Pleiotropic effects of Erythropoietin. Influence of Erythropoietin on processes of mesenchymal stem cells differentiation

Adverse hematological profiles associated with chlorpromazine antipsychotic treatment in male rats: Preventive and reversal mechanisms of taurine and coenzyme-Q10

Chlorpromazine (CPZ) is one of the most effective antipsychotic drugs used for managing psychotic related disorders owing to its dopamine receptor blocking action. However, pharmacological investigations against CPZ's cytotoxic effect have remained scarce. Hence, this study investigated the preventive and reversal effects of taurine and coenzyme-Q10 (COQ-10), which are compounds with proven natural antioxidant properties, against CPZ-induced hematological impairments in male rats. In the preventive study, rats received oral saline (10 ml/kg), taurine (150 mg/kg/day), COQ-10 (10 mg/kg/day) or in combination for 56 days, alongside CPZ (30 mg/kg, p.o.) between days 29-56. In the reversal protocol, rats had CPZ repeatedly for 56 days before taurine and COQ-10 treatments or their combination from days 29-56. Rats were also given taurine (150 mg/kg/day), and COQ-10 (10 mg/kg/day) alone for 56 days. Serums were extracted and assayed for hematological, with oxidative and inflammatory markers. CPZ induced decreased red/white blood cells, erythropoietin, platelet count, packed cell volume and hemoglobin, neutrophil, and lymphocyte, which were prevented and reversed by taurine and COQ-10, or their combination. Taurine and COQ-10 improved mean corpuscular volume, hemoglobin concentration, with increased erythropoietin levels relative to CPZ groups. CPZ-induced increased malondialdehyde, tumor necrosis factor-alpha and interleukin-6 levels with decreased interleukin-10, glutathione, and superoxide-dismutase were prevented and reversed by taurine and COQ-10 in comparison with CPZ groups. Taurine and COQ-10 alone notably improved the antioxidant/anti-inflammatory status relative to controls. Among other mechanisms, taurine and COQ-10 abated CPZ-induced hematological deficiencies, via decreased serum levels of oxidative stress, and pro-inflammatory cytokines release, with increased antioxidants and anti-inflammation function.

Bone Healing of Critical-Sized Femoral Defects in Rats Treated with Erythropoietin Alone or in Combination with Xenograft

Critical-size bone defect models are the standard in studies of the osteogenic potential of biomaterials. The present investigation aimed to evaluate the ability of recombinant human erythropoietin (EPO) to induce trabecular bone healing either alone or combined with a xenograft in a rat femoral critical-size defect model. Five-mm bone defects were created in the femoral diaphysis of fifty-six skeletally mature male Wistar albino rats. The animals were divided into six groups: one control group and five experimental groups. The defects in the control group were left empty, whereas an absorbable collagen cone soaked either with saline or erythropoietin (alone or in combination with xenograft) was placed in locally treated groups. The systemic treatment group received EPO subcutaneously. Bone formation was objectively evaluated through radiography, osteodensitometry and histological examination on post-operative days 30 and 90. The results demonstrate that EPO, locally applied on a collagen scaffold, was capable of inducing bone healing, whereas the single systemically administered high EPO dose had only an insignificant effect on bone formation. The combination of EPO with a bone substitute under the form of cancellous granules resulted in more rapid integration between the xenograft and host bone.

The Glycoprotein/Cytokine Erythropoietin Promotes Rapid Alveolar Ridge Regeneration In Vivo by Promoting New Bone Extracellular Matrix Deposition in Conjunction with Coupled Angiogenesis/Osteogenesis

The loss of bone following tooth extraction poses a significant clinical problem for maxillofacial esthetics, function, and future implant placement. In the present study, the efficacy of an erythropoietin-impregnated collagen scaffold as an alveolar ridge augmentation material versus a conventional collagen scaffold and a BioOss inorganic bovine bone xenograft was examined. The collagen/Erythropoietin (EPO) scaffold exhibited significantly more rapid and complete osseous regeneration of the alveolar defect when compared to bone xenograft and the collagen membrane alone. The new EPO induced extracellular matrix was rich in Collagen I, Collagen III, Fibronectin (Fn) and E-cadherin, and featured significantly increased levels of the osteogenic transcription factors Runt-related transcription factor 2 (Runx2) and Osterix (Osx). Histomorphometric evaluation revealed a significant two-fold increase in the number of capillaries between the EPO and the BioOss group. Moreover, there was a highly significant 3.5-fold higher level of vascular endothelial growth factor (VEGF) in the collagen/EPO-treated group compared to controls. The significant effect of EPO on VEGF, FN, and RUNX2 upregulation was confirmed in vitro, and VEGF pathway analysis using VEGF inhibitors confirmed that EPO modulated extracellular matrix protein expression through VEGF even in the absence of blood vessels. Together, these data demonstrate the effectiveness of an EPO-impregnated collagen scaffold for bone regeneration as it induces rapid matrix production and osseoinduction adjacent to new capillaries via VEGF.

Renoprotective effect of carbamylated darbepoetin and udenafil in ischemia-reperfusion of rat kidney due to the effect of preconditioning and inhibition of nuclear factor kappa B

Introduction: Acute kidney injury is a widespread complication in hospitalized patients, with a high mortality rate and long-term complications affecting prognosis and quality of life and with high human and financial costs. In addition, to date, no clear algorithm for the prevention of this type of damage has been developed.

Materials and methods: The research was carried out on male Wistar rats. A 40-minute renal ischemia-reperfusion model was used to model acute kidney injury. Further, the renoprotective properties of carbamylated darbepoetin, udenafil and their combination were assessed based on the analysis of the biochemical studies’ results, dynamics of the renal status and the renal microvasculature, and the pathomorphological picture. A series of experiments was also carried out to assess the contribution of adenosine triphosphate-dependent potassium channels and nuclear factor kappa B to the renoprotective properties of the said agents.

Results and discussion: Prophylactic administration of carbamylated darbepoetin at a dose of 50 µg/kg and udenafil at a dose of 8.7 mg/kg led to a statistically significant decrease in creatinine and blood urea nitrogen, an increase in glomerular filtration rate with a simultaneous decrease in fractional excretion of sodium, as well as an increase in the level of microcirculation in the kidneys and a decrease in the severity of damage according to the data of a pathomorphological examination at all time points of the experiment. A higher efficiency of correcting ischemic and reperfusion renal injuries was observed when using a combination of the said pharmacological agents. A series of experiments with glibenclamide demonstrated that its preliminary administration levels the renoprotective properties of carbamylated darbepoetin and udenafil. The ability of the studied pharmacological agents to reduce lipopolysaccharide-induced expression of nuclear factor kappa B in mononuclear cells was also demonstrated. The results of the research suggest that the renoprotective effects of carbamylated darbepoetin, udenafil, and their combination are realized through ATP-dependent potassium channels and nuclear factor kappa B.

Conclusion: Pharmacological preconditioning with carbamylated darbepoetin and udenafil reduces the severity of acute kidney injury induced by ischemia-reperfusion.

Graphical abstract:

Preclinical studies on pleiotropic functions of erythropoietin on bone healing

Erythropoietin (ЕPО) is a glycoprotein hormone, mainly known for its haemopoietic function. For orthopaedics, its pleiotropic effects – osteogenic and angiogenic potential, are of primary interest. The exact mechanism of EPO action is still unclear. The effects of EPO on bone healing were investigated through experiments with rats, mice, rabbits and pigs. Each of used models for experimental bone defects (calvarial models, long bone segmental defects, posterolateral spinal fusion and corticosteroid-induced femoral head osteonecrosis) has specific advantages and flaws. Obtaining specific and correct results is largely dependent on the used model. The brief evaluation of models could serve for standardisation of preclinical studies on bone regeneration.