Immunopotentiator Thymosin Alpha-1 Promotes Neurogenesis and Cognition in the Developing Mouse via a Systemic Th1 Bias

Th22 is the effector cell of thymosin β15-induced hair regeneration in mice

BACKGROUND

Thymosin beta family has a significant role in promoting hair regeneration, but which type of T cells play a key role in this process has not been deeply studied. This research aimed to find out the subtypes of T cell that play key role in hair regeneration mediated by thymosin beta 15 (Tβ15).

METHODS

Ready-to-use adenovirus expressing mouse Tmsb15b (thymosin beta 15 overexpression, Tβ15 OX) and lentivirus-Tβ15 short hairpin RNA (Tβ15 sh) were used to evaluate the role of Tβ15 in hair regeneration and development. The effect of Th22 cells on hair regeneration was further studied by optimized Th22-skewing condition medium and IL-22 binding protein (IL-22BP, an endogenous antagonist of IL-22, also known as IL-22RA2) in both ex vivo culture C57BL/6J mouse skin and BALB/c nude mice transplanted with thymus organoid model.

RESULTS

The results show that Tβ15, the homologous of Tβ4, can promote hair regeneration by increasing the proliferation activity of hair follicle cells. In addition, high-level expression of Tβ15 can not only increase the number of Th22 cells around hair follicles but also accelerate the transformation of hair follicles to maturity. Consistent with the expected results, when the IL-22BP inhibitor was used to interfere with Th22, the process of hair regeneration was blocked.

CONCLUSIONS

In conclusion, Th22 is the key effector cell of Tβ15 inducing hair regeneration. Both Tβ15 and Th22 may be the potential drug targets for hair regeneration.

Thymosin α-1 in cancer therapy: Immunoregulation and potential applications

Thymosin α-1 (Tα-1) is an immunomodulating polypeptide of 28 amino acids, which was the first peptide isolated from thymic tissue and has been widely used for the treatment of viral infections, immunodeficiencies, and especially malignancies. Tα-1 stimulates both innate and adaptive immune responses, and its regulation of innate immune cells and adaptive immune cells varies under different disease conditions. Pleiotropic regulation of immune cells by Tα-1 depends on activation of Toll-like receptors and its downstream signaling pathways in various immune microenvironments. For treatment of malignancies, the combination of Tα-1 and chemotherapy has a strong synergistic effect by enhancing the anti-tumor immune response. On the basis of the pleiotropic effect of Tα-1 on immune cells and the promising results of preclinical studies, Tα-1 may be a favorable immunomodulator to enhance the curative effect and decrease immune-related adverse events of immune checkpoint inhibitors to develop novel cancer therapies.

Potential anti neuro-inflammatory effect of BioCen-128 in animal models of dementia

Background

BioCen‐128 is a new active pharmaceutical ingredient composed of a specific bovine thymic fraction of a polypeptide nature. Positive results of similar thymus extracts have been shown to be effective in delaying the processes associated with aging, immunosenescence and Alzheimer's disease (AD), where the inflammation plays an important role. Because of the anti‐inflammatory potential of BioCen‐128, the aim of this study was to evaluate the granuloma model induced by a cotton wool implantation and the model induced by intracerebroventricular (ICV) administration of streptozotocin (STZ).

Method

The experiment was carried out using male OF‐1_cenp mice weighing 20 ± 2 g.

Results

Mice administered BioCen‐128 in via the IP route at 5, 10 and 20 mg/kg of corporal weigh showed a decrease in the wet and dry weights of the granuloma, providing evidence of a systemic anti‐inflammatory effect. In the ICV model of STZ, the administration of BioCen‐128 improved cognitive function.

Conclusion

These responses suggested an anti‐neuroinflammatory effect explainable by the action of thymosin β4 and thymosin alfa proteins. The results suggested that BioCen‐128 could be used in the prevention and treatment of some diseases, for example AD, where neuroinflammation is one of the biological events that take place.

Dietary supplementation with nanoparticle CMCS-20a enhances the resistance to GCRV infection in grass carp (Ctenopharyngodon idella)

Combination of antimicrobial proteins and nanomaterials provides a platform for the development of immunopotentiators. Oral administration of immunopotentiators can significantly enhance the immunity of organisms, which provides ideas for disease prevention. In this study, we confirmed that nanoparticles CMCS-20a can efficiently prevent grass carp reovirus (GCRV) infection. Firstly, we verified that CiCXCL20a is involved in the immune responses post GCRV challenge in vivo and alleviates the cell death post GCRV challenge in CIK cells. Then, we prepared nanoparticles CMCS-20a using carboxymethyl chitosan (CMCS) loaded with grass carp (Ctenopharyngodon idella) CXCL20a (CiCXCL20a). Meanwhile, we confirmed nanoparticles CMCS-20a can alleviate the degradation in intestine. Subsequently, we added it to the feed by low temperature vacuum drying method and high temperature spray drying method, respectively. Grass carp were oral administration for 28 days and challenged by GCRV. Low temperature vacuum drying group (LD-CMCS-20a) significantly improve grass carp survival rate, but not high temperature spray drying group (HD-CMCS-20a). To reveal the mechanisms, we investigated the serum biochemical indexes, intestinal mucus barrier, immune gene regulation and tissue damage. The complement component 3 content, lysozyme and total superoxide dismutase activities are highest in LD-CMCS-20a group. LD-CMCS-20a effectively attenuates the damage of GCRV to the number of intestinal villous goblet cells and mucin thickness. LD-CMCS-20a effectively regulates mRNA expressions of immune genes (IFN1, Mx2, Gig1 and IgM) in spleen and head kidney tissues. In addition, LD-CMCS-20a obviously alleviate tissue lesions and viral load in spleen. These results indicated that the nanoparticles CMCS-20a can enhance the disease resistance of fish by improving their immunity, which provides a new perspective for fish to prevent viral infections.

MultiPep: a hierarchical deep learning approach for multi-label classification of peptide bioactivities

Peptide-based therapeutics are here to stay and will prosper in the future. A key step in identifying novel peptide-drugs is the determination of their bioactivities. Recent advances in peptidomics screening approaches hold promise as a strategy for identifying novel drug targets. However, these screenings typically generate an immense number of peptides and tools for ranking these peptides prior to planning functional studies are warranted. Whereas a couple of tools in the literature predict multiple classes, these are constructed using multiple binary classifiers. We here aimed to use an innovative deep learning approach to generate an improved peptide bioactivity classifier with capacity of distinguishing between multiple classes. We present MultiPep: a deep learning multi-label classifier that assigns peptides to zero or more of 20 bioactivity classes. We train and test MultiPep on data from several publically available databases. The same data are used for a hierarchical clustering, whose dendrogram shapes the architecture of MultiPep. We test a new loss function that combines a customized version of Matthews correlation coefficient with binary cross entropy (BCE), and show that this is better than using class-weighted BCE as loss function. Further, we show that MultiPep surpasses state-of-the-art peptide bioactivity classifiers and that it predicts known and novel bioactivities of FDA-approved therapeutic peptides. In conclusion, we present innovative machine learning techniques used to produce a peptide prediction tool to aid peptide-based therapy development and hypothesis generation.

Cyclosporin A impairs neurogenesis and cognitive abilities in brain development via the IFN-γ-Shh-BDNF pathway

A wealth of evidence indicate that the peripheral immune activation alters brain development. However, it is still largely unclear whether and how peripheral immunosuppression affects neurodevelopment. Here, we found that the immunosuppressant cyclosporin A (CsA) decreased the number of BrdU+, BrdU+/DCX+, BrdU+/NeuN + cells in the hippocampus, impaired learning and memory and inhibited protein levels of the shh signaling pathway, including Shh, Smo and Gli1. However, the shh pathway receptor agonist SAG could block the impairment of cognitive ability and the decrease of hippocampal neurogenesis and brain-derived neurotrophic factor (BDNF) level induced by CsA. We also found that CsA decreased the level of interferon-gamma (IFN-γ), while up-regulation of IFN-γ altered the inhibitory effect of the shh signaling pathway and the decrease of BDNF induced by CsA. Collectively, these data indicate that peripheral CsA impairs neurogenesis and cognition in brain development through downregulating the IFN-γ-Shh-BDNF pathway. The present study guides us to correctly apply immunomodulatory drugs in early life and suggests that the IFN-γ-Shh-BDNF pathway may represent a novel protective target for neurodevelopment under the condition of immunosuppression.

Improvement in cognitive dysfunction following blast induced traumatic brain injury by thymosin α1 in rats: Involvement of inhibition of tau phosphorylation at the Thr205 epitope

Cognitive impairment is a significant sequela of traumatic brain injury (TBI) especially blast induced traumatic brain injury (bTBI), which is characterized by rapid impairments of learning and memory ability. Although several neuroprotective agents have been postulated as promising drugs for bTBI in animal studies, very few ideal therapeutic options exist to improve cognitive impairment following bTBI. Thymosin α1(Tα1), a 28-amino-acid protein that possesses immunomodulatory functions, has exhibited beneficial effects in the treatment of infectious diseases, immunodeficiency diseases and cancers. However, it remains unclear whether Tα1 has a therapeutic role in bTBI. Thus, we hypothesized that Tα1 administration could reverse the outcomes of bTBI. The blast induced TBI (bTBI) rat model was established with the compressed gas driven blast injury model system. A consecutive Tα1 therapy (in 1 ml saline, twice a day) at a dose of 200 µg/kg or normal saline (NS) (1 ml, twice a day) for 3 days or 2 weeks was performed. Utilizing our newly designed bTBI model, we investigated the beneficial effects of Tα1 therapy on rats exposed to bTBI including: cognitive functions, general histology, regulatory T (Treg) cells, edema, inflammation reactions and the expression and phosphorylation level of tau via Morris Water Maze test (MWM test), HE staining, flow cytometry, brain water content (BWC) calculation, IL-6 assay and Western blotting, respectively. Tα1 treatment seemed to reduce the 24-hour mortality, albeit with no statistical significance. Moreover, Tα1 treatment markedly improved cognitive dysfunction by decreasing the escape latency in the acquisition phase, and increasing the crossing numbers in the probe phase of MWM test. More interestingly, Tα1 significantly inhibited tau phosphorylation at the Thr205 epitope, but not at the Ser404 and Ser262 epitopes. Tα1 increased the percentage of Treg cells and inhibited plasma IL-6 production on 3d post bTBI. Moreover, Tα1 suppressed brain edema as demonstrated by decrease of BWC. However, there was a lack of obvious change in histopathology in the brain upon Tα1 treatment. This is the first study showing that Tα1 improves neurological deficits after bTBI in rats, which is potentially related to the inhibition of tau phosphorylation at the Thr205 epitope, increased Treg cells and decreased inflammatory reactions and brain edema.

Fusion of thymosin alpha 1 with mutant IgG1 CH3 prolongs half-life and enhances antitumor effects in vivo

Thymosin alpha 1 (Tα1) is an immunomodulatory polypeptide secreted from the thymus. Tα1 has a wide range of biological functions, such as immunomodulation and endocrine regulation. Tα1 also displays antiviral and antitumor activities. Tα1 has been successfully used in clinical adjuvant therapy for solid tumors to improve the immune response of patients undergoing chemotherapy and radiotherapy. However, the half-life of Tα1 in the body is short, so frequent administration is required to maintain efficacy. In order to improve the pharmacokinetic profile of Tα1, we linked the mutated CH3 (mCH3) fragment of IgG1 (human) to the C-terminus of Tα1 to produce a long-acting fusion protein, Tα1-mCH3. The half-life of Tα1-mCH3 (47 h) was substantially increased compared with that of the parent molecule Tα1 (3 h). In vivo studies indicated that mCH3 fusion retained the original biological activity of Tα1, and Tα1-mCH3 showed slightly better immunomodulatory effect than Ta1. In the 4 T1 and B16F10 tumor xenograft models, Tα1-mCH3 induced a greater abundance of CD4⁺ and CD8⁺ T-cells in tumor tissues compared with Ta1. Tα1-mCH3 exhibited better effect in promoting the production of IL-2 and IFN-γ compared with Tα1. Therefore, Tα1-mCH3 more efficiently inhibited the growth of 4 T1 and B16F10 tumors than Tα1. In conclusion, fusion with mCH3 is an attractive strategy to lengthen the half-life and increase the activity of Tα1.

Thymosin Alpha-1 Inhibits Complete Freund's Adjuvant-Induced Pain and Production of Microglia-Mediated Pro-inflammatory Cytokines in Spinal Cord

Activation of inflammatory responses regulates the transmission of pain pathways through an integrated network in the peripheral and central nervous systems. The immunopotentiator thymosin alpha-1 (Tα1) has recently been reported to have anti-inflammatory and neuroprotective functions in rodents. However, how Tα1 affects inflammatory pain remains unclear. In the present study, intraperitoneal injection of Tα1 attenuated complete Freund's adjuvant (CFA)-induced pain hypersensitivity, and decreased the up-regulation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in inflamed skin and the spinal cord. We found that CFA-induced peripheral inflammation evoked strong microglial activation, but the effect was reversed by Tα1. Notably, Tα1 reversed the CFA-induced up-regulation of vesicular glutamate transporter (VGLUT) and down-regulated the vesicular γ-aminobutyric acid transporter (VGAT) in the spinal cord. Taken together, these results suggest that Tα1 plays a therapeutic role in inflammatory pain and in the modulation of microglia-induced pro-inflammatory cytokine production in addition to mediation of VGLUT and VGAT expression in the spinal cord.

Deciphering cellular biological processes to clinical application: a new perspective for Tα1 treatment targeting multiple diseases

BACKGROUND

Thymosin alpha 1 (Tα1) is a well-recognized immune response modulator in a wide range of disorders, particularly infections and cancer. The bioinformatic analysis of public databases allows drug repositioning, predicting a new potential area of clinical intervention. We aimed to decipher the cellular network induced by Tα1 treatment to confirm present use and identify new potential clinical applications.

RESEARCH DESIGN AND METHODS

We used the transcriptional profile of human peripheral blood mononuclear cells treated in vitro with Tα1 to perform the enrichment network analysis by the Metascape online tools and the disease enrichment analysis by the DAVID online tool.

RESULTS

Networked cellular responses reflected Tα1 regulated biological processes including immune and metabolic responses, response to compounds and oxidative stress, ion homeostasis, peroxisome biogenesis and drug metabolic process. Beyond cancer and infections, the analysis evidenced the association with disorders such as kidney chronic failure, diabetes, cardiovascular, chronic respiratory, neuropsychiatric, neurodegenerative and autoimmune diseases.

CONCLUSIONS

In addition to the known ability to promote immune response pathways, the network enrichment analysis demonstrated that Tα1 regulates cellular metabolic processes and oxidative stress response. Notable, the analysis highlighted the association with several diseases, suggesting new translational implication of Tα1 treatment in pathological conditions unexpected until now.

Anti-inflammatory potential of thymosin β4 in the central nervous system: implications for progressive neurodegenerative diseases

INTRODUCTION

The actin-sequestering thymosin beta4 (Tβ4) is the most abundant member of the β-thymosins, and is widely expressed in the central nervous system (CNS), but its functions in the healthy and diseased brain are poorly understood. The expression of Tβ4 in neurons and microglia, the resident immune cells of the brain, suggests that it can play a role in modulating behavioral processes and immunological mechanisms in the brain. The purpose of this review is to shed lights on the role of Tβ4 in CNS function and diseases without antecedent autoimmune inflammation or injury, and to question its therapeutic potential for neurodegenerative disorders such as Alzheimer's disease.

AREAS COVERED

This review presents the evidence supporting a role for Tβ4 in behaviors that are affected in CNS disorders, as well as studies linking Tβ4 upregulation in microglia to neuroinflammatory processes associated with these disorders. Finally, the implication of Tβ4 in the process of microglial activation and the mechanisms underlying its ability to suppress pro-inflammatory signaling in microglia are discussed.

EXPERT OPINION

Tβ4 has the potential to control inflammatory processes in the brain, opening avenues for new therapeutic applications to a range of neurodegenerative conditions.

Laminar Distribution of Neurochemically-Identified Interneurons and Cellular Co-expression of Molecular Markers in Epileptic Human Cortex

Inhibitory GABAergic interneurons are fundamental elements of cortical circuits and play critical roles in shaping network activity. Dysfunction of interneurons can lead to various brain disorders, including epilepsy, schizophrenia, and anxiety. Based on the electrophysiological properties, cell morphology, and molecular identity, interneurons could be classified into various subgroups. In this study, we investigated the density and laminar distribution of different interneuron types and the co-expression of molecular markers in epileptic human cortex. We found that parvalbumin (PV) and somatostatin (SST) neurons were distributed in all cortical layers except layer I, while tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were abundant in the deep layers and white matter. Cholecystokinin (CCK) neurons showed a high density in layers IV and VI. Neurons with these markers constituted ~7.2% (PV), 2.6% (SST), 0.5% (TH), 0.5% (NPY), and 4.4% (CCK) of the gray-matter neuron population. Double- and triple-labeling revealed that NPY neurons were also SST-immunoreactive (97.7%), and TH neurons were more likely to express SST (34.2%) than PV (14.6%). A subpopulation of CCK neurons (28.0%) also expressed PV, but none contained SST. Together, these results revealed the density and distribution patterns of different interneuron populations and the overlap between molecular markers in epileptic human cortex.

The short-term improvements of enriched environment in behaviors and pathological changes of APP/PS1 mice via regulating cytokines

OBJECTIVE

To study the effect of enriched environment (EE) on cognitive function and pathological changes in Alzheimer's disease (AD) mice.

METHOD

6-month-old of the male mice were divided into 3 groups (n = 8), the wild type C57BL/6 mice in the control group, the APP/PS1 transgenic mice of AD reared in either the standard environment or the EE. Mice were feeding for 8 weeks, and then moved into standard environment. The activity and cognitive function were measured by Open-field test and Morris-water Maze. Immunofluorescence was used to detect Aβ plaque, hydroxylamine colorimetric assay was used to detect the activity of Ach, ChAT and AchE, and ELISA was used to detect the Aβ protein and the inflammatory factors IL-1β, IL-6, TNF-α and IFN-γ in serum, as well as the trophic cytokines BDNF, NGF and IGF-1 in hippocampus.

RESULT

Compared with the controls, the behaviors of AD mice were degraded, the Aβ deposition could be detected in the brain, the activity of Ach and ChAT decreased while the AchE increased, and the inflammatory factors increased significantly in serum while the trophic factors decreased in hippocampus. By means of rearing in EE, the activity and cognitive functions of AD mice were improved, and the Aβ plaques were significantly reduced. Meanwhile, the inflammatory factors in serum were reduced while the trophic cytokines increased. Besides, the cholinergic system in the brain were improved without statistic difference. However, 3 months later, these improvements in AD mice which were previously raised in EE disappeared.

CONCLUSION

The EE can improve the behaviors of AD mice, reduce the Aβ deposition in the brain, regulate the levels of cytokines, and have benefit in pathological changes in AD, but these improvements are short-term.