to high gingipain activity.


Subject(s)
Adhesins, Bacterial/genetics , Cell Adhesion/genetics , Gingipain Cysteine Endopeptidases/genetics , Porphyromonas gingivalis/genetics , Porphyromonas gingivalis/metabolism , Wound Healing/genetics , Biofilms/growth & development , Cell Line , Culture Media, Conditioned/pharmacology , Epithelial Cells/microbiology , Gene Deletion , Gingipain Cysteine Endopeptidases/metabolism , Hemagglutination/genetics , Humans , Pigmentation/genetics
19.
World J Stem Cells ; 12(8): 776-786, 2020 Aug 26.
Article in English | MEDLINE | ID: mdl-32952858

ABSTRACT

Mesenchymal stem cells (MSCs) have been widely exploited as promising candidates in clinical settings for bone repair and regeneration in view of their self-renewal capacity and multipotentiality. However, little is known about the mechanisms underlying their fate determination, which would illustrate their effectiveness in regenerative medicine. Recent evidence has shed light on a fundamental biological role of autophagy in the maintenance of the regenerative capability of MSCs and bone homeostasis. Autophagy has been implicated in provoking an immediately available cytoprotective mechanism in MSCs against stress, while dysfunction of autophagy impairs the function of MSCs, leading to imbalances of bone remodeling and a wide range of aging and degenerative bone diseases. This review aims to summarize the up-to-date knowledge about the effects of autophagy on MSC fate determination and its role as a stress adaptation response. Meanwhile, we highlight autophagy as a dynamic process and a double-edged sword to account for some discrepancies in the current research. We also discuss the contribution of autophagy to the regulation of bone cells and bone remodeling and emphasize its potential involvement in bone disease.

20.
Regen Biomater ; 7(3): 233-245, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32523726

ABSTRACT

Biomaterials as bone substitutes are always considered as foreign bodies that can trigger host immune responses. Traditional designing principles have been always aimed at minimizing the immune reactions by fabricating inert biomaterials. However, clinical evidence revealed that those methods still have limitations and many of which were only feasible in the laboratory. Currently, osteoimmunology, the very pioneering concept is drawing more and more attention-it does not simply regard the immune response as an obstacle during bone healing but emphasizes the intimate relationship of the immune and skeletal system, which includes diverse cells, cytokines, and signaling pathways. Properties of biomaterials like topography, wettability, surface charge, the release of cytokines, mediators, ions and other bioactive molecules can impose effects on immune responses to interfere with the skeletal system. Based on the bone formation mechanisms, the designing methods of the biomaterials change from immune evasive to immune reprogramming. Here, we discuss the osteoimmunomodulatory effects of the new modification strategies-adjusting properties of bone biomaterials to induce a favorable osteoimmune environment. Such strategies showed potential to benefit the development of bone materials and lay a solid foundation for the future clinical application.

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