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The development of novel strategies to counteract diseases related to barrier dysfunction is a priority, since sepsis and acute respiratory distress syndrome are still associated with high mortality rates. In the present study, we focus on the effects of the unfolded protein response suppressor (UPR) 4-Phenylbutyrate (4-PBA) in Lipopolysaccharides (LPS)-induced endothelial injury, to investigate the effects of that compound in the corresponding damage. 4-PBA suppressed binding immunoglobulin protein (BiP) - a UPR activation marker - and potentiated LPS - induced signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated protein kinase (ERK) 1/2 activation. In addition to those effects, 4-PBA enhanced paracellular hyperperme-ability in inflamed bovine pulmonary endothelial cells, and did not affect cell viability in moderate concentrations. Our observations suggest that UPR suppression due to 4-PBA augments LPS-induced endothelial injury, as well as the corresponding barrier disruption. [ABSTRACT FROM AUTHOR]

Background: Nutritional anemia is a significant public health concern worldwide, particularly affecting young adults and children in Saudi Arabia, where inadequate nutrition is considered a primary contributing factor. This study aims to (i) examine the levels of serum iron, folate, and vitamin B12 in young adult students, with a focus on identifying any deficiencies and their association with anemia; (ii) explore the prevalence of mixed-deficiency anemia resulting from deficiencies in serum iron, folate, and vitamin B12 (iii) explore how sociodemographic characteristics and dietary habits influence serum iron, folate, and vitamin B12 levels. Materials and Methods: This cross-sectional study encompassed 158 young adult students at Jazan University, Saudi Arabia. Blood samples were collected following a comprehensive questionnaire addressing sociodemographic and health characteristics. These samples were analyzed for complete blood count, serum iron, folate, and vitamin B12 levels. Results: The findings of this study revealed a significant decrease in serum iron levels, with 70.6% of males and 88% in females exhibiting reduced level. Additionally, low levels of folate were observed in 4% of the study population, while deficiency in vitamin B12 was found in 2.2% of the study population. However, the simultaneous presence of low serum iron levels along with deficiencies in folate or vitamin B12 was not observed in the study participants. Conclusion: The study indicates that there is a high incidence of low serum iron and ferritin levels among university students in Saudi Arabia, which poses a considerable public health concern. Conversely, the prevalence of folate and vitamin B12 deficiencies among the students was comparatively low, and notably, there were no cases where these deficiencies were observed alongside iron deficiency. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) is a major health burden affecting 537 million adults worldwide, characterized by chronic metabolic disorder and various complications. This case control study aimed to assess the impact of type 2 diabetes mellitus (T2DM), including hyperglycemia levels, on hematological parameters and complete blood count (CBC) derived parameters.Methods: A total of 250 known diabetic patients from the Jazan Diabetic Center, Saudi Arabia, between January 2021 and December 2022, along with 175 healthy adult controls were recruited from Jazan Hospital's blood donation center. Demographic characteristics, medical histories, and relevant factors such as gender, age, BMI, treatment, disease duration, and comorbidities were collected with informed consent.Results: The results of the red blood cell (RBC) count, RBC indices, and mean platelet volume showed significant differences between patients and controls, while the white cell (WBC) and platelet count were comparable between the two groups. CBC-derived parameters, especially neutrophil/lymphocyte ratio (NLR), and platelet/neutrophil ratio (PNR) exhibited significant differences.Conclusion: CBC and derived parameters serve as inexpensive tools for T2DM patients monitoring, indicating early blood cell alterations and potential development of anemia. Further studies are needed to explore their role in predicting T2DM pathogenesis and progression, aiming to reduce severe complications, mortality and morbidity. [ABSTRACT FROM AUTHOR]

T-activation polyagglutination can be caused by bacteria or viruses and has been associated with haemolytic anaemia. Coronavirus disease-19 (COVID-19) is also associated with haemolytic anaemia. The presented study aims to determine T activation polyagglutination in critically ill COVID-19 patients. Anti-T Arachis hypogaea lectin was incubated with the red blood cells of the COVID-19 patient and checked for agglutination. Thirty-four percent (34.3%) of COVID-19 patients in the intensive care unit (ICU) had potentially activated T cells and polyagglutinable red blood cells, as demonstrated by their cryptantigen exposure that caused agglutination. The study revealed a high prevalence of anti-T among ICU-admitted COVID-19 patients, suggesting that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may cause transient T activation, polyagglutination in critically ill COVID-19 patients in vitro and possibly haemolysis in vivo. [ABSTRACT FROM AUTHOR]

Advanced mitochondrial multi-omics indicate a multi-facet involvement of mitochondria in the physiology of the cell, changing the perception of mitochondria from being just the energy-generating organelles to organelles that highly influence cell structure, function, signaling, and cell fate. This sets mitochondrial dysfunction in the centerstage of numerous acquired and genetic diseases. Sickle cell disease is also being increasingly associated with mitochondrial anomalies and the pathophysiology of sickle cell disease finds mitochondria at crucial intersections in the pathological cascade. Altered mitophagy, increased ROS, and mitochondrial DNA all contribute to the condition and its severity. Such mitochondrial aberrations lead to consequent mitochondrial retention in red blood cells in sickle cell diseases, increased oxidation in the cellular environment, inflammation, worsened vaso-occlusive crisis, etc. There are increasing studies indicating mitochondrial significance in sickle cell disease, consequently providing an opportunity to target it for improving the outcomes of treatment. Identification of the impaired mitochondrial attributes in sickle cell disease and their modulation by therapeutic interventions can impart a better management of the disease. This review aims to describe the mitochondria in the perspective of sicke cell disease so as to provide the reader an overview of the emerging mitochondrial stance in sickle cell disease. [ABSTRACT FROM AUTHOR]

The discovery of hypothalamic hormones propelled exciting advances in pharmacotherapy and improved life quality worldwide. Growth hormone–releasing hormone (GHRH) is a crucial element in homeostasis maintenance, and regulates the release of growth hormone from the anterior pituitary gland. Accumulating evidence suggests that this neuropeptide can also promote malignancies, as well as inflammation. Our review is focused on the role of that 44 - amino acid peptide (GHRH) and its antagonists in inflammation and vascular function, summarizing recent findings in the corresponding field. Preclinical studies demonstrate the protective role of GHRH antagonists against endothelial barrier dysfunction, suggesting that the development of those peptides may lead to new therapies against pathologies related to vascular remodeling (eg, sepsis, acute respiratory distress syndrome). Targeted therapies for those diseases do not exist. [ABSTRACT FROM AUTHOR]

Introduction: Coronavirus disease-19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still posing detrimental effects on people. An association between contracting COVID-19 and the ABO blood group type has been determined. However, factors that determine the severity of COVID-19 are not yet fully understood. Thus, the current study aimed to investigate whether the ABO blood group type has a role in the severity of complications due to COVID-19. Materials and methods: Eighty-Six ICU-admitted COVID-19 patients and 80 matched-healthy controls were recruited in the study from Baish general hospital, Saudi Arabia. ABO blood grouping, complete blood count (CBC), CBC-derived inflammatory markers, coagulation profile, D-Dimer and anti-T antigen were reported. Results: Our data showed that patients with blood groups O and B are more protective against severe complications from COVID-19, as compared to patients with blood groups A and AB. This could be partially attributed to the presence of anti-T in blood group A individuals, compared to non-blood group A. Conclusion: The current study reports an association between the ABO blood group and the susceptibility to severe complications from COVID-19, with a possible role of anti-T in driving the mechanism of the thrombotic tendency, as it was also correlated with an elevation in D-dimer levels. [ABSTRACT FROM AUTHOR]

Growth hormone-releasing hormone (GHRH) and its receptors are expressed in a variety of human cancers, and have been involved in malignancies. GHRH antagonists (GHRHAnt) were developed to suppress tumor progression and metastasis. Previous studies demonstrate the involvement of reactive oxygen species (ROS) in cancer progression. Herein, we investigate the effect of a commercially available GHRH antagonist, namely JV-1-36, in the redox status of the A549 human cancer cell line. Our results suggest that this peptide significantly reduces ROS production in those cells in a time-dependent manner and counteracts H2O2-induced ROS. Our study supports the anti-oxidative effects of JV-1-36 and contributes in our knowledge towards the in vitro effects of GHRHAnt in cancers. [ABSTRACT FROM AUTHOR]

Dysfunction of the blood–brain barrier (BBB) endothelium increases infiltration of lymphocytes and innate immune cells in the brain, leading to the development of neurological disorders. Heat shock protein 90 (Hsp90) inhibitors are anti‐inflammatory agents and P53 inducers, which reduce the production of reactive oxygen species (ROS) in a diverse variety of human tissues. In this study, we investigate the effects of those compounds in LPS‐induced brain endothelial inflammation, by utilizing human cerebral microvascular endothelial cells (hCMEC/D3). Our results suggest that Hsp90 inhibitors suppress inflammation by inhibiting the LPS‐induced signal transducer and activator of transcription 3 (STAT3); and P38 activation. Moreover, those compounds reduce the P53 suppressors murine double minute 2 (MDM2) and murine double minute 4 (MDM4). Immunoglobulin heavy chain binding protein/glucose‐regulated protein 78 (BiP/Grp78)—a key element of endothelial barrier integrity‐was also increased by Hsp90 inhibition. Hence, we conclude that application of Hsp90 inhibitors in diseases related to BBB dysfunction may deliver a novel therapeutic possibility in the affected population. [ABSTRACT FROM AUTHOR]

Introduction: Rh and Kell blood group systems are amongst the most important blood group systems; being highly immunogenic after ABO system. The aim of this study was to evaluate the frequencies of Rh antigens, haplotypes and K antigen among blood donors belonging to various ethnicities in Samtah, Jazan, Saudi Arabia. Methods: This study was conducted during January 2019 and August 2020 at Samtah General Hospital, Samtah. Records of all blood donors recruited during this period were included for data acquisition. A total of 4977 blood donors' records were reviewed and data were analysed. A total of 3863 donors' results were considered in the final analysis. Results: In comparison to Saudi blood donors, C antigen was less frequent in Sudanese donors (69.7% and 34.0%), the c antigen was less frequent in Indian (79.2% and 59.3%) and Philippine (79.2% and 40.0%) donors and more frequent in Sudanese (79.2% and 97.9%) donors, the E antigen was less frequent in Yemini (27.0% and 19.5%) and the e antigen was more frequent in Yemini (96.7% and 99.2%) donors. The DcE haplotype was less frequent (3.1% and 0.7%) and the ce haplotype was more frequent (4.3% and 7.6%) in Yemini donors. The K antigen was less frequent in Pakistani (11.9% and 4.1%; p =.041) and Indian (11.9% and 1.9%; p =.023) donors. Conclusion: Rh and K antigens showed marked variations in their frequencies among blood donors of different ethnicities. Utilization of blood from various ethnicities warrant extended phenotyping of Rh and K antigens to avoid the risk of alloimmunization in multiply transfused patients. [ABSTRACT FROM AUTHOR]

Background: The hypercoagulability and thrombotic tendency in coronavirus disease 2019 (COVID-19) is multifactorial, driven mainly by inflammation, and endothelial dysfunction. Elevated levels of procoagulant microvesicles (MVs) and tissue factor–bearing microvesicles (TF-bearing MVs) have been observed in many diseases with thrombotic tendency. The current study aimed to measure the levels of procoagulant MVs and TF-bearing MVs in patients with COVID-19 and healthy controls and to correlate their levels with platelet counts, D-Dimer levels, and other proposed calculated inflammatory markers. Materials and Methods: Forty ICU-admitted patients with COVID-19 and 37 healthy controls were recruited in the study. Levels of procoagulant MVs and TF-bearing MVs in the plasma of the study population were measured using enzyme linked immunosorbent assay. Results: COVID-19 patients had significantly elevated levels of procoagulant MVs and TF-bearing MVs as compared with healthy controls (P< 0.001). Procoagulant MVs significantly correlated with TF-bearing MVs, D-dimer levels, and platelet count, but not with calculated inflammatory markers (neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, and platelet/neutrophil ratio). Conclusion: Elevated levels of procoagulant MVs and TF-bearing MVs in patients with COVID-19 are suggested to be (i) early potential markers to predict the severity of COVID-19 (ii) a novel circulatory biomarker to evaluate the procoagulant activity and severity of COVID-19. [ABSTRACT FROM AUTHOR]

Background: Deep Vein Thrombosis (DVT) is a multicausal disease involving both acquired as well as genetic factors. Nitric oxide is an influential endogenous factor having its role in the development of deep vein thrombosis. It maintains the vascular integrity and any alterations in its levels may lead to a thrombotic event. It may also modulate homocysteine metabolism to cause hyperhomocysteinemia, which is a prominent risk factor for thrombosis. The objective of the study was to study if endothelial nitric oxide gene polymorphisms, 894G/T, and 2479G/A alter the plasma nitric oxide and homocysteine levels which may eventually increase the risk of deep vein thrombosis. Methods: One hundred Doppler ultrasonography and computerized tomography confirmed (for cerebral venous thrombosis), non-related DVT patients (M:F = 58:42; age range = 18 to 61 years) served as the study population. Two hundred hospital staff and their relatives or unrelated attendants of the patients served as the controls. Nitric oxide levels were determined by measuring its metabolites (NOx), and EIA was used to measure homocysteine levels. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for detecting the eNOS polymorphisms 894G/T and 2479G/A. Results: In total, DVT subjects have 25% higher plasma levels of homocysteine and 37% lower levels of NOx in their circulation when compared to controls. In tertile analysis of nitric oxide and homocysteine levels, 894G/T and 2479G/A polymorphisms were associated with plasma nitric oxide and homocysteine levels. The increased risk of deep vein thrombosis was associated with endothelial nitric oxide gene polymorphisms and nitric oxide levels, but homocysteine levels were not a risk for deep vein thrombosis. Conclusion: The present study demonstrates that 894G/T and 2479G/A polymorphisms interact with lower levels of nitric oxide and higher levels of homocysteine that may possess the risk of deep vein thrombosis. [ABSTRACT FROM AUTHOR]

aims of the current study were to evaluate the importance of MPR and NLR as prognostic markers in ICU-admitted COVID-19 patients and to investigate the impact of COVID-19 on hematological and coagulation parameters in patients from Jazan region of Saudi Arabia. Methods: This retrospective study was conducted between October 2020 and January 2021 at King Fahad Central Hospital, Jazan region. Medical files, which included the results of complete blood count (CBC), calculated mean platelet volume to platelet count ratio (MPR) and neutrophils-to-lymphocytes ratio (NLR) parameters, coagulation profile and D-dimer test, of 96 (64 male and 32 female) COVID-19-infected patients admitted to the intensive care unit were reviewed. Associations between the test results and COVID-19 infection outcomes (discharged [DC] or passed away [PA]) were measured. Results: The results of the current study demonstrate overall significant differences in CBC parameters between PA group as compared to DC group (P < 0.05). The PA group had a significantly elevated MPR (10.15± 12.16 vs 4.04± 1.5; P < 0.01) and NLR (18.29± 19.82 vs 7.35± 9.68; P < 0.01) as compared to the DC group, suggesting an association between these parameters and mortality. Odds ratios analysis also showed that adjustment for demographic variables and comorbidities did not weaken the observed association. Conclusion: Elevated MPR and NLR are associated with poor prognosis in COVID-19 patients and could be useful as therapy management indicators. [ABSTRACT FROM AUTHOR]

Endothelial barrier dysfunction (EBD) is the hallmark of Acute Respiratory Distress Syndrome (ARDS), a potentially lethal respiratory disorder associated with the COVID-19 – related deaths. Herein, we employed a cecal ligation and puncture (CLP) murine model of sepsis, to evaluate the effects of sepsis-induced EBD in the expression of the never in mitosis A (NIMA)-related kinases (NEKs). Members of that family of kinases regulate the activity and expression of the tumor suppressor P53, previously shown to modulate the actin cytoskeleton remodeling. Our results introduce the induction of NEK2, NEK3, NEK4, NEK7, and NEK9 in a CLP model of sepsis. Hence, we suggest that NEKs are involved in inflammatory processes and are holding the potential to serve as novel therapeutic targets for pathologies related to EBD, including ARDS and sepsis. Further studies will delineate the underlying molecular events and their interrelations with P53. [ABSTRACT FROM AUTHOR]

Background: Sickle cell disease (SCD) is a common hematological genetic disorder in Saudi Arabia, Africa, the Mediterranean region, and India. The present study aimed to characterize βS haplotypes found in the Jazan region, Saudi Arabia. Methods: One hundred sickle cell trait (SCT) individuals, diagnosed during their visit to the premarital screening clinic at King Fahad Central Hospital, were included in the study. Molecular analysis was carried out by polymerase chain reaction (PCR) and six polymorphic sites of the β-globin gene were analyzed using restriction endonucleases Hind II, Xmn-I, Hind III, and Ava II. Results: The results of the current study revealed the presence of five typical haplotypes in which Benin, Bantu, and Senegal were found in homozygous state with 29%, 3% and 1% frequencies, respectively. Interestingly, 29% of the studied population showed atypical haplotypes in heterozygous state and 2% in homozygous state for the first time in Jazan region. Conclusions: In addition to the typical haplotypes, high frequency of atypical haplotypes in this study indicates a diverse genetic mechanism that might have a crucial effect on the severity of SCD in this region. Therefore, considering this study in a cohort population with SCD in Jazan region may provide more in-depth details about the correlation between haplotypes and the clinical manifestation of the disease. [ABSTRACT FROM AUTHOR]

Growth hormone‐releasing hormone (GHRH) is a hypothalamic hormone, which regulates the secretion of growth hormone (GH) from the anterior pituitary gland. The effects of GHRH extend beyond the GH—insulin‐like growth factor I axis, and that neuropeptide has been involved in the potentiation of several malignancies and other inflammatory disorders. The development of GHRH antagonists (GHRHAnt) delivers an exciting possibility to counteract the pathogenesis of the GHRH‐related effects in human pathophysiology, especially when considered that GHRHAnt support endothelial barrier integrity. Those GHRHAnt‐mediated effects are exerted at least in part due to the suppression of major inflammatory pathways, and the modulation of major cytoskeletal components. In the present study, we measured the production of reactive oxygen species (ROS) in bovine pulmonary artery endothelial cells, human cerebral microvascular endothelial cells, and human lung microvascular endothelial cells exposed to GHRH or a commercially available GHRHAnt. Our findings reveal the antioxidative effects of GHRHAnt in all three cell lines, which express GHRH receptors. The redox status of NIH/3T3 cells, which do not produce GHRH receptors, was not significantly affected by GHRH or GHRHAnt. Hence, the application of GHRHAnt in pathologies related to increased ROS production should be further investigated. [ABSTRACT FROM AUTHOR]

Purpose: Anemia is one of the most common disorders affecting the population in both low-income and developing countries. This study aimed to determine the prevalence of anemia and iron deficiency in apparently normal male and female students of Jazan University, Saudi Arabia. Material and Methods: This cross-sectional study was conducted at the Faculty of Applied Medical Sciences, Jazan University, Gizan, Saudi Arabia. One hundred thirty-four (85 males and 49 females) healthy students with no outward signs of illness were recruited. A specific questionnaire related to sociodemographic and health characteristics was designed and validated. The collected samples were analyzed for complete blood count, serum iron, and serum ferritin. Results: In the male group, 81 participants (95.3%) were nonanemic with normal hemoglobin (14.99 ± 1.11g/dl), whereas only 4 males were anemic (hemoglobin < 13.0 g/dl). On the other hand, anemia was more prevalent in female students, as 67.35% had hemoglobin values less than 12.0 g/dl. In addition, 26.54% of the anemic females had low serum iron and serum ferritin, indicating iron-deficiency anemia. Although the majority of male participants had normal hemoglobin levels, 37.6% of them had low mean cell volume (MCV), low mean cell hemoglobin (MCH), low mean cell hemoglobin concentration (MCHC), and high red blood cell (RBC) counts, suggesting thalassemia. Conclusion: Anemia, in particular iron-deficiency anemia, was found to be highly prevalent in females, whereas more than one-third of the male participants might be carriers of alpha or beta thalassemia. Additionally, low dietary iron intake and irregular meal consumption could be two of the possible causes of anemia in the study population. Conducting this study on a large scale of male and female students from different faculties of Jazan University will provide in-depth details about the prevalence and types of anemia among them. [ABSTRACT FROM AUTHOR]

Background: The levels of procoagulant microvesicles (MVs) and tissue factor (TF)-bearing MVs may be increased in many conditions, including dengue fever (DF). This study aimed to measure the levels of MVs and TF-bearing MVs in patients with DF and matched healthy controls. Materials & methods: Levels of MVs and TF-bearing MVs in the plasma of patients with DF and matched healthy controls were measured using functional assay. Results: The patient group had significantly elevated levels of MVs (p < 0.001) and slightly increased levels of TF-bearing MVs (p = 0.454) compared with the matched healthy controls. Conclusion: Elevated levels of MVs and TF-bearing MVs could be used as biomarkers to evaluate the hemostatic function of patients with DF. [ABSTRACT FROM AUTHOR]

Growth hormone releasing hormone is a hypothalamic neuropeptide, which regulates the release of growth hormone from the anterior pituitary gland. Growth hormone releasing hormone antagonists are anticancer agents, associated with strong anti-inflammatory activities. In the present study, we investigated the effects of the GHRH antagonist MIA-602 in the integrity of the brain microvascular endothelium in vitro. Our observations suggest that MIA-602 protects against the H2 O2-induced breakdown of the brain endothelium and enhances its integrity by inducing P53, deactivating cofilin, and suppressing the RhoA inflammatory pathway. Thus, GHRH antagonists may offer an exciting possibility for the treatment of pathologies related to the blood brain barrier dysfunction, including the Parkinson's and Alzheimer's diseases. [ABSTRACT FROM AUTHOR]

The anti-inflammatory activities of P53 in the vasculature have been associated with the enhancement of the endothelial barrier function. In the present study, we employed human and bovine lung endothelial cells, to investigate whether P53 expression levels affect the redox status of pulmonary cells. Moreover, we tested the possibility that those events affect the endothelial integrity of the lung microvascular monolayers. Our observations suggest that P53 suppression by LPS, pifithrin, or small interfering RNA increased the expression of the redox marker malondialdehyde. In contrast, P53 induction by Nutlin or the Hsp90 inhibitor AUY922 exerted the opposite effects, namely, suppressed that lipid oxidation marker. The direct measurement of the reactive oxygen species by 2,7-Dichlorodihydrofluorescein diacetate confirmed the antioxidant activity of P53 in the vasculature. Furthermore, the increased reactive oxygen species production due to P53 suppression was associated with lung hyperpermeability responses. In conclusion, P53 supports endothelial barrier function, at least in part, via the modulation of the reactive oxygen species. [ABSTRACT FROM AUTHOR]

Growth Hormone-Releasing Hormone (GHRH) regulates the release of growth hormone from the anterior pituitary gland. GHRH also acts as a growth and inflammatory factor in a variety of experimental models in oncology. In the current study, we used bovine pulmonary arterial cells in order to investigate the effects of GHRH and its antagonistic and agonistic analogs in key intracellular pathways that regulate endothelial permeability. GHRH antagonists suppressed the activation of MLC2, ERK1/2, JAK2/STAT3 pathway and increased the intracellular P53 and pAMPK levels. In contrast, both GHRH and GHRH agonist MR409 exerted the opposite effects. Furthermore, GHRH antagonists supported the integrity of endothelial barrier, while GHRH and GHRH agonists had the contrary effects, as reflected in measurements of transendothelial resistance. Our observations support the evidence for the anti – inflammatory role of GHRH antagonists in the vasculature. Moreover, our results suggest that GHRH antagonists should be considered as promising therapeutic agents for treating severe respiratory abnormalities, such as the lethal Acute Respiratory Distress Syndrome (ARDS). [ABSTRACT FROM AUTHOR]

Endothelial hyperpermeability is associated with sepsis and acute respiratory distress syndrome (ARDS). The identification of molecular pathways involved in barrier dysfunction; may reveal promising therapeutic targets to combat ARDS. Unfolded protein response (UPR) is a highly conserved molecular pathway, which ameliorates endoplasmic reticulum stress. The present work focuses on the effects of ATF6, which is a UPR sensor, in lipopolysaccharides (LPS)-induced endothelial hyperpermeability. The in vitro effects of AA147 and Ceapin-A7 in LPS-induced endothelial barrier dysfunction were investigated in bovine pulmonary artery endothelial cells (BPAEC). Small interfering (si) RNA was utilized to "silence" ATF6, and electric cell-substrate impedance sensing (ECIS) measured transendothelial resistance. Fluorescein isothiocyanate (FITC)-dextran assay was utilized to assess paracellular permeability. Protein expression levels were evaluated with Western blotting, and cell viability with MTT assay. We demonstrated that AA147 prevents LPS-induced barrier disruption by counteracting Cofilin and myosin light chain 2 (MLC2) activation, as well as VE-Cadherin phosphorylation. Moreover, this ATF6 inducer opposed LPS-triggered decrease in transendothelial resistance (TEER), as well as LPS-induced paracellular hyperpermeability. On the other hand, ATF6 suppression due to Ceapin-A7 or small interfering RNA exerted the opposite effects, and potentiated LPS-induced endothelial barrier disruption. Moderate concentrations of both ATF6 modulators did not affect cell viability. ATF6 activation protects against endothelial barrier function, suggesting that this UPR sensor may serve as a therapeutic target for sepsis and ARDS. • Endothelial barrier dysfunction is associated with sepsis and Acute Respiratory Distress Syndrome. • Unfolded protein response protects against endoplasmic reticulum stress. • Activating transcription factor-6 is an unfolded protein response sensor. • Activating transcription factor-6 activation due to AA147 enhances barrier integrity and protects against vascular leak. • ATF6 may represent a therapeutic target towards disorders related to endothelial dysregulation. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) cause thousands of deaths every year and are associated with high mortality rates (~40%) due to the lack of efficient therapies. Understanding the molecular mechanisms associated with those diseases will most probably lead to novel therapeutics. In the present study, we investigated the effects of the Hsp90 inhibitor AUY-922 in the major inflammatory pathways of mouse lungs. Mice were treated with LPS (1.6 mg/kg) via intratracheal instillation for 24 h and were then post-treated intraperitoneally with AUY-922 (10 mg/kg). The animals were examined 48 h after AUY-922 injection. LPS activated the TLR4-mediated signaling pathways, which in turn induced the release of different inflammatory cytokines and chemokines. AUY-922 suppressed the LPS-induced inflammation by inhibiting major pro-inflammatory pathways (e.g., JAK2/STAT3, MAPKs), and downregulated the IL-1β, IL-6, MCP-1 and TNFα. The expression levels of the redox regulator APE1/Ref1, as well as the DNA-damage inducible kinases ATM and ATR, were also increased after LPS treatment. Those effects were counteracted by AUY-922. Interestingly, this Hsp90 inhibitor abolished the LPS-induced pIRE1α suppression, a major component of the unfolded protein response. Our study elucidates the molecular pathways involved in the progression of murine inflammation and supports our efforts on the development of new therapeutics against lung inflammatory diseases and sepsis. [ABSTRACT FROM AUTHOR]

Senior individuals are more susceptible to the irreversible outcomes of endothelial barrier dysfunction, the hallmark of Acute Respiratory Distress Syndrome (ARDS). The Severe Acute Respiratory Syndrome Coronovirus 2 (SARS-CoV-2) - inflicted ARDS delivers the devastating outcomes of the COVID-19 worldwide. Endothelial hyperpermeability has been associated with both the progression and establishment of the COVID-19 - related respiratory failure. In the present study we investigated the in vitro effects of Metformin in the permeability of bovine pulmonary artery endothelial cells. Our preliminary results suggest that moderate doses (0.1, 0.5, 1.0 mM) of this anti-diabetic agent enhance the vascular barrier integrity, since it produces an increase in the transendothelial resistance of endothelial monolayers. Thus, we speculate that Metformin may deliver a new therapeutic possibility in ARDS, alone or in combination with other barrier enhancers. [ABSTRACT FROM AUTHOR]

The unfolded protein response (UPR) is a highly conserved molecular machinery, which protects the cells against a diverse variety of stimuli. Activation of this element has been associated with both human health and disease. The purpose of the current manuscript is to provide the most updated information on the involvement of UPR towards the improvement; or deterioration of cardiovascular functions. Since UPR is consisted of three distinct elements, namely the activating transcription factor 6, the protein kinase RNA-like endoplasmic reticulum kinase; and the inositol-requiring enzyme-1α, a highly orchestrated manipulation of those molecular branches may provide new therapeutic possibilities against the severe outcomes of cardiovascular disease. • UPR protects against environmental stimuli. • UPR is activated upon endoplasmic reticulum stress. • UPR is consisted of the ATF6, PERK and IRE1α. • Modulation of UPR may result to efficient therapeutic approaches towards cardiovascular disease. [ABSTRACT FROM AUTHOR]

Lung endothelial barrier dysfunction leads to severe pathologies, including the lethal Acute Respiratory Distress Syndrome. P53 has been associated with anti‐inflammatory activities. The current study employs a variety of unfolded protein response (UPR) activators and inhibitors to investigate the regulation of P53 by UPR in lung cells. The bovine cells that were exposed to the UPR inductors brefeldin A, dithiothreitol, and thapsigargin; demonstrated elevated expression levels of P53 compared to the vehicle‐treated cells. On the contrary, the UPR inhibitors N‐acetyl cysteine, kifunensine, and ATP‐competitive IRE1α kinase‐inhibiting RNase attenuator; produced the opposite effects. The outcomes of the present study reveal a positive regulation between UPR and P53. Since it has been shown that a mild induction of the unfolded protein response opposes inflammation, we suggest that P53 is involved in those protective activities in the lung. [ABSTRACT FROM AUTHOR]

The unfolded protein response element protects against endoplasmic reticulum stress and delivers protection towards potentially harmful challenges. The components of this multi-branch molecular machinery, namely the protein kinase RNA-like ER kinase, the activating transcription factor 6, and the inositol-requiring enzyme-1α; expand the endoplasmic reticulum capacity to support cellular function under stress conditions. In the present study, we employed bovine pulmonary aortic endothelial cells and mice to investigate the possibility that the Hsp90 inhibitors Tanespimycin (17-AAG) and Luminespib (AUY-922) exert the capacity to trigger the unfolded protein response. The induction of the unfolded protein response regulators immunoglobulin heavy-chain-binding protein, endoplasmic reticulum oxidoreductin-1alpha; and protein disulfide isomerase was also examined. It appears that both inhibitors capacitate the induction of the unfolded protein response element in vitro, since lung cells exposed to 1, 2 and 10 μM of 17-AAG or AUY-922 for 4, 6, 8, 16 and 48 h demonstrated increased levels of those proteins. Similar events occurred in the lungs of mice treated with AUY-922. Thus, our study demonstrates that Hsp90 inhibition triggers the activities of the unfolded protein response, and suggests that this molecular machinery contributes in the protective action of Hsp90 inhibitors in the lung microvasculature. • Acute Respiratory Distress Syndrome is Associated with Endothelial Dysfunction. • The Unfolded Protein Response Protects Against Endothelial Dysfunction. • Hsp90 inhibitors induce the Unfolded Protein Response Element. • A Mild Unfolded Protein Response Activation May Represent an Exciting New Therapeutic Possibility for ARDS treatment. [ABSTRACT FROM AUTHOR]

Background: Hematotoxicity is an underexplored endpoint of toxicity in most of the chemical exposures. An adverse effect on the hematological system arising out of xenobiotic exposure causes impaired hemostasis and coagulation leading to disease. BPA and acetaminophen are widely used synthetic chemicals worldwide and both are known and have numerous toxic effects. Since both can be simultaneously exposed to humans over a period of time, we hypothesized that their exposure can cause hematotoxicity, which may be ameliorated by melatonin., Objective: In the current study, we aimed to find the effect of single and co-treatment of bisphenol A and acetaminophen on the RBC and coagulation factors in rats, and amelioration of impairment by melatonin., Methods: Oxidative stress in red blood cells, bleeding time, blood clotting time, prothrombin time, partial thromboplastin time, and fibrinogen levels were assessed as indicators of hematotoxicity with single and co-exposure to bisphenol A and acetaminophen in rats. The effect of melatonin as a hemato-protective agent was assessed in the co-exposure., Results: An increase in RBC oxidative stress and decrease in bleeding time, blood clotting time, prothrombin time, and partial thromboplastin time along with an increase in fibrinogen levels were observed with bisphenol A and acetaminophen treatment, which were further aggravated with cotreatment of the two. Melatonin treatment, however, was seen to decrease the increase in oxidative stress and ameliorate the impairment in coagulation factors., Conclusion: Bisphenol A and acetaminophen cause an increase in the oxidative stress in the red blood cells, and cause a shift toward pro-coagulation, which is alleviated by treatment with melatonin., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The discovery of hypothalamic hormones propelled exciting advances in pharmacotherapy and improved life quality worldwide. Growth hormone-releasing hormone (GHRH) is a crucial element in homeostasis maintenance, and regulates the release of growth hormone from the anterior pituitary gland. Accumulating evidence suggests that this neuropeptide can also promote malignancies, as well as inflammation. Our review is focused on the role of that 44 - amino acid peptide (GHRH) and its antagonists in inflammation and vascular function, summarizing recent findings in the corresponding field. Preclinical studies demonstrate the protective role of GHRH antagonists against endothelial barrier dysfunction, suggesting that the development of those peptides may lead to new therapies against pathologies related to vascular remodeling (eg, sepsis, acute respiratory distress syndrome). Targeted therapies for those diseases do not exist., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Endothelial barrier dysfunction in the elderly has been associated with severe disorders, including acute respiratory distress syndrome, sepsis and COVID-19. Herein we deliver an opinion regarding the development of alternative therapeutic avenues to counteract the pathogenesis of the corresponding diseases., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS) represent a significant cause of morbidity and mortality in critically ill hospitalized patients. Emerging evidence suggest that the expression levels of P53 in the lungs are associated with the supportive effects of heat shock protein 90 inhibitors and growth hormone releasing hormone antagonists in the endothelium. In the current study, we employed an in vivo model of intratracheal administration of lipopolysaccharides (LPS)-induced ALI to investigate the role of P53 in counteracting LPS-induced lung inflammatory responses. In wild type mice, LPS induced the expression of IL-1α, IL-1β, and TNFα in the lungs, increased bronchoalveolar lavage fluid protein concentration, and activated cofilin. Remarkably; those responses were more potent in P53 knockout mice, suggesting the crucial role of P53 in orchestrating rigorous endothelial defenses against inflammatory stimuli. The present study supports previous endeavors on the protective role of P53 against lung inflammatory disease, and enrich our knowledge on the development of medical countermeasures against ARDS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.