MASP-2 Is a Heparin-Binding Protease; Identification of Blocking Oligosaccharides

The niche matters: origin, function and fate of CNS-associated macrophages during health and disease

There are several cellular and acellular structural barriers associated with the brain interfaces, which include the dura, the leptomeninges, the perivascular space and the choroid plexus epithelium. Each structure is enriched by distinct myeloid populations, which mainly originate from erythromyeloid precursors (EMP) in the embryonic yolk sac and seed the CNS during embryogenesis. However, depending on the precise microanatomical environment, resident myeloid cells differ in their marker profile, turnover and the extent to which they can be replenished by blood-derived cells. While some EMP-derived cells seed the parenchyma to become microglia, others engraft the meninges and become CNS-associated macrophages (CAMs), also referred to as border-associated macrophages (BAMs), e.g., leptomeningeal macrophages (MnMΦ). Recent data revealed that MnMΦ migrate into perivascular spaces postnatally where they differentiate into perivascular macrophages (PvMΦ). Under homeostatic conditions in pathogen-free mice, there is virtually no contribution of bone marrow-derived cells to MnMΦ and PvMΦ, but rather to macrophages of the choroid plexus and dura. In neuropathological conditions in which the blood-brain barrier is compromised, however, an influx of bone marrow-derived cells into the CNS can occur, potentially contributing to the pool of CNS myeloid cells. Simultaneously, resident CAMs may also proliferate and undergo transcriptional and proteomic changes, thereby, contributing to the disease outcome. Thus, both resident and infiltrating myeloid cells together act within their microenvironmental niche, but both populations play crucial roles in the overall disease course. Here, we summarize the current understanding of the sources and fates of resident CAMs in health and disease, and the role of the microenvironment in influencing their maintenance and function.

Human dermal fibroblast-derived extracellular matrix reduces postinflammatory hyperpigmentation after fractional carbon dioxide laser facial resurfacing in Asians

BACKGROUND

Extracellular matrix (ECM) components promote the development of skin wounds by providing biological scaffolds and regenerative microenvironments.

AIMS

To evaluate the beneficial effects of human dermal fibroblast-derived ECM after fractional carbon dioxide laser resurfacing in Asians.

PATIENTS/METHODS

In this double-blind, randomized, vehicle-controlled, split-face study, 15 participants with features of facial skin aging were treated with a single session of fractional carbon dioxide laser, followed by the application of either ECM (ECM group) or placebo (control group). In vivo skin parameters were measured at baseline and after 4 and 12 weeks of treatment using the Antera 3D®, Cutometer® MPA580, Dermascan®, and Tewameter®.

RESULTS

A total of 14 participants (mean age 45.1 ± 9.7 years) completed the study. The change in melanin level was significantly lower in the ECM group than in the control group at week 12 (p < 0.05). Transient increase in erythema level was observed at week 4 in the control group, and the change in the erythema level was greater in the control group than in the ECM group (p = 0.014). Though the ECM group showed improvements in the dermal density, texture, transepidermal water loss, marionette lines (volume, maximum depth, and average depth), and nasolabial folds (volume, maximum depth, and length), no significant differences were found between the two groups. Treatment-related adverse events were not reported.

CONCLUSIONS

We suggest that human dermal fibroblast-derived ECM may be used as adjunctive therapy after fractional carbon dioxide resurfacing to prevent postinflammatory hyperpigmentation in Asians.

Therapeutic Applications of Fucoidans and their Potential to Act Against COVID-19

In this review article, we present the updated evidence of therapeutic applications of fucoidan (a seaweed polysaccharide) and its novel potential to treat infectious diseases such as coronavirus disease (COVID-19). Because of their many biological activities, seaweeds have been identified as a rich and useful source of bioactive chemicals. Sulfated polysaccharides from the sea are considered a source of physiologically active chemicals that might be used in medication development. Antitumor, antiviral, antioxidant, antibacterial, anticoagulant, and immune-inflammatory properties have all been described for these compounds. By interfering at various phases of viral infection, marine sulfated polysaccharide has a virucidal effect. As a result, it opens the door to the development of antiviral treatments. Virus entry into host cells is an initial process, avoiding this type of entry makes any precautionary measure effective. The inhibitory action of certain marine sulfated polysaccharides against coronavirus was tested, and fucoidan, iota-carrageenan, and sea cucumber sulfated polysaccharides all showed a substantial antiviral impact. Fucoidan is one of the useful sulfated polysaccharides that has been widely studied and explored in various research. There are different sources of fucoidans, which have been used in the treatment of viral infection. Additionally, we highlight the mechanism of action of fuocidan against COVID-19. Hence, we could suggest that COVID-19 might be prevented and treated using these sulfated polysaccharides. This review thus highlights ample evidence to support the hypothesis that a large number of drugs have been developed from powerful compounds isolated from marine seaweeds.

The Endothelial Glycocalyx: A Possible Therapeutic Target in Cardiovascular Disorders

The physiological, anti-inflammatory, and anti-coagulant properties of endothelial cells (ECs) rely on a complex carbohydrate-rich layer covering the luminal surface of ECs, called the glycocalyx. In a range of cardiovascular disorders, glycocalyx shedding causes endothelial dysfunction and inflammation, underscoring the importance of glycocalyx preservation to avoid disease initiation and progression. In this review we discuss the physiological functions of the glycocalyx with particular focus on how loss of endothelial glycocalyx integrity is linked to cardiovascular risk factors, like hypertension, aging, diabetes and obesity, and contributes to the development of thrombo-inflammatory conditions. Finally, we consider the role of glycocalyx components in regulating inflammatory responses and discuss possible therapeutic interventions aiming at preserving or restoring the endothelial glycocalyx and therefore protecting against cardiovascular disease.

The glycosaminoglycan interactome 2.0

Glycosaminoglycans (GAGs) are complex linear polysaccharides, which are covalently attached to core proteins (except for hyaluronan) to form proteoglycans. They play key roles in the organization of the extracellular matrix, and at the cell surface where they contribute to the regulation of cell signaling and of cell adhesion. To explore the mechanisms and pathways underlying their functions, we have generated an expanded dataset of 4290 interactions corresponding to 3464 unique GAG-binding proteins, four times more than the first version of the GAG interactome (Vallet and Ricard-Blum, 2021 J Histochem Cytochem 69:93-104). The increased size of the GAG network is mostly due to the addition of GAG-binding proteins captured from cell lysates and biological fluids by affinity chromatography and identified by mass spectrometry. We review here the interaction repertoire of natural GAGs and of synthetic sulfated hyaluronan, the specificity and molecular functions of GAG-binding proteins, and the biological processes and pathways they are involved in. This dataset is also used to investigate the differences between proteins binding to iduronic acid-containing GAGs (dermatan sulfate and heparin/heparan sulfate) and those interacting with GAGs lacking iduronic acid (chondroitin sulfate, hyaluronan, and keratan sulfate).

Is complement the main accomplice in IgA nephropathy? From initial observations to potential complement-targeted therapies

IgA Nephropathy (IgAN) is the main cause of primary glomerulonephritis, globally. This disease is associated with a wide range of clinical presentations, variable prognosis and a spectrum of histological findings. More than fifty years after its first description, this heterogeneity continues to complicate efforts to understand the pathogenesis. Nevertheless, involvement of the complement system in IgAN was identified early on. Dysfunction of the immunoglobulin A (IgA) system, the principal offender in this disease, including modification of isoforms and glycoforms of IgA1, the nature of immune complexes and autoantibodies to galactose deficient IgA1 might all be responsible for complement activation in IgAN. However, the specific mechanisms engaging complement are still under examination. Research in this domain should allow for identification of patients that may benefit from complement-targeted therapy, in the foreseeable future.