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Exposure of cells or biological tissues to high-power pulses of terahertz (THz) radiation leads to changes in a variety of intracellular processes. However, the role of heating effects due to strong absorption of THz radiation by water molecules still stays unclear. In this study, we performed numerical modelling in order to estimate the thermal impact on water of a single THz pulse as well as a series of THz pulses. A finite-element (FE) model that provides numerical solutions for the heat conduction equation is employed to compute the temperature increase. A simple expression for temperature estimation in the center of the spot of THz radiation is presented for given frequency and fluence of the THz pulse. It has been demonstrated that thermal effect is determined by either the average power of radiation or by the fluence of a single THz pulse depending on pulse repetition rate. Human dermal fibroblasts have been exposed to THz pulses (with an energy of 15 μ J and repetition rate of 100 Hz) to estimate the thermal effect. Analysis of heat shock proteins expression has demonstrated no statistically significant difference ( p < 0.05 ) between control and experimental groups after 3 h of irradiation. [ABSTRACT FROM AUTHOR]

THz radiation induces a variety of processes in cells and has attracted the attention of researchers in recent decades. Here, data on the effects of high-intensity terahertz (THz) radiation on human directly reprogrammed neural progenitor cells (drNPCs) and on neuroblastoma cells (SK-N-BE (2)) were obtained for the first time. The results demonstrated that the exposure of non-tumor and tumor cells to broadband (0.1-3 THz) THz pulses with the intensity of 21 GW/cm 2 and the electric field strength of 2.8 MV/cm for 30 min induced neither a noticeable genotoxic effect nor a statistically significant change in the proliferative activity and cell differentiation. It was also shown that the combined effect of THz radiation and salinomycin, a promising antitumor agent, on neuroblastoma cells did not enhance the genotoxic effect of this antibiotic. However, further studies involving chemotherapy drugs and other exposure parameters are warranted to introduce this new concept into anti-tumor clinical practice and to enhance the efficacy of the existing approaches.

Previous phase I studies demonstrated safety and some beneficial effects of mesenchymal stem cells (MSCs) in patients with mild to moderate idiopathic pulmonary fibrosis (IPF). The aim of our study was to evaluate the safety, tolerability, and efficacy of a high cumulative dose of bone marrow MSCs in patients with rapid progressive course of severe to moderate IPF. Twenty patients with forced ventilation capacity (FVC) ≥40% and diffusing capacity of the lung for carbon monoxide (DLCO) ≥20% with a decline of both >10% over the previous 12 months were randomized into two groups: one group received two intravenous doses of allogeneic MSCs (2 × 10 8  cells) every 3 months, and the second group received a placebo. A total amount of 1.6 × 10 9 MSCs had been administered to each patient after the study completion. There were no significant adverse effects after administration of MSCs in any patients. In the group of MSC therapy, we observed significantly better improvement for the 6-minute walk distance in 13 weeks, for DLCO in 26 weeks, and for FVC in 39 weeks compared with placebo. FVC for 12 months in the MSCs therapy group increased by 7.8% from baseline, whereas it declined by 5.9% in the placebo group. We did not find differences between the groups in mortality (two patients died in each group) or any changes in the high-resolution computed tomography fibrosis score. In patients with IPF and a rapid pulmonary function decline, therapy with high doses of allogeneic MSCs is a safe and promising method to reduce disease progression., (© The Authors. Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Background Nonhuman primates (NHP) may provide the most adequate (in terms of neuroanatomy and neurophysiology) model of spinal cord injury (SCI) for testing regenerative therapies, but bioethical considerations exclude their use in severe SCI. New Method A reproducible model of SCI at the lower thoracic level has been developed in Rhesus macaques. The model comprises surgical resection of 25% of the spinal cord in the projection of the dorsal funiculus and dorsolateral corticospinal pathways, controlled via registration of intraoperative evoked potentials (EPs). The animals were evaluated using the modified Hindlimb score, MRI, SSEP, and MEP over a time period of 8-12 weeks post-SCI, followed by histological examination. Results Complete disappearance of intraoperative EPs from distal hindlimb muscles without restoration within two weeks post-SCI was an indicator for irreversible disruption of the abovementioned pathways. As a result, controlled damage to the spinal cord was achieved in three NHPs, clinically manifested as irreversible lower monoplegia. No significant functional restoration was observed in these NHPs up to 12 weeks post-SCI. Demyelination of the damaged ascending tracts was detected. Disturbances in pelvic organ function were not observed in all animals. Comparison with existing methods The new method of EPs-guided SCI allows a more controlled and irreversible damage to the spinal cord compared with contusion and other transection approaches. Conclusions This method to induce complete SCI in NHP is well tolerated, reproducible and ethically acceptable: these are valuable attributes in a preclinical model that will hopefully help advance testing of new regenerative therapies in SCI., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Ischemic Heart Disease (IHD) has been recognized as the main cause of mortality in the modern world. Application of cell therapy technologies for the IHD treatment has been actively studied from the beginning of 2000s. The review is dedicated to the use of mesenchymal stem cells (MSC) in the therapy of IHD. The strategies of the MSC modification in vitro for improvement of their regenerative potential are extensively discussed, including preconditioning to enhance the cell survival, boosting their paracrine effect and manipulating their cardiomyogenic differentiation. The optimization of the MSC delivery and opportunities related to the use of biomaterials as cell carriers are also discussed. The results of the most important clinical studies on the MSC-based IHD therapy are presented, including those completed and published in the literature and the ongoing clinical trials registered at clinicaltrials.gov by June 2018., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

This article describes the results of systemic transplantations of cardiomyoblasts grown from autologous or allogeneic bone marrow-derived mesenchymal stem cells, in the complex therapy of the late radiation da- mage of the heart, which developed after radiation therapy in 16 female patients with Hodgkin disease (HD) or breast cancer (BC). The cell therapy drastically improved the efficacy of the drug treatment, which earlier was the only option for the therapy of the radiation damage of vital organs. The effect of such therapy was clinically observed in the patients already in the first year of observation, and consisted in the decrease of the degree of the cardiac failure severity and improvement of their quality of life in the absence of HD or BC progression.

In this study, we were focused on the differences between certain circulating cytokine levels in patients with or without sinus arrhythmia, according to the median IL-6 level. All patients were stable with regards to symptoms and therapy for at least one month prior to the measurements conducted within this study.Exclusion criteria were: patients with sleep apnea, asthma, respiratory insufficiency of any genesis, active infection, allergy, inflammatory diseases, cancer, diabetes of any type and treatment with anti-inflammatory drugs. The study was approved by the Institutional Review Board. All recruited patients gave their verbal and written consent for participation in the study. The study group consisted of 74 patients divided into two groups: with (38) and without sinus arrhythmia but with diagnosed coronary artery disease (36). Sinus arrhythmia was confirmed by 24h Holter monitoring. From all test parameters only cytokines IL-2, IL-8, IL-10, IL-17 and IL-18, showed statistically significant increasing in patients with statistically higher IL-6 levels. It is possible that IL-6 may not be a marker for the selection of patients with sinus arrhythmia or coronary artery disease. The findings indicate that IL-6 represents a reliable indicator for increased expression of IL-2, IL-8, IL-10, IL-17 and IL-18 in patients with sinus arrhythmia or coronary artery disease. Further studies in a large number of patients would be necessary to confirm our observations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In recent years, engineering of blood vessels, which can provide the effective transport of nutrients and various metabolites, is one of the major challenges in tissue reconstruction. Many researches are carried out to develop cell-seeded bioconstructs based on natural polymers, particularly on PEGylated fibrin. Therefore, the aim of this study was to reveal the optimal component ratio for modified fibrin hydrogels in order to provide favorable conditions for vascular development of endothelial and mesenchymal stem cell co-culture. It has been found out that the PEGylated fibrin hydrogels can support 3D cell growth in HUVECs and hASCs co-culture. The microporous filamentous hydrogel prepared from PEGylated 5 : 1 fibrinogen and using the 1 : 0.2 protein to thrombin ratio had the most favorable microenvironment for cell distribution, growth and development in the studied co-culture that resulted in high levels of expression of proteins required for angiogenesis.

Arterial calcification (AC) is a hallmark of many serious diseases, including atherosclerosis, chronic kidney disease, and diabetes. AC may also develop as a side-effect of therapy with anticoagulants, such as warfarin which is widely used for prophylaxis of thrombosis. In our studies, we established the relation between warfarin-induced AC and activation of enzyme transglutaminase 2 (TG2) and β-catenin signaling. We showed that TG2-specific inhibitor KCC-009 significantly attenuated the damaging effects of warfarin on arterial tissue. A similar protective effect was also achieved with a dietary bioflavonoid quercetin that inhibits TG2 and β-catenin signaling. We have shown that quercetin intercepts the chondrogenic transformation of vascular smooth muscle and also drastically attenuates calcifying cartilaginous metaplasia in another model of AC caused by genetic loss of matrix gla protein (MGP). These findings suggest that quercetin may be considered as a promising anti-AC therapeutic in the clinical settings of warfarin supplementation and MGP dysfunction. Further studies are required to test the efficacy of quercetin on other types of AC.

We tested the hypothesis that simultaneous transgenic overexpression of a select quartet of growth factors activates diverse signaling pathways for mobilization and participation of various stem/progenitor cells for cardiogenesis in the infarcted heart. Human insulin growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1a), and hepatocyte growth factor (HGF) plasmids were synthesized and transfected into skeletal myoblasts (SM) from young male wild-type or transgenic rats expressing green fluorescent protein (GFP). Overexpression of growth factors in transfected SM ((Trans)SM) was confirmed by reverse transcription polymerase chain reaction, western blotting, and fluorescence immunostaining. Using our custom-made growth factor array and western blotting, multiple angiogenic and prosurvival factors were detected in (Trans)SM, including secreted frizzled related protein-1,2,4,5, matrix metalloproteinases-3 and 9, connexin-43, netrin-1, Nos-2, Wnt-3, Akt, MAPK42/44, Stat3, nuclear factor kappa B (NFκB), hypoxia-inducible factor 1 (HIF-1α), and protein kinase C (PKC). The conditioned medium (CM) from (Trans)SM was cytoprotective for cardiomyocytes following H(2)O(2) treatment [P<0.01 vs. CM from native SM ((Nat)SM)], promoted a higher transwell migration of human umbilical cord vein endothelial cells (223.3±1.8, P<0.01) and in vitro tube formation (47.8±1.9, P<0.01). Intramyocardial transplantation of 1.5×10(6) (Trans)SM (group-3) in a rat model of acute myocardial infarction induced extensive mobilization of cMet(+), ckit(+), ckit(+)/GATA(4+), CXCR4(+), CD44(+), CD31(+), and CD59(+) cells into the infarcted heart on day 7 and improved integration of (Trans)SM in the heart compared to (Nat)SM (group 2) (P<0.05). Extensive neomyogenesis and angiogenesis in group-3 (P<0.01 vs. group-2), with resultant attenuation of infarct size (P<0.01 vs. group-2) and improvement in global heart function (P<0.01 vs. group-2) was observed at 8 weeks. In conclusion, simultaneous activation of diverse signaling pathways by overexpression of multiple growth factors caused massive mobilization and homing of stem/progenitor cells from peripheral circulation, the bone marrow, and the heart for accelerated repair of the infarcted myocardium.

Objective: In vitro, transglutaminase-2 (TG2)-mediated activation of the β-catenin signaling pathway is central in warfarin-induced calcification, warranting inquiry into the importance of this signaling axis as a target for preventive therapy of vascular calcification in vivo., Methods and Results: The adverse effects of warfarin-induced elastocalcinosis in a rat model include calcification of the aortic media, loss of the cellular component in the vessel wall, and isolated systolic hypertension, associated with accumulation and activation of TG2 and activation of β-catenin signaling. These effects of warfarin can be completely reversed by intraperitoneal administration of the TG2-specific inhibitor KCC-009 or dietary supplementation with the bioflavonoid quercetin, known to inhibit β-catenin signaling. Our study also uncovers a previously uncharacterized ability of quercetin to inhibit TG2. Quercetin reversed the warfarin-induced increase in systolic pressure, underlying the functional consequence of this treatment. Molecular analysis shows that quercetin diet stabilizes the phenotype of smooth muscle and prevents its transformation into osteoblastic cells., Conclusions: Inhibition of the TG2/β-catenin signaling axis seems to prevent warfarin-induced elastocalcinosis and to control isolated systolic hypertension.

Stem cells provide an alternative curative intervention for the infarcted heart by compensating for the cardiomyocyte loss subsequent to myocardial injury. The presence of resident stem and progenitor cell populations in the heart, and nuclear reprogramming of somatic cells with genetic induction of pluripotency markers are the emerging new developments in stem cell-based regenerative medicine. However, until safety and feasibility of these cells are established by extensive experimentation in in vitro and in vivo experimental models, skeletal muscle-derived myoblasts, and bone marrow cells remain the most well-studied donor cell types for myocardial regeneration and repair. This article provides a critical review of skeletal myoblasts as donor cells for transplantation in the light of published experimental and clinical data, and indepth discussion of the advantages and disadvantages of skeletal myoblast-based therapeutic intervention for augmentation of myocardial function in the infarcted heart. Furthermore, strategies to overcome the problems of arrhythmogenicity and failure of the transplanted skeletal myoblasts to integrate with the host cardiomyocytes are discussed.

Donor-recipient cell interactions are essential for functional engraftment after nonautologous cell transplantation. During this process, transplant engraftment is characterized and defined by interactions between transplanted cells with local and recruited inflammatory cells. The outcome of these interactions determines donor cell fate. Here, we provide evidence that lineage-committed embryonic stem cell (ESC)-derived vascular progenitor cells are the target of major histocompatibility complex (MHC) class I-dependent, natural killer (NK) cell-mediated elimination in vitro and in vivo. Treatment with interferon γ was found to significantly upregulate MHC class I expression on ESC-derived vascular progenitor cells, rendering them less susceptible to syngeneic NK cell-mediated killing in vitro and enhancing their survival and differentiation potential in vivo. Furthermore, in vivo ablation of NK cells led to enhanced progenitor cell survival after transplantation into a syngeneic murine ischemic hindlimb model, providing additional evidence that NK cells mediate ESC-derived progenitor cell transplant rejection. These data highlight the importance of recipient immune-donor cell interactions, and indicate a functional role for MHC-I antigen expression during successful ESC-derived syngeneic transplant engraftment.

Recruitment and retention of circulating progenitor cells at the site of injured or ischemic tissues facilitates adult neo-vascularization. We hypothesized that cell therapy could modulate local neo-vascularization through the vascular endothelial growth factor (VEGF)/stromal cell-derived factor-1 (SDF-1) axis and by paracrine effects on local endothelial cells. We isolated from rat bone marrow a subset of multipotent adult progenitor cell-derived progenitor cells (MDPC). In vitro, MDPCs secreted multiple cytokines related to inflammation and angiogenesis, including monocyte chemotactic protein-1, SDF-1, basic fibroblast growth factor, and VEGF, and expressed the chemokine receptors CXCR4 and VEGFR1. To investigate in vivo properties, we transplanted MDPCs into the ischemic hind limbs of rats. Elevated levels of the chemokine SDF-1 and colocalization of CD11b(+) cells marked the initial phase of tissue remodeling after cell transplantation. Prolonged engraftment was observed in the adventitial-medial border region of arterioles of ischemic muscles. However, engrafted cells did not differentiate into endothelial or smooth muscle cells. Limb perfusion normalized 4 weeks after cell injection. Inhibition of SDF-1 reduced the engraftment of transplanted cells and decreased endothelial cell proliferation. These findings suggest a two-stage model whereby transplanted MDPCs modulate wound repair through recruitment of inflammatory cells to ischemic tissue. This is an important potential mechanism for cell transplantation, in addition to the direct modulation of local vascular cells through paracrine mechanisms.

Phytosterols are plant sterols found in foods such as oils, nuts and vegetables. Phytosterols, in the same way as cholesterol, contain a double bond and are susceptible to oxidation. The objective of the present study was to assess the potential toxic effects of beta-sitosterol oxides on U937 cells. The effects of increasing concentrations (0-120 microm) of beta-sitosterol oxides on cellular cytotoxicity, apoptosis, antioxidant status and genotoxicity was assessed over 12, 24 and 48 h exposure periods. Following 12 h, the viability of cells treated with 120 microm-beta-sitosterol oxides was reduced to 51.7 % relative to control. At 24 and 48 h, both 60 and 120 microm-beta-sitosterol oxides caused a significant decrease in cell viability. For comparison, a decrease in viability of cells treated with a cholesterol oxide, 7beta-hydroxycholesterol (7beta-OH, 30 microm), was evident at 24 h. An increase in apoptotic cells, assessed using Hoechst 33342, indicates that the mode of cell death in U937 cells following exposure to 7beta-OH (30 microm) and beta-sitosterol oxides (60 and 120 microm) was by apoptosis. The increase in apoptotic cells after 12 h following treatment with 120 microm-beta-sitosterol oxides was accompanied by a decrease in cellular glutathione. Similarly, 7beta-OH (30 microm) treatment resulted in decreased glutathione at 12 h. Catalase activity was not affected by any of the treatments. beta-Sitosterol oxides had no genotoxic effects on U937 and V79 cells as assessed by the comet and sister chromatid exchange assays respectively. In general, the results indicate that thermally oxidised derivatives of beta-sitosterol demonstrate similar biological effects as 7beta-OH in U937 cells, but at higher concentrations.

Etoposide (VP-16)-induced DNA strand breaks and repair and apoptosis of unstimulated human lymphocytes have been studied using DNA comet assay, electrophoresis of low-molecular-weight DNA extracts, and fluorescence microscopy. Incubation of unstimulated human lymphocytes with VP-16 (50-200 microg/ml) for 3 or 24 h induced apoptosis. This conclusion is supported by results of morphological studies, evaluation of the proportion of hypodiploidy and internucleosomal degradation of DNA in lymphocytes. Etoposide-induced formation of DNA strand breaks preceded the appearance of these conventional apoptotic manifestations. The number of single-strand breaks depended on VP-16 concentration, and 2-3 h after its removal from the incubation medium they were repaired. The hydroxyl group at the C-4; position of the etoposide dimethoxyphenol ring may be responsible for the formation of single-strand breaks. Double-strand breaks were unrepaired 20 h after the change of the incubation medium. The number of double-strand breaks and a proportion of apoptotic cells did not exhibit any dependence on VP-16 concentration and/or duration of cell exposure to this agent. We suggest that the cytotoxic effect of VP-16 on unstimulated lymphocytes is mediated by a topoisomerase II isoform, topoisomerase II-beta, which is localized in the nucleolus and is not related to the cell cycle.