Current Approach to Risk Factors and Biomarkers of Intestinal Fibrosis in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD), especially Crohn's disease (CD), characterized by a chronic inflammatory process and progressive intestinal tissue damage, leads to the unrestrained proliferation of mesenchymal cells and the development of bowel strictures. Complications induced by fibrosis are related to high rates of morbidity and mortality and lead to a substantial number of hospitalizations and surgical procedures, generating high healthcare costs. The development of easily obtained, reliable fibrogenesis biomarkers is essential to provide an important complementary tool to existing diagnostic and prognostic methods in IBD management, guiding decisions on the intensification of pharmacotherapy, proceeding to surgical methods of treatment and monitoring the efficacy of anti-fibrotic therapy in the future. The most promising potential markers of fibrosis include cartilage oligomeric matrix protein (COMP), hepatocyte growth factor activator (HGFA), and fibronectin isoform- extra domain A (ED-A), as well as antibodies against granulocyte macrophage colony-stimulating factor (GM-CSF Ab), cathelicidin (LL-37), or circulatory miRNAs: miR-19a-3p and miR-19b-3p. This review summarizes the role of genetic predisposition, and risk factors and serological markers potentially contributing to the pathophysiology of fibrotic strictures in the course of IBD.

Stem cell- derived extracellular vesicles as new tools in regenerative medicine - Immunomodulatory role and future perspectives.

In the last few decades, the practical use of stem cells (SCs) in the clinic has attracted significant attention in the regenerative medicine due to the ability of these cells to proliferate and differentiate into other cell types. However, recent findings have demonstrated that the therapeutic capacity of SCs may also be mediated by their ability to secrete biologically active factors, including extracellular vesicles (EVs). Such submicron circular membrane-enveloped vesicles may be released from the cell surface and harbour bioactive cargo in the form of proteins, lipids, mRNA, miRNA, and other regulatory factors. Notably, growing evidence has indicated that EVs may transfer their bioactive content into recipient cells and greatly modulate their functional fate. Thus, they have been recently envisioned as a new class of paracrine factors in cell-to-cell communication. Importantly, EVs may modulate the activity of immune system, playing an important role in the regulation of inflammation, exhibiting broad spectrum of the immunomodulatory activity that promotes the transition from pro-inflammatory to pro-regenerative environment in the site of tissue injury. Consequently, growing interest is placed on attempts to utilize EVs in clinical applications of inflammatory-related dysfunctions as potential next-generation therapeutic factors, alternative to cell-based approaches. In this review we will discuss the current knowledge on the biological properties of SC-derived EVs, with special focus on their role in the regulation of inflammatory response. We will also address recent findings on the immunomodulatory and pro-regenerative activity of EVs in several disease models, including in vitro and in vivo preclinical, as well as clinical studies. Finally, we will highlight the current perspectives and future challenges of emerging EV-based therapeutic strategies of inflammation-related diseases treatment.

Neurological Manifestations and Psychiatric Disorders in the Course of Inflammatory Bowel Diseases.

Inflammatory bowel diseases (IBD) are characterized by cumbersome symptoms with varying severity. However, regardless of the intensity of disease activity the patients may experience extraintestinal manifestations which further deteriorate the patients' quality of life. According to the literature, nearly half of the patients with IBD will develop at least one extraintestinal manifestation in their lifespan. Apart from the most common and often well-surveilled such as articular, ocular, dermatologic or hepatic entities, the neurological and psychiatric ones are often disregarded or not sought. We reviewed the latest literature on the most frequent disorders occurring in patients with IBD covering these two fields.

Efficacy, Safety and Future Perspectives of JAK Inhibitors in the IBD Treatment.

Although development of biologics has importantly improved the effectiveness in inducing and maintaining remission in inflammatory bowel disease (IBD), biologic therapies still have several limitations. Effective, low-cost drug therapy with good safety profile and compliance is therefore a substantial unmet medical need. A promising target for IBD treatment strategies are Janus kinase (JAK) inhibitors, which are small molecules that interact with cytokines implicated in pathogenesis of IBD. In contrast to monoclonal antibodies, which are able to block a single cytokine, JAK inhibitors have the potential to affect multiple cytokine-dependent immune pathways, which may improve the therapeutic response in some IBD patients. Tofacitinib, inhibiting signaling via different types of JAKs, has been already approved for ulcerative colitis, and several other small-molecule are still under investigation. However, one of the main concerns about using JAK inhibitors is the risk of thromboembolic events. Moreover, patients with COVID-19 appear to have an increased susceptibility for immunothrombosis. Therefore, thrombotic complications may become a serious limitation in the use of JAK inhibitors in the SARS-CoV-2 pandemic. As many questions about safety and efficacy of small molecules still remain unclear, in our review we present the current data regarding approved JAK inhibitors, as well as those in clinical development for the treatment of IBD.