Cytokines in equine platelet lysate and related blood products

Abstract

In equine medicine, the use of regenerative therapeutics has gained growing attention, but is still a new and complex field with room for improvement. Platelet lysate (PL) can be used as therapeutic agent but is also a promising supplement for the culture of multipotent mesenchymal stromal cells. To enable a targeted use of PL both in clinic and laboratory, it is crucial to learn more details on its effective ingredients. While so far, mainly growth factor components have been analyzed in platelet-based products such as PL, the current study focuses on the content of cytokines in serum, plasma, platelet concentrate and PL. Blood was harvested from 20 clinically healthy horses and subjected to blood count and chemistry analysis, as well as to further processing to PL. Plasma and platelet concentrate were produced by a buffy-coat-based method and PL was produced from the concentrate by freeze-thawing. Samples from each horse were analyzed regarding interleukin (IL)-1β, −4, −6 and −10, interferon-γ and tumor necrosis factor-α concentrations using sandwich ELISAs. Cytokine concentrations in serum, plasma, concentrate and PL were similar and correlated significantly. However, there was a large inter-individual variability in cytokine concentrations between the different donor horses. The samples from some donor animals had overall very high cytokine concentrations, while samples from other donors had no measurable cytokine ingredient. This pattern was observed for all cytokines. There was a noticeable link between high cytokine concentrations in the blood products and abnormal findings in blood chemistry. Cytokine concentrations in samples from horses with abnormal findings were significantly higher than in samples from the remaining horses. The interindividual differences in cytokine concentrations could be highly relevant when using PL for therapy and cell culture, as the mode of action of the PL is likely changed depending on the presence of pro- and anti-inflammatory cytokines. Blood chemistry might be useful to predict cytokine concentrations in blood products.

Impact of platelet lysate on immunoregulatory characteristics of equine mesenchymal stromal cells

“…Equine PL contains a naturally composed mix of cytokines, and therefore might mimic inflammation to an extent that beneficially impacts on MSC. However, donor effects on PL composition should be considered: in a previous study, we found that cytokine levels in PL were subject to high individual variation ( 4 ). Particularly horses with increased alkaline phosphatase, creatinine and lactate dehydrogenase values also had an increased concentration of IFN-γ, TNF-α, IL-4, IL-6, IL-10 and IL-1β in their blood products including PL.…”

“…PL contains a diversity of nutrients and growth factors such as TGF-β and PDGF ( 1 , 3 ). However, even while using a leukocyte-poor platelet concentrate for PL production ( 1 ), the resulting PL also contains a variety of cytokines including IFN-γ, IL-10, IL-1β, IL-4, IL-6 and TNF-α ( 4 ). Cytokines are a group of peptides that regulate the proliferation and differentiation of cells.…”

The PTP1B Inhibitor Trodusquemine (MSI-1436) Improves Glucose Uptake in Equine Metabolic Syndrome Affected Liver through Anti-Inflammatory and Antifibrotic Activity

“…Along with the aforementioned cytokines, adipocytes also produce other molecules such as leptin (LEP) and C-reactive protein (CRP), which together with infammation are responsible for inhibiting the expression of genes regulating the metabolism of fatty acids and glucose and decreased secretion of certain antihyperglycemic adipokines [9][10][11][12]. In addition, to the abundant proinfammatory adipokines described previously, AT also secretes some anti-infammatory factors, as for instance IL-4 or IL-10 [13,14]. Although exerting a pleiotropy of biological activities, interleukins 4 and 10 are essentially recognized for their immunosuppressive efects mediated through proinfammatory cytokine expression lowering and inducing type-switching of M1 to M2 macrophages under acute or prolonged infammatory states [15,16].…”