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Blood Advances Jan 2022Idiopathic purpura fulminans (IPF) is a rare but severe prothrombotic coagulation disorder that can occur after chickenpox or human herpesvirus 6 (HHV-6) infection. IPF...
Idiopathic purpura fulminans (IPF) is a rare but severe prothrombotic coagulation disorder that can occur after chickenpox or human herpesvirus 6 (HHV-6) infection. IPF leads to an autoantibody-mediated decrease in the plasma concentration of protein S. We conducted a retrospective multicenter study involving patients with IPF from 13 French pediatric centers and a systematic review of cases in published literature. Eighteen patients were included in our case series, and 34 patients were included as literature review cases. The median age was 4.9 years, and the diagnostic delay after the first signs of viral infection was 7 days. The lower limbs were involved in 49 patients (94%) with typical lesions. In all, 41 patients (78%) had a recent history of varicella-zoster virus infection, and 7 patients (14%) had been infected by HHV-6. Most of the patients received heparin (n = 51; 98%) and fresh frozen plasma transfusions (n = 41; 79%); other treatment options were immunoglobulin infusion, platelet transfusion, corticosteroid therapy, plasmapheresis, and coagulation regulator concentrate infusion. The antithrombin level and platelet count at diagnosis seemed to be associated with severe complications. Given the rarity of this disease, the creation of a prospective international registry is required to consolidate these findings.
Topics: Child; Child, Preschool; Humans; Chickenpox; Delayed Diagnosis; Prospective Studies; Protein S; Purpura Fulminans; Retrospective Studies
PubMed: 34788405
DOI: 10.1182/bloodadvances.2021005126 -
Traffic (Copenhagen, Denmark) Dec 2021Endoplasmic reticulum (ER)-to-Golgi trafficking is an essential and highly conserved cellular process. The coat protein complex-II (COPII) arm of the trafficking... (Review)
Review
Endoplasmic reticulum (ER)-to-Golgi trafficking is an essential and highly conserved cellular process. The coat protein complex-II (COPII) arm of the trafficking machinery incorporates a wide array of cargo proteins into vesicles through direct or indirect interactions with Sec24, the principal subunit of the COPII coat. Approximately one-third of all mammalian proteins rely on the COPII-mediated secretory pathway for membrane insertion or secretion. There are four mammalian Sec24 paralogs and three yeast Sec24 paralogs with emerging evidence of paralog-specific cargo interaction motifs. Furthermore, individual paralogs also differ in their affinity for a subset of sorting motifs present on cargo proteins. As with many aspects of protein trafficking, we lack a systematic and thorough understanding of the interaction of Sec24 with cargoes. This systematic review focuses on the current knowledge of cargo binding to both yeast and mammalian Sec24 paralogs and their ER export motifs. The analyses show that Sec24 paralog specificity of cargo (and cargo receptors) range from exclusive paralog dependence or preference to partial redundancy. We also discuss how the Sec24 secretion system is hijacked by viral (eg, VSV-G, Hepatitis B envelope protein) and bacterial (eg, the enteropathogenic Escherichia coli type III secretion system effector NleA/EspI) pathogens.
Topics: Animals; COP-Coated Vesicles; Endoplasmic Reticulum; Golgi Apparatus; Mammals; Membrane Proteins; Protein Transport; Proteins; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Secretory Pathway
PubMed: 34533884
DOI: 10.1111/tra.12817 -
BioMed Research International 2021The SARS-CoV-2 virus is the cause of the latest pandemic of the 21st century; it is responsible for the development of COVID-19. Within the multiple study models for...
BACKGROUND
The SARS-CoV-2 virus is the cause of the latest pandemic of the 21st century; it is responsible for the development of COVID-19. Within the multiple study models for both the biology and the treatment of SARS-CoV-2, the use of stem cells has been proposed because of their ability to increase the immune response and to repair tissue. Therefore, the objective of this review is to evaluate the role of stem cells against SARS-CoV-2 and COVID-19 in order to identify their potential as a study model and as a possible therapeutic source against tissue damage caused by this virus. Therefore, the following research question was established: What is the role of stem cells in the study of SARS-CoV-2 and the treatment of COVID-19?
MATERIALS AND METHODS
A search was carried out in the electronic databases of PUBMED, Scopus, and ScienceDirect. The following keywords were used: "SARS-CoV-2," "COVID-19," and "STEM CELL," plus independent search strategies with the Boolean operators "OR" and "AND." The identified reports were those whose main objective was the study of stem cells in relation to SARS-CoV-2 or COVID-19. For the development of this study, the following inclusion criteria were taken into account: studies whose main objective was the study of stem cells in relation to SARS-CoV-2 or COVID-19 and clinical case studies, case reports, clinical trials, pilot studies, in vitro, or in vivo studies. For assessment of the risk of bias for in vitro studies, the SciRAP tool was used. The data collected for each type of study, clinical or in vitro, were analyzed with descriptive statistics using the SPSS V.22 program.
RESULTS
Of the total of studies included ( = 39), 22 corresponded to in vitro investigations and 17 to human studies (clinical cases ( = 9), case series ( = 2), pilot clinical trials ( = 5), clinical trials ( = 1)). In vitro studies that induced pluripotent stem cells were the most used ( = 12), and in clinical studies, the umbilical stem cells derived were the most reported ( = 11). The mean age of the study subjects was 58.3 years. After the application of stem cell therapy, the follow-up period was 8 days minimum and 90 days maximum. . The mechanism by which the virus enters the cell is through protein "S," located on the surface of the membrane, by recognizing the ACE2 receptor located on the target cell. The evidence that the expression of ACE2 and TMPRSS2 in stem cells indicates that stem cells from bone marrow and amniotic fluid have very little expression. This shows that stem cell has a low risk of infection with SARS-CoV-2.
CONCLUSION
The use of stem cells is a highly relevant therapeutic option. It has been shown in both in vitro studies and clinical trials that it counteracts the excessive secretion of cytokines. There are even more studies that focus on long-term follow-up; thus, the potential for major side effects can be analyzed more clearly. Finally, the ethical use of stem cells from fetal or infant origin needs to be regulated. The study was registered in PROSPERO (no. CRD42021229038). The limitations of the study were because of the methodology employed, the sample was not very large, and the follow-up period of the clinical studies was relatively short.
Topics: COVID-19; Clinical Trials as Topic; Humans; SARS-CoV-2; Stem Cell Transplantation; Stem Cells
PubMed: 34458372
DOI: 10.1155/2021/9915927 -
Frontiers in Immunology 2021The immune system is unique among all biological sub-systems in its usage of DNA-editing enzymes to introduce targeted gene mutations and double-strand DNA breaks to...
Evolutionary Comparative Analyses of DNA-Editing Enzymes of the Immune System: From 5-Dimensional Description of Protein Structures to Immunological Insights and Applications to Protein Engineering.
The immune system is unique among all biological sub-systems in its usage of DNA-editing enzymes to introduce targeted gene mutations and double-strand DNA breaks to diversify antigen receptor genes and combat viral infections. These processes, initiated by specific DNA-editing enzymes, often result in mistargeted induction of genome lesions that initiate and drive cancers. Like other molecules involved in human health and disease, the DNA-editing enzymes of the immune system have been intensively studied in humans and mice, with little attention paid (< 1% of published studies) to the same enzymes in evolutionarily distant species. Here, we present a systematic review of the literature on the characterization of one such DNA-editing enzyme, activation-induced cytidine deaminase (AID), from an evolutionary comparative perspective. The central thesis of this review is that although the evolutionary comparative approach represents a minuscule fraction of published works on this and other DNA-editing enzymes, this approach has made significant impacts across the fields of structural biology, immunology, and cancer research. Using AID as an example, we highlight the value of the evolutionary comparative approach in discoveries already made, and in the context of emerging directions in immunology and protein engineering. We introduce the concept of 5-dimensional (5D) description of protein structures, a more nuanced view of a structure that is made possible by evolutionary comparative studies. In this higher dimensional view of a protein's structure, the classical 3-dimensional (3D) structure is integrated in the context of real-time conformations and evolutionary time shifts (4 dimension) and the relevance of these dynamics to its biological function (5 dimension).
Topics: Animals; Biological Evolution; Cytidine Deaminase; DNA; Humans; Protein Conformation; Protein Engineering
PubMed: 34135887
DOI: 10.3389/fimmu.2021.642343 -
Journal of Thrombosis and Haemostasis :... Dec 2020Retinal vascular occlusion is a leading cause of sight loss. Both retinal artery occlusion (RAO) and retinal vein occlusion (RVO) have been associated with... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Retinal vascular occlusion is a leading cause of sight loss. Both retinal artery occlusion (RAO) and retinal vein occlusion (RVO) have been associated with hypercoagulable states; however, the burden of thrombophilia in these patients is unclear.
OBJECTIVES
This study aims at estimating the prevalence of inherited and acquired thrombophilias in adults with RAO or RVO through a systematic review and meta-analysis of the literature.
PATIENTS/METHODS
PubMed and EMBASE were systematically searched from inception to 29 February 2020. All studies reporting prevalences of factor V Leiden (FVL) and prothrombin (F-II) G20210A mutations, methylenetetrahydrofolate reductase (MTHFR) C677T and plasminogen activator inhibitor (PAI) 4G polymorphisms, antithrombin III (AT-III), protein C (PC) and protein S (PS) activity deficiencies, hyperhomocysteinemia, and antiphospholipid (APL) antibodies in adults with RAO or RVO were included. Pooled prevalences and 95% confidence intervals (CI) were calculated.
RESULTS
Ninety-five studies were included; FVL and F-II mutations were found in 6% (95% CI: 5-8) and 3% (95% CI: 2-4) of individuals with RVO, respectively, whereas AT-III, PC, and PS activity deficiencies were found in <2%. The MTHFR C677T and PAI 4G homozygous polymorphism were observed in 13% (95% CI: 10-17) and 23% (95% CI: 16-31) of RVO, respectively; 8% presented APL antibodies. Similar findings were observed in individuals with RAO.
CONCLUSIONS
Compared with healthy subjects, patients with retinal vascular occlusion showed similar prevalences of inherited and acquired thrombophilias. These findings do not support routine thrombophilia screening in individuals with RAO or RVO.
Topics: Adult; Factor V; Humans; Methylenetetrahydrofolate Reductase (NADPH2); Prothrombin; Retinal Vein Occlusion; Risk Factors; Thrombophilia
PubMed: 32805772
DOI: 10.1111/jth.15068 -
Virologica Sinica Feb 2021Tyro3, Axl, and Mertk (TAM) receptors play multiple roles in a myriad of physiological and pathological processes, varying from promoting the phagocytic clearance of...
Tyro3, Axl, and Mertk (TAM) receptors play multiple roles in a myriad of physiological and pathological processes, varying from promoting the phagocytic clearance of apoptotic cells, sustaining the immune and inflammatory homeostasis, maintaining the blood-brain barrier (BBB) integrity and central nervous system (CNS) homeostasis, to mediating cancer malignancy and chemoresistance. Growth arrest-specific protein 6 (Gas6) and protein S (Pros1) are the two ligands that activate TAM receptors. Recently, TAM receptors have been reported to mediate cell entry and infection of multitudinous enveloped viruses in a manner called apoptotic mimicry. Moreover, TAM receptors are revitalized during viral entry and infection, which sequesters innate immune and inflammatory responses, facilitating viral replication and immune evasion. However, accumulating evidence have now proposed that TAM receptors are not required for the infection of these viruses in vivo. In addition, TAM receptors protect mice against the CNS infection of neuroinvasive viruses and relieve the brain lesions during encephalitis. These protective effects are achieved through maintaining BBB integrity, attenuating proinflammatory cytokine production, and promoting neural cell survival. TAM receptors also regulate the programmed cell death modes of virus-infected cells, which have profound impacts on the pathogenesis and outcome of infection. Here, we systematically review the functionalities and underlying mechanisms of TAM receptors and propose the potential application of TAM agonists to prevent severe viral encephalitis.
Topics: Animals; Mice; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Signal Transduction; Virus Diseases; c-Mer Tyrosine Kinase
PubMed: 32720213
DOI: 10.1007/s12250-020-00264-9 -
Frontiers in Immunology 2020To ultimately combat the emerging COVID-19 pandemic, it is desired to develop an effective and safe vaccine against this highly contagious disease caused by the...
To ultimately combat the emerging COVID-19 pandemic, it is desired to develop an effective and safe vaccine against this highly contagious disease caused by the SARS-CoV-2 coronavirus. Our literature and clinical trial survey showed that the whole virus, as well as the spike (S) protein, nucleocapsid (N) protein, and membrane (M) protein, have been tested for vaccine development against SARS and MERS. However, these vaccine candidates might lack the induction of complete protection and have safety concerns. We then applied the Vaxign and the newly developed machine learning-based Vaxign-ML reverse vaccinology tools to predict COVID-19 vaccine candidates. Our Vaxign analysis found that the SARS-CoV-2 N protein sequence is conserved with SARS-CoV and MERS-CoV but not from the other four human coronaviruses causing mild symptoms. By investigating the entire proteome of SARS-CoV-2, six proteins, including the S protein and five non-structural proteins (nsp3, 3CL-pro, and nsp8-10), were predicted to be adhesins, which are crucial to the viral adhering and host invasion. The S, nsp3, and nsp8 proteins were also predicted by Vaxign-ML to induce high protective antigenicity. Besides the commonly used S protein, the nsp3 protein has not been tested in any coronavirus vaccine studies and was selected for further investigation. The nsp3 was found to be more conserved among SARS-CoV-2, SARS-CoV, and MERS-CoV than among 15 coronaviruses infecting human and other animals. The protein was also predicted to contain promiscuous MHC-I and MHC-II T-cell epitopes, and the predicted linear B-cell epitopes were found to be localized on the surface of the protein. Our predicted vaccine targets have the potential for effective and safe COVID-19 vaccine development. We also propose that an "Sp/Nsp cocktail vaccine" containing a structural protein(s) (Sp) and a non-structural protein(s) (Nsp) would stimulate effective complementary immune responses.
Topics: Animals; Betacoronavirus; COVID-19; COVID-19 Vaccines; Coronavirus Infections; Epitopes, B-Lymphocyte; Humans; Immunogenicity, Vaccine; Machine Learning; Middle East Respiratory Syndrome Coronavirus; Pandemics; Pneumonia, Viral; SARS-CoV-2; Viral Proteins; Viral Vaccines
PubMed: 32719684
DOI: 10.3389/fimmu.2020.01581 -
Cureus Apr 2020Cerebral venous sinus thrombosis (CVST) is a rare condition characterized by elevated intracranial pressure due to impaired cerebral venous drainage, potentially... (Review)
Review
Cerebral venous sinus thrombosis (CVST) is a rare condition characterized by elevated intracranial pressure due to impaired cerebral venous drainage, potentially leading to life-threatening consequences. We searched the PubMed electronic database for 'cerebral venous sinus thrombosis' and 'prothrombotic' cases reported in adults (19+ years) and conducted a systematic review for the published literature in the English language pooled with a case from our institution. Data were analyzed regarding patient demographics, risk factors, clinical features, treatment modalities, and outcomes when available. Thirty cases of CVST were identified (29 case reports, of whom two were described in a case series, and the one case from our institution). The patients' mean age was 39 years (range: 19 - 65). The male: female ratio was 1.14:1. The majority (73.3%) had at least one preexisting risk factor, with prescription drug use being the most common risk factor (33.3%) shared among all patients. Most patients (83.3%) presented with at least two symptoms. The most common presenting symptoms were headache (70%), gastrointestinal disturbance (50%), and seizures (40%). Focal deficits (36.7%), vision disturbances (30%), and altered consciousness (20%) were the remaining presenting complaints. Twelve cases (40%) commented on papilledema, with 10 (83.3%) having papilledema present. Anticoagulation abnormalities were examined in 26 cases (86.7%), out of which four cases (15.4%) had isolated protein S (PS) deficiency, three cases (11.5%) had isolated antithrombin III (ATIII) deficiency, and one case (3.8%) had isolated protein C (PC) deficiency. The most common initial imaging modality (22 cases, 73.3%), and most commonly used overall (23 cases, 76.7%), was computed tomography (CT). Magnetic resonance imaging (MRI) was the second most common imaging modality for initial use (five cases, 16.7%), diagnosis or confirmation of CVST (eight cases, 26.7%), and overall (21 cases, 70%). Heparin treatment was involved in the treatment of 18 cases (60%), and warfarin treatment was used in 10 cases (33.3%). Heparin-warfarin combination treatment was utilized in eight cases (26.7%). Most patients survived (28 cases, 93.3%), while the two remaining patients died secondary to brain death from the CVST (6.7%). The findings from this study highlight the clinical characteristics of CVST. Therefore, this study aims to increase awareness of this rare entity. Physicians should maintain a high index of suspicion in order to diagnose patients presenting in the proper clinical context, given this case shares various forms of presentations with other common clinical conditions but requires long-term anticoagulation.
PubMed: 32411555
DOI: 10.7759/cureus.7654 -
Journal of the American Heart... Oct 2019Background Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial thrombosis, such as arterial... (Meta-Analysis)
Meta-Analysis
Background Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial thrombosis, such as arterial ischemic stroke, remains uncertain. We aimed to evaluate the association between inherited thrombophilia (factor V Leiden, prothrombin G20210A mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency) and risk of arterial ischemic stroke in adults. Methods and Results We searched PubMed, EMBASE, and Cochrane Library Databases from inception to December 31, 2018. We included case-control or cohort studies of adults reporting the prevalence of inherited thrombophilias in those with arterial ischemic stroke and subjects without arterial ischemic stroke. Two reviewers (T.C., E.D.) independently searched the literature and extracted data. Pooled odds ratios (ORs) and 95% CIs were calculated using random-effects model. We identified 68 eligible studies, which collectively enrolled 11 916 stroke patients and 96 057 controls. The number of studies reporting factor V Leiden, prothrombin G20210A mutation, protein C deficiency, protein S deficiency, and antithrombin deficiency were 56, 45, 15, 17, and 12, respectively. Compared with controls, patients with arterial ischemic stroke were significantly more likely to have the following inherited thrombophilias: factor V Leiden (OR, 1.25; 95% CI, 1.08-1.44; I=0%), prothrombin G20210A mutation (OR, 1.48; 95% CI, 1.22-1.80; I=0%), protein C deficiency (OR, 2.13; 95% CI, 1.16-3.90; I=0%), and protein S deficiency (OR, 2.26; 95% CI, 1.34-3.80; I=8.8%). Statistical significance was not reached for antithrombin deficiency (OR, 1.25; 95% CI, 0.58-2.67; I=8.8%). Conclusions Inherited thrombophilias (factor V Leiden, prothrombin G20210A mutation, protein C deficiency, and protein S deficiency) are associated with an increased risk of arterial ischemic stroke in adults. The implications of these findings with respect to clinical management of patients with ischemic stroke require further investigation.
Topics: Adult; Aged; Blood Coagulation; Blood Coagulation Disorders, Inherited; Brain Ischemia; Female; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Phenotype; Prognosis; Risk Assessment; Risk Factors; Stroke; Thrombophilia
PubMed: 31549567
DOI: 10.1161/JAHA.119.012877 -
Thrombosis Research Mar 2018Despite high rates of venous thromboembolism (VTE) among patients with hematologic malignancies, few tools exist to assist providers in identifying those patients at... (Review)
Review
INTRODUCTION
Despite high rates of venous thromboembolism (VTE) among patients with hematologic malignancies, few tools exist to assist providers in identifying those patients at highest risk for this potentially fatal complication. Laboratory biomarkers, such as d-dimer, have demonstrated utility in some clinical settings to distinguish patients at increased risk.
MATERIALS AND METHODS
We performed a systematic review of the literature utilizing search terms including "biomarker", "venous thromboembolism", "hematologic malignancy", "lymphoma", "myeloma" and "leukemia" in the Medline database. A total of 25 studies investigating laboratory biomarkers of increased thrombotic risk in the setting of hematologic malignancy were identified and included in this review.
RESULTS AND CONCLUSIONS
The most studied biomarkers, d-dimer and fibrinogen, demonstrated some degree of efficacy in identifying high-risk patients at levels >4.0 mg/L or <1.0 g/L respectively. Additional markers which demonstrated promise included thrombin generation, mean platelet volume, soluble VEGF, soluble P-selectin and extracellular vesicles. Other biomarkers reviewed, which did not consistently demonstrate significant associations with VTE included prothrombin fragments F1 + 2, factor VIII, protein C, protein S, von Willebrand antigen and activity, antithrombin, thrombin antithrombin complex, antiphospholopid antibody, plasminogen activator inhibitor, tissue factor pathway inhibitor and several variants associated with known hypercoagulable states (factor V Leiden, prothrombin gene variant, methylenetetrahydrofolate reductase variant). Data to support any of the biomarkers discussed here in routine clinical decision-making are currently lacking, but additional investigation in clinical studies, ideally in combination with clinical factors known to be associated with increased thrombotic risk, is warranted.
Topics: Biomarkers; Female; Hematologic Neoplasms; Humans; Male; Risk Factors; Venous Thromboembolism
PubMed: 29407626
DOI: 10.1016/j.thromres.2018.01.037