Kristina Nešporová

Therapies based on mesenchymal stromal cells (MSCs) have high potential in the field of regenerative medicine due mainly to their immunomodulatory properties. However, their clinical translation is hampered by a lack of sufficiently standardised potency tests. Since macrophages constitute key mediators of the effects of MSCs, macrophage-based assays potentially provide a relevant in vitro tool for the evaluation of the activity of MSC products. This study involved the coculturing of canine adipose-derived mesenchymal stromal cells (ASCs) with macrophages derived from human THP-1 and U937 monocyte cell lines, murine RAW264.7 macrophages and primary human macrophages. The M2 polarisation was assessed following stimulation with IL-4/IL-13 in THP-1 and U937 macrophages. The mRNA expression of the pro- and anti-inflammatory markers was analysed using qPCR. The ASC transwell coculture altered the LPS-induced inflammatory mRNA expression in a strongly model- and marker-dependent manner. The U937-derived macrophages exhibited the most consistent suppression of the tested inflammatory transcripts and the RAW264.7 cells provided a practical readout for selected inflammatory markers, whereas the THP-1 macrophages evinced the suppression of TNFA but not IL1B or PTGS2 under the selected stimulation conditions. IL-4/IL-13 induced moderate but statistically non-significant changes in IL10 and TGFB1 in the U937-derived macrophages but no reproducible response in the THP-1-derived macrophages. In a subsequent U937 coculture experiment, ASC-derived paracrine factors altered selected M2-associated transcripts at specific time points. The results thus provided support for macrophage-based transcriptional readouts as an early-stage tool for comparing responder macrophage models and detecting the selected anti-inflammatory paracrine effects of canine ASCs; the U937 cells were found to be particularly suitable for the study of inflammatory polarisation and the RAW264.7 cells for the purpose of standardised screening.

Therapies based on mesenchymal stromal cells (MSCs) have high potential in the field of regenerative medicine due mainly to their immunomodulatory properties. However, their clinical translation is hampered by a lack of sufficiently standardised potency tests. Since macrophages comprise key mediators of the effects of MSCs, macrophage-based assays potentially provide a relevant in vitro tool for the evaluation of the activity of MSC products. This study involved the coculturing of canine adipose-derived mesenchymal stem cells (ASCs) with macrophages derived from human THP-1 and U937 monocyte cell lines, murine RAW264.7 macrophages and primary human macrophages. The M2 polarisation was assessed following stimulation with IL-4/IL-13. The mRNA expression of the pro- and anti-inflammatory markers was analysed applying qPCR. The ASC secretome acted to reduce the pro-inflammatory mRNA expression across all the macrophage models, albeit with a certain degree of model–dependent variability. Only the U937 macrophages responded consistently to the M2-polarising stimuli, while the RAW264.7 cells provided practical advantages in terms of routine screening. The results thus provided support for the application of macrophage-based potency assays as a suitable platform for the testing of MSC products; the U937 cells were found to be particularly suitable for the study of polarisation and the RAW264.7 cells for standardised screening.

Canine adipose-derived mesenchymal stem cells (cASC) are promising for regenerative veterinary medicine due to their immunomodulatory and reparative capacities. Three-dimensional (3D) culturing provides a more physiologically relevant environment than conventional two-dimensional (2D) monolayers, enhancing paracrine activity and therapeutic potential of mesenchymal stem cells (MSC). This study investigates the production and biological characterization of cASC secretome generated under hypoxic conditions with platelet lysate (PLT) supplementation, either in a 2D culture or in a stirred-tank 3D culture. Secretomes obtained from 3D cultures were compared with those from 2D cultures prepared under identical hypoxic and PLT-supplemented conditions. Quantitative analyses revealed enhanced secretion of key factors, including monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF), in 3D-derived secretomes. Functional in vitro assays demonstrated superior anti-inflammatory, pro-migratory, and antifibrotic effects of the 3D secretome, evidenced by nuclear factor kappa B (NF-κB) inhibition, increased fibroblast migration, and modulation of extracellular matrix gene expression. Additionally, the bioreactor system enabled consistent secretome production with reproducible biological activity. These findings indicate that 3D bioreactor cultivation under hypoxia with PLT supplementation can generate a biologically active secretome from canine adipose-derived stem cells, providing a promising basis for further exploration in veterinary regenerative applications.

This prospective, single-arm, exploratory postmarketing study preliminarily evaluated the clinical response and plasma biomarker changes in 18 client-owned dogs with naturally occurring osteoarthritis (OA) treated with sodium hyaluronate (Bonharen). Patients received intravenous injections of Bonharen Intravenous at a dose of 0.15 mL/kg (1.3–1.6 mg/kg hyaluronic acid once a week for consecutive five weeks). Clinical parameters (lameness, joint pain, mobility, swelling) were assessed weekly and two weeks after the final dose was given via standardized scoring. The plasma concentrations of selected inflammatory, cartilage-related, and oxidative stress biomarkers were measured before treatment and two weeks after the final dose. Clinical improvement in lameness and/or joint pain on palpation was observed in nearly half of the patients. No clinical deterioration was recorded at any time point. Physical activity increased in all patients with reduced baseline activity. Significant decreases in the plasma levels of prostaglandin E₂, Δ17-6-keto prostaglandin F1α, malondialdehyde, and hyaluronan were detected, indicating reduced systemic inflammation and oxidative stress. In addition, an increase in plasma hydroxybutyrate and decrease in the collagen-breakdown marker prolyl-hydroxyproline were observed. No adverse effects were reported. These findings suggest that intravenous hyaluronic acid (Bonharen) may represent a safe and promising component to multimodal OA management in dogs and demonstrate the feasibility of integrating plasma biomarkers in canine OA studies.

Hyaluronan and hyaluronidases are critical in tissue remodeling, inflammation, and tumor progression. This chapter provides a comprehensive guide to hyaluronan zymography, a powerful technique for detecting and quantifying hyaluronidase activity in complex biological samples. The method involves separating proteins by polyacrylamide gel electrophoresis with hyaluronan incorporated into the gel matrix. Following electrophoresis, the gel is incubated to allow hyaluronidases to degrade the hyaluronan substrate, resulting in clear digestion zones. Detailed protocols for sample preparation and the zymographic process are included, offering researchers a robust tool for studying hyaluronidase activity and regulation in various biological contexts.

In a world where the incidence of non-specific lower back pain (LBP) is steadily increasing, researchers are still searching for effective solutions for patients. Hyaluronic acid (HA) viscosupplementation is commonly used to restore lubrication in osteoarthritis (OA) and other medical applications, but its rapid metabolism limits efficacy. This study evaluates whether an HA derivative can replace native HA for the treatment of non-specific LBP while maintaining or enhancing its frictional properties and improving in vivo stability. Six HA-based lubricants, both native and derivatized, were tested in a tribological rabbit fascia model and a new synthetic model. Reduced HA derivative showed better tribological properties and longer in vivo residence time compared to native HA, as demonstrated in pharmacokinetic studies in rabbits. The 316 kDa HA and reduced HA exhibited the most stable tribological properties, which were influenced by their molecular weight and concentration. These findings suggest that both native and reduced HA are promising viscosupplements for intrafascial injection in the treatment of LBP, with reduced HA potentially enhancing effectiveness through a prolonged effect.

The physical stresses during cryopreservation affect stem cell survival and further proliferation. To minimize or prevent cryoinjury, cryoprotective agents (CPAs) are indispensable. Despite the widespread use of 10% dimethyl sulfoxide (DMSO), there are concerns about its potential adverse effects. To bypass those effects, combinations of CPAs have been investigated. This study aimed to verify whether high-molecular-hyaluronic acid (HMW-HA) serves as a cryoprotectant when preserving human mesenchymal stem cells (hMSCs) to reduce the DMSO concentration in the cryopreservation medium. We studied how 0.1% or 0.2% HMW-HA combined with reduced DMSO concentrations (from 10% to 5%, and 3%) affected total cell count, viability, immunophenotype, and differentiation potential post-cryopreservation. Immediately after cell revival, the highest total cell count was observed in 10% DMSO-stored hMSC. However, two weeks after cell cultivation an increased cell count was seen in the HMW-HA-stored groups along with a continued increase in hMSCs stored using 3% DMSO and 0.1% HMW-HA. The increased total cell count corresponded to elevated expression of stemness marker CD49f. The HA-supplemented cryomedium did not affect the differential potential of hMSC. Our results will participate in producing a ready-to-use product for cryopreservation of mesenchymal stem cells.