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.

Comparison of Thymulin Activity with Other Measures of Marginal Zinc Deficiency

Activity of the immunoregulatory peptide thymulin reflects differences in zinc status. This study compared thymulin activity with four other zinc status measures in rats fed zinc at either 5 or 25 ppm. Rats fed the lower zinc showed the following results compared with rats with adequate zinc intake: serum thymulin activity 61% lower, serum zinc 31% lower, serum extracellular superoxide dismutase 18% lower, serum 5'-nucleotidase activity 26% lower, and liver metallothionein 28% lower. Thus, thymulin activities showed more sensitivity to restricted zinc intake than did four other parameters.

Thymulin treatment attenuates inflammatory pain by modulating spinal cellular and molecular signaling pathways

Thymulin is a peptide hormone which is mainly produced by thymic epithelial cells and it has immune-modulatory and anti-inflammatory effects. In this study, we investigated the effects of different doses and various timings of thymulin intraperitoneal administration on spinal microglial activity and intracellular pathways in an inflammatory rat model of Complete Freund's adjuvant (CFA). Thymulin treatment was implemented following CFA-induced inflammation for 21 days. After conducting behavioral tests (edema and hyperalgesia), the cellular and molecular aspects were examined to detect the thymulin effect on inflammatory factors and microglial activity. We demonstrated that thymulin treatment notably reduced thermal hyperalgesia and paw edema induced by CFA. Furthermore, molecular investigations showed that thymulin reduced CFA-induced activation of microglia cells, phosphorylation of p38 MAPK and the production of spinal pro-inflammatory cytokines (TNF-α, IL-6) during the study. Our results suggest that thymulin treatment attenuates CFA-induced inflammation. This effect may be mediated by inhibition of spinal microglia and production of central inflammatory mediators which seems to be associated with the ability of thymulin to reduce p38 MAPK phosphorylation. These data provide evidence of the anti-hyperalgesic effect of thymulin on inflammatory pain and characterize some of the underlying spinal mechanisms.

A new adenovector system for implementing thymulin gene therapy for inflammatory disorders

Thymulin is a thymic peptide possessing anti-inflammatory effects. In order to manipulate thymulin expression in gene therapy studies, we built a bidirectional regulatable two-vector Tet-Off system and the corresponding control system. The experimental two-vector system, ETV, consists of a recombinant adenovector (RAd) harboring an expression cassette centered on a Tet-Off bidirectional promoter flanked by a synthetic gene for thymulin and the gene for humanized Green Fluorescent Protein (hGFP). The second adenovector of this system, RAd-tTA, constitutively expresses the regulatory protein tTA. When cells are co-transduced by the two adenovector components, tTA activates the bidirectional promoter and both transgenes are expressed. In the presence of the antibiotic doxycycline (DOX) transgene expression is deactivated. The control two-vector system, termed CTV, is similar to ETV but only expresses hGFP. In CHO-K1, BHK, and C2C12 cells, ETV and CTV induced a dose-dependent hGFP expression. In CHO-K1 cells, transgene expression was almost completely inhibited by DOX (1mg/ml). After intracerebroventricular injection of ETV in rats, thymulin levels increased significantly in the cerebrospinal fluid and there was high hGFP expression in the ependymal cell layer. When injected intramuscularly the ETV system induced a progressive increase in serum thymulin levels, which were inhibited when DOX was added to the drinking water. We conclude that our regulatable two-adenovector system is an effective molecular tool for implementing short and long-term anti-inflammatory thymulin gene therapy in animal models of acute or chronic inflammation.

Homeopathic treatments modify inflammation but not behavioral response to influenza antigen challenge in BALB/c mice

BACKGROUND

Influenza affects thousands of people worldwide every year, motivating the development of new therapies. In this work, the effects of two homeopathic preparations (influenza biotherapies and thymulin) were chosen following two different rationales: isotherapy and endo-isotherapy models. The homeopathic effects were evaluated individually considering the inflammatory and behavioral responses against influenza virus antigen were studied in BALB/c mice.

METHODS

Male adult mice were treated orally and blindly for 21 days with highly diluted influenza virus or with thymulin, and were divided in two sets of experiments. The first series of experiments aimed to describe their behavior, using an open field (OF) device. In the second series, mice were challenged subcutaneously with influenza hemagglutinin antigen (7 μg/200 μl) at day 21. At day 42, behavior and inflammation response were evaluated.

RESULTS

No behavioral changes were seen in OF tests at any time point after treatments. Flow cytometry and morphometry revealed significant changes in T and B cell balance after influenza antigen challenge, varying according to treatment.

CONCLUSION

The results show that both homeopathic treatments induced subtle changes in acquired immune anti-viral response regulation. A deeper understanding of the mechanism could elucidate their possible use in influenza epidemiological situations.

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.

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.

Modulation of inflammation response to murine cutaneous Leishmaniosis by homeopathic medicines: thymulin 5cH

BACKGROUND

In previous studies, we observed that thymulin 5cH could modulate BCG (Bacillus Calmette-Guerin) induced chronic inflammation by increasing peritoneal B1 stem cells differentiation into phagocytes and improving phagocytosis efficiency.

METHODS

We used the same protocol to study the effects of thymulin 5cH in the experimental murine Leishmaniasis, in order to elucidate some aspects of the parasite-host relation under this homeopathic treatment. Male Balb/c mice were orally treated with thymulin 5cH or vehicle during 60 days, after the subcutaneous inoculation of 2 × 10(6) units of Leishmania (L.) amazonensis into the footpad. Washied inflammatory cell suspension from peritoneal cavity, spleen, local lymph node and infected subcutaneous tissue were harvested after 2 and 60 days from infection to quantify the inflammation cells by flow cytometry and histometry methods.

RESULTS

After a transitory increase of peritoneal T reg cells, treated mice presented, chronically, increase in the peritoneal and spleen B1 cells percentage (p = 0.0001) in relation to other cell types; more organized and exuberant inflammation response in the infection site, and decrease in the number of parasites per field inside the primary lesion (p = 0.05). No difference was seen in local lymph node histology.

CONCLUSIONS

Thymulin 5cH is able to improve B1 cell activation and Leishmania (L) amazonensis phagocytosis efficiency in mice, similarly to that observed previously in BCG experimental infection.

DNA nanoparticle-mediated thymulin gene therapy prevents airway remodeling in experimental allergic asthma

Thymulin has been shown to present anti-inflammatory and anti-fibrotic properties in experimental lung diseases. We hypothesized that a biologically active thymulin analog gene, methionine serum thymus factor, delivered by highly compacted DNA nanoparticles may prevent lung inflammation and remodeling in a mouse model of allergic asthma. The DNA nanoparticles are composed of a single molecule of plasmid DNA compacted with block copolymers of poly-L-lysine and polyethylene glycol (CK30PEG), which have been found safe in a human phase I/II clinical trial. Thymulin plasmids were detected in the lungs of ovalbumin-challenged asthmatic mice up to 27days after administration of DNA nanoparticles carrying thymulin plasmids. A single dose of DNA nanoparticles carrying thymulin plasmids prevented lung inflammation, collagen deposition and smooth muscle hypertrophy in the lungs of a murine model of ovalbumin-challenged allergic asthma, leading to improved lung mechanics. In the present model of chronic allergic asthma, highly compacted DNA nanoparticles using thymulin analog gene modulated the inflammatory and remodeling processes improving lung mechanics.