Angiogenin as a Possible Mediator of Macrophage-Mediated Regulation of Fibroblast Functions.

We studied angiogenin production by human macrophages and evaluated the role of this factor in the macrophage-mediated regulation of fibroblasts. All macrophage subtypes, and especially the efferocytosis-polarized macrophages, M2(LS), actively produced angiogenin. Exogenous recombinant angiogenin dose-dependently enhanced the proliferation and differentiation of dermal fibroblasts. The addition of the angiogenin inhibitor to fibroblasts cultures suppressed the stimulating effect of exogenous angiogenin or M2(LS) conditioned media. These findings indicate the involvement of angiogenin in the macrophage-mediated paracrine regulation of skin fibroblasts.

Effect of M2 Macrophage-Derived Soluble Factors on Behavioral Patterns and Cytokine Production in Various Brain Structures in Depression-Like Mice.

We studied the effect of soluble factors derived from human macrophages polarized to M2 phenotype under conditions of serum deprivation (M2-SF) on behavioral pattern and cytokine production in various brain structures in mice with modeled stress-induced depression. Intranasal administration of M2-SF for 7 days led to stimulation of locomotor and exploratory activities and a decrease in emotional reactivity in the open-field test as well as reduction in depression-like behavior in Porsolt forced swimming test and a decrease in anxiety and anhedonia. Correction of depression-like behavior was accompanied by down-regulation of proinflammatory cytokines (IL-1ß, IL-6, TNFα, and IFNγ) in pathogenetically important brain structures (striatum, hippocampus, and frontal cortex). These data indicate that the antidepressant potential of M2 type macrophages can be mediated by the anti-inflammatory effects of M2-SF.

Comparative Efficacy of the Stromal-Vascular Fraction Cells of Lipoaspirate and Hyaluronic Acid in the Treatment of Gonarthrosis: Results of an Interim Analysis.

The use of cell technologies, in particular the stromal-vascular fraction of adipose tissue, is a new direction in the treatment of osteoarthritis of the weight-bearing joints. Stromal-vascular fraction cells have anti-inflammatory and immunomodulatory effects and are able to differentiate into connective tissue cells, including cartilage, tendons, and ligaments. Our clinical study showed the safety and good tolerability of intra-articular administration of autologous stromal-vascular fraction cells in 16 patients with severe manifestations of osteoarthritis. Single administration of stromal-vascular fraction cells led to more pronounced and stable (up to 12 months) clinical improvement in the main symptoms of the disease, including pain and functional activity of the affected joints, in comparison with intra-articular injection of hyaluronic acid (10 patients of the comparison group).

Influence of Secretome of Different Functional Phenotypes of Macrophages on Proliferation, Differentiation, and Collagen-Producing Activity of Dermal Fibroblasts In Vitro.

We studied the effect of conditioned media of GM-CSF-differentiated human macrophages polarized in M1(LPS), M2a(IL-4), M2c(dexamethasone), and M2(low serum) phenotypes on proliferation, differentiation, and collagen-producing activity of dermal fibroblasts. It was found that M1(LPS) and M2a(IL-4) were characterized by moderate influence on functional activity of fibroblasts. At the same time, soluble factors of M2c(dexamethasone) significantly enhanced the proliferative response of fibroblasts, but not their differentiation and type I collagen production. On the contrary, M2(low serum) generated under conditions of growth factors deficiency had a pronounced stimulating effect on the differentiation of fibroblasts and production of type I collagen by these cells, but moderately stimulated the fibroblast proliferation. Thus, the secretory activity of various functional phenotypes of macrophages is an important mechanism of fibrogenesis regulation.

Effect of M2 Macrophage-Derived Soluble Factors on Proliferation and Apoptosis of SH-SY5Y Cells.

Macrophages play the key role in the regulation of neuroregeneration. For evaluation of the neuroregenerative potential of M2 macrophages, we studied the effect of macrophages polarized with IL-4 (M2a (IL-4)) and by efferocytosis under conditions of serum deprivation (LS, Low Serum; M2(LS)) on proliferative activity and apoptosis of SH-SY5Y cells under conditions of deficiency of growth/serum factors. Conditioned media of both M2(LS) and M2a(IL-4) stimulated proliferation of SH-SY5Y cells. Moreover, soluble factors of M2(LS) and M2a(IL-4) reduced the degree of early apoptosis of SH-SY5Y cells and the protective effect of M2(LS) was observed at earlier terms of culturing. Our findings suggest that M2 macrophages have high neuroregenerative potential that is mediated through soluble factors and manifests itself both in stimulation of proliferation and inhibition of apoptosis of SH-SY5Y cells.

Efferocytosis Modulates Arginase-1 and Tyrosine Kinase Mer Expression in GM-CSF-Differentiated Human Macrophages.

We studied the expression of arginase-1 (Arg1) and tyrosine kinase Mer (MerTK) in GMCSF-differentiated human macrophage populations М0, М1(IFNγ), М2а(IL-4), and М2(low serum) generated under conditions of growth/serum factor deficiency. The maximum relative content of Arg1+ and MerTK+ cells was found in М2 macrophage populations: М2а(IL-4) and М2(low serum). As the uptake of apoptotic cells is the key mechanism of M2 polarization during M2(low serum) generation, we performed a special series of experiments and showed that incubation with allogeneic apoptotic neutrophils significantly increased the percentages of CD206+ macrophages co-expressing Arg1 and MerTK.

Effect of Apoptotic Neutrophils on the Production of Erythropoietin, MMP-9, and TIMP-1 in Cultures of Human Macrophages.

We studied the effect of apoptotic neutrophils on the production of erythropoietin, MMP-9, and TIMP-1 by GM-CSF-induced human macrophages. GM-CSF-induced macrophages spontaneously produce erythropoietin and secrete MMP-9 and TIMP-1. Polarization of these macrophages towards the M2-like phenotype after exposure to apoptotic neutrophils considerably increased the production of erythropoietin; the MMP-9/TIMP-1 ratio tended to increase under these conditions due to a decrease in TIMP-1.

The Phenotypic and Functional Features of Human M2 Macrophages Generated Under Low Serum Conditions.

The phenotypic and functional features of human M2 macrophages, in particular, their immunosuppressive activity, can considerably vary depending on M2 polarizing stimulus. This study was aimed at the investigation of cytokine production and pro-apoptogenic/inhibitory molecule expression in macrophages generated with GM-CSF using either standard conditions (M1) or deficiency of serum/growth factors (M2-LS cells). In contrast to M1, M2-LS cells were characterized by an enhanced content of CD206(+), B7-H1(+), FasL(+) and TRAIL(+) cells along with a decreased production of IFN-γ, IL-5, IL-6, IL-13, TNF-α, IL-17 and MCP-1. In addition, M2-LS exhibited a lower T cell stimulatory activity in MLC that was associated with the higher numbers of apoptotic and the lower numbers of proliferating T cells. B7-H1 plays a key role in M2-LS-mediated cytotoxic effects as the neutralization of B7-H1 reduces the apoptosis-inducing activity of M2-LS, while the blocking of CD206 and TRAIL reduces the cytostatic activity of M2 macrophages.

Efficiency of Cell Therapy in Liver Cirrhosis.

We studied safety and clinical efficacy of transplantation of autologous bone marrow cell in complex therapy of 158 patients with chronic hepatitis and cirrhosis of the liver. The efficiency of cell therapy was assessed in 12 months after single injection of the cells. The positive response (alleviation of liver cirrhosis or stabilization of the pathological process) was observed in 70% cases. The efficacy of therapy correlated with the severity and etiology of the disease and was maximum in patients with Child-Pugh class A (in 82.5% cases) and class B liver cirrhosis (in 79% cases); in patients with class C liver cirrhosis, the positive response was achieved in 42.5% cases. In 39 patients, ultrasonic examination performed in 3 years after transplantation revealed no focal lesions or ectopic ossification foci.

Intranasal immunotherapy with M2 macrophage soluble factors in post-COVID hyposmia: A pilot study.

Olfactory dysfunction is an early marker of COVID-19 infection. However, individuals may develop chronic olfactory impairment for more than six months in 1-10 % of cases. The study's objective is to evaluate the efficacy and safety of intranasal immunotherapy using bioactive substances produced by M2 macrophages for the treatment of people with long-term post-COVID-19 hyposmia. Seven individuals with long-term persistent hyposmia (7 to 24 months), associated with PCR-confirmed coronavirus infection were evaluated for olfactory function at baseline, one, and six to twelve months after therapy. The intranasal inhalation of M2 macrophage conditioned medum (one time per day for 28-30 days) was well tolerated. Furthermore, olfactometry demonstrated that the patients restored their capacity to perceive (Kruskal-Wallis H test 14.123, p = 0.0009) and recognize odours (H = 11.674, p = 0.0029). In addition, the subjective evaluation of smell significantly improved (H = 11.935, p = 0.0026). At the 6- to 12-month follow-up, the majority of patients (5/7) reported extremely high levels of satisfaction with the outcomes, and the remaining two patients also felt generally positive about the therapy's success. Overall, our study showed that the use of intranasal inhalations as a method of delivering bioactive factors and the conditioned medium of M2 macrophages as a therapeutic agent are both safe, well tolerated and, according to preliminary data, clinically effective in the treatment of patients with long-term post-COVID-19 hyposmia.

Multiplex analysis of cytokines, chemokines, growth factors, MMP-9 and TIMP-1 produced by human bone marrow, adipose tissue, and placental mesenchymal stromal cells.

Comparative analysis of mesenchymal stromal cells isolated from human BM, adipose tissue, and placenta was carried out. The cells were compared by the levels of constitutive, spontaneous, and LPS-induced production of Th1/proinflammatory (IFN-γ, IL-2, IL-1ß, TNF-α, IL-12, IL-17) and Th2/anti-inflammatory cytokines (IL-4, IL-5, IL-6, IL-10, IL-13), chemokines (IL-8, MCP-1, MIP-1ß), growth factors (IL-7, granulocytic CSF, granulocytic macrophageal CSF, erythropoietin, VEGF, EGF, IGF-1, main FGF), matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1. Mesenchymal stromal cells originating from different tissues were characterized by functional potential for hemopoiesis support (through production of granulocytic CSF, granulocytic macrophage CSF, erythropoietin), immunomodulation (through production of IFN-γ, IL-2, IL-6, IL-1ß, TNF-α and chemokines IL-8, MCP-1, MIP-1ß), and stimulation of reparative processes (through production of VEGF, FGF, IGF-1, IL-6 tissue inhibitor of metalloproteinase-1, and matrix metalloproteinase-9). By the type and levels of spontaneous (basal) production of cytokines, the adipose tissue mesenchymal stromal cells more distinctly demonstrated the proinflammatory (IL-1ß TNF-α), immunoregulatory (IFN-γ, IL-2, IL-4, IL-6, IL-8, MCP-1, MIP-1ß), and hemopoiesis-stimulating (granulocytic CSF, granulocytic macrophage CSF) phenotype and at the same time were characterized by lower sensitivity to lipopolysaccharide stimulation than BM and placental mesenchymal cells.

Mesenchymal cells in the treatment of focal brain injury induced by venous circulation disturbances in rats.

We studied the efficiency of bone marrow multipotent mesenchymal stem cells for correction of neurological deficit in rats with experimental sustained focal brain injury caused by venous outflow disturbances. It was found that neurological deficit in animals with transplantation of multipotent mesenchymal stromal cells decreased by 54-75% (vs. 14-17% in the control group) by day 21. The efficiency of mesenchymal stromal cell transplantation (intravenous or local) on day 1 of postoperation period was significantly higher than on day 7. This manifested in more pronounced decrease in the severity of neurological disorders (according to modified neurological severity score) and more rapid recovery of autonomic feeding. Moreover, transplantation of multipotent mesenchymal stromal cells on day 1 abolished the need in antiedematous therapy, while in animals receiving cell therapy on day 7, administration of glucocorticoids was necessary. Comparison of two regimens of cell administration at early terms revealed no advantages of local transplantation of multipotent mesenchymal stromal cells over intravenous injection.

A new approach to evaluation of osteogenic potential of mesenchymal stromal cells.

We developed a new approach to evaluation of the intensity of osteogenic differentiation of mesenchymal stromal stem cells based on measurement of optical density of mesenchymal stromal cell cultures in a concentration range 625-10,000 cells per well after their culturing in osteogenic induction medium and staining of calcium deposits by the method of von Kossa. The proposed method allows comparative semiquantitative evaluation of osteogenic properties of mesenchymal stem cells depending on tissue sources (bone marrow, adipose tissue, placenta), in vitro cell density, number of passages, duration of culturing, and concentration of serum growth factors in the microenvironment. The developed approach makes it possible to compare functional activity of mesenchymal stromal cells in various pathologies. The proposed method can be used in traumatology and orthopedics for improving the efficiency of transplantation of mesenchymal stromal cells for stimulation of reparative osteogenesis.

Autologous bone marrow cells in the treatment of cirrhosis of the liver.

The data characterizing tolerance and efficiency of autologous bone marrow cells in the treatment of patients with cirrhosis of the liver are presented. Injection of autologous bone marrow cells was not associated with the development of adverse reactions. Cell therapy of patients with compensated cirrhosis arrested asthenic syndrome, reduced cytolysis, increased the level of serum albumin and platelet count. Ultrasonic examination revealed reduction of portal hypertension (the area of the spleen and the portal vein lumen decreased). In patients with decompensated cirrhosis, a positive response presenting as reduction of the disease severity (by 1.9 points) was observed in 48.6% cases. Positive shifts in these patients were associated with a decrease of ALT and AST levels, reduction of laboratory signs of cirrhosis, increase in platelet count, and reduction of the asthenic syndrome. Hence, therapy with autologous bone marrow cells is safe and, according to preliminary results, can be regarded as a new approach to the treatment of patients with cirrhosis of the liver.

Application of autologous bone marrow stem cells in the therapy of spinal cord injury patients.

We studied the safety and efficiency of transplantation of autologous bone marrow cells in complex therapy of patients with spinal cord injury in the late period of the disease. In control group patients, meningomyeloradiculolis was performed, while in the main group surgical treatment was supplemented by transplantation of autologous bone marrow cells. Transplantation of BM stem cells into the cyst cavity and intravenously was well tolerated, did not cause allergic or inflammatory reactions in the early and delayed periods after surgery, and did not induce the formation of ossification foci in the nervous tissue. Analysis of the neurological status by ASIA, Bartel, and Ashworth scales showed that in the main group the positive clinical dynamics was more often observed than in the control. The decrease in neurological deficit included improvement of sensory and motor activity and conducting sensory function. Thus, transplantation of autologous bone marrow cells can be a novel safe strategy for the treatment of patients in the late period after spinal trauma.

Characteristics of bone marrow cells under conditions of impaired innervation in patients with spinal trauma.

We studied quantitative and functional parameters of bone marrow stem cells and mature lymphocyte population under conditions of impaired innervation in patients with injuries to the cervical and thoracic portions of the spinal cord. Our findings indicated the absence of deficiency of quantitative and proliferative potentials of stem cells and demonstrated intact subpopulation structure of mature lymphocytes and T-cell proliferative activity similar to that in donors. The content of CD34+ cells in patients did not differ from that in donors. The percentage of CD34+CD38- hemopoietic stem cells was elevated in patients, presumably due to increased proliferative activity of hemopoietic stem cells. The possibility of derivation and in vitro culturing of fibroblast-like cells with mesenchymal stem cell phenotype was demonstrated.