Results from part A of the multi-center, double-blind, randomized, placebo-controlled NefIgArd trial, which evaluated targeted-release formulation of budesonide for the treatment of primary immunoglobulin A nephropathy

The therapeutic potential of a novel, targeted-release formulation of oral budesonide (Nefecon) for the treatment of IgA nephropathy (IgAN) was first demonstrated by the phase 2b NEFIGAN trial. To verify these findings, the phase 3 NefigArd trial tested the efficacy and safety of nine months of treatment with Nefecon (16 mg/d) versus placebo in adult patients with primary IgAN at risk of progressing to kidney failure (ClinicalTrials.gov: NCT03643965). NefIgArd was a multicenter, randomized, double-blind, placebo-controlled two-part trial. In Part A, 199 patients with IgAN were treated with Nefecon or placebo for nine months and observed for an additional three months. The primary endpoint for Part A was 24-hour urine protein-to-creatinine ratio (UPCR) after nine months. Secondary efficacy outcomes evaluated included estimated glomerular filtration rate (eGFR) at nine and 12 months and the UPCR at 12 months. At nine months, UPCR was 27% lower in the Nefecon group compared with placebo, along with a benefit in eGFR preservation corresponding to a 3.87 ml/min/1.73 m2 difference versus placebo (both significant). Nefecon was well-tolerated, and treatment-emergent adverse events were mostly mild to moderate in severity and reversible. Part B is ongoing and will be reported on later. Thus, NefIgArd is the first phase 3 IgA nephropathy trial to show clinically important improvements in UPCR and eGFR and confirms the findings from the phase 2b NEFIGAN study.

Randomised non-inferiority trial: 1600 mg versus 400 mg tablets of mesalazine for the treatment of mild-to-moderate ulcerative colitis

BACKGROUND

High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC).

AIM

To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations.

METHODS

Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored.

RESULTS

At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low.

CONCLUSIONS

Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).

Yeast red pigment modifies cloned human α-synuclein pathogenesis in Parkinson disease models in Saccharomyces cerevisiae and Drosophila melanogaster

Recently, we identified the yeast red pigment (RP), a polymer of 1-(5'-Phosphoribosyl)-5-aminoimidazole, as a novel potential anti-amyloid agent for the therapy of neurodegenerative diseases. The purpose of this study was to further validate RP for treatment of Parkinson's disease (PD) and to clarify molecular mechanisms involved in the reduction of amyloid cytotoxicity. We investigated RP effects in vivo using Saccharomyces cerevisiae and Drosophila melanogaster PD models. Western blot analysis revealed reduction in the levels of insoluble α-synuclein in both models, while soluble α-synuclein decreased only in Drosophila. In both models RP significantly reduced α-synuclein cytotoxicity, as was revealed by immunohistochemistry in Drosophila (p < 0.001, n = 27 flies per genotype/assay) and by flow cytometry in yeast (p < 0.05). Data obtained from the yeast PD model suggests that RP antitoxic effects are associated with a drop in ROS accumulation, and slower cellular transition from the early to late apoptotic stage. Using Drosophila brain tissue sections, we have demonstrated that RP helps to compensate for an α-synuclein-mediated reduction in the number of dopaminergic neurons and leads to better performance in animal climbing tests (p < 0.001, n = 120-150 flies per genotype/assay). Taken together, these results demonstrate the potential of RP for the treatment of PD, at least in model systems.

The Relationship Between Cytokine Production, CSF2RA, and IL1R2 Expression in Mammary Adenocarcinoma, Tumor Histopathological Parameters, and Lymph Node Metastasis

Objective:

The aim of this study was to evaluate the relationship between cytokine production, GM-CSF receptor (CSF2RA), and IL-1 receptor (IL1R2) expression in mammary adenocarcinoma and their association with it histopathological parameters and lymph node metastasis.

Methods:

We analyzed tumor biopsy samples (cultured in vitro) from 50 women (aged 43-75) with invasive ductal mammary adenocarcinomas. Enzyme-linked immunosorbent assay method the concentrations of interleukin 2, interleukin 6, interleukin 8, interleukin 10, interleukin 17, interleukin 18, interleukin 1β, interleukin 1Ra, tumor necrosis factor α, interferon γ, granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor, and vascular endothelial growth factor A were determined in culture supernatants. The expression of CSF2RA and IL1R2 in tumor biopsy was evaluated by immunohistochemical method.

Results:

We showed that the “cytokine profile” of a tumor (the ability of tumor cells and its microenvironment to produce different cytokines) is very individual. It has been shown that the features of the cytokine profile of the mammary adenocarcinoma are important for the formation and realization of the metastatic potential of the mammary adenocarcinoma. We found correlations between some histopathological parameters of mammary adenocarcinoma and coefficients K_{GM-CSF/CSF2RA} and K_IL-1β/IL1R2, which are the ratios of concentrations of granulocyte macrophage colony-stimulating factor and interleukin -1β to expression of CSF2RA and IL1R2, respectively. K_{GM-CSF/CSF2RA} positively correlated with highly differentiated cells, and K_IL-1β/IL1R2 positively correlated with the number of mitoses, poorly differentiated cells, and a number of lymph nodes with metastases. K_{GM-CSF/CSF2RA} positively correlated with the concentrations of interleukin 6, interleukin 8, interleukin 1Ra, and granulocyte colony-stimulating factor. K_IL-1β/IL1R2 positively correlated with concentrations of interleukin 1β and interferon γ and negative correlated with the concentrations of vascular endothelial growth factor A and tumor necrosis factor α. It is shown that K_IL-1β/IL1R2 can be considered as a prognostic indicator predicting the probability of mammary adenocarcinoma metastasis to regional lymph nodes.

Conclusions:

The ratios of granulocyte macrophage colony-stimulating factor and interleukin 1β cytokines, produced in tumor, to the expression of CSF2RA and IL1R2 depend on levels of interleukin 6, interleukin 8, tumor necrosis factor α, interferon γ, granulocyte colony-stimulating factor, and vascular endothelial growth factor A and are important factors affecting the progression and metastasis of the breast cancer.

Cytokine production in mammary adenocarcinoma and its microenvironmental cells in patients with or without metastases in regional lymph nodes

In recent years, the concept of formation of a sufficiently autonomous cytokine network in a malignant tumour has emerged. In this regard, the data on the role of this network and its signalling pathways in the process of metastasis are an interesting topic. The aim of this study was to evaluate the in vitro cytokine-producing potential of mammary adenocarcinoma (MAC; and cells of its microenvironment) from patients with or without metastases in regional lymph nodes (LNs). By enzyme-linked immunosorbent assays of culture supernatants, we studied the cytokine production by biopsy samples of MAC: spontaneous and stimulated by polyclonal activators (PAs: phytohaemagglutinin, concanavalin A and lipopolysaccharide). The levels of spontaneous production of interleukin (IL)-10 and granulocyte colony-stimulating factor (G-CSF) and the amounts of IL-2, IL-10, G-CSF and monocyte chemoattractant protein-1 (MCP-1) produced during stimulation by PAs, as well as the index of stimulation by polyclonal activators (ISPA) for IL-2 production, were lower for MAC with LN metastasis than for MAC without LN metastasis. The levels of spontaneous production of IL-2 and interferon (IFN)-γ and the ISPA for granulocyte-macrophage colony-stimulating factor (GM-CSF) production were higher for MAC with LN metastasis. There were only three pairwise correlations between the produced cytokines that were specific to MAC with LN metastasis: IL-2 and IFN-γ, IL-6 and GM-CSF, and IL-8 and GM-CSF. There were 10 pairwise correlations between the produced cytokines that were specific to nonmetastasising MAC: IL-6 and IL-10, IL-6 and MCP-1, IL-8 and IL-10, IL-8 and MCP-1, IL-10 and G-CSF, IL-10 and MCP-1, IFN-γ and MCP-1, MCP-1 and G-CSF, G-CSF and IL-1Ra, and GM-CSF and tumour necrosis factor (TNF)-α. Our data indicate that metastatic tumours show desynchronisation of many pathways of induction and synthesis of cytokines that are characteristic of nonmetastatic tumours.

Fullerenes on a Nanodiamond Platform Demonstrate Antibacterial Activity with Low Cytotoxicity

Carbon nanoparticles with antimicrobial properties, such as fullerenes, can be distinguished among the promising means of combating pathogens characterized by resistance to commercial antibiotics. However, they have a number of limitations for their use in medicine. In particular, the insolubility of carbon nanoparticles in water leads to a low biocompatibility and especially strong aggregation when transferred to liquid media. To overcome the negative factors and enhance the action of fullerenes in an extended range of applications, for example, in antimicrobial photodynamic therapy, we created new water-soluble complexes containing, in addition to C60 fullerene, purified detonation nanodiamonds (AC960) and/or polyvinylpyrrolidone (PVP). The in vitro antibacterial activity and toxicity to human cells of the three-component complex C60+AC960+PVP were analyzed in comparison with binary C60+PVP and C60+AC960. All complexes showed a low toxicity to cultured human skin fibroblasts and ECV lines, as well as significant antimicrobial activity, which depend on the type of microorganisms exposed, the chemical composition of the complex, its dosage and exposure time. Complex C60+PVP+AC960 at a concentration of 175 µg/mL showed the most stable and pronounced inhibitory microbicidal/microbiostatic effect.

VEGF-R2 and TNF-R1 expression and cytokine production by samples of mammary adenocarcinomas and correlations with histopathological parameters of these malignant tumors

Currently, the role of cytokines in the tumor progression, including breast cancer, is universally recognized. At the same time, there are still many questions concerning the role of individual cytokines and receptors for cytokines in various morphogenetic processes underlying the tumor progression. The objective of this work was to study cytokine production and vascular endothelial growth factor (VEGF)-R2 and VEGF-R1 expression by mammary adenocarcinoma (MAC) and the correlations with histopathological parameters of malignant tumors. The object of the study was cultured tumor biopsy samples from 47 women aged 43-75 years with invasive ductal carcinoma, which was classified as grade II-III adenocarcinoma. It was shown that the cytokine profiles of the supernatants of MAC samples from patients differ greatly. A correlation between the levels of VEGF-R2 and tumor necrosis factor (TNF)-R1 expression was observed. Correlations were also revealed during analysis of the relations of histopathological MAC indicators with KVEGF-R2/VEGF-A and KTNF-R1/TNF-α coefficients, which are equal, respectively, to the ratio of expression values of receptors VEGF-R2 and TNF-R1 to the concentrations of the relevant cytokines (VEGF-A and TNF-α) in the culture supernatants of the same MAC samples. A direct correlation was identified between KVEGF-R/VEGF-A and some histopathological MAC characteristics: proportion of cells undergoing mitosis or pathological mitosis in MAC and poorly differentiated cells. KVEGF-R2/VEGF-A directly correlated with the concentration in supernatant interleukin (IL)-18 and interferon (IFN)-γ. KTNF-R1/TNF-α was inversely correlated with the concentration in supernatant of IL-1Ra, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF). The data obtained show that the high-level production of IL-18 and IL-1β by MAC, overexpression of VEGF-R2 in tumor (at relatively low VEGF-A production), and the high level of IFN-γ production are attributed factors contributing to the formation of a population of low-grade cells in the tumor. The factors regulating the population of moderately differentiated cells in the tumor are referred to as IL-1Ra, IL-8, and GM-CSF.

Effects of polyclonal activators on cell differentiation and cytokine production of cultured invasive breast carcinoma of no special type, their association with tumour histopathological parameters and lymph node metastasis

Currently, a number of promising strategies and approaches to cancer treatment include differentiation therapy. However, theoretical and methodological foundations of this field are not yet well developed. The objective of this study was to determine the effects of a mixture of polyclonal activators (PAs; phytohaemagglutinin, concanavalin A and lipopolysaccharide) on cytokine production by biopsy samples of invasive breast carcinoma of no special type (IBC-NST) having various differentiation abilities and metastatic potentials as well as on differentiation status of the IBC-NST biopsy samples. We used ELISAs to investigate spontaneous and PA-stimulated cytokine production in the IBC-NST biopsy samples; from these data, we calculated a cytokine production stimulation index (SIPA). The effect of PAs on tumour cell differentiation was determined via a differentiation stimulation index (DSI). DSI was found to vary within the range 1.0-5.0. After treatment with PAs, in the IBC-NST biopsy samples of group I (DSI <1.25), the production of IL-2, IL-6, IL-8, IL-17, IL-18, IL-1β, IL-1Ra, TNF-α and GM-CSF increased; in the biopsy samples of group II (DSI >1.25), the production of IL-6, IL-1β, IL-1Ra, TNF-α, G-CSF and GM-CSF significantly increased, while the production of VEGF-A decreased. Receiver operating characteristic (ROC) analysis of SIPA revealed that increased production of IL-18 in the IBC-NST biopsy samples after exposure to PAs may block the PA-driven, cytokine-mediated differentiation of moderately differentiated into highly differentiated tumour cells. The ROC analysis also uncovered an association between the responses of tumour cells to PAs and lymph node metastasis observed in the patients. The findings suggest that there is a need for research aimed at finding new drugs for differentiating cancer therapy and at searching for targeted inducers of cytokine production or specific suppressors of their induction.

[Design of Guide RNA for CRISPR/Cas Plant Genome Editing]

CRISPR/Cas technology of genome editing is a powerful tool for making targeted changes in the DNA of various organisms, including plants. The choice of the precise nucleotide sequence (protospacer) in the gene to be edited is important in the design of guide RNA, which can be carried out by specialized software. We review and compare all the known on-line and off-line resources for guide RNA design, with special attention paid to tools capable of searching for off-target edits sites in plant genomes. The use of Cas12a may be preferable to Cas9. Techniques allowing C→T and G→A base editing without DNA cleavage are discussed along with the basic requirements for the design of effective and highly specific guide RNAs. Ways for improving guide RNA design software are presented. We also discuss the lesser risks of off-target editing in plant genomes as opposed to animal genomes. Examples of edited plant genomes including those that do not lead to the creation of transgenic plants are reviewed.

[Endogenous erythropoietin, acute kidney injury, and prognosis in patients with acute coronary syndrome]

AIM

To investigate the prognostic value of serum endogenous erythropoietin (EPO) in patients with acute coronary syndrome (ACS), including that in the development of acute kidney injury (AKI).

SUBJECTS AND METHODS

Eighty-four patients (46 men, 38 women; mean age 63 ± 11 years) with ACS were examined. Twenty-one (25%) patents were diagnosed with ECG ST-segment elevation acute myocardial infarction (STSEAMI), 12 (14%) had ECG non-STSEAMI, and 51 (61%) had unstable angina. Thrombolytic therapy was performed in 10 (48%) patients with STSEAMI. The patients whom had not undergone coronarography were included in the investigation to exclude the nephrotoxic effect of X-ray contrast agents.

RESULTS

AKI was observed in 7 of the patients with acute myocardial infarction and in only 1 of those with unstable angina. Four (5%) patients died during hospitalization. The EPO level of > 10.5 IU/ml predicted the development of AKI in the ACS patients with a sensitivity of 71% and a specificity of 67%. That of > 13.7 IU/ml was associated with hospital death in the ACS patients with a sensitivity of 100% and a specificity of 75% (AUC = 0.93%).

CONCLUSION

High serum EPO levels in an ACS patent during his hospital stay may serve as a biomarker for a high risk for AKI and high death rates.

[Endothelial damage and circadian blood pressure profile in rheumatoid arthritis]

AIM

To study the influence of the state of endothelium on the daily profile of arterial pressure (AP) in patients with rheumatoid arthritis (RA).

MATERIALS AND METHODS

In 70 RA pts carried out C-reactive protein (CRP), vascular endothelial adhesion molecule type 1 (sVCAM-1), antigen von Willebrand Factor (AG WF), interleukin-8 (Il-8), rheumatoid factor (RF), IgG, endotheline-1 (ET-1), number of desquamated endotheliocytes cells (DE), VS, activity of renin by immunoenzyme analysis. The dysfunction of endothelium was evaluated by calculation of DE. The functional methods included the daily monitoring of arterial pressure (AP).

RESULTS

Arterial hypertension (AH) occurred in 40 (57.1%) pts. RA pts are revealed the signs of endothelial dysfunction, about which significant differences among the indices of activation of endothelium in comparison with control group testify. ET-1, sVCAM-1, vWF AG, Il-8, CRP content was higher in RA pts. Reliably above there was a number of DE. Reliable differences according to these indices depending of RA activity were discovered. With conducting of correlation analysis it is revealed, that markers of the activation of endothelium: sVCAM-1, vWF AG positively correlated with increasing RF IgG and indices of the immune inflammation: CRP, and DE number. In patients suffering from RA, showed signs of endothelial dysfunction. The positive correlation between endothelial damage and daily profile of AP show the relationship of these processes.

CONCLUSION

Positive correlations between the damage of endothelium and disturbance of AP daily profile testify about the interrelation of these processes.

[Oxidative stress in focal symptomatic and cryptogenic epilepsy in young patients]

OBJECTIVE

To study oxidative stress in young patients with focal symptomatic and cryptogenic epilepsy and after the new-onset epileptic seizures.

MATERIAL AND METHODS

Patients, aged from 19 to 44 years, were distributed into three groups, 30 patients in each: patients after a few (first) epileptic seizures, patients in the clinical remission that has lasted at least one year, and patients with treatment-resistant epileptic seizures. The control group included 20 healthy people. Parameters of the pro-oxidant status (TBA-reactive products) and the antioxidant defense (total superoxide-scavenging activity, catalase, total antioxidant activity, and reduced thiols (SH groups)) were measured in the blood plasma.

RESULTS

No significant differences in the concentrations of TBA-reactive products were identified in patients with epilepsy compared with healthy controls while concentrations of reduced SH groups, total superoxide-scavenging activity, catalase activity and the total antioxidant activity were significantly decreased in patients. In addition, some of the parameters displayed significant differences between different groups of patients.

CONCLUSION

In patients with epilepsy, the changes in the free-radical processes are seen already after the first seizures and persist in the treatment-resistant epilepsy and in clinical remission. Since the parameters of the activity of the antioxidant defense are significantly different in different groups of patients, one can assume that different elements of the oxidative stress are present after the first epileptic seizures and in different courses of the disease.

Type 1 melanocortin receptors in pro-opiomelanocortin-, vasopressin-, and oxytocin-immunopositive neurons in different areas of mouse brain

Information on the localization of the Type 1 melanocortin receptors (MC1Rs) in different regions of the brain is very scarce. As a result, the role of MC1Rs in the functioning of brain neurons and in the central regulation of physiological functions has not been studied. This work aimed to study the expression and distribution of MС1Rs in different brain areas of female C57Bl/6J mice. Using real-time polymerase chain reaction, we demonstrated the Mс1R gene expression in the cerebral cortex, midbrain, hypothalamus, medulla oblongata, and hippocampus. Using an immunohistochemical approach, we showed the MС1R localization in neurons of the hypothalamic arcuate, paraventricular and supraoptic nuclei, nucleus tractus solitarius (NTS), dorsal hippocampus, substantia nigra, and cerebral cortex. Using double immunolabeling, the MC1Rs were visualized on the surface and in the bodies and outgrowths of pro-opiomelanocortin (POMC)-immunopositive neurons in the hypothalamic arcuate nucleus, NTS, hippocampal CA3 and CA1 regions, and cerebral cortex. Co-localization with POMC indicates that MC1R, like MC3R, is able to function as an autoreceptor. In the paraventricular and supraoptic nuclei, MC1Rs were visualized on the surface and in the cell bodies of vasopressin- and oxytocin-immunopositive neurons, indicating a relationship between hypothalamic MC1R signaling and vasopressin and oxytocin production. The data obtained indicate a wide distribution of MC1Rs in different areas of the mouse brain and their localization in POMC-, vasopressin- and oxytocin-immunopositive neurons, which may indicate the participation of MC1Rs in the control of many physiological processes in the central nervous system.

A Model of Short Bowel Syndrome in Rodents in a Long-Term Experiment

Simulation of short bowel syndrome (SBS) in experimental animals is of great interest for studies in translational medicine. The processes of intestinal adaptation are most often studied in rats aged 8-10 weeks with up to 70% resection the small bowel. In this case, the animals are euthanized in 2 weeks after the surgery; further development of the pathological process remains practically unexplored. In our experiment, a number of blood biochemical parameters and morphological signs of intestinal adaptation were assessed within 34 weeks after surgery. It was shown that after resection of 70% of the small bowel in rats (180±15 g), clinical symptoms are observed only during the first 2 weeks, however, the mortality in the group was observed throughout the entire period of the study in the absence of clear clinical signs. Morphological compensatory changes in the walls of the small intestine continued up to 34 weeks after resection, and their morphometry can be used to describe adaptation in the dynamics of the study.

CHARACTERISTICS OF AMYLOID DEPOSITS DETECTED IN THE INTERNAL ORGANS OF mdx MICE

The dystrophin-deficient mdx mouse is the most commonly used experimental model of Duchenne muscular dystrophy (DMD). Although the amyloid has been shown in the muscle biopsies of patients with different types of muscular dystrophies, there are no data on the amyloid accumulations in the biopsy of DMD patients or mdx mouse. Therefore, the aim of the present study was to testify the hypothesis of probable accumulation of amyloid in the visceral organs of mdx mouse. Specimens of myocardium, kidneys, and liver of male and female mdx mice aged from 2 months to 1.5 years (n = 9) were used in the study. The histochemical staining with Congo red demonstrated amyloid accumulations in the studied organs of the mdx mice. Morphology and localization of the found accumulations were described in details and analyzed. The mass-spectrometric study determined the vitronectin and apolipoprotein A-II as the most probable components of the amyloid accumulations in the mdx mouse.

[Pregnancy with Rh-isoimmunization. Results of a retrospective analysis in the maternity hospital "Maichin Dom"]

The aim of the study is to analyze the outcome of pregnancies complicated by Rh-isoimmunization for the period 1996-2001 and to outline the aspects of optimization of the obstetrical conduct.

MATERIAL AND METHODS

The current study includes 39 pregnant women with Rh-isoimmunisation to whom amniocentesis and cordocentesis was performed. All cases were analyzed using medical history, serology (indirect Coombs, PAP test), ultrasound examination, amniocentesis, cordocentesis, NST.

RESULTS

From 39 pregnancies, complicated by severe Rh-isoimmunization 36 resulted in a live delivery, 2 resulted in intrauterine death of the fetus and 1 in early neonatal death. The titre of the antibodies is of prognostical value only in the first isoimmunised pregnancy. In this case there is a reliable correlation between the condition of the newborn and the zone from the Liley curve, antenatally found. With history of former immune pregnancies with unfavourable perinatal outcome most precise information about the condition of the foetus gives the cordocentesis.

CONCLUSION

In all of the discussed cases the Rh-isoimmunization is a result of no andi-D immunoglobulin profilaxis post partum or following abortion. That is why the efforts should be directed towards conduction of proper profilaxis to all Rh-negative pregnant women.

Antibody to Endogenous Cardiotonic Steroid Reverses Vascular Fibrosis and Restores Vasorelaxation in Chronic Kidney Disease

Marinobufagenin (MBG) is implicated in chronic kidney disease, where it removes Fli1-induced inhibition of the collagen-1. We hypothesized that (i) in nephrectomized rats, aortic fibrosis develops due to elevated plasma MBG and inhibited Fli1, and (ii) that the antibody to MBG reduces collagen-1 and improves vasodilatation. A partial nephrectomy was performed in male Sprague-Dawley rats. Sham-operated animals comprised the control group. At 5 weeks following nephrectomy, rats were administered the vehicle (n = 8), or the anti-MBG antibody (n = 8). Isolated aortic rings were tested for their responsiveness to sodium nitroprusside following endothelin-1-induced constriction. In nephrectomized rats, there was an increase in the intensity of collagen staining in the aortic wall vs. the controls. In antibody-treated rats, the structure of bundles of collagen fibers had ordered organization. Western blots of the aorta had lower levels of Fli1 (arbitrary units, 1 ± 0.05 vs. 0.2 ± 0.01; p < 0.001) and greater collagen-1 (arbitrary units, 1 ± 0.01 vs. 9 ± 0.4; p < 0.001) vs. the control group. Administration of the MBG antibody to rats reversed the effect of the nephrectomy on Fli1 and collagen-1 proteins. Aortic rings pretreated with endothelin-1 exhibited 50% relaxation following the addition of sodium nitroprusside (EC50 = 0.28 μmol/L). The responsiveness of the aortic rings obtained from nephrectomized rats was markedly reduced (EC50 = 3.5 mol/L) compared to the control rings. Treatment of rats with the antibody restored vasorelaxation. Thus, the anti-MBG antibody counteracts the Fli1-collagen-1 system and reduces aortic fibrosis.

Fli1 and Tissue Fibrosis in Various Diseases

Being initially described as a factor of virally-induced leukemias, Fli1 (Friend leukemia integration 1) has attracted considerable interest lately due to its role in both healthy physiology and a variety of pathological conditions. Over the past few years, Fli1 has been found to be one of the crucial regulators of normal hematopoiesis, vasculogenesis, and immune response. However, abnormal expression of Fli1 due to genetic predisposition, epigenetic reprogramming (modifications), or environmental factors is associated with a few diseases of different etiology. Fli1 hyperexpression leads to malignant transformation of cells and progression of cancers such as Ewing's sarcoma. Deficiency in Fli1 is implicated in the development of systemic sclerosis and hypertensive disorders, which are often accompanied by pronounced fibrosis in different organs. This review summarizes the initial findings and the most recent advances in defining the role of Fli1 in diseases of different origin with emphasis on its pro-fibrotic potential.