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1.
Crit Rev Eukaryot Gene Expr ; 32(3): 9-20, 2022.
Article in English | MEDLINE | ID: covidwho-1869252

ABSTRACT

Knowledge of the pathogenic mechanisms of severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) is certainly a priority for the scientific community. Two main elements are involved in the biology of the most severe forms of coronavirus disease 2019 (COVID-19): the direct cytopathic effect of the virus against the host tissues, and a dysfunction of the immune system, characterized by the exhaustion of T lymphocytes. The exhaustion of T cells in COVID-19 is poorly understand, but some data could suggest a possible role of PD-1/PD-L1 axis. The aim of this study was to evaluate the possible role of PD-L1 expression in the pulmonary tissue in subjects affected by COVID-19. The presence of SARS-CoV-2 in the pulmonary tissue, and its exact location, was indagated by in situ hybridization; the expression of PD-L1 and CD8 in the same tissue was indagated by immunohistochemistry. Overall, PD-L1 resulted diffusely expressed in 70% of the cases, and an intense expression was observed in 43.5% of cases. Diffuse and intense presence of SARS-CoV-2 by in situ hybridization significantly correlated with an intense PD-L1 expression, and with expression of PD-L1 by pneumocytes. PD-L1 is overexpressed in the pulmonary tissue of subjects died from COVID-19, and mainly in subjects with a high viral load. These data suggest a possible role of PD-L1 in the immune system exhaustion at the basis of the severe forms of the disease.


Subject(s)
B7-H1 Antigen/metabolism , COVID-19 , B7-H1 Antigen/genetics , Humans , Immune System , Lung , SARS-CoV-2
2.
Virchows Arch ; 480(3): 597-607, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1661693

ABSTRACT

Post-mortem examination plays a pivotal role in understanding the pathobiology of the SARS-CoV-2; thus, the optimization of virus detection on the post-mortem formalin-fixed paraffin-embedded (FFPE) tissue is needed. Different techniques are available for the identification of the SARS-CoV-2, including reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. The main goal of this study is to compare ISH versus RT-PCR to detect SARS-CoV-2 on post-mortem lung samples of positive deceased subjects. A total of 27 samples were analyzed by RT-PCR targeting different viral RNA sequences of SARS-CoV-2, including envelope (E), nucleocapsid (N), spike (S), and open reading frame (ORF1ab) genes and ISH targeting S and Orf1ab. All 27 cases showed the N gene amplification, 22 out of 27 the E gene amplification, 26 out of 27 the S gene amplification, and only 6 the ORF1ab gene amplification. The S ISH was positive only in 12 out of 26 cases positive by RT-PCR. The S ISH positive cases with strong and diffuse staining showed a correlation with low values of the number of the amplification cycles by S RT-PCR suggesting that ISH is a sensitive assay mainly in cases carrying high levels of S RNA. In conclusion, our findings demonstrated that ISH assay has lower sensitivity to detect SARS-CoV-2 in FFPE compared to RT-PCR; however, it is able to localize the virus in the cellular context since it preserves the morphology.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Humans , In Situ Hybridization/methods , Lung , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Sensitivity and Specificity
4.
Int J Environ Res Public Health ; 19(1)2021 Dec 21.
Article in English | MEDLINE | ID: covidwho-1580863

ABSTRACT

The syndemic framework proposed by the 2021-2030 World Health Organization (WHO) action plan for patient safety and the introduction of enabling technologies in health services involve a more effective interpretation of the data to understand causation. Based on the Systemic Theory, this communication proposes the "Systemic Clinical Risk Management" (SCRM) to improve the Quality of Care and Patient Safety. This is a new Clinical Risk Management model capable of developing the ability to observe and synthesize different elements in ways that lead to in-depth interventions to achieve solutions aligned with the sustainable development of health services. In order to avoid uncontrolled decision-making related to the use of enabling technologies, we devised an internal Learning Algorithm Risk Management (LARM) level based on a Bayesian approach. Moreover, according to the ethics of Job Well Done, the SCRM, instead of giving an opinion on events that have already occurred, proposes a bioethical co-working because it suggests the best way to act from a scientific point of view.


Subject(s)
COVID-19 , Bayes Theorem , Humans , Pandemics/prevention & control , Risk Management , SARS-CoV-2 , Syndemic
5.
Cardiovasc Diabetol ; 20(1): 99, 2021 05 07.
Article in English | MEDLINE | ID: covidwho-1219133

ABSTRACT

RATIONALE: About 50% of hospitalized coronavirus disease 2019 (COVID-19) patients with diabetes mellitus (DM) developed myocardial damage. The mechanisms of direct SARS-CoV-2 cardiomyocyte infection include viral invasion via ACE2-Spike glycoprotein-binding. In DM patients, the impact of glycation of ACE2 on cardiomyocyte invasion by SARS-CoV-2 can be of high importance. OBJECTIVE: To evaluate the presence of SARS-CoV-2 in cardiomyocytes from heart autopsy of DM cases compared to Non-DM; to investigate the role of DM in SARS-COV-2 entry in cardiomyocytes. METHODS AND RESULTS: We evaluated consecutive autopsy cases, deceased for COVID-19, from Italy between Apr 30, 2020 and Jan 18, 2021. We evaluated SARS-CoV-2 in cardiomyocytes, expression of ACE2 (total and glycosylated form), and transmembrane protease serine protease-2 (TMPRSS2) protein. In order to study the role of diabetes on cardiomyocyte alterations, independently of COVID-19, we investigated ACE2, glycosylated ACE2, and TMPRSS2 proteins in cardiomyocytes from DM and Non-DM explanted-hearts. Finally, to investigate the effects of DM on ACE2 protein modification, an in vitro glycation study of recombinant human ACE2 (hACE2) was performed to evaluate the effects on binding to SARS-CoV-2 Spike protein. The authors included cardiac tissue from 97 autopsies. DM was diagnosed in 37 patients (38%). Fourth-seven out of 97 autopsies (48%) had SARS-CoV-2 RNA in cardiomyocytes. Thirty out of 37 DM autopsy cases (81%) and 17 out of 60 Non-DM autopsy cases (28%) had SARS-CoV-2 RNA in cardiomyocytes. Total ACE2, glycosylated ACE2, and TMPRSS2 protein expressions were higher in cardiomyocytes from autopsied and explanted hearts of DM than Non-DM. In vitro exposure of monomeric hACE2 to 120 mM glucose for 12 days led to non-enzymatic glycation of four lysine residues in the neck domain affecting the protein oligomerization. CONCLUSIONS: The upregulation of ACE2 expression (total and glycosylated forms) in DM cardiomyocytes, along with non-enzymatic glycation, could increase the susceptibility to COVID-19 infection in DM patients by favouring the cellular entry of SARS-CoV2.


Subject(s)
Angiotensin-Converting Enzyme 2/biosynthesis , COVID-19/metabolism , Diabetes Mellitus/metabolism , Myocytes, Cardiac/metabolism , SARS-CoV-2/metabolism , Aged , Amino Acid Sequence , Autopsy , COVID-19/epidemiology , COVID-19/pathology , Cohort Studies , Diabetes Mellitus/pathology , Female , Humans , Italy/epidemiology , Male , Middle Aged , Myocytes, Cardiac/pathology , Protein Binding/physiology , Protein Structure, Secondary
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