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1.
J Med Virol ; 95(1): e28412, 2023 01.
Article in English | MEDLINE | ID: mdl-36527332

ABSTRACT

Considering the global trend to confine the COVID-19 pandemic by applying various preventive health measures, preprocedural mouth rinsing has been proposed to mitigate the transmission risk of SARS-CoV-2 in dental clinics. The study aimed to investigate the effect of different mouth rinses on salivary viral load in COVID-19 patients. This study was a single-center, randomized, double-blind, six-parallel-group, placebo-controlled clinical trial that investigated the effect of four mouth rinses (1% povidone-iodine, 1.5% hydrogen peroxide, 0.075% cetylpyridinium chloride, and 80 ppm hypochlorous acid) on salivary SARS-CoV-2 viral load relative to the distilled water and no-rinse control groups. The viral load was measured by quantitative reverse transcription PCR (RT-qPCR) at baseline and 5, 30, and 60 min post rinsing. The viral load pattern within each mouth rinse group showed a reduction overtime; however, this reduction was only statistically significant in the hydrogen peroxide group. Further, a significant reduction in the viral load was observed between povidone-iodine, hydrogen peroxide, and cetylpyridinium chloride compared to the no-rinse group at 60 min, indicating their late antiviral potential. Interestingly, a similar statistically significant reduction was also observed in the distilled water control group compared to the no-rinse group at 60 min, proposing mechanical washing of the viral particles through the rinsing procedure. Therefore, results suggest using preprocedural mouth rinses, particularly hydrogen peroxide, as a risk-mitigation step before dental procedures, along with strict adherence to other infection control measures.


Subject(s)
COVID-19 , Mouthwashes , Humans , Mouthwashes/therapeutic use , SARS-CoV-2 , Hydrogen Peroxide , Povidone-Iodine/therapeutic use , Cetylpyridinium/therapeutic use , Pandemics , Viral Load , Water
2.
Article in English | MEDLINE | ID: mdl-35677372

ABSTRACT

The diterpenoid, sugiol, has been reported to exert anticancer effects against a number of human cancers. However, the anticancer effects of sugiol have not been evaluated against the human glioma cells. The present study was designed to examine the effects of sugiol on the proliferation of human U87 glioma cells. The results showed that sugiol significantly (P < 0.05) suppressed the viability of the U87 cells in a concentration dependent manner and exhibited an IC50 value of 15 µM. On the other hand, the growth inhibitory effects of sugiol were minimal on the normal human astrocytes. Acridine orange and ethidium bromide staining (AO/EB) staining revealed that sugiol induces apoptosis which was further confirmed by Western blot analysis, wherein upregulation of Bax and downregulation of Bcl-2 were observed in U87 cells. Flow cytometry showed that sugiol causes cell cycle arrest at the G 0/G 1 stage. The relative percentage of G1 phase was found to be increased from 26.58% at 0 µM to 70.96% at 30 µM sugiol. Taken together, the results suggest sugiol inhibits the growth of glioma cells and may prove to be a lead molecule in the management of human glioma.

3.
Comput Biol Chem ; 98: 107645, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35276575

ABSTRACT

In this paper, a compartmental mathematical model has been utilized to gain a better insight about the future dynamics of COVID-19. The total human population is divided into eight various compartments including susceptible, exposed, pre-asymptomatic, asymptomatic, symptomatic, quarantined, hospitalized and recovered or removed individuals. The problem was modeled in terms of highly nonlinear coupled system of classical order ordinary differential equations (ODEs) which was further generalized with the Atangana-Balaeanu (ABC) fractional derivative in Caputo sense with nonlocal kernel. Furthermore, some theoretical analyses have been done such as boundedness, positivity, existence and uniqueness of the considered. Disease-free and endemic equilibrium points were also assessed. The basic reproduction was calculated through next generation technique. Due to high risk of infection, in the present study, we have considered the reported cases from three continents namely Americas, Europe, and south-east Asia. The reported cases were considered between 1st May 2021 and 31st July 2021 and on the basis of this data, the spread of infection is predicted for the next 200 days. The graphical solution of the considered nonlinear fractional model was obtained via numerical scheme by implementing the MATLAB software. Based on the fitted values of parameters, the basic reproduction number ℜ0 for the case of America, Asia and Europe were calculated as ℜ0≈2.92819, ℜ0≈2.87970 and ℜ0≈2.23507 respectively. It is also observed that the spread of infection in America is comparatively high followed by Asia and Europe. Moreover, the effect of fractional parameter is shown on the dynamics of spread of infection among different classes. Additionally, the effect of quarantined and treatment of infected individuals is also shown graphically. From the present analysis it is observed that awareness of being quarantine and proper treatment can reduce the infection rate dramatically and a minimal variation in quarantine and treatment rates of infected individuals can lead us to decrease the rate of infection.


Subject(s)
COVID-19 , Quarantine , Asia , Basic Reproduction Number , COVID-19/epidemiology , Hospitalization , Humans
4.
J Clin Lab Anal ; 35(6): e23771, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33792964

ABSTRACT

BACKGROUND: Several pre-analytical factors can affect the measurement of intact Parathyroid Hormone (IPTH). In this study, we have investigated the effects of using different types of tubes, time elapsed before separation, and storage conditions over time on the measured values of IPTH. METHOD: Blood samples from 30 subjects were collected into plain, SST, and EDTA tubes. All serum and plasma were separated immediately (first set) and after 2 hrs delay (second set). The first set of samples were aliquoted and stored at RT (25°C), at fridge (4°C), and freezer (-20°C). IPTH was measured in all the stored aliquots at 2,4, and 8 days after collection using Architect analyzer. RESULTS: Paired T test and ANOVA repeated measures showed no significant difference between IPTH levels in all tubes. The second set of serum and plasma were significantly lower (3.8% and 7.4%, p < 0.001, respectively) when compared to samples measured initially. Serum samples stored at RT were significantly lower (by 45%,59%, and 77%) on days 2,4, and 8 when compared to the initial time (p < 0.001 in all cases). Plasma samples stored at RT, were significantly lower on day 8 after collection, by 30.8% (p < 0.001). These differences would be clinically important. CONCLUSION: Plasma IPTH can be stored at RT for up to four days. Both plasma and serum IPTH are not affected by a delay in the separation of up to two h and they can be stored for up to 8 days in a fridge or freezer without any clinically significant changes in their values.


Subject(s)
Blood Specimen Collection/methods , Parathyroid Hormone/blood , Adult , Blood Preservation/methods , Blood Specimen Collection/instrumentation , Female , Humans , Male , Reproducibility of Results , Time Factors
5.
Front Bioeng Biotechnol ; 8: 568186, 2020.
Article in English | MEDLINE | ID: mdl-33042969

ABSTRACT

Three-dimensional (3D) printing has experienced a steady increase in popularity for direct manufacturing, where complex geometric items can be produced without the aid of templating tools, and manufacturing waste can be remarkably reduced. While customized medical devices and daily life items can be made by 3D printing of thermoplastics, microbial contamination has been a serious obstacle during their usage. A very clever approaches to overcome this challenge is to incorporate antimicrobial metal or metal oxide (M/MO) nanoparticles within the thermoplastics during or prior to 3D printing. Many M/MO nanoparticles can prevent contamination from a wide range of microorganism, including antibiotic-resistant bacteria via various antimicrobial mechanisms. Additionally, they can be easily printed with thermoplastic without losing their integrity and functionality. In this mini review, we summarize recent advancements and discuss future trends related to the development of 3D printed antimicrobial thermoplastic nanocomposites by addition of M/MO nanoparticles.

6.
Cureus ; 12(9): e10287, 2020 Sep 07.
Article in English | MEDLINE | ID: mdl-33047079

ABSTRACT

Background Giardia lamblia is a pathogenic intestinal flagellate transmitted by the ingestion of contaminated water or food with the cyst stage of the parasite. Giardiasis can cause severe acute diarrhea and malabsorption or may persist as a chronic infection. Effective treatment and control measures depend on proper laboratory diagnosis using diagnostic methods with high sensitivity and specificity. Objective To compare the sensitivity and specificity of direct smear, Ritchie sedimentation technique, two brands of rapid chromatographic immunoassay test, and real-time polymerase chain reaction (PCR) for the detection of G. lamblia in clinical human fecal samples. Materials and methods Unpreserved 100 stool specimens were collected in clean plastic containers and labeled with the patient's information and examined through light microscopy, immunochromatographic test (ICTs), and real-time PCR. Results Out of 100 fresh stool samples obtained from workers analyzed, real-time PCR targeting the SSU rRNA gene was able to detect Giardia deoxyribonucleic acid (DNA) in (42) samples followed by ImmunoCard STAT! (31) samples (Meridian Bioscience, Germany), direct smear (23) samples, CerTest (19) samples (Biotec, Zaragoza, Spain), and Ritchie technique (17) samples. Real-time PCR was the most sensitive for the diagnosis of G. lamblia in comparison to the other techniques. Conclusions All the techniques investigated were sensitive for the detection of G. lamblia in stool samples. Further studies are recommended using multiplex real-time PCR assay in order to increase the possibility of the presence or absence of the infection.

7.
Int J Microbiol ; 2020: 2716202, 2020.
Article in English | MEDLINE | ID: mdl-32802068

ABSTRACT

Urinary tract infection (UTI) is one of the most prevalent bacterial infections in the world affecting the bladder and the kidney. Escherichia coli (E. coli) is the main causative agent of 80-90% of community-acquired UTIs, about 40% of nosocomial UTIs, and 25% of recurrent UTIs. The field of proteomics has emerged as a great tool to analyze expressed proteins to identify possible biomarkers associated with many pathological states and, to the same extent, those associated with bacterial pathogenesis and their ability to cause recurrent infections. Here, in a descriptive cross-sectional pilot study, we employed proteomic techniques to investigate the effects of environmental stress on protein profiles of E. coli simulated by sequential passaging of samples from patients with UTIs to screen for unique proteins that arise under stressful environment and could aid in the early detection of UTIs. Four urine samples were collected from individuals with recurrent UTI and sequentially subcultured; protein samples were extracted from bacterial pellets and analyzed using 2-dimensional gel electrophoresis (2DGE). Protein spots of interest arising from changes in the protein profile were analyzed using liquid chromatography-mass spectrometry (LC-MS/MS) and matched against known databases to identify related proteins. We identified ATPB_ECOBW, ASPA ECOLI, DPS ECOL6, and DCEB ECOLI as proteins associated with higher passaging. We concluded that passaging resulted in identifiable changes in the protein profile of E. coli, namely, proteins that are associated with survival and possible adaptation of bacteria, suggestive of factors contributing to antibiotic resistance and recurrent UTIs. Furthermore, our method could be further used to identify indicator-protein candidates that could be a part of a growing protein database to diagnose and identify causative agents in UTIs.

8.
PLoS One ; 15(5): e0232790, 2020.
Article in English | MEDLINE | ID: mdl-32453746

ABSTRACT

The Middle East Respiratory Syndrome-Coronavirus (MERS-CoV) is an endemic virus in dromedaries. Annually, Saudi Arabia imports thousands of camels from the Horn of Africa, yet the epidemiology of MERS-CoV in these animals is largely unknown. Here, MERS-CoV prevalence was compared in imported African camels and their local counterparts. A total of 1399 paired sera and nasal swabs were collected from camels between 2016 and 2018. Imported animals from Sudan (n = 829) and Djibouti (n = 328) were sampled on incoming ships at Jeddah Islamic seaport before unloading, and local camels were sampled from Jeddah (n = 242). Samples were screened for neutralizing antibodies (nAbs) and MERS-CoV viral RNA. The overall seroprevalence was 92.7% and RNA detection rate was 17.2%. Imported camels had higher seroprevalence compared to resident herds (93.8% vs 87.6%, p <0.01) in contrast to RNA detection (13.3% vs 35.5%, p <0.0001). Seroprevalence significantly increased with age (p<0.0001) and viral RNA detection rate was ~2-folds higher in camels <2-year-old compared to older animals. RNA detection was higher in males verses females (24.3% vs 12.6%, p<0.0001) but seroprevalence was similar. Concurrent positivity for viral RNA and nAbs was found in >87% of the RNA positive animals, increased with age and was sex-dependent. Importantly, reduced viral RNA load was positively correlated with nAb titers. Our data confirm the widespread of MERS-CoV in imported and domestic camels in Saudi Arabia and highlight the need for continuous active surveillance and better prevention measures. Further studies are also warranted to understand camels correlates of protection for proper vaccine development.


Subject(s)
Antibodies, Viral/blood , Camelus/virology , Coronavirus Infections/epidemiology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , RNA, Viral/blood , Animals , Antibodies, Neutralizing/blood , Coronavirus Infections/virology , Cross-Sectional Studies , Disease Reservoirs/virology , Djibouti/epidemiology , Female , Male , Middle East Respiratory Syndrome Coronavirus/genetics , Prevalence , Saudi Arabia/epidemiology , Seroepidemiologic Studies , Sudan/epidemiology
9.
PLoS One ; 15(4): e0230895, 2020.
Article in English | MEDLINE | ID: mdl-32348307

ABSTRACT

The gut microbiota is often affected by the dietary and lifestyle habits of the host, resulting in a better efficacy that favors energy harvesting from the consumed food. Our objective was to characterize the composition of gut microbiota in adult Saudis and investigate possible association with lifestyle and dietary practices. Feces from 104 Saudi volunteers (48% males) were tested for microbiota by sequencing the V3-V4 region of bacterial 16S ribosomal RNA (rRNA). For all participants, data were collected related to their lifestyle habits and dietary practices. The relative abundance (RA) of Fusobacteria was significantly higher in normal weight Saudis (P = 0.005, false discovery rate-FDR = 0.014). Individuals who consumed more coffee presented marginally significant more RA of Fusobacteria (P = 0.02, FDR = 0.20) in their gut microbiota compared to those reporting low or no coffee intake, but the RA of Fusobacteria was significantly higher in smokers compared to non-smokers (P = 0.009, FDR = 0.027). The RA of Fusobacteria was also significantly higher in those reporting daily consumption of bread (P = 0.005, FDR = 0.015). At the species level, the gut microbiota of people who consumed coffee was dominated by Bacteroides thetaiotaomicron followed by Phascolarctobacterium faecium and Eubacterium rectale. Similarly, the gut microbiota of smokers was also enriched by B. thetaiotaomicron and Lactobacillus amylovorus. Smoking cessation, bread and coffee consumption induce changes in the intestinal microbial composition of Saudis. This indicates the significance of diet and lifestyle practices in the determination of the composition of the gut microbiota, which could possibly lead later to changes in metabolic profile and weight.


Subject(s)
Bread , Coffee , Gastrointestinal Microbiome , Smoking Cessation , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Saudi Arabia , Young Adult
10.
J Infect Public Health ; 13(5): 697-703, 2020 May.
Article in English | MEDLINE | ID: mdl-32005618

ABSTRACT

BACKGROUND: The Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly recognized zoonotic coronavirus. Current evidence confirms the role of dromedaries in primary human infections but does not explain the sporadic community cases. However, asymptomatic or subclinical cases could represent a possible source of infection in the community. METHODS: Archived human sera (7461) collected between 2011 and 2016 from healthy adult blood donors from 50 different nationalities in the western part of Saudi Arabia were obtained for MERS-CoV seroprevalence investigation. Samples were tested for MERS-CoV S1-specific antibodies (Abs) by ELISA and confirmed by testing for neutralizing Abs (nAbs) using both pseudotyped and live virus neutralization assays. RESULTS: Out of 7461 samples, 174 sera from individuals with 18 different nationalities were ELISA positive (2.3%, 95% CI 2.0-2.7). Presence of nAbs was confirmed in 17 samples (0.23%, 95% CI 0.1-0.4) of which one sample exhibited positivity in both neutralization assays. Confirmed seropositivity was identified in young (15-44 years) men and women from Saudi Arabia, Egypt, Yemen, Pakistan, Palestine, Sudan, and India without significant preference. CONCLUSIONS: An increasing trend of MERS-CoV seroprevalence was observed in the general population in western Saudi Arabia, suggesting that asymptomatic or mild infections might exist and act as an unrecognized source of infection. Seropositivity of individuals from different nationalities underscores the potential MERS exportation outside of the Arabian Peninsula. Thus, enhanced and continuous surveillance is highly warranted.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/epidemiology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Adolescent , Adult , Animals , Blood Donors , Camelus/virology , Coronavirus Infections/blood , Coronavirus Infections/immunology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Middle East Respiratory Syndrome Coronavirus/immunology , Saudi Arabia/epidemiology , Seroepidemiologic Studies , Young Adult
11.
Saudi J Biol Sci ; 27(1): 6-11, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31889810

ABSTRACT

Obesity is a chronic disorder that is associated with body mass index (BMI) of greater or equal to 30 kg/m2. The prevalence of obesity in the Kingdom of Saudi Arabia (KSA) is increasing at an alarming rate and is expected to reach 41% in men and up to 78% in women by 2022. Since chemokines are associated with involuntary weight loss, the objective of this study was to elucidate their association with BMI among Saudis. A questionnaire was used to collect information about diet, health conditions, and demographics from 15 men and 16 women who participated in the study. BMI was calculated based on clinical measurements and participants were classified according to their BMI category as: normal, underweight, overweight, or obese. Serum samples were collected for a multiplex assay using the Human Chemokine Magnetic 30-plex panel. The serum concentration of either the monokine induced by gamma interferon (MIG) or the CXC-motif chemokine ligand 9 (CXCL-9) was significantly increased in obese men (P = 0.0194) and women (P = 0.043) as compared to underweight men and women, respectively. However, the serum levels of other chemokines were not significantly different among the groups. We found that MIG levels are differentially regulated in serum, based on individuals' BMI.

12.
Ann Saudi Med ; 39(6): 403-409, 2019.
Article in English | MEDLINE | ID: mdl-31804132

ABSTRACT

BACKGROUND: Human papillomaviruses (HPVs) are small, non-enveloped, double-stranded DNA viruses that consist of more than 200 genotypes. Low-risk genotypes are associated with warts or benign lesions, whereas high-risk genotypes are usually associated with malignancies and cancers including cervical cancer. However, the real prevalence and incidence of HPV in Saudi Arabia may be understated due to a lack of comprehensive data reporting. OBJECTIVES: Determine the positivity rate of HPV in men and women in Jeddah, Saudi Arabia. DESIGN: Cross-sectional. SETTING: Tertiary care center in Jeddah. SUBJECTS AND METHODS: Self-collected vaginal swab samples were obtained from females attending the gynecological clinic in the period between October 2017 and April 2018 at a tertiary care center, Jeddah, Saudi Arabia. PCR-positive HPV samples were sequenced to determine genotype. Additionally, serum samples were collected from healthy male and female blood donors and screened for HPV IgG antibodies by ELISA. MAIN OUTCOME MEASURES: Molecular and serological positivity for HPV. SAMPLE SIZE: 119 self-collected vaginal swabs from females at a gynecology clinic and 966 serum samples from healthy blood donors. RESULTS: Of the 119 tested vaginal swabs, 7 samples (5.9%) were positive for HPV DNA. Several genotypes were identified. Most of the positive samples were from Saudi females in the age range of 31-50 years seeking care for infertility. Of the 966 serum samples, only 16 samples (1.7%) were positive for HPV IgG antibodies. CONCLUSION: While the prevalence of HPV in men and women in our sample from the western region of Saudi Arabia was low, our data clearly show that it is not uncommon among high-risk groups and people are still exposed to the risk of HPV infection. Most importantly, these data provide valuable information that could aid in enhancing national awareness about HPV and in introducing an HPV vaccination program. LIMITATIONS: Single hospital and a convenience sample CONFLICT OF INTEREST: None.


Subject(s)
Papillomavirus Infections/epidemiology , Adolescent , Adult , Age Factors , Aged , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Papillomaviridae , Prevalence , Risk Factors , Saudi Arabia/epidemiology , Seroepidemiologic Studies , Young Adult
13.
J Immunol Methods ; 466: 41-46, 2019 03.
Article in English | MEDLINE | ID: mdl-30659836

ABSTRACT

Since 2012, MERS-CoV has caused up to 2220 cases and 790 deaths in 27 countries with Saudi Arabia being the most affected country with ~83.1% of the cases and ~38.8% local death rate. Current serological assays such as microneutralization (MN), plaque reduction neutralization, immunofluorescence, protein microarray or pseudoparticle neutralization assays rely on handling of live MERS-CoV in high containment laboratories or need for expensive and special equipment and reagents and highly trained personnel which represent a technical hurdle for most laboratories in resource-limited MERS-CoV endemic countries. Here, we developed, compared and evaluated three different indirect ELISAs based on MERS-CoV nucleocapsid protein (N), spike (S) ectodomain (amino acids 1-1297) and S1 subunit (amino acids 1-725) and compared them with MN assay. The developed ELISAs were evaluated using large number of confirmed seropositive (79 samples) and seronegative (274 samples) MERS-CoV human serum samples. Both rS1- and rS-ELISAs maintained high sensitivity and specificity (≥90%) across a wider range of OD values compared to rN-ELISA. Moreover, rS1- and rS-based ELISAs showed better agreement and correlation with MN assay in contrast to rN-ELISA. Collectively, our data demonstrate that rS1-ELISA and rS-ELISA are more reliable than rN-ELISA and represent a suitable choice for seroepidemiological testing and surveillance in MERS-CoV endemic regions.


Subject(s)
Enzyme-Linked Immunosorbent Assay , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Serologic Tests , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , Chlorocebus aethiops , Humans , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , Recombinant Proteins/blood , Recombinant Proteins/immunology , Vero Cells
14.
Neurosciences (Riyadh) ; 23(3): 227-237, 2018 Jul.
Article in English | MEDLINE | ID: mdl-30007999

ABSTRACT

OBJECTIVE: To investigate individuals` knowledge about central nervous system tumors (CNST) signs and symptoms and risk factors, as well as their readiness to seek medical advice. The signs and symptoms associated with CNSTs are often vague, and failure to recognize them could lead to delays in seeking help and possibly fatal results. METHODS: This was a cross-sectional survey that utilized 2 delivery methods. A total of 1,500 personally delivered and 1,500 online self-administered questionnaires were completed in parallel between June 2015 and June 2016 for the occupants of the Kingdom of Saudi Arabia. RESULTS: Significant differences were observed for the sociodemographic characteristics of participants recruited via the 2 methods. The most recognized symptom was "Headaches" (45.2%), and the most recognized risk factor was "Radioactive location/occupation" (84.1%). Overall knowledge scores were low, significantly predicted by employment and cancer contact (p<0.05), while the scores significantly higher for participants who were willing to see their doctors within a week (p<0.005). The most recognized barrier to seeking help was "Worry about what the doctor might find" (74.0%). CONCLUSION: The level of awareness of CNSTs was low. Using a questionnaire delivered in 2 different ways enabled the recruitment of sample pools with different sociodemographic characteristics.


Subject(s)
Central Nervous System Neoplasms/psychology , Health Knowledge, Attitudes, Practice , Adolescent , Adult , Female , Humans , Male , Middle Aged , Saudi Arabia
15.
Biochem J ; 464(1): 99-108, 2014 Nov 15.
Article in English | MEDLINE | ID: mdl-25190348

ABSTRACT

The intracellular kinase MEKK2 (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase kinase 2) is an upstream regulator of JNK (c-Jun N-terminal kinase), but additional functions for MEKK2 have not been well defined. Silencing MEKK2 expression in invasive breast tumour cells markedly inhibits xenograft metastasis, indicating that MEKK2 controls tumour cell function required for tumour progression. In our previous investigation of MEKK2 function, we discovered that tumour cell attachment to fibronectin recruits MEKK2 to focal adhesion complexes, and that MEKK2 knockdown is associated with stabilized focal adhesions and significant inhibition of tumour cell migration. In the present study we investigate MEKK2 function in focal adhesions and we report that MEKK2 physically associates with the LD1 motif of the focal adhesion protein paxillin. We reveal that MEKK2 induces paxillin ubiquitylation, and that this function requires both the paxillin LD1 motif and MEKK2 kinase activity. Finally, we demonstrate that MEKK2 promotes paxillin redistribution from focal adhesions into the cytoplasm, but does not promote paxillin degradation. Taken together, our results reveal a novel function for MEKK2 as a regulator of ubiquitylation-dependent paxillin redistribution in breast tumour cells.


Subject(s)
Breast Neoplasms/metabolism , MAP Kinase Kinase Kinases/physiology , Paxillin/metabolism , Ubiquitination/physiology , Cell Line, Tumor , Female , HEK293 Cells , Humans , MAP Kinase Kinase Kinase 2 , MCF-7 Cells , Paxillin/analysis
16.
Biochim Biophys Acta ; 1843(5): 945-54, 2014 May.
Article in English | MEDLINE | ID: mdl-24491810

ABSTRACT

MEK Kinase 2 (MEKK2) is a serine/threonine kinase that functions as a MAPK kinase kinase (MAP3K) to regulate activation of Mitogen-activated Protein Kinases (MAPKs). We recently have demonstrated that ablation of MEKK2 expression in invasive breast tumor cells dramatically inhibits xenograft metastasis, but the mechanism by which MEKK2 influences metastasis-related tumor cell function is unknown. In this study, we investigate MEKK2 function and demonstrate that silencing MEKK2 expression in breast tumor cell significantly enhances cell spread area and focal adhesion stability while reducing cell migration. We show that cell attachment to the matrix proteins fibronectin or Matrigel induces MEKK2 activation and localization to focal adhesions. Further, we reveal that MEKK2 ablation enhances focal adhesion size and frequency, thereby linking MEKK2 function to focal adhesion stability. Finally, we show that MEKK2 knockdown inhibits fibronectin-induced Extracellular Signal-Regulated Kinase 5 (ERK5) signaling and Focal Adhesion Kinase (FAK) autophosphorylation. Taken together, our results strongly support a role for MEKK2 as a regulator of signaling that modulates breast tumor cell spread area and migration through control of focal adhesion stability.


Subject(s)
Breast Neoplasms/pathology , Focal Adhesions/physiology , MAP Kinase Kinase Kinases/physiology , Neoplasm Invasiveness , Breast Neoplasms/enzymology , Breast Neoplasms/metabolism , Cell Line, Tumor , Female , Fibronectins/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Gene Silencing , Humans , MAP Kinase Kinase Kinase 2 , MAP Kinase Kinase Kinases/genetics , Phosphorylation
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