Osteoarthritis is a common cause of disability worldwide. Although commonly referred to as a disease of the joint cartilage, osteoarthritis affects all joint tissues equally. The pathogenesis of this degenerative process is not completely understood; however, a low-grade inflammation leading to an imbalance between anabolic and katabolic processes is a well-established factor. The complex network of cytokines regulating these processes and cell communication has a central role in the development and progression of osteoarthritis. Concentrations of both proinflammatory and anti-inflammatory cytokines were found to be altered depending on the osteoarthritis stage and activity. In this review, we analyzed individual cytokines involved in the immune processes with an emphasis on their function in osteoarthritis.

The Pandemic of COVID-19, an infectious disease caused by SARS-CoV-2 motivated the scientific community to work together in order to gather, organize, process and distribute data on the novel biomedical hazard. Here, we analyzed how the scientific community responded to this challenge by quantifying distribution and availability patterns of the academic information related to COVID-19. The aim of this study was to assess the quality of the information flow and scientific collaboration, two factors we believe to be critical for finding new solutions for the ongoing pandemic. The RISmed R package, and a custom Python script were used to fetch metadata on articles indexed in PubMed and published on Rxiv preprint server. Scopus was manually searched and the metadata was exported in BibTex file. Publication rate and publication status, affiliation and author count per article, and submission-to-publication time were analysed in R. Biblioshiny application was used to create a world collaboration map. Preliminary data suggest that COVID-19 pandemic resulted in generation of a large amount of scientific data, and demonstrates potential problems regarding the information velocity, availability, and scientific collaboration in the early stages of the pandemic. More specifically, the results indicate precarious overload of the standard publication systems, significant problems with data availability and apparent deficient collaboration. In conclusion, we believe the scientific community could have used the data more efficiently in order to create proper foundations for finding new solutions for the COVID-19 pandemic. Moreover, we believe we can learn from this on the go and adopt open science principles and a more mindful approach to COVID-19-related data to accelerate the discovery of more efficient solutions. We take this opportunity to invite our colleagues to contribute to this global scientific collaboration by publishing their findings with maximal transparency.

Metabolic pathways play important roles in proliferation and differentiation of malignant cells. 5-Aminoimidazole-4-carboxamide ribonucleoside (AICAr), a precursor in purine biosynthesis and a well-established activator of AMP-activated protein kinase (AMPK), induces widespread metabolic alterations and is commonly used for dissecting the role of metabolism in cancer. We have previously reported that AICAr promotes differentiation and inhibits proliferation of myeloid leukemia cells. Here, using metabolic assays, immunoblotting, flow cytometry analyses, and siRNA-mediated gene silencing in leukemia cell lines, we show that AICAr-mediated differentiation was independent of the known metabolic effects of AMPK, including glucose consumption, but instead depends on the activation of the DNA damage–associated enzyme checkpoint kinase 1 (Chk1) induced by pyrimidine depletion. LC/MS/MS metabolomics analysis revealed that AICAr increases orotate levels and decreases uridine monophosphate (UMP) levels, consistent with inhibition of UMP synthesis at a step downstream of dihydroorotate dehydrogenase (DHODH). AICAr and the DHODH inhibitor brequinar had similar effects on differentiation markers and S-phase arrest, and genetic or pharmacological Chk1 inactivation abrogated both of these effects. Our results delineate an AMPK-independent effect of AICAr on myeloid leukemia differentiation that involves perturbation of pyrimidine biosynthesis and activation of the DNA damage response network.