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1.
J Virol ; 97(11): e0138923, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37888983

ABSTRACT

IMPORTANCE: Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-causing human herpesvirus that establishes a persistent infection in humans. The lytic viral cycle plays a crucial part in lifelong infection as it is involved in the viral dissemination. The master regulator of the KSHV lytic replication cycle is the viral replication and transcription activator (RTA) protein, which is necessary and sufficient to push the virus from latency into the lytic phase. Thus, the identification of host factors utilized by RTA for controlling the lytic cycle can help to find novel targets that could be used for the development of antiviral therapies against KSHV. Using a proteomics approach, we have identified a novel interaction between RTA and the cellular E3 ubiquitin ligase complex RNF20/40, which we have shown to be necessary for promoting RTA-induced KSHV lytic cycle.


Subject(s)
Herpesvirus 8, Human , Host Microbial Interactions , Immediate-Early Proteins , Ubiquitin-Protein Ligases , Viral Proteins , Virus Activation , Virus Latency , Virus Replication , Humans , Herpesvirus 8, Human/growth & development , Herpesvirus 8, Human/physiology , Immediate-Early Proteins/metabolism , Protein Binding , Proteomics , Trans-Activators/metabolism , Ubiquitin-Protein Ligases/metabolism , Viral Proteins/metabolism
2.
J Virol ; 97(3): e0169622, 2023 03 30.
Article in English | MEDLINE | ID: mdl-36815831

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus that can replicate in oral epithelial cells to promote viral transmission via saliva. To identify novel regulators of KSHV oral infection, we performed a transcriptome analysis of KSHV-infected primary human gingival epithelial (HGEP) cells, which identified the gene coding for the host transcription factor FOXQ1 as the top induced host gene. FOXQ1 is nearly undetectable in uninfected HGEP and telomerase-immortalized gingival keratinocytes (TIGK) cells but is highly expressed within hours of KSHV infection. We found that while the FOXQ1 promoter lacks activating histone acetylation marks in uninfected oral epithelial cells, these marks accumulate in the FOXQ1 promoter in infected cells, revealing a rapid epigenetic reprogramming event. To evaluate FOXQ1 function, we depleted FOXQ1 in KSHV-infected TIGK cells, which resulted in reduced accumulation of KSHV lytic proteins and viral DNA over the course of 4 days of infection, uncovering a novel lytic cycle-sustaining role of FOXQ1. A screen of KSHV lytic proteins demonstrated that the immediate early proteins ORF45 and replication and transcription activator (RTA) were both sufficient for FOXQ1 induction in oral epithelial cells, indicating active involvement of incoming and rapidly expressed factors in altering host gene expression. ORF45 is known to sustain extracellular signal-regulated kinase (ERK) p90 ribosomal s6 kinase (RSK) pathway activity to promote lytic infection. We found that an ORF45 mutant lacking RSK activation function failed to induce FOXQ1 in TIGK cells, revealing that ORF45 uses a shared mechanism to rapidly induce both host and viral genes to sustain lytic infection in oral epithelial cells. IMPORTANCE The oral cavity is a primary site of initial contact and entry for many viruses. Viral replication in the oral epithelium promotes viral shedding in saliva, allowing interpersonal transmission, as well as spread to other cell types, where chronic infection can be established. Understanding the regulation of KSHV infection in the oral epithelium would allow for the design of universal strategies to target the first stage of viral infection, thereby halting systemic viral pathogenesis. Overall, we uncover a novel positive feedback loop in which immediate early KSHV factors drive rapid host reprogramming of oral epithelial cells to sustain the lytic cycle in the oral cavity.


Subject(s)
Feedback, Physiological , Forkhead Transcription Factors , Gene Expression Regulation, Viral , Herpesvirus 8, Human , Immediate-Early Proteins , Humans , Epithelial Cells/metabolism , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression Regulation, Viral/genetics , Herpesvirus 8, Human/physiology , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Virus Replication/physiology , Host Microbial Interactions , Cell Line , Promoter Regions, Genetic
3.
J Virol ; 97(11): e0097223, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37909728

ABSTRACT

IMPORTANCE: The current view is that the default pathway of Kaposi's sarcoma-associated herpesvirus (KSHV) infection is the establishment of latency, which is a prerequisite for lifelong infection and viral oncogenesis. This view about KSHV infection is supported by the observations that KSHV latently infects most of the cell lines cultured in vitro in the absence of any environmental stresses that may occur in vivo. The goal of this study was to determine the effect of hypoxia, a natural stress stimulus, on primary KSHV infection. Our data indicate that hypoxia promotes euchromatin formation on the KSHV genome following infection and supports lytic de novo KSHV infection. We also discovered that hypoxia-inducible factor-1α is required and sufficient for allowing lytic KSHV infection. Based on our results, we propose that hypoxia promotes lytic de novo infection in cells that otherwise support latent infection under normoxia; that is, the environmental conditions can determine the outcome of KSHV primary infection.


Subject(s)
Herpesviridae Infections , Hypoxia-Inducible Factor 1, alpha Subunit , Hypoxia , Humans , Gene Expression Regulation, Viral , Herpesvirus 8, Human , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Sarcoma, Kaposi , Virus Latency
4.
PLoS Pathog ; 18(8): e1010801, 2022 08.
Article in English | MEDLINE | ID: mdl-36026503

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus that causes lifelong infection in humans by establishing latency after primary infection. Latent infection is a prerequisite for both persistent infection and the development of KSHV-associated cancers. While viral lytic genes are transiently expressed after primary infection, their expression is significantly restricted and concomitant with the binding of host epigenetic repressors Polycomb Repressive Complex 1 and 2 (PRC1 and PRC2) to lytic genes. PRC1 and PRC2 mediate the repressive histone marks H2AK119ub and H3K27me3, respectively, and maintain heterochromatin structure on KSHV lytic genes to inhibit their expression. In contrast to PRC2, little is known about the recruitment and role of PRC1 factors on the KSHV genome following de novo infection. Thus, the goal of this study was to examine the function of PRC1 factors in the establishment of KSHV latency. To address this question, we performed an shRNA screen targeting 7 different components of the canonical and non-canonical PRC1 complexes during primary KSHV infection. We found that RYBP, a main subunit of the non-canonical PRC1 complexes, is a potent repressor of KSHV lytic genes that can bind to the viral genome and inhibit lytic genes as early as 4 hours post infection. Surprisingly, our ChIP analyses showed that RYBP binds to lytic viral gene promoters in a PRC1-independent manner, does not affect PRC1 activity on the KSHV genome, and can reduce the level of histone marks associated with transcription elongation. Our data also suggest that RYBP can repress the viral lytic cycle after primary infection by inhibiting the transcription elongation of the lytic cycle inducer KSHV gene RTA. Based on our results we propose that RYBP uses a PRC1-independent mechanism to block KSHV RTA expression thereby promoting the establishment of KSHV latency following de novo infection.


Subject(s)
Herpesviridae Infections , Herpesvirus 8, Human , Cell Cycle Proteins/metabolism , Gene Expression Regulation, Viral , Herpesviridae Infections/metabolism , Herpesvirus 8, Human/genetics , Herpesvirus 8, Human/metabolism , Histones/genetics , Histones/metabolism , Humans , Polycomb Repressive Complex 2/genetics , Polycomb Repressive Complex 2/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Virus Latency/genetics
5.
J Virol ; 96(12): e0010122, 2022 06 22.
Article in English | MEDLINE | ID: mdl-35604218

ABSTRACT

The immediate early viral protein replication and transcription activator (RTA) of Kaposi's sarcoma-associated herpesvirus (KSHV) is essential for activating the lytic cycle of KSHV. RTA induces the KSHV lytic cycle by several mechanisms, acting as a viral transcription factor that directly induces viral and host genes and acting as a viral E3 ubiquitin ligase by degrading host proteins that block viral lytic replication. Recently, we have characterized the global gene expression changes in primary effusion lymphoma (PEL) upon lytic reactivation of KSHV, which also led to the identification of rapidly downregulated genes such as ID2, an inhibitor of basic helix-loop-helix transcription factors. Here, we demonstrate that ID2 overexpression in PEL ablates KSHV lytic reactivation, indicating that ID2 inhibits the KSHV lytic cycle. Furthermore, we show that while ID2 is highly expressed during latency, its protein level is rapidly reduced by 4 h postinduction during lytic reactivation. Our results indicate that RTA binds to ID2 and induces its degradation during the KSHV lytic cycle by N-terminal ubiquitination through the ubiquitin-proteasome pathway. Importantly, we found that not only KSHV RTA but also its Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV68) homologs interact with ID2, and they can induce the degradation of all four members of the ID protein family, suggesting an evolutionarily conserved interplay between gammaherpesvirus RTAs and ID proteins. Taken together, we propose that ID2 acts as a repressor of the KSHV lytic cycle, which is counteracted by its RTA-mediated degradation. We also predict that ID proteins may act as restriction factors of the lytic phase of the other gammaherpesviruses as well. IMPORTANCE In addition to its transcription regulatory role, RTA is also known to have an E3 ubiquitin ligase activity, which RTA utilizes for inducing protein degradation. However, it is still largely unknown what host factors are downregulated during KSHV lytic reactivation by RTA-mediated protein degradation and what the biological significance of the degradation of these host factors is. In this study, we discovered that RTA employs N-terminal ubiquitination to induce degradation of ID2, a potent transcription repressor of host genes, via the ubiquitin-proteasome pathway to promote KSHV lytic reactivation in PEL cells. Furthermore, we found that not only KSHV RTA but also RTA of EBV and MHV68 gammaherpesviruses can induce the degradation of all four human ID proteins, indicating that the interplay between gammaherpesvirus RTAs and ID proteins is evolutionarily conserved.


Subject(s)
Herpesvirus 8, Human , Immediate-Early Proteins , Inhibitor of Differentiation Protein 2 , Trans-Activators , Gene Expression Regulation, Viral , Herpesvirus 8, Human/physiology , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Inhibitor of Differentiation Protein 2/genetics , Inhibitor of Differentiation Protein 2/metabolism , Proteasome Endopeptidase Complex/metabolism , Trans-Activators/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Ubiquitins/metabolism , Virus Replication
6.
PLoS Pathog ; 17(1): e1009179, 2021 01.
Article in English | MEDLINE | ID: mdl-33471866

ABSTRACT

Primary effusion lymphoma (PEL) is an aggressive B cell lymphoma that is etiologically linked to Kaposi's sarcoma-associated herpesvirus (KSHV). Despite standard multi-chemotherapy treatment, PEL continues to cause high mortality. Thus, new strategies to control PEL are needed urgently. Here, we show that a phosphodegron motif within the KSHV protein, latency-associated nuclear antigen (LANA), specifically interacts with E3 ubiquitin ligase FBW7, thereby competitively inhibiting the binding of the anti-apoptotic protein MCL-1 to FBW7. Consequently, LANA-FBW7 interaction enhances the stability of MCL-1 by preventing its proteasome-mediated degradation, which inhibits caspase-3-mediated apoptosis in PEL cells. Importantly, MCL-1 inhibitors markedly suppress colony formation on soft agar and tumor growth of KSHV+PEL/BCBL-1 in a xenograft mouse model. These results strongly support the conclusion that high levels of MCL-1 expression enable the oncogenesis of PEL cells and thus, MCL-1 could be a potential drug target for KSHV-associated PEL. This work also unravels a mechanism by which an oncogenic virus perturbs a key component of the ubiquitination pathway to induce tumorigenesis.


Subject(s)
Antigens, Viral/metabolism , F-Box-WD Repeat-Containing Protein 7/metabolism , Herpesvirus 8, Human/physiology , Lymphoma, Primary Effusion/virology , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Nuclear Proteins/metabolism , Sarcoma, Kaposi/virology , Amino Acid Sequence , Animals , Antigens, Viral/genetics , Apoptosis , Cell Proliferation , F-Box-WD Repeat-Containing Protein 7/genetics , Female , Humans , Lymphoma, Primary Effusion/genetics , Lymphoma, Primary Effusion/metabolism , Lymphoma, Primary Effusion/pathology , Mice , Mice, Inbred NOD , Mice, SCID , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Nuclear Proteins/genetics , Phosphorylation , Sarcoma, Kaposi/genetics , Sarcoma, Kaposi/metabolism , Sarcoma, Kaposi/pathology , Tumor Cells, Cultured , Ubiquitination , Xenograft Model Antitumor Assays
7.
Ecol Appl ; 33(4): e2848, 2023 06.
Article in English | MEDLINE | ID: mdl-36938710

ABSTRACT

Urban-induced habitat conversion drastically changes soil life in a variety of ways. Soil sealing, human disturbance, habitat fragmentation, industrial and vehicular pollution are the main causes of urban soil degradation. Soil arthropods, as one of the most abundant and diverse group of soil fauna, are involved in many soil processes that are of great importance in maintaining soil health and multifunctionality. Nevertheless, soil quality is still mainly characterized by physical, chemical, and microbiological parameters. Here, we assessed and compared the biological soil quality in woody (REF: reference forest, REM: remnant forest) and nonwoody (TURF: public turfgrass, and RUD: ruderal habitat) types of urban green spaces along a disturbance and management intensity gradient in the Budapest metropolitan area (Hungary), using community metrics and soil arthropod-based indicators. Vegetation cover and landscape characteristics of study sites were quantified through vegetation and urbanization indices, respectively. Basic soil properties, total and bioavailable concentrations of the main heavy metals (Cd, Co, Hg, Ni, Zn) were also measured. Acari, Collembola, and Hymenoptera (mainly Formicidae) were the most abundant groups. Litter-dweller taxa, particularly Protura, proved to be the most sensitive to urban disturbance. Representatives of Hemiptera, Diptera, Symphyla, and Pauropoda were common in low densities. The taxonomic diversity of soil arthropod assemblages in nonwoody and woody habitats was similar. Although the integrated faunal indices showed no differences among soil habitat types, they provided different responses and, consequently, different information. Our findings demonstrated that the biological quality and arthropod community structure of soils were strongly impacted by soil C/N and heavy metal contamination. We found that low and moderate levels of pollution have adverse effects on edaphic fauna, suggesting biological degradation of soils, even below pollution limits. Nevertheless, more disturbed urban green spaces have been shown to play a significant role in maintaining belowground biodiversity, thereby soil functions.


Subject(s)
Arthropods , Metals, Heavy , Soil Pollutants , Animals , Humans , Soil/chemistry , Ecosystem , Environmental Pollution , Metals, Heavy/analysis , Soil Pollutants/analysis , Environmental Monitoring , China
8.
BMC Health Serv Res ; 23(1): 686, 2023 Jun 24.
Article in English | MEDLINE | ID: mdl-37353814

ABSTRACT

BACKGROUND: Preterm birth remains a significant burden to families, health systems and societies. The aim was to quantify the incremental prematurity-related public health expenditure in Hungary and to estimate the potential impact of a decrease in the prevalence of prematurity on the public payer's spending. METHODS: Over a 6-year time horizon, public financing data of inpatient, outpatient and pharmaceutical care for children born at ≥ 25 weeks of gestation in 2009/2010 were retrieved from the Hungarian National Health Insurance Fund database. In descriptive analysis, the public payer's spending was given as cost/capita. The impact of a decrease in prematurity prevalence was specified as the total budget impact. An exchange rate of 294 Hungarian forint/Euro was applied. RESULTS: A total of 93,124 children (including 8.6% who were premature babies) were included in the analysis. A strong negative relationship was shown between gestational age and per capita cost. The 6-year cost of care for the cohort born at 26 weeks of gestation (28,470 Euro per capita) was 24 times higher than that for the cohort born at 40 weeks. First-year inpatient spending accounted for the largest proportion of total health care spending across all gestational ages. All investigated prematurity complications (retinopathy of prematurity, necrotizing enterocolitis, bronchopulmonary dysplasia, intraventricular cerebral bleeding and leukomalacia) resulted in additional significant incremental spending. If 70% of pregnancies ending with preterm birth could be prolonged by 1 week, the savings would be almost 7.0 million Euros in the first 6 years of life. CONCLUSION: This comprehensive analysis of prematurity-related health care spending confirmed that premature infants have much higher costs for care than those born at term in Hungary. These quantitative outcomes can provide essential inputs for the cost-effectiveness analysis of medical technologies and public health interventions that can decrease the prevalence of premature birth. TRIAL REGISTRATION: Not applicable.


Subject(s)
Infant, Premature, Diseases , Premature Birth , Infant , Pregnancy , Child , Female , Infant, Newborn , Humans , Premature Birth/epidemiology , Hungary/epidemiology , Infant, Premature, Diseases/epidemiology , Public Health , Infant, Premature , Gestational Age
9.
J Virol ; 95(11)2021 05 10.
Article in English | MEDLINE | ID: mdl-33692209

ABSTRACT

It is still largely unknown what host factors are involved in controlling the expression of the lytic viral gene RTA during primary infection, which determines if Kaposi's sarcoma-associated herpesvirus (KSHV) establishes latent or lytic infection. We have recently identified the histone demethylase KDM2B as a repressor of RTA expression during both de novo KSHV infection and latency based on an epigenetic factor siRNA screen. Here, we report that surprisingly, KDM2B overexpression can promote lytic de novo infection by using a mechanism that differs from what is needed for its repressor function. Our study revealed that while the DNA-binding and demethylase activities of KDM2B linked to its transcription repressive function are dispensable, its C-terminal F-box and LRR domains are required for the lytic infection-inducing function of KDM2B. We found that overexpressed KDM2B increases the half-life of the AP-1 subunit c-Jun protein and induces the AP-1 signaling pathway. This effect is dependent upon the binding of KDM2B to the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase complex via its F-box domain. Importantly, the inhibition of AP-1 reduces KDM2B-mediated lytic de novo KSHV infection. Overall, our findings indicate that KDM2B may induce the degradation of some host factors by using the SCF complex resulting in the enrichment of c-Jun. This leads to increased AP-1 transcriptional activity, which facilitates lytic gene expression following de novo infection interfering with the establishment of viral latency.SignificanceThe expression of epigenetic factors is often dysregulated in cancers or upon specific stress signals, which often results in a display of non-canonical functions of the epigenetic factors that are independent from their chromatin-modifying roles. We have previously demonstrated that KDM2B normally inhibits KSHV lytic cycle using its histone demethylase activity. Surprisingly, we found that KDM2B overexpression can promote lytic de novo infection, which does not require its histone demethylase or DNA-binding functions. Instead, KDM2B uses the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase complex to induce AP-1 transcriptional activity, which promotes lytic gene expression. This is the first report that demonstrates a functional link between SFCKDM2B and AP-1 in the regulation of KSHV lytic cycle.

10.
PLoS Pathog ; 16(1): e1008268, 2020 01.
Article in English | MEDLINE | ID: mdl-31923286

ABSTRACT

Establishment of viral latency is not only essential for lifelong Kaposi's sarcoma-associated herpesvirus (KSHV) infection, but it is also a prerequisite of viral tumorigenesis. The latent viral DNA has a complex chromatin structure, which is established in a stepwise manner regulated by host epigenetic factors during de novo infection. However, despite the importance of viral latency in KSHV pathogenesis, we still have limited information about the repertoire of epigenetic factors that are critical for the establishment and maintenance of KSHV latency. Therefore, the goal of this study was to identify host epigenetic factors that suppress lytic KSHV genes during primary viral infection, which would indicate their role in latency establishment. We performed an siRNA screen targeting 392 host epigenetic factors during primary infection and analyzed which ones affect the expression of the viral replication and transcription activator (RTA) and/or the latency-associated nuclear antigen (LANA), which are viral genes essential for lytic replication and latency, respectively. As a result, we identified the Nucleosome Remodeling and Deacetylase (NuRD) complex, Tip60 and Tip60-associated co-repressors, and the histone demethylase KDM2B as repressors of KSHV lytic genes during both de novo infection and the maintenance of viral latency. Furthermore, we showed that KDM2B rapidly binds to the incoming viral DNA as early as 8 hpi, and can limit the enrichment of activating histone marks on the RTA promoter favoring the downregulation of RTA expression even prior to the polycomb proteins-regulated heterochromatin establishment on the viral genome. Strikingly, KDM2B can also suppress viral gene expression and replication during lytic infection of primary gingival epithelial cells, revealing that KDM2B can act as a host restriction factor of the lytic cycle of KSHV during both latent and lytic infections in multiple different cell types.


Subject(s)
Herpesviridae Infections/genetics , Herpesvirus 8, Human/physiology , RNA, Small Interfering/genetics , Antigens, Viral/genetics , Antigens, Viral/metabolism , Epigenesis, Genetic , F-Box Proteins/genetics , F-Box Proteins/metabolism , Gene Expression Regulation, Viral , Herpesviridae Infections/metabolism , Herpesviridae Infections/virology , Herpesvirus 8, Human/genetics , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Jumonji Domain-Containing Histone Demethylases/genetics , Jumonji Domain-Containing Histone Demethylases/metabolism , Lysine Acetyltransferase 5/genetics , Lysine Acetyltransferase 5/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , RNA, Small Interfering/metabolism , Trans-Activators/genetics , Trans-Activators/metabolism , Virus Latency
11.
Medicina (Kaunas) ; 58(10)2022 Oct 01.
Article in English | MEDLINE | ID: mdl-36295543

ABSTRACT

Background and objectives: In the last couple of years, pharmacological management of patients with type 2 diabetes mellitus (T2DM) have been markedly renewed. The aim of this study was to analyse the changes in prescribing patterns of antidiabetic drugs for treating patients with T2DM in Hungary between 2015 and 2020. Material and Methods: In this retrospective, nationwide analysis, we used the central database of the National Health Insurance Fund. We present annual numbers and their proportion of T2DM patients with different treatment regimens. Results: In the period of 2015−2020, the number of incident cases decreased from 60,049 to 29,865, while prevalent cases increased from 682,274 to 752,367. Patients with metformin (MET) monotherapy had the highest prevalence (31% in 2020). Prevalence of insulin (INS) monotherapy continuously but slightly decreased from 29% to 27% while that of sulfonylurea (SU) monotherapy markedly decreased from 37% to 20%. Dipeptidyl peptidase (DPP-4) inhibitors remained popular in 2020 as monotherapy (5%), in dual combination with MET (12%) and in triple combination with MET and SU (5%). The prevalence of patients with sodium-glucose co-transporter-2 (SGLT-2) inhibitors increased from 1% to 4% in monotherapy, from <1% to 6% in dual combination with MET, and from <1% to 2% in triple oral combination with MET and SU or DPP-4-inhibitors. The prevalence of patients using glucagon-like peptide-1 receptor agonists (GLP-1-RAs) also increased but remained around 1−2% both in monotherapy and combinations. For initiating antihyperglycaemic treatment, MET monotherapy was the most frequently used regime in 2020 (50%), followed by monotherapy with SUs (16%) or INS (10%). After initial MET monotherapy, the incidence rates of patients with add-on GLP-1-RAs (2%, 3%, and 4%) and those of add-on SGLT-2 inhibitors (4%, 6%, and 8%) slowly increased in the subsequent 24, 48, and 72 months, respectively. Conclusions: In the period of 2015−2020, we documented important changes in trends of antihyperglycaemic therapeutic patterns in patients with T2DM which followed the new scientific recommendations but remained below our expectations regarding timing and magnitude. More efforts are warranted to implement new agents with cardiovascular/renal benefits into therapeutic management in time, in a much larger proportion of T2DM population, and without delay.


Subject(s)
Diabetes Mellitus, Type 2 , Dipeptidyl-Peptidase IV Inhibitors , Metformin , Sodium-Glucose Transporter 2 Inhibitors , Symporters , Humans , Hypoglycemic Agents , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/epidemiology , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Glucagon-Like Peptide-1 Receptor/therapeutic use , Retrospective Studies , Hungary/epidemiology , Blood Glucose , Sulfonylurea Compounds/therapeutic use , Metformin/therapeutic use , Insulin/therapeutic use , Glucagon-Like Peptide 1/therapeutic use , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/therapeutic use , Symporters/therapeutic use , Sodium
12.
Anaerobe ; 70: 102404, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34146701

ABSTRACT

Members of oral bacterial communities form biofilms not only on tooth surfaces but also on the surface of dental implants that replace natural teeth. Prolonged interaction of host cells with biofilm-forming anaerobes frequently elicits peri-implantitis, a destructive inflammatory disease accompanied by alveolar bone loss leading to implant failure. Here we wish to overview how the deposition of bioactive peptides to dental implant surfaces could potentially inhibit bacterial colonization and the development of peri-implantisis. One preventive strategy is based on natural antimicrobial peptides (AMPs) immobilized on titanium surfaces. AMPs are capable to destroy both Gram positive and Gram negative bacteria directly. An alternative strategy aims at coating implant surfaces - especially the transmucosal part - with peptides facilitating the attachment of gingival epithelial cells and connective tissue cells. These cells produce AMPs and may form a soft tissue seal that prevents oral bacteria from accessing the apical part of the osseointegrated implant. Because a wide variety of titanium-bound peptides were studied in vitro, we wish to concentrate on bioactive peptides of human origin and some of their derivatives. Furthermore, special attention will be given to peptides effective under in vivo test conditions.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antimicrobial Peptides/pharmacology , Dental Implants/microbiology , Peri-Implantitis/prevention & control , Animals , Anti-Bacterial Agents/chemistry , Bacteria/drug effects , Bacteria/growth & development , Biofilms , Humans , Peri-Implantitis/microbiology , Titanium/chemistry
13.
Int J Mol Sci ; 22(24)2021 Dec 09.
Article in English | MEDLINE | ID: mdl-34948048

ABSTRACT

Due to its tensile strength and excellent biocompatibility, titanium (Ti) is commonly used as an implant material in medicine and dentistry. The success of dental implants depends on the formation of a contact between the oxidized surface of Ti implant and the surrounding bone tissue. The adsorption of proteins and peptides to the implant surface allows the bone-forming osteoblast cells to adhere to such modified surfaces. Recently, it has been observed that tetrapeptide KRSR (Lys-Arg-Ser-Arg) functionalization could promote osteoblast adhesion to implant surfaces. This may facilitate the establishment of an efficient bone-to implant contact and improve implant stability during the healing process. GROMACS, a molecular dynamics software package was used to perform a 200 ns simulation of adsorption of the KRSR peptide to the TiO2 (anatase) surface in an aqueous environment. The molecule conformations were mapped with Replica Exchange Molecular Dynamics (REMD) simulations to assess the possible peptide conformations on the anatase surface, and the umbrella sampling method was used to calculate the binding energy of the most common conformation. The simulations have shown that the KRSR peptide migrates and attaches to the surface in a stable position. The dominant amino acid residue interacting with the TiO2 surface was the N-terminal charged lysine (K) residue. REMD indicated that there is a distinct conformation that is taken by the KRSR peptide. In this conformation the surface interacts only with the lysine residue while the ser (S) and arg (R) residues interact with water molecules farther from the surface. The binding free energy of the most common conformation of KRSR peptide to the anatase (100) surface was ΔG = -8.817 kcal/mol. Our result suggests that the N-terminal lysine residue plays an important role in the adhesion of KRSR to the TiO2 surface and may influence the osseointegration of dental implants.


Subject(s)
Oligopeptides/chemistry , Titanium/chemistry , Models, Molecular , Molecular Conformation , Molecular Dynamics Simulation
14.
BMC Oral Health ; 21(1): 86, 2021 02 25.
Article in English | MEDLINE | ID: mdl-33632191

ABSTRACT

BACKGROUND: In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement. METHODS: The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal-Wallis statistical test and as a post-hoc test Mann-Whitney U test was performed to analyze experimental results. RESULTS: According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal-Wallis test showed significant differences between the intact and predrilled bones. CONCLUSION: The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.


Subject(s)
Dental Implantation, Endosseous , Dental Implants , Animals , Dental Prosthesis, Implant-Supported , Swine
15.
J Virol ; 93(5)2019 03 01.
Article in English | MEDLINE | ID: mdl-30541837

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) is a human oncogenic virus, which maintains the persistent infection of the host by intermittently reactivating from latently infected cells to produce viral progenies. While it is established that the replication and transcription activator (RTA) viral transcription factor is required for the induction of lytic viral genes for KSHV lytic reactivation, it is still unknown to what extent RTA alters the host transcriptome to promote KSHV lytic cycle and viral pathogenesis. To address this question, we performed a comprehensive time course transcriptome analysis during KSHV reactivation in B-cell lymphoma cells and determined RTA-binding sites on both the viral and host genomes, which resulted in the identification of the core RTA-induced host genes (core RIGs). We found that the majority of RTA-binding sites at core RIGs contained the canonical RBP-Jκ-binding DNA motif. Subsequently, we demonstrated the vital role of the Notch signaling transcription factor RBP-Jκ for RTA-driven rapid host gene induction, which is consistent with RBP-Jκ being essential for KSHV lytic reactivation. Importantly, many of the core RIGs encode plasma membrane proteins and key regulators of signaling pathways and cell death; however, their contribution to the lytic cycle is largely unknown. We show that the cell cycle and chromatin regulator geminin and the plasma membrane protein gamma-glutamyltransferase 6, two of the core RIGs, are required for efficient KSHV reactivation and virus production. Our results indicate that host genes that RTA rapidly and directly induces can be pivotal for driving the KSHV lytic cycle.IMPORTANCE The lytic cycle of KSHV is involved not only in the dissemination of the virus but also viral oncogenesis, in which the effect of RTA on the host transcriptome is still unclear. Using genomics approaches, we identified a core set of host genes which are rapidly and directly induced by RTA in the early phase of KSHV lytic reactivation. We found that RTA does not need viral cofactors but requires its host cofactor RBP-Jκ for inducing many of its core RIGs. Importantly, we show a critical role for two of the core RIGs in efficient lytic reactivation and replication, highlighting their significance in the KSHV lytic cycle. We propose that the unbiased identification of RTA-induced host genes can uncover potential therapeutic targets for inhibiting KSHV replication and viral pathogenesis.


Subject(s)
Herpesvirus 8, Human/genetics , Immediate-Early Proteins/genetics , Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism , Trans-Activators/genetics , Virus Activation/genetics , Cell Line, Tumor , Geminin/genetics , Geminin/metabolism , Gene Expression Profiling , Gene Expression Regulation, Viral/genetics , HEK293 Cells , Herpesvirus 8, Human/metabolism , Herpesvirus 8, Human/pathogenicity , Humans , RNA Interference , RNA, Small Interfering/genetics , Virus Latency/genetics , gamma-Glutamyltransferase/genetics , gamma-Glutamyltransferase/metabolism
16.
Diabetes Metab Res Rev ; 35(8): e3190, 2019 11.
Article in English | MEDLINE | ID: mdl-31140677

ABSTRACT

BACKGROUND: There are few papers comparing complications of type 1 diabetes with those of a similarly young age with type 2 diabetes. The aim of our nationwide study was to compare the risks of mortality and morbidities between the two types of diabetes (age ≤ 40). METHODS: We identified all young adult patients with type 1 diabetes who were recorded in the database of the Hungarian National Health Insurance Fund between 2001 and 2014 (n = 11 863) and compared them with a population of similar age with young adult type 2 diabetes (n = 47 931). The incidence of all-cause mortality, myocardial infarction, stroke, any type of cancer, diabetic ketoacidosis, and hypoglycemia was followed from the onset of diabetes to the date of death or end of study period. RESULTS: The risks of all-cause mortality were significantly higher in patients with type 1 compared with patients with type 2 diabetes (hazard ratio, 95%CI; 2.17, 1.95-2.41; P < .0001). The risks of myocardial infarction (0.90, 0.71-1.13; P = 0.36) and stroke (1.06, 0.87-1.29; P = .582) were not significantly different in type 1 compared with type 2. In contrast, the risk of cancer (1.35, 1.15-1.59; P = .0003), dialysis (2.20, 1.76-2.75; P < .0001), hypoglycemia (7.70, 6.45-9.18; P < .0001), and ketoacidosis (22.12, 19.60-25.00; P < .0001) was higher among patients with type 1 compared with those with type 2 diabetes. CONCLUSIONS: A comparatively higher incidence of diabetic ketoacidosis and hypoglycemia and higher risk of cancer and dialysis in patients with type 1 diabetes than in those with type 2 may play a role in the higher risk of mortality.


Subject(s)
Biomarkers/analysis , Diabetes Mellitus, Type 1/mortality , Diabetes Mellitus, Type 2/mortality , Hypoglycemic Agents/therapeutic use , Adult , Age Factors , Blood Glucose/analysis , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/pathology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/pathology , Female , Follow-Up Studies , Glycated Hemoglobin/analysis , Humans , Hungary/epidemiology , Male , Prognosis , Retrospective Studies , Risk Factors , Survival Rate , Young Adult
17.
Acta Vet Hung ; 67(3): 456-462, 2019 09.
Article in English | MEDLINE | ID: mdl-31549547

ABSTRACT

The length of the streak canal and the area of the teat end were studied by ultrasound during the dry period in 40 Holstein-Friesian cows. In the first week, the values of these teat parameters decreased significantly (P < 0.05) and this did not change significantly until the middle of the dry period. In the last month of gestation, the length of the streak canal was significantly reduced (P < 0.05), while the area of the teat end did not decrease significantly (P > 0.05). At each of the five examination times, a very strong positive correlation (r = 0.85-0.94) was found between the two teat parameters. In healthy cows, the streak canal and the area of teat end, both of which are part of the udder's defence system, can regenerate sufficiently during the dry period, minimising the risk of contamination through the streak canal and the development of mastitis. If the regeneration of this defence system fails, the chances of infection through the streak canal increase.


Subject(s)
Mammary Glands, Animal/diagnostic imaging , Ultrasonography/veterinary , Animals , Cattle , Female , Lactation
18.
PLoS Pathog ; 12(9): e1005878, 2016 09.
Article in English | MEDLINE | ID: mdl-27606464

ABSTRACT

One of the hallmarks of the latent phase of Kaposi's sarcoma-associated herpesvirus (KSHV) infection is the global repression of lytic viral gene expression. Following de novo KSHV infection, the establishment of latency involves the chromatinization of the incoming viral genomes and recruitment of the host Polycomb repressive complexes (PRC1 and PRC2) to the promoters of lytic genes, which is accompanied by the inhibition of lytic genes. However, the mechanism of how PRCs are recruited to the KSHV episome is still unknown. Utilizing a genetic screen of latent genes in the context of KSHV genome, we identified the latency-associated nuclear antigen (LANA) to be responsible for the genome-wide recruitment of PRCs onto the lytic promoters following infection. We found that LANA initially bound to the KSHV genome right after infection and subsequently recruited PRCs onto the viral lytic promoters, thereby repressing lytic gene expression. Furthermore, both the DNA and chromatin binding activities of LANA were required for the binding of LANA to the KSHV promoters, which was necessary for the recruitment of PRC2 to the lytic promoters during de novo KSHV infection. Consequently, the LANA-knockout KSHV could not recruit PRCs to its viral genome upon de novo infection, resulting in aberrant lytic gene expression and dysregulation of expression of host genes involved in cell cycle and proliferation pathways. In this report, we demonstrate that KSHV LANA recruits host PRCs onto the lytic promoters to suppress lytic gene expression following de novo infection.


Subject(s)
Antigens, Viral/metabolism , Herpesviridae Infections/metabolism , Herpesvirus 8, Human/metabolism , Nuclear Proteins/metabolism , Plasmids/metabolism , Polycomb Repressive Complex 2/metabolism , Promoter Regions, Genetic , Antigens, Viral/genetics , Gene Knockdown Techniques , Herpesviridae Infections/genetics , Herpesviridae Infections/pathology , Herpesvirus 8, Human/genetics , Humans , Nuclear Proteins/genetics , Plasmids/genetics , Polycomb Repressive Complex 2/genetics
19.
Cardiovasc Diabetol ; 17(1): 107, 2018 07 27.
Article in English | MEDLINE | ID: mdl-30053870

ABSTRACT

BACKGROUND: The excess risks of mortality and cardiovascular morbidity among patients with type 2 diabetes mellitus (T2DM) is well known. In this nationwide study, we assessed risks of mortality and cardiovascular events comparing patients with T2DM and matched controls. METHODS: We identified patients with T2DM in a retrospective cohort study using the database of the National Health Insurance Fund between 1 January 2010 and 31 December, 2013. Controls were randomly included and matched according to age, gender, and zip code of residence. Patients were divided into subgroups according to age decades for outcome analyses. RESULTS: During the mean follow-up period of 2.3 years, 152,678 patients with T2DM and 305,356 matched controls were included. Patients with T2DM showed significantly higher risk for all-cause mortality (HR 1.26, 95% CI 1.22-1.29, p < 0.0001), myocardial infarction (HR 1.81, 95% CI 1.69-1.94, p < 0.0001) and stroke (HR 1.40, 95% CI 1.35-1.46, p < 0.0001) compared to matched controls. The higher risk associated with T2DM for mortality, myocardial infarction and stroke differed significantly between age groups (pinteraction < 0.05 for all outcomes) with significantly higher risk observed in younger patients. CONCLUSIONS: The risk of cardiovascular outcomes and all-cause mortality is significantly higher in patients with T2DM. Notably, the relative hazard increases with decreasing age suggesting that younger patients with T2DM should receive more attention for cardiovascular prevention.


Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Myocardial Infarction/epidemiology , Stroke/epidemiology , Adult , Age Factors , Aged , Cause of Death , Databases, Factual , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/mortality , Female , Health Surveys , Humans , Hungary/epidemiology , Male , Middle Aged , Myocardial Infarction/diagnosis , Myocardial Infarction/mortality , Prognosis , Retrospective Studies , Risk Assessment , Risk Factors , Sex Factors , Stroke/diagnosis , Stroke/mortality , Time Factors , Young Adult
20.
J Nanosci Nanotechnol ; 18(6): 3916-3924, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29442727

ABSTRACT

Failure of dental implants is caused mainly by peri-implant infections resulting in loss of supporting bone. Since there is no ideal therapy of peri-implantitis, the focus of research has been shifted toward better prevention and the development of antibacterial surfaces. In our study we examined the attachment and proliferation of primary epithelial and MG-63 osteosarcoma cells on Ti dental implants coated with photocatalytic nanohybrid films. Two polyacrylate resin based layers were investigated on commercially pure (CP4) Ti discs: 60 wt% TiO2/40 wt% copolymer and 60 wt% Ag-TiO2/40 wt% copolymer ([Ag] = 0,001 wt%). Surface properties were examined by scanning electron microscopy (SEM) and profilometry. Cell responses were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and visualized with fluorescence microscopy. Profilometry revealed significant changes in surface roughness of TiO2 (Ra = 1.79 µm) and Ag-TiO2 layers (Ra = 5.76 µm) compared to the polished (Ra(P) = 0.13 µm) and sandblasted, acid-etched control surfaces (Ra(SA) = 1.26 µm). MTT results demonstrated that the attachment (24 h) of epithelial cells was significantly higher on the Ag-TiO2 coated samples (OD540 = 0.079) than on the polished control surfaces (OD540 = 0.046), whereas MG-63 cells did not show any difference in attachment between the groups. After one week, epithelial cells showed slightly increased survival as compared to MG-63 cells. The results suggest that the tested coatings are cytocompatible with epithelial cells, which means that they are not only antibacterial, but they also appear to be promising candidates for implantological use.


Subject(s)
Cell Proliferation/drug effects , Epithelial Cells/drug effects , Nanocomposites , Titanium , Dental Implants , Humans , Microscopy, Electron, Scanning , Surface Properties
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