Myths, reality and future of mesenchymal stem cell therapy.

Mesenchymal stem cell (MSC) therapy represents an alternative approach for tissue regeneration and inflammation control. In spite of a huge amount of preclinical data that has been accumulated on the therapeutic properties of MSCs, there are many conflicting results, possibly due to differences in the properties of MSCs obtained from different sources or underestimated mechanisms of MSC in vivo behavior. This review consolidates the in vivo effects of MSC therapy, discusses the fate of MSCs after intravascular and local delivery and proposes possible trends in MSC therapy.

Purification of high-molecular-weight subfraction from porcine skin inhibiting proliferation of A431 human carcinoma epidermoid cells.

Subfraction with a molecular weight >250 kDa isolated from porcine skin and inhibiting the proliferation of A431 human carcinoma epidermoid cells was purified by DEAE 32 anion exchange chromatography with NaCl concentration step-gradient. The effects of the initial subfraction and fractions obtained by separation in DEAE 32 on the proliferation of A431 human carcinoma epidermoid cells were studied in vitro in two tests (MTT and fluorescent test). The more sensitive fluorescent test showed the highest inhibitory activity of fraction No. 2 released from the column at 0.15 M NaCl. One major protein component and a series of minor protein components were detected in this fraction by vertical PAAG-SDS electrophoresis.

[Autocrine factor participation in defence of cytotoxic CTLL-2 cells from oxidative stress].

The role of autocrine factors (AF) secreted by cytotoxic IL-2-dependent CTLL-2 cells along with pyruvate in cell defense from oxidative stress was investigated. The addition of conditioned medium (CM) containing pyruvate and AF into CTLL-2 cell cultures increased significantly cell survival under oxidative stress condition. The kinetics of hydrogen peroxide removal from cell cultures under oxidative stress in the case of CM addition has been obtained. The removal of H2O2 mostly by means of its reaction with pyruvate that is contained in CM has been shown at the beginning of oxidative stress (up to 15 min). Pyruvate content in CM was determined as 138 +/- 7 microM. Cell filtration on column with Bio-Gel P-10 was used for removal pyruvate from CM. Three fractions of CM (A, B and C) were obtained as a result of gel filtration. Pyruvate was not detected in any fraction. The fraction A was eluted from column as the first one and contained the largest molecules. Cell survival test showed the fraction B to have the highest ability to protect CTLL-2 cells under oxidative stress. The fraction A supported cell survival to a less degree and fraction C was shown to have no protective ability. The addition of the fraction B to the cell cultures resulted in preservation of significantly higher intracellular ATP level in the cells under oxidative stress than in the control ones. Moreover, AF of the fraction B was shown to react directly with hydrogen peroxide and inactivate it in the absence of cells. AF of the fraction A did not have such properties.

[Influence of autocrine factor deficit in culture on survival and energy metabolism of CTLL-2 cells under oxidative stress].

A lot of data has shown recently that survival of mammalian cells is under a control of growth factors and autocrine survival factors (AF). We studied the influence of AF deficit on survival, intracellular ATP content, and transmembrane potential of mitochondria of IL-2-dependent CTLL-2 cells under oxidative stress. CTLL-2 cells cultivated under deficit of AF have been shown to be more susceptible to oxidative injury in comparison with the cells cultivated without deficit of AF (control); they died at smaller concentrations of H2O2 than control cells did. The ATP content in CTLL-2 cells was decreased under AF deficit conditions even without any stress and treatment of the cells by hydrogen peroxide resulted in additional large decrease of it. ATP depression was accompanied by disruption of cell membrane (blebbing) and drop of mitochondrial potential. Cell death under oxidative stress in the presence of AF deficit has been shown to proceed by both apoptosis and necrosis.

[Use of neurotransplantation in the treatment of Parkinson's disease]. / Ispol'zovanie neirotransplantatsii v lechenii bolezni parkinsona.

The outcomes of transplantation of the human embryonal mid-brain into the striatum of patients with Parkinson's disease are presented. For this, a procedure for obtaining, isolating, preparing the human embryonic midbrain, as well as a method for stereotactic administration of embryonal nerve tissue suspension having high dopaminergic neuron levels into the patients' striatum are specified. Patients underwent neurological examinations by the international protocol Core Assessment Program for Intracerebral Transplantation including monthly video recording within 3 months before and 3-24 months after surgery. Electrophysiological, neuropsychological, and immunological examinations were made at the same intervals. Most patients had positive dynamics: diminution of the severity of main disease symptoms, reduction in the efficiency of a single dose of DOPA-containing drugs, decrease in the magnitude of side effects of drug therapy.

Study of immunomodulatory properties of N-acetylmuramyl-L-alanyl-D-isoglutamine and N-acetylglucosaminyl-(beta 1----4)-N-acetylmuramyl-L-alanyl-D-isoglutamine.

The immunomodulatory activities of two synthetic muramylpeptides (MP), a muramyl dipeptide and a glucosaminyl-muramyl dipeptide, have been compared and have been found to exhibit many common features in their effects. In addition, the differential effects of low and high concentrations of MP on the primary humoral immune response in vitro were examined in detail. At high concentrations MP augmented the frequency of induced T-suppressor cells, while at low concentrations the primary immune response was stimulated by enhancement of the antigen-presenting function of accessory cells and by increasing the frequency of induced T-helper cells.

[Characteristics of the B lymphocytes participating in the reaction of allogeneic stem cell inactivation]. / Kharakteristika B-limfotsitov, uchastvuiushchikh v reaktsii inaktivatsii allogennykh stvolovykh kletok.

In this work the B-cells of mouse lymph nodes are characterized. B-cells produce a helper effect on the capacity of the T-lymphocytes of the lymph nodes for inactivating nonsyngeneic stem cells. The study has revealed that the genetic heterogeneity of the B-lymphocytes does not lead to the abolition of their helper activity. B-lymphocytes of "B-mice" have also been shown to be capable of enhancing the inactivating activity of T-cells.

[Effect of irradiation on the regulatory function of B-lymphocytes]. / Vliianie oblucheniia na reguliatornuiu funktsiiu B-limfotsitov.

A study was made of the effect of irradiation of B-lymphocytes with doses of 0-464.4 mC/kg on their regulatory function in activating the allogenic haemopoietic stem cells of mice. Irradiation changed the function of B-lymphocytes leading to transformation of their helper effect into the suppressible one. The parameters of the radiation damage to B-lymphocytes-regulators were determined.

[Interaction of the lymph node and splenic lymphocytes of mice in inactivation of allogeneic hematopoietic stem cells]. / Vzaimodeistvie limfotsitov limfaticheskikh uzlov i selezenki myshei pri inaktivatsii allogennykh krovetvornykh stvolovykh kletok.

A study was made of interaction of mouse spleen and lymph node lymphocytes in inactivation of allogeneic stem cells. It was established that T lymphocytes of the lymph nodes and spleen lymphocytes do not interact on combined administration; their action is of additive nature. B lymphocytes of the lymph nodes have a regulating activity both in respect to T lymphocytes of the lymph nodes and lymphocytes of the spleen. The stem cells serve as target. Depending on the stem cells/B lymphocytes ratio B lymphocytes are capable of exerting either helper or suppressor action.

[Regulating role of the B-lymphocytes in lymphocyte interaction with allogeneic hematopoietic stem cells]. / Reguliruiushchaia rol' B-limfotsitov vo vzaimodeistvii limfotsitov s allogennymi krovetvornymi stvolovymi kletkami.

The preparative separation of lymph-node cells according to their charge and the study of the activity of each fraction have revealed that B-lymphocytes in the lymph nodes of mice have a regulating function in the phenomenon of the inactivation of allogeneic hematopoietic stem cells. The analysis of the dependence of effects, obtained in various experiments, on the ratio of B-lymphocytes and hematopoietic stem cells indicates that stem cells serve as targets for B-lymphocytes and the most probable mechanism of the above-mentioned effects is the direct interaction of the cells, one regulatory B-lymphocyte being capable of interacting with one target cell. Depending on the ratio of B-lymphocytes and stem cells, the inactivating effect may be either suppressed (the suppressor activity of B-lymphocytes) or enhanced (the helper activity of B-lymphocytes). The quantitative characteristics of the regulating activity of B-lymphocytes have been introduced.

[Adaptive T-lymphocyte differentiation in an allogeneic environment]. / Adaptivnaia differentsirovka T-limfotsitov v allogennom okruzhenii.

Some patterns of adaptive changes of the hemopoietic stem cells in allogenic environment and the functional activity and specificity of cytotoxic T-lymphocytes developing from them and responsible for the inactivation of allogenic hemopoietic stem cells were studied on the radiation chimaeras. The allogenic environment did not prevent the functional maturation of these T-lymphocytes. The phenotype of T-lymphocytes matured under the conditions of allogenic recipient is similar but not identical with that of lymphocytes of the recipient mouse strain.

[Action of radiation on cell interactions in the phenomenon of nonsyngeneic stem cell inactivation. Quantitative parameters of the regulating effect of B-lymphocytes]. / Deistvie radiatsii ne kletochnye vzaimodeistviia v fenomene inaktivatsii nesingennykh stvolovykh kletok. Kolichestvennye parametry reguliruiushchego vliianiia B-limfotsitov.

Quantitative regularities have been revealed in the regulatory action of B-lymphocytes from mouse lymph nodes on killer activity of T-lymphocytes of low electrophoretic motility. It was shown that the radiation-induced changes in the mode of action of B-lymphocytes may be attributed to a decrease in the number of active cells.

[Effect of size-fractionated thymocytes on the number of hematopoietic stem cells in the bone marrow of sublethally irradiated mice]. / Vliianie fraktsionirovannykh po razmeru timotsitov na kolichestvo stvolovykh krovetvornykh kletok v kostnom mozge myshei posle subletal'nogo oblucheniia.

A study was of the influence of size-fractionated thymocytes in the density gradient of bovine serum albumin on the number of CFUs in the bone marrow of mice exposed to sublethal irradiation. Subject to separation were thymocytes obtained from intact mice and mice after multiple injections of dexamethasone (DM). Two cell populations were demonstrated during separation of thymocytes from intact mice. Injection of the first cell population brought about a decrease in the number of CFUs in the bone marrow during postradiation recovery, whereas injection of other thymocyte subpopulation resulted in an increase in CFUs. The use of thymocytes obtained from DM treated mice enabled the detection of an increase in bone marrow CFUs, induced by both unfractionated thymocytes and two fractions of thymocytes.

[Effect of radiation on cell interactions in the phenomenon of non-syngeneic stem cell inactivation. Changes in B-lymphocyte function after irradiation]. / Deistvie radiatsii na kletochnye vzaimodeistviia v fenomene inaktivatsii nesingennykh stvolovykh kletok. Izmenenie funktsii B-limfotsitov pri obluchenii.

A study was made of the changes in the mode of interaction between T- and B-lymphocytes of mouse lymph nodes with respect to the phenomenon of inactivation of non-syngeneic haemopoietic stem cells. It was shown that irradiation of B-lymphocytes with doses of 77.4--232.2 mC/kg changes their helper activity into a suppressor activity with regard to T-cell-killers having a low electrophoretic mobility.