Increase in venous thromboembolism in SARS-CoV-2 infected lung tissue: proteome analysis of lung parenchyma, isolated endothelium, and thrombi

AIMS

COVID-19 pneumonia is characterized by an increased rate of deep venous thrombosis and pulmonary embolism. To better understand the pathophysiology behind thrombosis in COVID-19, we performed proteomics analysis on SARS-CoV-2 infected lung tissue.

METHODS

Liquid chromatography mass spectrometry was performed on SARS-CoV-2 infected postmortem lung tissue samples. Five protein profiling analyses were performed: whole slide lung parenchyma analysis, followed by analysis of isolated thrombi and endothelium, both stratified by disease (COVID-19 versus influenza) and thrombus morphology (embolism versus in situ). Influenza autopsy cases with pulmonary thrombi were used as controls.

RESULTS

Compared to influenza controls, both analyses of COVID-19 whole-tissue and isolated endothelium showed upregulation of proteins and pathways related to liver metabolism including urea cycle activation, with arginase being among the top upregulated proteins in COVID-19 lung tissue. Analysis of isolated COVID-19 thrombi showed significant downregulation of pathways related to platelet activation compared to influenza thrombi. Analysis of isolated thrombi based on histomorphology shows that in situ thrombi have significant upregulation of coronavirus pathogenesis proteins.

CONCLUSIONS

The decrease in platelet activation pathways in severe COVID-19 thrombi suggests a relative increase in venous thromboembolism, as thrombi from venous origin tend to contain fewer platelets than arterial thrombi. Based on histomorphology, in situ thrombi show upregulation of various proteins related to SARS-CoV-2 pathogenesis compared to thromboemboli, which may indicate increased in situ pulmonary thrombosis in COVID-19. Therefore, this study supports the increase of venous thromboembolism without undercutting the involvement of in situ thrombosis in severe COVID-19.

FTMS and TOF/TOF mass spectrometry in concert: Identifying peptides with high reliability using matrix prespotted MALDI target plates

In this paper we describe a combination of the mass spectrometric techniques MALDI-TOF/TOF and MALDI-FTMS to identify proteins in complex samples using prespotted MALDI target plates. By this procedure accurate FTMS mass measurements and TOF/TOF data are obtained from the same spot. We have found that this combination of techniques leads to more reliable identification of peptides.

New approach for the identification of folate-related pathways in human embryogenesis

The role of natural folate intake and synthetic folic acid supplementation in the prevention of some congenital malformations is known, but on a molecular biological level poorly understood. In a first approach to identify folate-regulated pathways in human embryogenesis, tryptic digests of Epstein Barr Virus-immortalized B-lymphoblasts proteins from 6 cleft lip and/or palate patients and 2 controls were compared using matrix assisted laser desorption ionisation--time of flight (MALDI-TOF) mass spectrometry. After immortalisation, the lymphoblasts were cultured for 22 days in folate-rich, i.e. 5-methyltetrahydrofolate (5-mTHF), or folate-free medium. On day 22, 5-mTHF was added to the folate-free cultures and the profiles on day 22 and 23 were compared. After background correction for the peptide profiles of the folate-rich cultures, we found in the folate-free mediaseveral differentially expressed peptide peaks upon addition of 5-mTHF. These peptide peaks were mass annotated and matched withthe MSDB human database. The results suggest some folate-regulated protein candidates as Frizzled and the Rho GTP-ases WRCH and Chp that are known in human embryogenesis. Differential folate expressed proteins in patients and controls, however, have to be further investigated.

Alveolar hydatid disease of the liver: a report on thirty-nine surgical cases in eastern Anatolia, Turkey

The charts of 39 consecutive patients who underwent surgery between 1979 and 1989 with a diagnosis of alveolar hydatid disease (AHD) of the liver were reviewed. The analysis of these cases from eastern Anatolia, which is the endemic region in Turkey, was undertaken to determine the current experience for AHD lesions. Of these patients, 33 (84.6%) had unresectable disease and the remaining six patients (15.4%) were treated by hepatic resection of the primary lesion. In the unresectable cases, laparotomy with biopsy was the most commonly used surgical procedure (56.4%), followed by tube drainage of the necrotic cavity (18.0%), marsupialization (5.1%), and cystojejunostomy (5.1%). Diagnostic studies and operative findings were useful in detecting the AHD lesions. Differential diagnosis was established mainly by histopathologic examination of a biopsy specimen or resected tissue. Pulmonary metastases were seen in two cases, and mortality occurred due to brain metastases in two other cases. Mebendazole was administered postoperatively to 19 patients with indications for 1) advanced AHD, 2) adjuvant therapy to radical and palliative surgical procedures, and 3) recurrences of disease after hepatic resection. The patients were treated with daily doses of approximately 50 mg/kg for periods of one and six years (median 3.2 years). Encouraging results were obtained in 11 of nineteen patients. Five-year survival was seen in 8 of the patients with AHD in this series. There were 18 deaths (46.2%) in our 39 patients. Long-term follow-up was not possible in four cases, and 17 patients (43.6%) were still living. The causes of mortality were advanced AHD in 14 cases, brain metastases in two, and acute myocardial infarction in another two.(ABSTRACT TRUNCATED AT 250 WORDS)