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Chakkour M, Hammoud Z, Farhat S, El Roz A, Ezzeddine Z, Ghssein G. Overview of Proteus mirabilis pathogenicity and virulence. Insights into the role of metals. Front Microbiol 2024; 15:1383618. [PMID: 38646633 PMCID: PMC11026637 DOI: 10.3389/fmicb.2024.1383618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/15/2024] [Indexed: 04/23/2024] Open
Abstract
Proteus mirabilis is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, P. mirabilis is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of P. mirabilis infections, emphasizing its association with UTIs. The bacterium's genome analysis revealed the presence of resistance genes against commonly used antibiotics, an antibiotic-resistant phenotype that poses a serious clinical challenge. Particularly, the emergence of extended-spectrum β-lactamases (ESBLs) and carbapenemases resistant P. mirabilis strains. On a molecular level, P. mirabilis possesses a wide array of virulence factors including the production of fimbriae, urease, hemolysins, metallophores, and biofilm formation. This review thoroughly tackles a substantial gap in understanding the role of metallophores in shaping the virulence factors of P. mirabilis virulence. Siderophores, iron metal chelating and transporting metallophores, particularly contribute to the complex pathogenic strategies, displaying a potential target for therapeutic intervention.
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Affiliation(s)
- Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Zeinab Hammoud
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Solay Farhat
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Ali El Roz
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde, Lebanon
| | - Zeinab Ezzeddine
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde, Lebanon
| | - Ghassan Ghssein
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde, Lebanon
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Chakkour M, Greenberg ML. Insights into the roles of inositol hexakisphosphate kinase 1 (IP6K1) in mammalian cellular processes. J Biol Chem 2024; 300:107116. [PMID: 38403246 DOI: 10.1016/j.jbc.2024.107116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/27/2024] Open
Abstract
Inositol phosphates and their metabolites play a significant role in several biochemical pathways, gene expression regulation, and phosphate homeostasis. Among the different inositol phosphates, inositol hexakisphosphate (IP6) is a substrate of inositol hexakisphosphate kinases (IP6Ks), which phosphorylate one or more of the IP6 phosphate groups. Pyrophosphorylation of IP6 leads to the formation of inositol pyrophosphates, high-energy signaling molecules that mediate physiological processes through their ability to modify target protein activities, either by directly binding to their target protein or by pyrophosphorylating protein serine residues. 5-diphosphoinositol pentakisphosphate, the most abundant inositol pyrophosphate in mammals, has been extensively studied and found to be significantly involved in a wide range of physiological processes. Three IP6K (IP6K1, IP6K2, and IP6K3) isoforms regulate IP7 synthesis in mammals. Here, we summarize our current understanding of IP6K1's roles in cytoskeletal remodeling, trafficking, cellular migration, metabolism, gene expression, DNA repair, and immunity. We also briefly discuss current gaps in knowledge, highlighting the need for further investigation.
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Affiliation(s)
- Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
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Abbas R, Chakkour M, Zein El Dine H, Obaseki EF, Obeid ST, Jezzini A, Ghssein G, Ezzeddine Z. General Overview of Klebsiella pneumonia: Epidemiology and the Role of Siderophores in Its Pathogenicity. Biology (Basel) 2024; 13:78. [PMID: 38392297 PMCID: PMC10886558 DOI: 10.3390/biology13020078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/24/2024]
Abstract
The opportunistic pathogen Klebsiella pneumoniae (K. pneumoniae) can colonize mucosal surfaces and spread from mucosae to other tissues, causing fatal infections. Medical equipment and the healthcare setting can become colonized by Klebsiella species, which are widely distributed in nature and can be found in water, soil, and animals. Moreover, a substantial number of community-acquired illnesses are also caused by this organism worldwide. These infections are characterized by a high rate of morbidity and mortality as well as the capacity to spread metastatically. Hypervirulent Klebsiella strains are thought to be connected to these infections. Four components are critical to this bacterium's pathogenicity-the capsule, lipopolysaccharide, fimbriae, and siderophores. Siderophores are secondary metabolites that allow iron to sequester from the surrounding medium and transport it to the intracellular compartment of the bacteria. A number of variables may lead to K. pneumoniae colonization in a specific area. Risk factors for infection include local healthcare practices, antibiotic use and misuse, infection control procedures, nutrition, gender, and age.
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Affiliation(s)
- Rim Abbas
- Faculty of Health Sciences, Beirut Arab University, Beirut P.O. Box 11-5020, Lebanon
| | - Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Hiba Zein El Dine
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | | | - Soumaya T Obeid
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Aya Jezzini
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Ghassan Ghssein
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Zeinab Ezzeddine
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
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Noureddine FY, Chakkour M, El Roz A, Reda J, Al Sahily R, Assi A, Joma M, Salami H, Hashem SJ, Harb B, Salami A, Ghssein G. The Emergence of SARS-CoV-2 Variant(s) and Its Impact on the Prevalence of COVID-19 Cases in the Nabatieh Region, Lebanon. Med Sci (Basel) 2021; 9:medsci9020040. [PMID: 34199617 PMCID: PMC8293406 DOI: 10.3390/medsci9020040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 12/21/2022] Open
Abstract
Background: An outbreak of an unknown respiratory illness caused by a novel coronavirus, SARS-CoV-2, emerged in the city of Wuhan in Hubei Province, China, in December 2019 and was referred to as coronavirus disease-2019 (COVID-19). Soon after, it was declared as a global pandemic by the World Health Organization (WHO) in March 2020. SARS-CoV-2 mainly infects the respiratory tract with different outcomes ranging from asymptomatic infection to severe critical illness leading to death. Different SARS-CoV-2 variants are emerging of which three have raised concerns worldwide due to their high transmissibility among populations. Objective: To study the prevalence of COVID-19 in the region of Nabatieh-South Lebanon during the past year and assess the presence of SARS-CoV-2 variants and their effect on the spread of infection during times of lockdown. Methods: In our study, 37,474 nasopharyngeal swab samples were collected and analyzed for the detection of SARS-CoV-2 virus in suspected patients attending a tertiary health care center in South Lebanon during the period between 16 March 2020 and 21 February 2021. Results: The results demonstrated a variation in the prevalence rates ranging from less than 1% during full lockdown of the country to 8.4% upon easing lockdown restrictions and reaching 27.5% after the holidays and 2021 New Year celebrations. Interestingly, a new variant(s) appeared starting January 2021 with a significant positive association between the prevalence of positive tests and the percentage of the variant(s). Conclusions: Our results indicate that the lockdown implemented by the Lebanese officials was an effective intervention to contain COVID-19 spread. Our study also showed that lifting lockdown measures during the holidays, which allowed indoor crowded gatherings to occur, caused a surge in COVID-19 cases and rise in the mortality rates nationwide. More importantly, we confirmed the presence of a highly transmissible SARS-CoV-2 variant(s) circulating in the Lebanese community from at least January 2021 onwards.
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Affiliation(s)
- Fatima Y. Noureddine
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Mohamed Chakkour
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut P.O. Box 11-0236, Lebanon;
| | - Ali El Roz
- Department of Biology, Faculty of Sciences, Lebanese University, Nabatieh P.O. Box 6573/14, Lebanon;
| | - Jana Reda
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Reem Al Sahily
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Ali Assi
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Mohamed Joma
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Hassan Salami
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Sadek J. Hashem
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
| | - Batoul Harb
- Medical administration, SRHUH, Nabatieh P.O. Box 1700, Lebanon;
| | - Ali Salami
- Department of Mathematics, Faculty of Sciences, Lebanese University, Nabatieh P.O. Box 6573/14, Lebanon
- Correspondence: (A.S.); (G.G.); Tel.: +961-7-761-980 (A.S. & G.G.)
| | - Ghassan Ghssein
- Medical Analysis Laboratory, Molecular Genetics Unit, Sheikh Ragheb Harb University Hospital (SRHUH), Nabatieh P.O. Box 1700, Lebanon; (F.Y.N.); (J.R.); (R.A.S.); (A.A.); (M.J.); (H.S.); (S.J.H.)
- Department of Biology, Faculty of Sciences, Lebanese University, Nabatieh P.O. Box 6573/14, Lebanon;
- Department of Laboratory Sciences, Faculty of Nursing and Health Sciences, Islamic University of Lebanon, Khalde P.O. Box 30014, Lebanon
- Correspondence: (A.S.); (G.G.); Tel.: +961-7-761-980 (A.S. & G.G.)
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Hodeify R, Chakkour M, Rida R, Kreydiyyeh S. PGE2 upregulates the Na+/K+ ATPase in HepG2 cells via EP4 receptors and intracellular calcium. PLoS One 2021; 16:e0245400. [PMID: 33444342 PMCID: PMC7808645 DOI: 10.1371/journal.pone.0245400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/29/2020] [Indexed: 11/18/2022] Open
Abstract
The Na+/K+ ATPase is a key regulator of the hepatocytes ionic homeostasis, which when altered may lead to many liver disorders. We demonstrated recently, a significant stimulation of the Na+/K+ ATPase in HepG2 cells treated with the S1P analogue FTY 720P, that was mediated through PGE2. The mechanism by which the prostaglandin exerts its effect was not investigated, and is the focus of this work. The type of receptors involved was determined using pharmacological inhibitors, while western blot analysis, fluorescence imaging of GFP-tagged Na+/K+ ATPase, and time-lapse imaging on live cells were used to detect changes in membrane abundance of the Na+/K+ ATPase. The activity of the ATPase was assayed by measuring the amount of inorganic phosphate liberated in the presence and absence of ouabain. The enhanced activity of the ATPase was not observed when EP4 receptors were blocked but still appeared in presence inhibitors of EP1, EP2 and EP3 receptors. The involvement of EP4 was confirmed by the stimulation observed with EP4 agonist. The stimulatory effect of PGE2 did not appear in presence of Rp-cAMP, an inhibitor of PKA, and was imitated by db-cAMP, a PKA activator. Chelating intracellular calcium with BAPTA-AM abrogated the effect of db-cAMP as well as that of PGE2, but PGE2 treatment in a calcium-free PBS medium did not, suggesting an involvement of intracellular calcium, that was confirmed by the results obtained with 2-APB treatment. Live cell imaging showed movement of GFP–Na+/K+ ATPase-positive vesicles to the membrane and increased abundance of the ATPase at the membrane after PGE2 treatment. It was concluded that PGE2 acts via EP4, PKA, and intracellular calcium.
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Affiliation(s)
- Rawad Hodeify
- Department of Biotechnology, School of Arts and Sciences, American University of Ras Al Khaimah, Ras Al Khaimah, United Arab Emirates
| | - Mohamed Chakkour
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Reem Rida
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Sawsan Kreydiyyeh
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
- * E-mail:
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Chakkour M, Kreydiyyeh S. FTY720P Upregulates the Na+/K+ ATPase in HepG2 Cells by Activating S1PR3 and Inducing PGE2 Release. Cell Physiol Biochem 2019; 53:518-531. [PMID: 31502430 DOI: 10.33594/000000155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2019] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND/AIMS Liver regeneration is induced by S1P and accompanied with an increase in hepatic Na+/K+ ATPase activity, suggesting a potential modulatory role of the sphingolipid on the ATPase activity. The ability of S1P to alter the ATPase activity was confirmed in a previous work which showed a time dependent effect, with an inhibition appearing at 15min and a stimulation at two hours. The aim of this work was to investigate if FTY720-P, an analogue of S1P used in the treatment of multiple sclerosis, exerts a similar effect at 2 hours. METHODS HepG2 cells were treated with FTY720-P for two hours and the activity of the Na+/K+ ATPase was assayed by measuring the amount of inorganic phosphate liberated in presence and absence of ouabain. The involvement of NF-κB in the pathway was investigated by determining changes in the protein expression of IκB. RESULTS FTY720-P induced a 2.5-fold increase in the activity of the Na+/K+ ATPase which was maintained in the presence of JTE-013, a specific blocker of S1PR2, but disappeared completely in presence of CAY 10444, a specific S1PR3 antagonist. The involvement of S1PR3 was supported by the stimulation observed with Cym5541, a S1PR3 agonist. FTY720-P increased the expression of COX2, and reduced that of IκB. Its effect was not manifested in presence of indomethacin, a COX inhibitor, or in presence of an NF-κB inhibitor. Exogenous PGE2 induced a significant stimulatory effect. Inhibiting PKC and ERK with respectively calphostin C and PD98059 abolished the effect of FTY720-P on the ATPase and on IκB, but not that of exogenous PGE2 indicating that the two kinases are upstream of NF-κB and PGE2. The PKC activator PMA increased the activity of the Na+/K+ ATPase as well as the expression of phopho-ERK, inferring that PKC is upstream of ERK. CONCLUSION It was concluded that FTY720-P stimulates the Na+/K+ ATPase via PGE2 by activating sequentially S1PR3, PKC, ERK, NF-κB. The latter enhances COX-2 expression leading to PGE2 release.
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Affiliation(s)
- Mohamed Chakkour
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Sawsan Kreydiyyeh
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon,
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El Moussawi L, Chakkour M, Kreydiyyeh S. The epinephrine-induced PGE2 reduces Na+/K+ ATPase activity in Caco-2 cells via PKC, NF-κB and NO. PLoS One 2019; 14:e0220987. [PMID: 31393950 PMCID: PMC6687175 DOI: 10.1371/journal.pone.0220987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/26/2019] [Indexed: 12/03/2022] Open
Abstract
We showed previously an epinephrine-induced inhibition of the Na+/K+ ATPase in Caco-2 cells mediated via PGE2. This work is an attempt to further elucidate mediators downstream of PGE2 and involved in the observed inhibitory effect. The activity of the Na+/K+ ATPase was assayed by measuring the amount of inorganic phosphate liberated in presence and absence of ouabain, a specific inhibitor of the enzyme. Changes in the protein expression of the Na+/K+ ATPase were investigated by western blot analysis which revealed a significant decrease in the abundance of the ATPase in plasma membranes. Treating the cells with epinephrine or PGE2 in presence of SC19220, a blocker of EP1 receptors abolished completely the effect of the hormone and the prostaglandin while the effect was maintained unaltered in presence of antagonists to all other receptors. Treatment with calphostin C, PTIO, ODQ or KT5823, respective inhibitors of PKC, NO, soluble guanylate cyclase and PKG, abrogated completely the effect of epinephrine and PGE2, suggesting an involvement of these mediators. A significant inhibition of the ATPase was observed when cells were treated with PMA, an activator of PKC or with 8-Br-cGMP, a cell permeable cGMP analogue. PMA did reduce the protein expression of IκB, as shown by western blot analysis, and its effect on the ATPase was not manifested in presence of an inhibitor of NF-κB while that of SNAP, a nitric oxide donor, was not affected. The results infer that NF-κB is downstream PKC and upstream NO. The data support a pathway in which epinephrine induces the production of PGE2 which binds to EP1 receptors and activates PKC and NF-κB leading to NO synthesis. The latter activates soluble guanylate cyclase resulting in cGMP production and activation of PKG which through direct or indirect phosphorylation inhibits the Na+/K+ ATPase by inducing its internalization.
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Affiliation(s)
- Layla El Moussawi
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Mohamed Chakkour
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Sawsan Kreydiyyeh
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
- * E-mail:
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Salami A, Fakih H, Chakkour M, Salloum L, Bahmad HF, Ghssein G. Prevalence, risk factors and seasonal variations of different Enteropathogens in Lebanese hospitalized children with acute gastroenteritis. BMC Pediatr 2019; 19:137. [PMID: 31039787 PMCID: PMC6489254 DOI: 10.1186/s12887-019-1513-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/12/2019] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Acute gastroenteritis (AGE) is a major cause of pediatric morbidity and mortality around the world. It remains a frequent reason for infection-related admissions to emergency units among all age groups. Following the Syrian refugee crisis and insufficient clean water in our region, we sought to assess the etiological and epidemiological factors pertaining to AGE in South Lebanon. METHODS In this multi-center cross sectional clinical study, we analyzed the demographic, clinical and laboratory data of 619 Lebanese children from the age of 1 month to 5 years old who were admitted with AGE to pediatrics departments of three tertiary care centers in South Lebanon. RESULTS Our results revealed that males had a higher incidence of AGE (57.3%) than females. Enteropathogens were identified in 332/619 (53.6%) patients. Single pathogens were found in 294/619 (47.5%) patients, distributed as follows: Entamoeba histolytica in 172/619 (27.8%) patients, rotavirus in 84/619 (13.6%), and adenovirus in 38/619 (6.1%). Mixed co-pathogens were identified in 38/619 (6.1%) patients. Analyzing the clinical manifestations indicated that E. histolytica caused the most severe AGE. In addition, children who received rotavirus vaccine were significantly less prone to rotavirus infection. CONCLUSIONS Our findings alluded to the high prevalence of E. histolytica and other unidentified enteropathogens as major potential causes of pediatric AGE in hospitalized Lebanese children. This should drive us to widen our diagnostic panel by adopting new diagnostic techniques other than the routinely used ones (particularly specific for the pathogenic amoeba E. histolytica and for the unidentified enteropathogens), and to improve health services in this unfortunate area of the world where insanitary water supplies and lack of personal hygiene represent a major problem.
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Affiliation(s)
- Ali Salami
- Rammal Hassan Rammal Research Laboratory, Physio-toxicity (PhyTox) Research Group, Lebanese University, Faculty of Sciences (V), Nabatieh, Lebanon.
| | - Hadi Fakih
- Department of Pediatrics, Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Mohamed Chakkour
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
| | - Lamis Salloum
- Rammal Hassan Rammal Research Laboratory, Physio-toxicity (PhyTox) Research Group, Lebanese University, Faculty of Sciences (V), Nabatieh, Lebanon
| | - Hisham F Bahmad
- Faculty of Medicine, Beirut Arab University, Beirut, Lebanon
- Department of Anatomy, Cell Biology, and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Ghassan Ghssein
- Rammal Hassan Rammal Research Laboratory, Physio-toxicity (PhyTox) Research Group, Lebanese University, Faculty of Sciences (V), Nabatieh, Lebanon.
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Chakkour M, Kreydiyyeh S. FTY720‐P Activates Hepatic Na
+
/K
+
ATPase via S1PR3, PKC and PGE
2. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.lb425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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El Moussawi L, Chakkour M, Kreydiyyeh SI. Epinephrine modulates Na+/K+ ATPase activity in Caco-2 cells via Src, p38MAPK, ERK and PGE2. PLoS One 2018; 13:e0193139. [PMID: 29466417 PMCID: PMC5821373 DOI: 10.1371/journal.pone.0193139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/05/2018] [Indexed: 01/23/2023] Open
Abstract
Epinephrine, a key stress hormone, is known to affect ion transport in the colon. Stress has been associated with alterations in colonic functions leading to changes in water movements manifested as diarrhea or constipation. Colonic water movement is driven by the Na+-gradient created by the Na+/K+-ATPase. Whether epinephrine acts via an effect on the Na+/K+-ATPase hasn’t been studied before. The aim of this work was to investigate the effect of epinephrine on the Na+/K+-ATPase and to elucidate the signaling pathway involved using CaCo-2 cells as a model. The activity of the Na+/K+-ATPase was assayed by measuring the amount of inorganic phosphate released in presence and absence of ouabain, a specific inhibitor of the enzyme. Epinephrine, added for 20 minutes, decreased the activity of the Na+/K+-ATPase by around 50%. This effect was found to be mediated by α2 adrenergic receptors as it was fully abolished in the presence of yohimbine an α2-blocker, but persisted in presence of other adrenergic antagonists. Furthermore, treatment with Rp-cAMP, a PKA inhibitor, mimicked epinephrine’s negative effect and didn’t result in any additional inhibition when both were added simultaneously. Treatment with indomethacin, PP2, SB202190, and PD98059, respective inhibitors of COX enzymes, Src, p38MAPK, and ERK completely abrogated the effect of epinephrine. The effect of epinephrine did not appear also in presence of inhibitors of all four different types of PGE2 receptors. Western blot analysis revealed an epinephrine-induced increase in the phosphorylation of p38 MAPK and ERK that disappeared in presence of respectively PP2 and SB2020190. In addition, an inhibitory effect, similar to that of epinephrine’s, was observed upon incubation with PGE2. It was concluded that epinephrine inhibits the Na+/K+-ATPase by the sequential activation of α2 adrenergic receptors, Src, p38MAPK, and ERK leading to PGE2 release.
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Affiliation(s)
- Layla El Moussawi
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Mohamed Chakkour
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
| | - Sawsan I. Kreydiyyeh
- Department of Biology, Faculty of Arts & Sciences, American University of Beirut, Beirut, Lebanon
- * E-mail:
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