Glucocorticoid Effects on Proteoglycans and Glycosaminoglycans.

Glucocorticoids are steroid hormones that play diverse roles in numerous normal and pathological processes. They are actively used to treat a wide variety of diseases, including neurodegenerative and inflammatory diseases, cancers, and COVID-19, among others. However, the long-term use of glucocorticoids is associated with numerous side effects. Molecular mechanisms of these negative side effects are not completely understood. Recently, arguments have been made that one such mechanisms may be related to the influence of glucocorticoids on O-glycosylated components of the cell surface and extracellular matrix, in particular on proteoglycans and glycosaminoglycans. The potential toxic effects of glucocorticoids on these glycosylated macromolecules are particularly meaningful for brain physiology because proteoglycans/glycosaminoglycans are the main extracellular components of brain tissue. Here, we aim to review the known effects of glucocorticoids on proteoglycan expression and glycosaminoglycan content in different tissues, with a specific focus on the brain.

Hair Loss and Telogen Effluvium Related to COVID-19: The Potential Implication of Adipose-Derived Mesenchymal Stem Cells and Platelet-Rich Plasma as Regenerative Strategies.

The diffusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inducing coronavirus disease 2019 (COVID-19) has increased the incidence of several dermatological disorders, including hair loss (HL). This article aims to review the literature regarding the incidence of HL and telogen effluvium (TE) in COVID-19 patients and critically appraise the available evidence regarding the role of regenerative strategies like Platelet-Rich Plasma (PRP) and Human Follicle Stem Cells (HFSCs). A literature review regarding the correlation of HL and TE in COVID-19 patients analyzing the biomolecular pathway involved and the role of regenerative strategies was performed using PubMed, MEDLINE, Embase, PreMEDLINE, Scopus, and the Cochrane databases. Observational studies revealed an escalated incidence of pattern HL and TE in COVID-19 patients. Psychological stress, systemic inflammation, and oxidative stress are potential culprits. Proinflammatory cytokines and stress hormones negatively affect the normal metabolism of proteoglycans. Reduced anagenic expression of proteoglycans is a potential mediating mechanism that connects HL to COVID-19. Currently, only one study has been published on PRP against HL in COVID-19 patients. Further controlled trials are required to confirm PRP and HFSCs efficacy in COVID-19 patients.

Mineralocorticoid receptor-antagonism prevents COVID-19-dependent glycocalyx damage.

Proinflammatory cytokines target vascular endothelial cells during COVID-19 infections. In particular, the endothelial glycocalyx (eGC), a proteoglycan-rich layer on top of endothelial cells, was identified as a vulnerable, vasoprotective structure during infections. Thus, eGC damage can be seen as a hallmark in the development of endothelial dysfunction and inflammatory processes. Using sera derived from patients suffering from COVID-19, we could demonstrate that the eGC became progressively worse in relation to disease severity (mild vs severe course) and in correlation to IL-6 levels. This could be prevented by administering low doses of spironolactone, a well-known and highly specific aldosterone receptor antagonist. Our results confirm that SARS-CoV-2 infections cause eGC damage and endothelial dysfunction and we outline the underlying mechanisms and suggest potential therapeutic options.

HAPLN1 Affects Cell Viability and Promotes the Pro-Inflammatory Phenotype of Fibroblast-Like Synoviocytes.

HAPLN1 maintains aggregation and the binding activity of extracellular matrix (ECM) molecules (such as hyaluronic acid and proteoglycan) to stabilize the macromolecular structure of the ECM. An increase in HAPLN1 expression is observed in a few types of musculoskeletal diseases including rheumatoid arthritis (RA); however, its functions are obscure. This study examined the role of HAPLN1 in determining the viability, proliferation, mobility, and pro-inflammatory phenotype of RA- fibroblast-like synoviocytes (RA-FLSs) by using small interfering RNA (siHAPLN1), over-expression vector (HAPLN1OE), and a recombinant HAPLN1 (rHAPLN1) protein. HAPLN1 was found to promote proliferation but inhibit RA-FLS migration. Metformin, an AMPK activator, was previously found by us to be able to inhibit FLS activation but promote HAPLN1 secretion. In this study, we confirmed the up-regulation of HAPLN1 in RA patients, and found the positive relationship between HAPLN1 expression and the AMPK level. Treatment with either si-HAPLN1 or HAPLN1OE down-regulated the expression of AMPK-ɑ gene, although up-regulation of the level of p-AMPK-ɑ was observed in RA-FLSs. si-HAPLN1 down-regulated the expression of proinflammatory factors like TNF-ɑ, MMPs, and IL-6, while HAPLN1OE up-regulated their levels. qPCR assay indicated that the levels of TGF-ß, ACAN, fibronectin, collagen II, and Ki-67 were down-regulated upon si-HAPLN1 treatment, while HAPLN1OE treatment led to up-regulation of ACAN and Ki-67 and down-regulation of cyclin-D1. Proteomics of si-HAPLN1, rHAPLN1, and mRNA-Seq analysis of rHAPLN1 confirmed the functions of HAPLN1 in the activation of inflammation, proliferation, cell adhesion, and strengthening of ECM functions. Our results for the first time demonstrate the function of HAPLN1 in promoting the proliferation and pro-inflammatory phenotype of RA-FLSs, thereby contributing to RA pathogenesis. Future in-depth studies are required for better understanding the role of HAPLN1 in RA.

Syndecan-1 in liver pathophysiology.

Syndecan-1 (SDC-1) is a heparan sulfate (HS)/chondroitin sulfate proteoglycan (PG) of the cell surface and the extracellular matrix (ECM), which regulates a broad spectrum of physiological and pathological processes such as cell proliferation, migration, inflammation, matrix remodeling, wound healing, and tumorigenesis. Syndecan-1 represents the major PG of the liver, expressed by hepatocytes and cholangiocytes, and its elevated expression is a characteristic feature of liver diseases. The highest syndecan-1 expression is found in liver cirrhosis and in hepatocellular carcinoma (HCC) developed in cirrhotic livers. In addition, as being a hepatitis C receptor, hepatitis C virus (HCV)-infected livers produce extremely large amounts of syndecan-1. The serum levels of the cleaved (shedded) extracellular domain have clinical significance, as their increased concentration reflects on poor prognosis in cirrhosis as well as in cancer. In vivo experiments confirmed that syndecan-1 protects against early stages of fibrogenesis mainly by enhanced clearance of transforming growth factor ß1 (TGFß1) and thrombospondin-1 (THBS1) via circulation, and against hepatocarcinogenesis by interfering with several signaling pathways and enhancing cell cycle blockade. In addition, syndecan-1 is capable to hinder lipid metabolism and ribosomal biogenesis in induced cancer models. These observations together with its participation in the uptake of viruses (e.g., HCV and SARS-CoV-2) indicate that syndecan-1 is a central player in liver pathologies.

Can Serum Endocan Levels be Used as an Early Prognostic Marker for Endothelial Dysfunction in COVID-19?

In this study, we aimed to investigate whether degree of pneumonia and COVID-19 prognosis are associated with serum endocan levels at the early stage, when vascular damage has started. Patients between the ages of 18-85 years who were hospitalized and followed up with a diagnosis of COVID-19 were included in the study. A total of 80 patients were divided into 2 groups as mild/moderate pneumonia and severe pneumonia. Serum endocan levels were measured on the 8th day from the onset of symptoms in all patients. Of the 80 patients included in the study, 56.3% were female and 43.8% were male. There was no significant relationship between serum endocan levels and degree of pneumonia (P = .220) and prognosis of the disease (P = .761). The correlation analysis indicated a weak positive correlation between serum endocan levels and lactate level in venous blood gas (r = .270; P = .037). During the 28-day follow-up, the mortality rate was 3.75%. It was determined that the serum endocan levels was not associated with the degree of pneumonia and was not an early prognostic marker for COVID-19.

Brilliant glycans and glycosylation: Seq and ye shall find.

Proteoglycosylation is the addition of monosaccharides or glycans to the protein peptide chain. This is a common post-translational modification of proteins with a variety of biological functions. At present, more than half of all biopharmaceuticals in clinic are modified by glycosylation. Most glycoproteins are potential drug targets and biomarkers for disease diagnosis. Therefore, in-depth study of glycan structure of glycoproteins will ultimately improve the sensitivity and specificity of glycoproteins for clinical disease detection. With the deepening of research, the function and application value of glycans and glycosylation has gradually emerged. This review systematically introduces the latest research progress of glycans and glycosylation. It encompasses six cancers, four viruses, and their latest discoveries in Alzheimer's disease, allergic diseases, congenital diseases, gastrointestinal diseases, inflammation, and aging.

Diagnostic and Prognostic Value of Serum Endocan Levels in Patients With COVID-19.

We aimed to evaluate whether there was a relationship between endocan (human endothelial cell-specific molecule-1) levels and disease prognosis in patients who presented to the emergency department with coronavirus disease 2019 (COVID-19). A total of 60 patients with COVID-19 who were hospitalized from the emergency department to clinical wards and a control group consisting of healthy adult individuals (n = 28), were included in the study. The majority (93.3%) of the patients were discharged after recovery; 6.7% died. The median endocan value was 243.5 ng/mL in the patient group versus 201.5 ng/mL in the control group (P = .002). The median endocan level was 240.5 ng/mL in those discharged with recovery and 558 ng/mL in those who died (P = .001). There was no significant relationship in hospitalization duration, sex, tomography findings, and clinical outcomes. A 202 ng/mL serum endocan level had 86.7% sensitivity and 50% specificity for COVID-19. Serum endocan levels may be a useful biomarker both for the diagnosis of COVID-19 and to predict mortality.

COVID-19-Associated Invasive Aspergillosis: Data from the UK National Mycology Reference Laboratory.

COVID-19-associated pulmonary aspergillosis (CAPA) was recently reported as a potential infective complication affecting critically ill patients with acute respiratory distress syndrome following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with incidence rates varying from 8 to 33% depending on the study. However, definitive diagnosis of CAPA is challenging. Standardized diagnostic algorithms and definitions are lacking, clinicians are reticent to perform aerosol-generating bronchoalveolar lavages for galactomannan testing and microscopic and cultural examination, and questions surround the diagnostic sensitivity of different serum biomarkers. Between 11 March and 14 July 2020, the UK National Mycology Reference Laboratory received 1,267 serum and respiratory samples from 719 critically ill UK patients with COVID-19 and suspected pulmonary aspergillosis. The laboratory also received 46 isolates of Aspergillus fumigatus from COVID-19 patients (including three that exhibited environmental triazole resistance). Diagnostic tests performed included 1,000 (1-3)-ß-d-glucan and 516 galactomannan tests on serum samples. The results of this extensive testing are presented here. For a subset of 61 patients, respiratory specimens (bronchoalveolar lavage specimens, tracheal aspirates, and sputum samples) in addition to serum samples were submitted and subjected to galactomannan testing, Aspergillus-specific PCR, and microscopy and culture. The incidence of probable/proven and possible CAPA in this subset of patients was approximately 5% and 15%, respectively. Overall, our results highlight the challenges in biomarker-driven diagnosis of CAPA, especially when only limited clinical samples are available for testing, and the importance of a multimodal diagnostic approach involving regular and repeat testing of both serum and respiratory samples.

Serum Endocan Levels on Admission Are Associated With Worse Clinical Outcomes in COVID-19 Patients: A Pilot Study.

Thrombotic and embolic complications in the cardiovascular system are evident and associated with worse prognosis in coronavirus disease 2019 (COVID-19) patients. Endothelial-specific molecule 1 (endocan) plays a role in vascular pathology. We hypothesized serum endocan levels on admission are associated with primary composite end point (mortality and intensive care unit hospitalization) in COVID-19 patients. Patients (n = 80) with laboratory, clinical, and radiological confirmed COVID-19 were included in this cross-sectional study. Ten milliliter of peripheral venous blood were drawn within 24 hours of admission to estimate serum endocan levels. Data were analyzed using SPSS version 26.0 (IBM). Patients with the primary composite end point had significantly higher serum endocan levels than patients without (852.2 ± 522.7 vs 550.2 ± 440.8 ng/L, respectively; P < .01). In the logistic regression analysis, only increased serum endocan levels and increase in age were independent predictors of the primary composite end point (P < .05). In the receiver operating characteristics curve analysis, we found that a serum endocan level of 276.4 ng/L had a 97% sensitivity and 85% specificity for prediction of the primary composite end point. Baseline serum endocan levels may prove useful as a prognostic factor in patients hospitalized for COVID-19.