Protective effect of exogenous peroxiredoxin 6 and thymic peptide thymulin on BBB conditions in an experimental model of multiple sclerosis.

This study aimed to assess the effects of the immunomodulator thymulin, a thymic peptide with anti-inflammatory effects, and peroxiredoxin 6 (Prdx6), an antioxidant enzyme with dual peroxidase and phospholipase A2 activities, on the blood‒brain barrier (BBB) condition and general health status of animals with relapsing-remitting experimental autoimmune encephalomyelitis (EAE), which is a model of multiple sclerosis in humans. Both thymulin and Prdx6 significantly improved the condition of the BBB, which was impaired by EAE induction, as measured by Evans blue dye accumulation, tight-junction protein loss in brain tissue, and lymphocyte infiltration through the BBB. The effect was associated with significant amelioration of EAE symptoms. Thymulin treatment was accompanied by a decrease in immune cell activation as judged by interleukin-6, -17, and interferon-gamma cytokine levels in serum and NF-kappaB cascade activation in splenocytes of mice with EAE. Prdx6 did not induce significant immunomodulatory effects but abruptly decreased EAE-induced NOX1 and NOX4 gene expression in brain tissue, which may be one of the possible mechanisms of its beneficial effects on BBB conditions and health status. The simultaneous administration of thymulin and Prdx6 resulted in complete symptomatic restoration of mice with EAE. The results demonstrate prospective strategies for multiple sclerosis treatment.

Protective Effect of PBCA Nanoparticles Loaded with Thymulin Against the Relapsing-Remitting Form of Experimental Autoimmune Encephalomyelitis in Mice.

Relapsing-remitting experimental autoimmune encephalomyelitis (rEAE) in mice is a model that closely resembles relapsing-remitting multiple sclerosis in humans. This study aims to investigate a new approach to modulation of the inflammatory response in rEAE mice using a thymic peptide thymulin bound to polybutylcyanoacrylate (PBCA) nanoparticles. PBCA nanoparticles were used to prolong the presence of thymulin in the blood. Cytokine levels in blood were measured by ELISA; NF-κB and SAPK/JNK cascade activation, as well as Hsp72 and p53 protein expression, were measured by Western blotting. Animal health statuses were estimated using severity scores. Results showed that the cytokine response in rEAE was multi-staged: an early phase was accompanied by an increase in plasma interferon-γ, while the interleukin (IL)-17 response was markedly increased at a later stage. The stages were attributed to rEAE induction and maintenance phases. Thymulin significantly alleviated symptoms of rEAE and lowered plasma cytokine levels both in early and later stages of rEAE, and decreased NF-κB and SAPK/JNK cascade activation. Thymulin modulated NF-kappaB pathway activity via site-specific phosphorylation of RelA/p65 protein (at Ser276 and Ser536). The effect of nanoparticle-bound thymulin was more pronounced than the effect of free thymulin. Therefore, PBCA-thymulin can be considered a prospective treatment for this pathology.

[The influence of the thymus peptides on analgesia caused by acute and chronic immobilization].

OBJECTIVE: Our aim was to investigate the influence of thymic polypeptides on pain sensitivity and to analyze a possible role of the opioid system in the implementation of the analgesia caused by immobilization stress. METHODS: The study was performed on male Wistar rats at the Moscow state University named after M. V. Lomonosov. We studied effects of thymus peptides: thymuline (0.15 mg/kg), fraction 5 thymosin (0.25 microgram/kg) and cattle thymus extracted product (CTEP) (0.5 mg/kg) on pain sensitivity in rats using test "tail flick" without stress, with acute (3 h) and sub acute (12 h) immobilization stress. The comparison groups were animals treated with saline and spleen polypeptides. RESULTS: It is shown that preparations of thymus increase the threshold of pain sensitivity in the intact animals. Immobilization stress duration 3 and 12 h in thymus peptides treated rats caused a less pronounced increase in pain threshold than in the control groups (immobilization stress 3 h: CTEP--p = 0.025, thymuline--p = 0.022, fraction 5 thymosin--p = 0.033; immobilization stress 12 h: CTEP--p = 0.034, thymuline--p = 0.027, fraction 5 thymosin--p = 0.036). The opioid receptor blocker naloxone (1 mg/kg) did not completely block the stress-induced analgesia, indicating the presence of both opioid and non -opioid components in this state. In thymus peptides treated rats, opioid component was less pronounced than in the control groups (CTEP--p = 0.031, thymuline--p = 0.026, fraction 5 thymosin--p = 0.029). CONCLUSION: Pre-activation of the opioid system by the thymus polypeptides leads to an increase in the share of non-opioid component of the stress-induced analgesia and prevents the depletion of the opioid system in immobilization stress.

Anti-inflammatory effects of IKK inhibitor XII, thymulin, and fat-soluble antioxidants in LPS-treated mice.

The present study was designed to compare the anti-inflammatory effects of several agents applied in vivo, namely, a synthetic inhibitor of the NF-κB cascade, fat-soluble antioxidants, and the thymic peptide thymulin. Cytokine response in LPS-treated mice was analysed in tandem with the following parameters: the synthesis of inducible forms of the heat shock proteins HSP72 and HSP90α; activity of the NF-κB and SAPK/JNK signalling pathways; and TLR4 expression. Inflammation-bearing Balb/c male mice were pretreated with an inhibitor of IKK-α/ß kinases (IKK Inhibitor XII); with thymulin; with dietary coenzyme Q9, α-tocopherol, and ß-carotene; or with combinations of the inhibitor and peptide or antioxidants. Comparable anti-inflammatory effects were observed in inflammation-bearing mice treated separately with thymulin or with dietary antioxidants administered daily for two weeks before LPS treatment. When LPS-injected mice were treated with the inhibitor and antioxidants together, neither plasma cytokines, signal proteins, nor heat shock proteins recovered more efficiently than when mice were treated with these agents separately. In contrast to antioxidant diet, the thymulin was shown to increase the effect of IKK Inhibitor XII in preventing IKK activation in LPS-treated mice.

[The impact of immunoactive drugs on passive avoidance response].

AIM: The objective of this project was to explore the influence of immunoactive drugs (tactivin, thymulin, and thymosin fraction 5) on the development of the passive avoidance conditioned reflex. MATERIALS AND METHODS: Two types of passive avoidance boxes were used--a regular two-chamber box and a modified three-chamber box, comprising a dark chamber in which rats were exposed to electrical shock, a safe dark chamber, and a light chamber in the center. RESULTS: The project has established that the memory trace persists longer under the influence of the immunoactive drugs in both models, which is consistent with the reference nootropic piracetam test results. Notably, the immunoactive drugs' mnemotropic effect was more pronounced in the modified three-chamber box than in the standard two-chamber box. Using the modified box helped to establish the influence of tactivin, thymulin, and thymosin fraction 5 on the spatial memory component. Immunotropic preparations from thymus caused the animals to select the safe chamber 24 hours later and in subsequent tests. CONCLUSION: The project's results indicate that the drugs tested do possess mnemotropic properties, so their range of clinical use can be broadened.

Development of broiler chickens after treatment with thymulin 5cH: a zoo technical approach.

Modulation of immune response due to thymulin 5cH has been previously observed. The aim of the present study is to evaluate the development of broiler chickens treated with thymulin 5cH by conventional zoo technical indices, phytohemaglutinin induced inflammation test and histomorphometric analysis of lymphoid organs (thymus, Fabricius bursa and spleen). Animals were divided in two groups: (a) test: birds with free access to thymulin 5cH diluted into the drink water and (b) control: birds with free access to water only, from the 1st to the 42nd day of life. All experimental procedures were done in blind. The results show that thymulin 5cH treated group had increased productivity index compared to control (391.45 versus 261.93) associated with higher viability in the 7th week (p = 0.013), and a possible shunt to B lymphocyte activity. The data suggest that thymulin 5cH could be a viable method to improve productivity in poultry production due to its immune modulation properties.

Thymulin and peroxiredoxin 6 have protective effects against streptozotocin-induced type 1 diabetes in mice.

Protective effects of peroxiredoxin 6 (PRDX6) in RIN-m5F ß-cells and of thymulin in mice with alloxan-induced diabetes were recently reported. The present work was aimed at studying the efficiency of thymulin and PRDX6 in a type 1 diabetes mellitus model induced by streptozotocin in mice. Effects of prolonged treatment with PRDX6 or thymic peptide thymulin on diabetes development were evaluated. We assessed the effects of the drugs on the physiological status of diabetic mice by measuring blood glucose, body weight, and cell counts in several organs, as well as effects of thymulin and PRDX6 on the immune status of diabetic mice measuring concentrations of pro-inflammatory cytokines in blood plasma (TNF-α, interleukin-5 and 17, and interferon-γ), activity of NF-κB and JNK pathways, and Hsp90α expression in immune cells. Both thymulin and PRDX6 reduced the physiological impairments in diabetic mice at various levels. Thymulin and PRDX6 provide beneficial effects in the model of diabetes via very different mechanisms. Taken together, the results of our study indicated that the thymic peptide and the antioxidant enzyme have anti-inflammatory functions. As increasing evidences show diabetes mellitus as a distinct comorbidity leading to acute respiratory distress syndrome and increased mortality in patients with COVID-19 having cytokine storm, thymulin, and PRDX6 might serve as a supporting anti-inflammatory treatment in the therapy of COVID 19 in diabetic patients.

Nanoparticle-based thymulin gene therapy therapeutically reverses key pathology of experimental allergic asthma.

Despite long-standing efforts to enhance care for chronic asthma, symptomatic treatments remain the only option to manage this highly prevalent and debilitating disease. We demonstrate that key pathology of allergic asthma can be almost completely resolved in a therapeutic manner by inhaled gene therapy. After the disease was fully and stably established, we treated mice intratracheally with a single dose of thymulin-expressing plasmids delivered via nanoparticles engineered to have a unique ability to penetrate the airway mucus barrier. Twenty days after the treatment, we found that all key pathologic features found in the asthmatic lung, including chronic inflammation, pulmonary fibrosis, and mechanical dysregulation, were normalized. We conducted tissue- and cell-based analyses to confirm that the therapeutic intervention was mediated comprehensively by anti-inflammatory and antifibrotic effects of the therapy. We believe that our findings open a new avenue for clinical development of therapeutically effective gene therapy for chronic asthma.

Thymulin inhibits monocrotaline-induced pulmonary hypertension modulating interleukin-6 expression and suppressing p38 pathway.

The pathogenesis of pulmonary hypertension (PH) includes an inflammatory response. Thymulin, a zinc-dependent thymic hormone, has important immunobiological effects by inhibiting various proinflammatory cytokines and chemokines. We investigated morphological and hemodynamic effects of thymulin administration in a rat model of monocrotaline (MCT)-induced PH, as well as the pattern of proinflammatory cytokine gene expression and the intracellular pathways involved. Adult Wistar rats received an injection of MCT (60 mg/kg, sc) or an equal volume of saline. One day after, the animals randomly received during 3 wk an injection of saline, vehicle (zinc plus carboxymethyl cellulose), or thymulin (100 ng/kg, sc, daily). At d 23-25, the animals were anesthetized for hemodynamic recordings, whereas heart and lungs were collected for morphometric and molecular analysis. Thymulin prevented morphological, hemodynamic, and inflammatory cardiopulmonary profile characteristic of MCT-induced PH, whereas part of these effects were also observed in MCT-treated animals injected with the thymulin's vehicle containing zinc. The pulmonary thymulin effect was likely mediated through suppression of p38 pathway.

Thymulin, free or bound to PBCA nanoparticles, protects mice against chronic septic inflammation.

In the present work, we aimed to study the effects of free and polybutylcyanoacrylate nanoparticle-bound thymulin on immune cell activity in mice with chronic inflammation. NF-κB, MAPK, and PKC-θ signaling pathway activity was assessed, alongside Hsp72, Hsp90-α, and TLR4 expression and levels of apoptosis. In addition, plasma cytokines and blood and brain melatonin and serotonin levels were measured. In mice treated with gradually raised doses of lipopolysaccharide, significant increases in the activity of the signaling pathways tested, heat-shock protein and TLR4 expression, lymphocyte apoptosis, and plasma proinflammatory cytokine levels were noted. Moreover, we observed significantly heightened serotonin concentrations in the plasma and especially the brains of mice with inflammation. In contrast, melatonin levels were reduced in the tissues examined, particularly so in the brain. Treatment of these mice with thymulin alleviated fever, reduced apoptosis, increased splenic cell number, and decreased cytokine production, Hsp72, Hsp90, and TLR4 expression, and the activity of the signaling pathways examined. In addition, thymulin partially restored brain and blood serotonin and melatonin levels. Thus, thymulin suppressed the proinflammatory response in LPS-treated mice, indicating the potential of thymulin co-therapy in the treatment of sepsis. Nanoparticle-bound thymulin was more effective in several respects.

[Thymic factors influence on melatonin-producing pineal function in mice of different age: the possible mechanisms].

The aging peculiarities of thymic factors influence on pineal gland function in CBA mice were investigated. Significant increase of melatonin serum level in 3 h and decrease in 24 h after one injection of thymic preparation "thymalin" in adult mice was shown. The activating influence of thymalin was depended on season and linked with increase of thymic serum factor (FTS, thymulin) level and decrease of corticosterone blood level. Thymic stroma supernatant of adult mice, which had high level of FTS, intensified in vitro melatonin-producing pineal function. The activating influence of thymic factors in vivo and in vitro on pineal function in old mice was not revealed. FTS content increased and cortocosterone level did not change in old mice after injection of thymalin. The mechanisms of thymic factors influence on melatonin level in adult organism and their peculiarities in aging were discussed.

Signaling, stress response and apoptosis in pre-diabetes and diabetes: restoring immune balance in mice with alloxan-induced type 1 diabetes mellitus.

The aim of this study was to compare immune imbalances in "pre-diabetic" and diabetic mice and to evaluate the efficacy of several agents in improving the immunity of mice with type 1 diabetes. Pre-diabetic and diabetic models generated by a single or double alloxan injection were monitored for plasma glucose and pancreas immunohistochemistry. To study the immunity in pre-diabetic and diabetic Balb/C male mice; the levels of cytokines; synthesis of inducible heat shock proteins HSP72 and HSP90α; activity of the NF-κB, IFR3, SAPK/JNK, and TLR4 pathways; and apoptosis levels in thymuses were measured. Pre-diabetes resulted in a decrease in IL-4, IL-5 and IL-10 in plasma; in diabetic mice, plasma IFN-gamma, IL-6, TNF-alpha, and IL-10 were decreased. The NF-κB alternative pathway activity and TLR4 expression were significantly increased only in pre-diabetic mice, whereas SAPK/JNK activation was observed at both stages of diabetes. Other measured parameters also showed distinct altered patterns in the immunity of pre-diabetic and diabetic mice. Treatment with an inhibitor of NF-κB, thymulin, or a diet with an antioxidant improved or normalized the immune balance in diabetic mice and also notably decreased pancreatic cell damage in pre-diabetic mice.

Serum thymic factor, FTS, attenuates cisplatin nephrotoxicity by suppressing cisplatin-induced ERK activation.

Serum thymic factor (FTS), a thymic peptide hormone, has been reported to attenuate the bleomycin-induced pulmonary injury and also experimental pancreatitis and diabetes. In the present study, we investigated the effect of FTS on cis-diamminedichloroplatinum II (cisplatin)-induced nephrotoxicity. We have already demonstrated that cephaloridine, a nephrotoxic antibiotic, leads to extracellular signal-regulated protein kinase (ERK) activation in the rat kidney, which probably contributes to cephaloridine-induced renal dysfunction. The aim of this study was to examine the effect of cisplatin on ERK activation in the rat kidney and also the effect of FTS on cisplatin-induced nephrotoxicity in rats. In vitro treatment of LLC-PK1 cells with FTS significantly ameliorated cisplatin-induced cell injury. Treatment of rats with intravenous cisplatin for 3 days markedly induced renal dysfunction and increased platinum contents in the kidney cortex. An increase in pERK was detected in the nuclear fraction prepared from the rat kidney cortex from days 1 to 3 after injection of cisplatin. FTS suppressed cisplatin-induced renal dysfunction and ERK activation in the kidney. FTS did not influence any Pt contents in the kidney after cisplatin administration. FTS has been shown to enhance the in vivo expression of heat shock protein (HSP) 70 in the kidney cortex. The beneficial role of FTS against cisplatin nephrotoxicity may be mediated in part by HSP70, as suggested by its up-regulation in the kidney cortex treated with FTS alone. Our results suggest that FTS participates in protection from cisplatin-induced nephrotoxicity by suppressing ERK activation caused by cisplatin.

Augmentation with serum thymic factor of suppressive effects on retroviral tumor development in hosts immune to v-onc product.

Inbred adult female rats were immunized against syngeneic ST-FeSV induced sarcoma cells. ST-FeSV was injected subcutaneously into 57 neonates (vaccinated) born from these immunized females and into 60 non-vaccinated syngeneic neonates. Serum thymic factor (FTS) was injected subcutaneously into 10 of vaccinated and 30 of non-vaccinated rats. Sarcomas developed in 40.4% (19/47) of vaccinated (A), 20.0% (2/10) of vaccinated FTS injected (B), 63.3% (19/30) of non-vaccinated FTS injected (C), and 76.7% (23/30) of non-treated (D) rats. By AB immunostaining using antibody to v-fes product (P85), sarcomas developed in 10 of 13 rats of group C tested, and 3 of 6 rats of group D tested were positive, but those in 7 rats of group A and 2 rats of group B tested were all negative. Lung metastasis was observed in rats of all groups except those of B group. All sera of animals that developed sarcomas were positive to P85 in Western blot analysis. These results showed that FTS augmented suppressive effects on sarcoma development in hosts immune to the viral oncogene product.

Two different mechanisms for the inhibition of rosette formation in mice.

The vast majority of spleen T cells (T.sRFC) which spontaneously bind to sheep red blood cells (SRBC) in an antigen-specific fashion express the Thy-1+, CD3+, CD8+ phenotype. Inhibition of rosetting by antibodies to surface molecules occurs via distinct mechanisms according to the antibody. CD8 and CD3 molecules are located in proximity to SRBC receptors and steric hindrance is the most likely explanation for the inhibition of rosetting by antibodies to these molecules. On the other hand, anti-Thy-1 antibody bound to T.sRFC induces a dynamic process involving intracellular cAMP, and which results in the inaccessibility of SRBC receptors. Thymulin could restore normal sensitivity of T.sRFC from adult thymectomized (A.Tx) mice to all inhibitory antibodies whatever the mechanism by which they hinder rosette formation. These results reinforce the idea that thymulin may act on membrane characteristics.

Modulation of inflammatory response in mice with severe autoimmune disease by thymic peptide thymulin and an inhibitor of NF-kappaB signalling.

To investigate some cellular and molecular aspects of the autoimmune response and anti-inflammatory efficiency of potential therapeutic agents in a severe form of experimental autoimmune encephalomyelitis (sEAE), an inhibitor of NF-kappaB signalling, IKK Inhibitor XII, and/or thymic peptide thymulin, were injected intraperitoneally at 1.8 and 0.15mg/kg e.o.d, respectively, to C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein and several adjuvants. The immunization induced high lethality in three weeks. The biphasic cytokine response observed in earlier and delayed phases was attributed to the activity of Th1 and Th17 cells, respectively. Phosphorylation of RelA protein from the NF-kappaB family increased during the earlier phase and decreased in the delayed phase. SAPK/JNK signalling protein and heat shock protein Hsp72 significantly increased in lymphocytes. Both the IKK Inhibitor XII and thymulin reduced disease severity, attenuated immune imbalance, and increased mouse life-span. Co-administration of the agents produced no additive effect. Both the inhibitor and thymulin reduced the Th1 response but not the Th17 response. Therefore, RelA-associated Th1 activation and RelA-independent Th17 activation occurred in sEAE. Thymulin and the inhibitor demonstrate similar patterns of activity, potentially through the RelA pathway inhibition, resulting in a partial therapeutic effect on the animals' health status.

Differential regulation of apoptosis in AK-5 tumor cells by the proto-oncogene Bcl-2: presence of Bcl-2 dependent and independent pathways.

The anti-apoptotic protein Bcl-2 functions as a crucial negative regulator of apoptosis. Bcl-2 has been shown to prevent the efflux of apoptogenic factors from mitochondria to cytosol, thus inhibiting cell death. Here, we show the susceptibility of a spontaneously regressing, rat histiocytic tumor cell line, AK-5, to the apoptotic effects of diverse stimuli and the ability of Bcl-2 overexpression to block cell death. Bcl-2 overexpression selectively inhibits apoptosis induced by ceramide and serum factor from AK-5 tumor regressing animals but not actinomycin D and curcumin, whereas the pancaspase inhibitor z-Val-Ala-Asp fluoromethylketone completely blocks apoptosis, irrespective of the inducer used. The ability of Bcl-2 overexpression to block cell death does not depend on its ability to prevent cytochrome c release but correlates with its ability to prevent the dissipation of mitochondrial transmembrane potential. The results demonstrate that there are inducer dependent redundant activation pathways in a single cell, which may either be Bcl-2 dependent or independent.

In vitro lymphocyte-differentiating effects of thymulin (Zn-FTS) on lymphocyte subpopulations of severely malnourished children.

This work investigates how thymic dysfunction contributes to the depression of cell-mediated immunity in protein-energy malnutrition (PEM). In Bolivian children hospitalized for severe PEM, the size of the thymus was measured by echography, and the lymphocyte subpopulations were detected by using monoclonal antibodies. These data were compared with those obtained from healthy control subjects. Regardless of the clinical form of PEM, our results show a high degree of T lymphocyte immaturity in severely malnourished children, which correlates with a severe involution of the thymus. Before in vitro incubation with thymulin, this significant increase in the percentage of circulating immature T lymphocytes was concomitant with a decrease in mature T lymphocytes and a slight increase in cytotoxic T subpopulations. After in vitro incubation with thymulin, immature T lymphocytes decreased and mature T lymphocytes increased.

Thymic factor-induced reduction of pulmonary metastases in mice with FSA-1 fibrosarcoma.

The biological activities of two thymic factors, serum thymic factor thymulin normally present in serum and thymosin alpha-1 (Ta-1) extracted from the thymus gland, have been studied. The effects of the factors on the growth of pulmonary metastases and survival of mice were evaluated in pathogen-free C3H/fSed males. Mice were injected i.v. with the single cell suspension of the syngeneic methylcholanthrene-induced fibrosarcoma. The treatment with thymulin and Ta-1 started two days after injection of 5 x 10(4) to 2 x 10(5) tumor cells per mouse. Different doses of the thymic factors were administered S.C. in sets of 5 daily injections through a period of 2 or 3 weeks. Numbers of tumor colonies in the lung were determined two weeks after the cell injection. Treatment with 0.1 micrograms Ta-1 per injection through the period of two or three weeks, prolonged the survival of tumor-injected mice. Similar effects were observed in mice treated with 0.01 microgram thymulin per injection. Numbers of tumor colonies in lungs of these mice two weeks after the cell injection were also reduced in comparison with saline-treated controls. These findings correlated with prolonged survival time of identically treated mice. The effectiveness of thymic factors in reducing tumor growth was dependent on the tumour load. In addition, the effects induced by Ta-1 persisted longer than observed in thymulin-treated mice. Mice challenged 150 days after the primary tumor cell injection and treatment with Ta-1 demonstrated increased resistance to tumor, while mice treated with other factors behaved as saline-treated controls. The results indicate that both factors exert beneficial effects against tumor growth, although mode of action for each factor may be different.