Thymosin beta 10 loaded ZIF-8/sericin hydrogel promoting angiogenesis and osteogenesis for bone regeneration

Angiogenesis is pivotal for osteogenesis during bone regeneration. A hydrogel that promotes both angiogenesis and osteogenesis is essential in bone tissue engineering. However, creating scaffolds with the ideal balance of biodegradability, osteogenic, and angiogenic properties poses a challenge. Thymosin beta 10 (TMSB10), known for its dual role in angiogenesis and osteogenesis differentiation, faces limitations due to protein activity preservation. To tackle this issue, ZIF-8 was engineered as a carrier for TMSB10 (TMSB10@ZIF-8), and subsequently integrated into the self-assembled sericin hydrogel. The efficacy of the composite hydrogel in bone repair was assessed using a rat cranial defect model. Characterization of the nanocomposites confirmed the successful synthesis of TMSB10@ZIF-8, with a TMSB10 encapsulation efficiency of 88.21 %. The sustained release of TMSB10 from TMSB10@ZIF-8 has significantly enhanced tube formation in human umbilical vein endothelial cells (HUVECs) in vitro and promoted angiogenesis in the chicken chorioallantoic membrane (CAM) model in vivo. It has markedly improved the osteogenic differentiation ability of MC 3 T3-E1 cells in vitro. 8 weeks post-implantation, the TMSB10@ZIF-8/ Sericin hydrogel group exhibited significant bone healing (86.77 ± 8.91 %), outperforming controls. Thus, the TMSB10@ZIF-8/Sericin hydrogel, leveraging ZIF-8 for TMSB10 delivery, emerges as a promising bone regeneration scaffold with substantial clinical application potential.

Small Spleen Peptides (SSPs) Shape Dendritic Cell Differentiation through Modulation of Extracellular ATP Synthesis Profile

Restoring peripheral immune tolerance is crucial for addressing autoimmune diseases. An ancient mechanism in maintaining the balance between inflammation and tolerance is the ratio of extracellular ATP (exATP) and adenosine. Our previous research demonstrated the effectiveness of small spleen peptides (SSPs) in inhibiting psoriatic arthritis progression, even in the presence of the pro-inflammatory cytokine TNFα, by transforming dendritic cells (DCs) into tolerogenic cells and fostering regulatory Foxp3+ Treg cells. Here, we identified thymosins as the primary constituents of SSPs, but recombinant thymosin peptides were less efficient in inhibiting arthritis than SSPs. Since Tβ4 is an ecto-ATPase-binding protein, we hypothesized that SSPs regulate exATP profiles. Real-time investigation of exATP levels in DCs revealed that tolerogenic stimulation led to robust de novo exATP synthesis followed by significant degradation, while immunogenic stimulation resulted in a less pronounced increase in exATP and less effective degradation. These contrasting exATP profiles were crucial in determining whether DCs entered an inflammatory or tolerogenic state, highlighting the significance of SSPs as natural regulators of peripheral immunological tolerance, with potential therapeutic benefits for autoimmune diseases. Finally, we demonstrated that the tolerogenic phenotype of SSPs is mainly influenced by adenosine receptors, and in vivo administration of SSPs inhibits psoriatic skin inflammation.

Effect of prothymosin α on neuroplasticity following cerebral ischemia‑reperfusion injury

Prothymosin α (ProT), a highly acidic nuclear protein with multiple cellular functions, has shown potential neuroprotective properties attributed to its anti‑necrotic and anti‑apoptotic activities. The present study aimed to investigate the beneficial effect of ProT on neuroplasticity after ischemia‑reperfusion injury and elucidate its underlying mechanism of action. Primary cortical neurons were either treated with ProT or overexpressing ProT by gene transfection and exposed to oxygen‑glucose deprivation for 2 h in vitro. Immunofluorescence staining for ProT and MAP‑2 was performed to quantify ProT protein expression and assess neuronal arborization. Mice treated with vehicle or ProT (100 µg/kg) and ProT overexpression in transgenic mice received middle cerebral artery occlusion for 50 min to evaluate the effect of ProT on neuroplasticity‑associated protein following ischemia‑reperfusion injury. The results demonstrated that in cultured neurons ProT significantly increased neurite lengths and the number of branches, accompanied by an upregulation mRNA level of brain‑derived neurotrophic factor. Furthermore, ProT administration improved the protein expressions of synaptosomal‑associated protein, 25 kDa and postsynaptic density protein 95 after ischemic‑reperfusion injury in vivo. These findings suggested that ProT can potentially induce neuroplasticity effects following ischemia‑reperfusion injury.

Enhanced Immunomodulatory Effects of Thymosin-Alpha-1 in Combination with Polyanionic Carbosilane Dendrimers against HCMV Infection

Resistance and toxicity associated with current treatments for human cytomegalovirus (HCMV) infection highlight the need for alternatives and immunotherapy has emerged as a promising strategy. This study examined the in vitro immunological effects of co-administration of Thymosin-alpha-1 (Tα1) and polyanionic carbosilane dendrimers (PCDs) on peripheral blood mononuclear cells (PBMCs) during HCMV infection. The biocompatibility of PCDs was assessed via MTT and LDH assays. PBMCs were pre-treated with the co-administered compounds and then exposed to HCMV for 48 h. Morphological alterations in PBMCs were observed using optical microscopy and total dendritic cells (tDCs), myeloid dendritic cells (mDCs), and plasmacytoid dendritic cells (pDCs), along with CD4+/CD8+ T cells and regulatory T cells (Treg), and were characterized using multiparametric flow cytometry. The findings revealed that Tα1 + PCDs treatments increased DC activation and maturation. Furthermore, increased co-receptor expression, intracellular IFNγ production in T cells and elevated Treg functionality and reduced senescence were evident with Tα1 + G2-S24P treatment. Conversely, reduced co-receptor expression, intracellular cytokine production in T cells, lower functionality and higher senescence in Treg were observed with Tα1 + G2S16 treatment. In summary, Tα1 + PCDs treatments demonstrate synergistic effects during early HCMV infection, suggesting their use as an alternative therapeutic for preventing virus infection.

Ligustilide prevents thymic immune senescence by regulating Thymosin β15-dependent spatial distribution of thymic epithelial cells

BACKGROUND

Thymus is the most crucial organ connecting immunity and aging. The progressive senescence of thymic epithelial cells (TECs) leads to the involution of thymus under aging, chronic stress and other factors. Ligustilide (LIG) is a major active component of the anti-aging Chinese herbal medicine Angelica sinensis (Oliv.) Diels, but its role in preventing TEC-based thymic aging remains elusive.

PURPOSE

This study explored the protective role of Ligustilide in alleviating ADM (adriamycin) -induced thymic immune senescence and its underlying molecular mechanisms.

METHOD

The protective effect of Ligustilide on ADM-induced thymic atrophy was examined by mouse and organotypic models, and conformed by SA-β-gal staining in TECs. The abnormal spatial distribution of TECs in the senescent thymus was analyzed using H&E, immunofluorescence and flow cytometry. The possible mechanisms of Ligustilide in ADM-induced thymic aging were elucidated by qPCR, fluorescence labeling and Western blot. The mechanism of Ligustilide was subsequently validated through actin polymerization inhibitor, genetic engineering to regulate Thymosin β15 (Tβ15) and Tβ4 expression, molecular docking and β Thymosin-G-actin cross-linking assay.

RESULTS

At a 5 mg/kg dose, Ligustilide markedly ameliorated ADM-induced weight loss and limb grip weakness in mice. It also reversed thymic damage and restored positive selection impaired by ADM. In vitro, ADM disrupted thymic structure, reduced TECs number and hindered double negative (DN) T cell differentiation. Ligustilide counteracted these effects, promoted TEC proliferation and reticular differentiation, leading to an increase in CD4+ single positive (CD4SP) T cell proportion. Mechanistically, ADM diminished the microfilament quantity in immortalized TECs (iTECs), and lowered the expression of cytoskeletal marker proteins. Molecular docking and cross-linking assay revealed that Ligustilide inhibited the protein binding between G-actin and Tβ15 by inhibiting the formation of the Tβ15-G-actin complex, thus enhancing the microfilament assembly capacity in TECs.

CONCLUSION

This study, for the first time, reveals that Ligustilide can attenuate actin depolymerization, protects TECs from ADM-induced acute aging by inhibiting the binding of Tβ15 to G-actin, thereby improving thymic immune function. Moreover, it underscores the interesting role of Ligustilide in maintaining cytoskeletal assembly and network structure of TECs, offering a novel perspective for deeper understanding of anti thymic aging.

Therapeutic applications of thymosin peptides: a patent landscape 2018-present

INTRODUCTION

Thymosins are small proteins found mainly in the thymus. They are involved in several biological processes, including immunoregulation, angiogenesis, and anti-inflammatory activity. Due to these multiple activities, thymosins are widely used as therapeutics. In fact, these peptides have shown interesting results in the treatment of eye disorders, anticancer therapy, and dysregulated immune disorders.

AREA COVERED

We analyzed the thymosins therapeutic patent landscape describing the most significant patents published after 2018 and originally written in English, classified according to the different type of functions and diseases. We searched 'Thymosin' on Patentscope and Espacenet.

EXPERT OPINION

Thymalfasin (Zadaxin) is the only FDA-approved thymosine-based drug used to treat chronic hepatitis B and C and as a chemotherapy inducer. This outcome demonstrates how thymosins can be exploited as therapeutics, especially in immunological and anti-cancer therapies. However, the development of modified thymosins could expand their therapeutic interest and application in different diseases. In fact, by chemical modifications, it is possible to increase proteolytic stability in the biological environment, enhance cell permeability, and stabilize the secondary structure of the peptide. Finally, the development of shorter sequences could reduce the cost and production time of these thymosin-based drugs.

[The Thymic Hormone Thymosin-1α Reduces the Pro-Inflammatory Response of Raw 264.7 Cells Induced by Endotoxin]

The aim of this work was to study the effects of thymosin-1 alpha (Tα1) on the anti-inflammatory response of RAW 264.7 macrophages cultured in the presence of lipopolysaccharide (LPS) from the walls of gram-negative bacteria. As well, we evaluated production of pro-inflammatory cytokines and the activity of the NF-κB and SAPK/JNK signaling pathways. In addition, the level of expression of a number of genes that regulate cell apoptosis, as well as the activity of receptors involved in the pro-inflammatory response, was determined. First, the addition of Tα1 normalized the level of cytokine production to varying degrees, with a particularly noticeable effect on IL-1β and IL-6. Second, the addition of Tα1 normalized the activity of the NF-κB and SAPK/JNK signaling cascades and the expression of the Tlr4 gene. Third, Tα1 significantly reduced p53 and the activity of the P53 gene, which is a marker of cell apoptosis. Fourth, it was shown that the increase in Ar-1 gene expression under the influence of LPS was significantly reduced using Tα1. Thus, it was found that the presence of Tα1 in the RAW 264.7 cell culture medium significantly reduced the level of the pro-inflammatory response of cells.

[Research advances on thymosin β4 in promoting wound healing]

With the aging of population and the development of social economy, the incidence of chronic wounds is increasing day by day, while the incidence of burns and trauma remains at a high level, making wound repair an increasingly concerned area in clinical practice. Thymosin β4 is a naturally occurring small molecule protein in vivo, which is widely distributed in a variety of body fluids and cells, especially in platelets. Thymosin β4 has biological activities of promoting angiogenesis, anti-inflammation, anti-apoptosis, and anti-fibrosis, and has many important functions in wound repair. Thymosin β4 has been observed to promote the healing of various wounds, such as burns, diabetic ulcers, pressure ulcers. This paper will review the molecular structure, mechanism of wound healing promotion, pharmacokinetics, and clinical application of thymosin β4, aiming to introduce its potential in wound treatment and the shortcomings of current researches.

TMSB10 Promotes Progression of Clear Cell Renal Cell Carcinoma via JUN Transcription Regulation

OBJECTIVE

Thymosin b10 (TMSB10), a member of the thymosin family, is mainly located in cells and participates in the assembly and occurrence of cytoskeleton. We aimed to investigate the regulatory mechanism of TMSB10 in ccRCC.

METHODS

In this study, Xiantao Academic Tools were taken to perform the pan-cancer expression and immune infiltration analysis of TMSB10. Furthermore, it is found that there is a binding site for JUN in the promoter region of TMSB10 through the JASPAR database predictive analysis. The CHIP experiment is used to confirm that JUN regulates the expression of TMSB10 through transcription, and to further detect the mRNA expression level of TMSB10 and JUN in ccRCC cell lines by qRT-PCR. Proliferation and apoptosis function analysis was also carried out to determine the functional changes of ccRCC cell lines after the expression of TMSB10 was regulated by JUN transcription.

RESULTS

The results show that TMSB10 is significantly up-regulated in a variety of cancers. Moreover, JUN regulates the high expression of TMSB10 through transcription and further promotes the proliferation of ccRCC cells and inhibits their apoptosis.

CONCLUSIONS

In conclusion, this study shows that JUN transcription regulates the high expression of TMSB10 and promotes the progress of ccRCC.

Thymosin β4 Is an Endogenous Iron Chelator and Molecular Switcher of Ferroptosis

Thymosin β4 (Tβ4) was extracted forty years agofrom calf thymus. Since then, it has been identified as a G-actin binding protein involved in blood clotting, tissue regeneration, angiogenesis, and anti-inflammatory processes. Tβ4 has also been implicated in tumor metastasis and neurodegeneration. However, the precise roles and mechanism(s) of action of Tβ4 in these processes remain largely unknown, with the binding of the G-actin protein being insufficient to explain these multi-actions. Here we identify for the first time the important role of Tβ4 mechanism in ferroptosis, an iron-dependent form of cell death, which leads to neurodegeneration and somehow protects cancer cells against cell death. Specifically, we demonstrate four iron2+ and iron3+ binding regions along the peptide and show that the presence of Tβ4 in cell growing medium inhibits erastin and glutamate-induced ferroptosis in the macrophage cell line. Moreover, Tβ4 increases the expression of oxidative stress-related genes, namely BAX, hem oxygenase-1, heat shock protein 70 and thioredoxin reductase 1, which are downregulated during ferroptosis. We state the hypothesis that Tβ4 is an endogenous iron chelator and take part in iron homeostasis in the ferroptosis process. We discuss the literature data of parallel involvement of Tβ4 and ferroptosis in different human pathologies, mainly cancer and neurodegeneration. Our findings confronted with literature data show that controlled Tβ4 release could command on/off switching of ferroptosis and may provide novel therapeutic opportunities in cancer and tissue degeneration pathologies.

Adjunctive Thymosin Beta-4 Treatment Influences PMN Effector Cell Function during Pseudomonas aeruginosa-Induced Corneal Infection

Previous work examining the therapeutic efficacy of adjunct thymosin beta 4 (Tβ4) to ciprofloxacin for ocular infectious disease has revealed markedly reduced inflammation (inflammatory mediators and innate immune cells) with increased activation of wound healing pathways. Understanding the therapeutic mechanisms of action have further revealed a synergistic effect with ciprofloxacin to enhance bacterial killing along with a regulatory influence over macrophage effector cell function. As a natural extension of the aforementioned work, the current study uses an experimental model of P. aeruginosa-induced keratitis to examine the influence of Tβ4 regarding polymorphonuclear leukocyte (PMN/neutrophil) cellular function, contributing to improved disease response. Flow cytometry was utilized to phenotypically profile infiltrating PMNs after infection. The generation of reactive oxygen species (ROS), neutrophil extracellular traps (NETs), and PMN apoptosis were investigated to assess the functional activities of PMNs in response to Tβ4 therapy. In vitro work using peritoneal-derived PMNs was similarly carried out to verify and extend our in vivo findings. The results indicate that the numbers of infiltrated PMNs into infected corneas were significantly reduced with adjunctive Tβ4 treatment. This was paired with the downregulated expression of proinflammatory markers on these cells, as well. Data generated from PMN functional studies suggested that the corneas of adjunctive Tβ4 treated B6 mice exhibit a well-regulated production of ROS, NETs, and limited PMN apoptosis. In addition to confirming the in vivo results, the in vitro findings also demonstrated that neutrophil elastase (NE) was unnecessary for NETosis. Collectively, these data provide additional evidence that adjunctive Tβ4 + ciprofloxacin treatment is a promising option for bacterial keratitis that addresses both the infectious pathogen and cellular-mediated immune response, as revealed by the current study.

Discovery of thymosin β4 as a human exerkine and growth factor

Skeletal muscle is an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in interorgan cross talk. Using mass spectrometry (MS)-based proteomics, we characterized the secretome and identified thymosin β4 (TMSB4X) as the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in the plasma of exercising humans irrespective of the insulin resistance condition or exercise mode. Treatment of mice with TMSB4X did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration in vivo. However, TMSB4X increased osteoblast proliferation and neurite outgrowth, consistent with its WADA classification as a prohibited growth factor. Therefore, we report TMSB4X as a human exerkine with a potential role in cellular cross talk.

Thymosin β4 protects against aortic aneurysm via endocytic regulation of growth factor signaling

Vascular stability and tone are maintained by contractile smooth muscle cells (VSMCs). However, injury-induced growth factors stimulate a contractile-synthetic phenotypic modulation which increases susceptibility to abdominal aortic aneurysm (AAA). As a regulator of embryonic VSMC differentiation, we hypothesized that Thymosin β4 (Tβ4) may function to maintain healthy vasculature throughout postnatal life. This was supported by the identification of an interaction with low density lipoprotein receptor related protein 1 (LRP1), an endocytic regulator of platelet-derived growth factor BB (PDGF-BB) signaling and VSMC proliferation. LRP1 variants have been implicated by genome-wide association studies with risk of AAA and other arterial diseases. Tβ4-null mice displayed aortic VSMC and elastin defects that phenocopy those of LRP1 mutants, and their compromised vascular integrity predisposed them to Angiotensin II-induced aneurysm formation. Aneurysmal vessels were characterized by enhanced VSMC phenotypic modulation and augmented PDGFR-β signaling. In vitro, enhanced sensitivity to PDGF-BB upon loss of Tβ4 was associated with dysregulated endocytosis, with increased recycling and reduced lysosomal targeting of LRP1-PDGFR-β. Accordingly, the exacerbated aneurysmal phenotype in Tβ4-null mice was rescued upon treatment with the PDGFR-β antagonist Imatinib. Our study identifies Tβ4 as a key regulator of LRP1 for maintaining vascular health, and provides insights into the mechanisms of growth factor-controlled VSMC phenotypic modulation underlying aortic disease progression.

Multiple potential roles of thymosin β4 in the growth and development of hair follicles

The hair follicle (HF) is an important mini-organ of the skin, composed of many types of cells. Dermal papilla cells are important signalling components that guide the proliferation, upward migration and differentiation of HF stem cell progenitor cells to form other types of HF cells. Thymosin β4 (Tβ4), a major actin-sequestering protein, is involved in various cellular responses and has recently been shown to play key roles in HF growth and development. Endogenous Tβ4 can activate the mouse HF cycle transition and affect HF growth and development by promoting the migration and differentiation of HF stem cells and their progeny. In addition, exogenous Tβ4 increases the rate of hair growth in mice and promotes cashmere production by increasing the number of secondary HFs (hair follicles) in cashmere goats. However, the molecular mechanisms through which Tβ4 promotes HF growth and development have rarely been reported. Herein, we review the functions and mechanisms of Tβ4 in HF growth and development and describe the endogenous and exogenous actions of Tβ4 in HFs to provide insights into the roles of Tβ4 in HF growth and development.

Progress on the Function and Application of Thymosin β4

Thymosin β4 (Tβ4) is a multifunctional and widely distributed peptide that plays a pivotal role in several physiological and pathological processes in the body, namely, increasing angiogenesis and proliferation and inhibiting apoptosis and inflammation. Moreover, Tβ4 is effectively utilized for several indications in animal experiments or clinical trials, such as myocardial infarction and myocardial ischemia-reperfusion injury, xerophthalmia, liver and renal fibrosis, ulcerative colitis and colon cancer, and skin trauma. Recent studies have reported the potential application of Tβ4 and its underlying mechanisms. The present study reveals the progress regarding functions and applications of Tβ4.

Hormonal Regulation of the MHC Class I Gene in Thyroid Cells: Role of the Promoter "Tissue-Specific" Region

In previous studies we have demonstrated that the expression of the Major Histocompatibility Complex (MHC) class I gene in thyrocytes is controlled by several hormones, growth factors, and drugs. These substances mainly act on two regions of the MHC class I promoter a "tissue-specific" region (-800 to -676 bp) and a "hormone/cytokines-sensitive" region (-500 to -68 bp). In a previous study, we have shown that the role of the "tissue-specific" region in the MHC class I gene expression is dominant compared to that of the "hormone/cytokines-sensitive" region. In the present report we further investigate the dominant role of the "tissue-specific" region evaluating the effect of thyroid stimulating hormone (TSH), methimazole (MMI), phenylmethimazole (C10), glucose and thymosin-α1. By performing experiments of electrophoretic mobility shift assays (EMSAs) we show that TSH, MMI and C10, which inhibit MHC class I expression, act on the "tissue-specific" region increasing the formation of a silencer complex. Glucose and thymosin-α1, which stimulate MHC class I expression, act decreasing the formation of this complex. We further show that the silencer complex is formed by two distinct members of the transcription factors families activator protein-1 (AP-1) and nuclear factor-kB (NF-kB), c-jun and p65, respectively. These observations are important in order to understand the regulation of MHC class I gene expression in thyroid cells and its involvement in the development of thyroid autoimmunity.

Antimicrobial Effects of Thymosin Beta-4 and Ciprofloxacin Adjunctive Therapy in Pseudomonas aeruginosa Induced Keratitis

Prior work has indicated that thymosin beta 4 (Tβ4) administered with ciprofloxacin markedly improves disease outcome for Pseudomonas aeruginosa (PA)-induced keratitis. As a result, the goal of the current study was to elucidate mechanisms by which Tβ4 mitigates the corneal response; specifically, regarding its bactericidal influence and potential synergy with ciprofloxacin. An in vitro approach was carried out using minimum inhibitory concentration (MIC) assays to assess bactericidal activity against PA. In addition, antimicrobial peptide (AMP) production was evaluated at the mRNA levels using human corneal epithelial cells in response to lipopolysaccharide (LPS) challenge. The results of the MIC assays did not show direct bactericidal activity with Tβ4 alone, although ciprofloxacin exhibited significant killing at concentrations far lower than clinically dosed. Tβ4, however, displayed an indirect effect on bacterial killing, as shown by an upregulation of AMPs and related molecules. The cumulative data from this study indicate an indirect bactericidal role of Tβ4, as well as a synergistic relationship with ciprofloxacin. Furthermore, ciprofloxacin alone was found to influence cellular functions that otherwise have yet to be reported. These results highlight a mechanism of intracellular communication for Tβ4 and further strengthen its development as an adjunct therapy with antibiotics for corneal infections.

Transplantation of Endothelial Progenitor Cells in Obese Diabetic Rats Following Myocardial Infarction: Role of Thymosin Beta-4

Endothelial progenitor cells (EPCs) are bone-marrow derived cells that are critical in the maintenance of endothelial wall integrity and protection of ischemic myocardium through the formation of new blood vessels (vasculogenesis) or proliferation of pre-existing vasculature (angiogenesis). Diabetes mellitus (DM) and the metabolic syndrome are commonly associated with ischemic heart disease through its pathological effects on the endothelium and consequent endothelial dysfunction. Thymosin-β4 (Tβ4) which expressed in the embryonic heart is critical in epicardial and coronary artery formation. In this study, we explored the effects of Tβ4 treatment on diabetic EPCs in vitro and intramyocardial injection of Tβ4-treated and non-Tβ4 treated EPCs following acute myocardial infarction (MI) of diabetic rats in vivo. It was found that 10 ng/mL Tβ4 increased migration, tubule formation, and angiogenic factor secretion of diabetic EPCs in vitro. In vivo, although implantation of Tβ4 treated diabetic EPCs significantly increased capillary density and attracted more c-Kit positive progenitor cells into the infarcted hearts as compared with implantation of non-Tβ4 treated diabetic EPCs, the significantly improved left ventricular ejection fraction was only found in the rats which received non-Tβ4 treated EPCs. The data suggests that a low dose Tβ4 increases diabetic EPC migration, tubule formation, and angiogenic factor secretion. However, it did not improve the effects of EPCs on left ventricular pump function in diabetic rats with MI.

Beneficial actions of prothymosin alpha-mimetic hexapeptide on central post-stroke pain, reduced social activity, learning-deficit and depression following cerebral ischemia in mice

Prothymosin alpha (ProTα)-mimetic hexapeptide (amino acid: NEVDQE, P6Q) inhibits cerebral or retinal ischemia-induced behavioral, electrophysiological and histological damage. P6Q also abolishes cerebral hemorrhage induced by ischemia with tissue plasminogen activator (tPA). In the present study we examined the beneficial effects of P6Q on other post-stroke prognostic psychology-related symptoms, which obstruct the motivation toward physical therapy. Intravenous (i.v.) administration with tPA (10 mg/kg) at 6 h after photochemically induced thrombosis (PIT) in mice resulted in bilateral central post-stroke pain in thermal and mechanical nociception tests and loss of social activity in the nest building test, both of which were significantly blocked by P6Q (30 mg/kg, i.v.) given at 5 h after PIT. P6Q (30 mg/kg, i.v.) also improved the memory-learning deficit in the step-through test and depression-like behavior in the tail suspension test when it was given 1 day after bilateral common carotid arteries occlusion (BCCAO) in mice. Thus, these studies suggest that P6Q could be a promising candidate to prevent negative prognostic psychological symptoms following focal and global ischemia.

Experimental evidence for the involvement of F0/F1 ATPase and subsequent P2Y12 receptor activation in prothymosin alpha-induced protection of retinal ischemic damage

The inhibition of retinal ischemia-induced damage by post-ischemic prothymosin alpha (ProTα) was not affected in toll-like receptor 4 knockout (TLR4^-/-) mice but blocked by the pretreatment with antibody against F₀/F₁ ATPase α- or β-subunit, novel candidate for ProTα-receptor. In addition to the previous observation of ProTα-induced ATP release from cells, the present study showed a ProTα-induced enhancement of ATP hydrolysis activity of recombinant ATP5A1/5B complex. As the protection of retinal function by post-ischemic ProTα was abolished by anti-P2Y₁₂ antibody, the activation of F₀/F₁ ATPase and subsequent P2Y₁₂ receptor system may play roles in beneficial actions by post-ischemic ProTα.

Electrospun thymosin Beta-4 loaded PLGA/PLA nanofiber/ microfiber hybrid yarns for tendon tissue engineering application

Microfiber yarns (MY) have been widely employed to construct tendon tissue grafts. However, suboptimal ultrastructure and inappropriate environments for cell interactions limit their clinical application. Herein, we designed a modified electrospinning device to coat poly(lactic-co-glycolic acid) PLGA nanofibers onto polylactic acid (PLA) MY to generate PLGA/PLA hybrid yarns (HY), which had a well-aligned nanofibrous structure, resembling the ultrastructure of native tendon tissues and showed enhanced failure load compared to PLA MY. PLGA/PLA HY significantly improved the growth, proliferation, and tendon-specific gene expressions of human adipose derived mesenchymal stem cells (HADMSC) compared to PLA MY. Moreover, thymosin beta-4 (Tβ4) loaded PLGA/PLA HY presented a sustained drug release manner for 28 days and showed an additive effect on promoting HADMSC migration, proliferation, and tenogenic differentiation. Collectively, the combination of Tβ4 with the nano-topography of PLGA/PLA HY might be an efficient strategy to promote tenogenesis of adult stem cells for tendon tissue engineering.

Anti-Inflammatory Activity of β-thymosin Peptide Derived from Pacific Oyster (Crassostrea gigas) on NO and PGE₂ Production by Down-Regulating NF-κB in LPS-Induced RAW264.7 Macrophage Cells

β-thymosin is known for having 43 amino acids, being water-soluble, having a light molecular weight and ubiquitous polypeptide. The biological activities of β-thymosin are diverse and include the promotion of wound healing, reduction of inflammation, differentiation of T cells and inhibition of apoptosis. Our previous studies showed that oyster β-thymosin originated from the mantle of the Pacific oyster, Crassostrea gigas and had antimicrobial activity. In this study, we investigated the anti-inflammatory effects of oyster β-thymosin in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells using human β-thymosin as a control. Oyster β-thymosin inhibited the nitric oxide (NO) production as much as human β-thymosin in LPS-induced RAW264.7 cells. It also showed that oyster β-thymosin suppressed the expression of prostaglandin E₂ (PGE₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, oyster β-thymosin reduced inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6). Oyster β-thymosin also suppressed the nuclear translocation of phosphorylated nuclear factor-κB (NF-κB) and degradation of inhibitory κB (IκB) in LPS-induced RAW264.7 cells. These results suggest that oyster β-thymosin, which is derived from the mantle of the Pacific oyster, has as much anti-inflammatory effects as human β-thymosin. Additionally, oyster β-thymosin suppressed NO production, PGE₂ production and inflammatory cytokines expression via NF-κB in LPS-induced RAW264.7 cells.

Thymosin β4 Prevents Oxidative Stress, Inflammation, and Fibrosis in Ethanol- and LPS-Induced Liver Injury in Mice

Thymosin beta 4 (Tβ4), an actin-sequestering protein, is involved in tissue development and regeneration. It prevents inflammation and fibrosis in several tissues. We investigated the role of Tβ4 in chronic ethanol- and acute lipopolysaccharide- (LPS-) induced mouse liver injury. C57BL/6 mice were fed 5% ethanol in liquid diet for 4 weeks plus binge ethanol (5 g/kg, gavage) with or without LPS (2 mg/kg, intraperitoneal) for 6 hours. Tβ4 (1 mg/kg, intraperitoneal) was administered for 1 week. We demonstrated that Tβ4 prevented ethanol- and LPS-mediated increase in liver injury markers as well as changes in liver pathology. It also prevented ethanol- and LPS-mediated increase in oxidative stress by decreasing ROS and lipid peroxidation and increasing the antioxidants, reduced glutathione and manganese-dependent superoxide dismutase. It also prevented the activation of nuclear factor kappa B by blocking the phosphorylation of the inhibitory protein, IκB, thereby prevented proinflammatory cytokine production. Moreover, Tβ4 prevented fibrogenesis by suppressing the epigenetic repressor, methyl-CpG-binding protein 2, that coordinately reversed the expression of peroxisome proliferator-activated receptor-γ and downregulated fibrogenic genes, platelet-derived growth factor-β receptor, α-smooth muscle actin, collagen 1, and fibronectin, resulting in reduced fibrosis. Our data suggest that Tβ4 has antioxidant, anti-inflammatory, and antifibrotic potential during alcoholic liver injury.

Deer thymosin beta 10 functions as a novel factor for angiogenesis and chondrogenesis during antler growth and regeneration

BACKGROUND

Deer antlers are the only known mammalian organ with vascularized cartilage that can completely regenerate. Antlers are of real significance as a model of mammalian stem cell-based regeneration with particular relevance to the fields of chondrogenesis, angiogenesis, and regenerative medicine. Recent research found that thymosin beta 10 (TMSB10) is highly expressed in the growth centers of growing antlers. The present study reports here the expression, functions, and molecular interactions of deer TMSB10.

METHODS

The TMSB10 expression level in both tissue and cells in the antler growth center was measured. The effects of both exogenous (synthetic protein) and endogenous deer TMSB10 (lentivirus-based overexpression) on antlerogenic periosteal cells (APCs; nonactivated antler stem cells with no basal expression of TMSB10) and human umbilical vein endothelial cells (HUVECs; endothelial cells with no basal expression of TMSB10) were evaluated to determine whether TMSB10 functions on chondrogenesis and angiogenesis. Differences in deer and human TMSB10 in angiogenesis and molecular structure were determined using animal models and molecular dynamics simulation, respectively. The molecular mechanisms underlying deer TMSB10 in promoting angiogenesis were also explored.

RESULTS

Deer TMSB10 was identified as a novel proangiogenic factor both in vitro and in vivo. Immunohistochemistry revealed that TMSB10 was widely expressed in the antler growth center in situ, with the highest expression in the reserve mesenchyme, precartilage, and transitional zones. Western blot analysis using deer cell lines further supports this result. Both exogenous and endogenous deer TMSB10 significantly decreased proliferation of APCs (P < 0.05), while increasing the proliferation of HUVECs (P < 0.05). Moreover, deer TMSB10 enhanced chondrogenesis in micromass cultures and nerve growth as assessed using a dorsal root ganglion model (P < 0.05). Deer TMSB10 was proangiogenic using models of chicken chorioallantoic membrane, tube formation, and aortic arch assay. At the molecular level, endogenous deer TMSB10 elevated the expression of vascular endothelial growth factor (VEGF), VEGF-B, VEGF-C, and VEGF-D, and VEGFR2 and VEGFR3 in HUVECs (P < 0.05).

CONCLUSIONS

Deer TMSB10, in contrast to its human counterpart, was identified as a novel stimulating factor for angiogenesis, cartilage formation, and nerve growth, which is understandable given that deer antlers (as the arguably fastest mammalian growing tissue) may require this extra boost during a period of rapid growth and regeneration.

No effect of thymosin beta-4 on the expression of the transcription factor Islet-1 in the adult murine heart

The transcription factor Islet-1 marks a progenitor cell population of the second heart field during cardiogenesis. In the adult heart Islet-1 expression is limited to the sinoatrial node, the ventricular outflow tract, and parasympathetic ganglia. The regenerative effect in the injured mouse ventricle of thymosin beta-4 (TB4), a 43-aminoacid peptide, was associated with increased Islet-1 immunostaining, suggesting the induction of an Islet-1-positive progenitor state by TB4. Here we aimed to reassess this effect in a genetic model. Mice from the reporter mouse line Isl1-nLacZ were primed with TB4 and subsequently underwent myocardial infarction. Islet-1 expression was assessed 2, 7, and 14 days after infarction. We detected only a single Islet-1+ cell in 8 TB4 treated and infarcted hearts which located outside of the sinoatrial node, the outflow tract or cardiac ganglia (in ~2500 sections). Two cells were identified in 5 control infarcted hearts. TB4 did not induce LacZ positivity in ventricular explants cultures of Isl1-nLacZ mice nor did it affect the density of LacZ+ cells in explant cultures of nLacZ+ regions of the heart. In summary, we found no evidence that TB4 reactivates Islet-1 expression in adult mouse ventricle.

Thymosin β4 Reduces H₂O₂ Induced Oxidative Stress in MC3T3-E1 Cells on Titanium Surface

Thymosin β4 (Tβ4) is known to inhibit an inflammatory response and to increase the survival of osteoblasts on titanium (Ti) surfaces. Ti is the most widely used graft material in dentistry; however, an inflammatory response induced following implant placement results in the generation of reactive oxygen species (ROS). The oxidative stress from the production of ROS such as nitric oxide (NO) and hydrogen peroxide (H2O2) can damage surrounding cells, resulting in implant failure by decreasing cell viability. Thus, the aim of this study was to determine the biological effects of Tβ4 on the oxidative stress induced to MC3T3-E1 preosteoblasts on the Ti surface. Based on an MTT assay and bromodeoxyuridine immunofluorescence staining, Tβ4 was found to increase the proliferation of the H2O2-exposed MC3T3-E1 cells on Ti discs. Reverse transcription-polymerase chain reaction and western blot analyses showed that Tβ4 decreased the mRNA and protein expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in H2O2-exposed MC3T3-E1 cells on the Ti discs. Tβ4 inhibited the synthesis of intracellular ROS and the secretion of NO and prostaglandin E2 (PGE2) from H2O2-exposed MC3T3-E1 cells on the Ti discs. In conclusion, Tβ4 inhibits H2O2-induced iNOS and COX-2 expression with a decrease in ROS, NO, and PGE2 synthesis, which leads to improved cell survival with low cytotoxicity under an oxidative stress condition in MC3T3-E1 cells on the Ti surface. This suggests that Tβ4 may be a crucial molecule to reduce oxidative stress-induced cell damage or hypoxia, leading to promoted osseointegration on the Ti surface during implant placement.

Thymosin β4 alleviates renal fibrosis and tubular cell apoptosis through TGF-β pathway inhibition in UUO rat models

BACKGROUND

Thymosin β4 (Tβ4) is closely associated with the cytoskeleton, inflammation, wound healing, angiogenesis, apoptosis, and myocardial regeneration, but the effects of Tβ4 treatment on chronic renal tubular interstitial fibrosis (CRTIF) are poorly known. This study aimed to examine the effects of Tβ4 on the renal apoptosis and the expression of transforming growth factor (TGF-β), E-cadherin, and α-smooth muscle actin (α-SMA) in CRTIF rat models.

METHODS

Male SD rats were randomized into four groups (sham group, unilateral ureteral obstruction (UUO) group, UUO + low-dose Tβ4 group, and UUO + high-dose Tβ4 group). The pathological changes of kidney tissue and its function were assessed two weeks after UUO. In renal interstitial tissue,TGF-β, E-cadherin and α-SMA expression was detected by western blot. In tubular epithelial cells, E-cadherin and α-SMA expression was detected using Real-time qPCR and western blot. Cell apoptosis of rat renal interstitial tissue and tubular epithelial cells was evaluated by immunofluorescence and western blot.

RESULTS

Two weeks after UUO, no differences in blood urea nitrogen and creatinine were observed between the four groups (P > 0.05). Compared to the UUO group, Tβ4 treatment decreased the 24-h proteinuria (P < 0.001) and reduced the area of pathological change (P < 0.01); this effect was more apparent in the UUO + high-dose Tβ4 group. Compared to the UUO group, a significant decrease in TGF-β and α-SMA protein expression was observed in the high-dose Tβ4 group. The level of E-cadherin protein was lower in the UUO group than the Tβ4 groups, and high-dose Tβ4 treatment further increased E-cadherin expression and improved cell apoptosis in the renal interstitial tissue. Analysis of in vitro tubular epithelial cells showed that α-SMA mRNA and protein expression decreased, while E-cadherin mRNA and protein expression increased by Tβ4 treatment. Similarly, these changes were more significant in the UUO + high-dose Tβ4 group. Tβ4 treatment improved the apoptosis of In vitro tubular epithelial cells compared with pure TGF-β stimulation, and equally, the decrease of apoptosis was more apparent in the TGF-β + high-dose Tβ4 group.

CONCLUSIONS

Tβ4 treatment might alleviate the renal fibrosis and apoptosis of tubular epithelial cells through TGF-β pathway inhibition in UUO rats with CRTIF.

Prothymosin-α Variants Elicit Anti-HIV-1 Response via TLR4 Dependent and Independent Pathways

BACKGROUND

Prothymosin α (ProTα) (isoform 2: iso2) is a widely distributed, small acidic protein with intracellular and extracellular-associated functions. Recently, we identified two new ProTα variants with potent anti-HIV activity from CD8+ T cells and cervicovaginal lavage. The first is a splice variant of the ProTα gene known as isoB and the second is the product of ProTα pseudogene 7 (p7). Similarly to iso2, the anti-HIV activity of both variants is mediated by type I IFN. Here we tested whether the immunomodulatory activity of isoB and p7 are also TLR4 dependent and determined their kinetic of release in response to HIV-1 infection.

METHODS

Type I, type III, TNF-α and IL-6 mRNA inducing activity was determined in macrophages from wild type and TLR4 knockout mice treated with recombinant ProTα variants. Supernatants from mock and HIV infected cells were analyzed by mass spectrometry in positive and negative modes for the presence of ProTα variants. In silico structural and functional analysis of ProTα variants were performed.

RESULTS

We show that both isoB and p7 upregulate IFN-β, IFN-λ1, IL-6, TNF-α and RANTES mRNAs in primary human macrophages. The potent stimulation of IFN-β by the recombinant ProTα variants in human macrophages is dependent on the TLR4 pathway, whereas the induction of TNF-α and IL-6 may also occur independently of TLR4, suggesting the interaction of ProTα variants with other signaling molecules/receptors. In silico analyses confirmed that the novel isoB and p7 variants are intrinsically disordered proteins, which lack the NLS and mass spectrometry showed release of ProTα variants within minutes post HIV-1 infection. These features are consistent with the function of ProTα variants as damage associate molecular patterns (DAMPs).

CONCLUSIONS

Our findings indicate that ProTα variants strongly inhibit viral replication mainly, but not exclusively, through TLR4 signaling and that they are released within minutes of viral infection suggesting that they may function as DAMPs.

Safety and efficacy of autologous thymosin β4 pre-treated endothelial progenitor cell transplantation in patients with acute ST segment elevation myocardial infarction: A pilot study

BACKGROUND

Experimental studies and clinical trials suggest that endothelial progenitor cell (EPC) transplantation can repair "broken" heart. However, transplantation of autologous EPCs has numerous limitations, including the limited supply of expanded EPCs, the impaired function and activity of the transplanted cells and so on. Therefore, we investigated the feasibility, safety and initial clinical outcome of autologous thymosin β4 (Tβ4) pre-treated EPC transplantation in patients with acute ST segment elevation myocardial infarction (STEMI).

METHODS

Ten patients with STEMI were included; they were randomized to 2 groups: EPC transplantation group (control group; n = 5) and Tβ4-pre-treated EPC transplantation group (experimental group; n = 5). EPCs were pre-treated with Tβ4 24 hours before transplantation in experimental group. Cardiac function was evaluated using echocardiography and emission computed tomography, as well as the 6-min walking test before and 6 months after the intervention.

RESULTS

After 6 months of follow-up, the average 6-min walking distance was increased by 38.2 m (from 263 ± 42 m to 302 ± 34 m) in the control group and 75.7 m (from 264 ± 42 m to 340 ± 44 m) in the experimental group; the average difference of the 6-min walking distance was 37.5 m (95% confidence interval [CI], 28.7-56.3 m; P < 0.01). In addition, the cardiac function in the experimental group was more significantly improved than that of the control group. There were no severe complications related to the procedure in either group during the follow-up.

DISCUSSION

Our pilot study suggested that Tβ4-optimized EPC transplantation appeared to be feasible and safe, and might have beneficial effects on exercise capacity and left ventricular function in patients with STEMI.

Thymosin Beta-4 Suppresses Osteoclastic Differentiation and Inflammatory Responses in Human Periodontal Ligament Cells

Background

Recent reports suggest that thymosin beta-4 (Tβ4) is a key regulator for wound healing and anti-inflammation. However, the role of Tβ4 in osteoclast differentiation remains unclear.

Purpose

The purpose of this study was to evaluate Tβ4 expression in H₂O₂-stimulated human periodontal ligament cells (PDLCs), the effects of Tβ4 activation on inflammatory response in PDLCs and osteoclastic differentiation in mouse bone marrow-derived macrophages (BMMs), and identify the underlying mechanism.

Methods

Reverse transcription-polymerase chain reactions and Western blot analyses were used to measure mRNA and protein levels, respectively. Osteoclastic differentiation was assessed in mouse bone marrow-derived macrophages (BMMs) using conditioned medium (CM) from H₂O₂-treated PDLCs.

Results

Tβ4 was down-regulated in H₂O₂-exposed PDLCs in dose- and time-dependent manners. Tβ4 activation with a Tβ4 peptide attenuated the H₂O₂-induced production of NO and PGE₂ and up-regulated iNOS, COX-2, and osteoclastogenic cytokines (TNF-α, IL-1β, IL-6, IL-8, and IL-17) as well as reversed the effect on RANKL and OPG in PDLCs. Tβ4 peptide inhibited the effects of H₂O₂ on the activation of ERK and JNK MAPK, and NF-κB in PDLCs. Furthermore, Tβ4 peptide inhibited osteoclast differentiation, osteoclast-specific gene expression, and p38, ERK, and JNK phosphorylation and NF-κB activation in RANKL-stimulated BMMs. In addition, H₂O₂ up-regulated Wnt5a and its cell surface receptors, Frizzled and Ror2 in PDLCs. Wnt5a inhibition by Wnt5a siRNA enhanced the effects of Tβ4 on H₂O₂-mediated induction of pro-inflammatory cytokines and osteoclastogenic cytokines as well as helping osteoclastic differentiation whereas Wnt5a activation by Wnt5a peptide reversed it.

Conclusion

In conclusion, this study demonstrated, for the first time, that Tβ4 was down-regulated in ROS-stimulated PDLCs as well as Tβ4 activation exhibited anti-inflammatory effects and anti-osteoclastogenesis in vitro. Thus, Tβ4 activation might be a therapeutic target for inflammatory osteolytic disease, such as periodontitis.

Neuroprotective impact of prothymosin alpha-derived hexapeptide against retinal ischemia-reperfusion

Prothymosin alpha (ProTα) has robustness roles against brain and retinal ischemia or serum-starvation stress. In the ProTα sequence, the active core 30-amino acid peptide/P30 (a.a.49-78) is necessary for the original neuroprotective actions against ischemia. Moreover, the 9-amino acid peptide sequence/P9 (a.a.52-60) in P30 still shows neuroprotective activity against brain and retinal ischemia, though P9 is less potent than P30. As the previous structure-activity relationship study for ProTα may not be enough, the possibility still exists that any sequence smaller than P9 retains potent neuroprotective activity. When different P9- and P30-related peptides were intravitreally injected 24h after retinal ischemia in mice, the 6-amino acid peptide/P6 (NEVDEE, a.a.51-56) showed potent protective effects against ischemia-induced retinal functional deficits, which are equipotent to the level of P30 peptide in electroretinography (ERG) and histological damage in Hematoxylin and Eosin (HE) staining. Further studies using ERG and HE staining suggested that intravitreal or intravenous (i.v.) injection with modified P6 peptide/P6Q (NEVDQE) potently inhibited retinal ischemia-induced functional and histological damage. In an immunohistochemical analysis, the ischemia-induced loss of retinal ganglion, bipolar, amacrine and photoreceptor cells were inhibited by a systemic administration with P6Q peptide 24h after the ischemic stress. In addition, systemic post-treatment with P6Q peptide significantly inhibited retinal ischemia-induced microglia and astrocyte activation in terms of increased ionized calcium-binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) intensity, respectively, as well as their morphological changes, increased number and migration. Thus, this study demonstrates the therapeutic significance of modified P6 peptide P6Q (NEVDQE) derived from 6-amino acid peptide (P6) in ProTα against ischemic damage.

[The Effects of Thymosin alpha1 on Immune Function of Mice after Skin Transplantation]

OBJECTIVE

By establishing C57-BABL/c mice allogeneic skin transplantation model, to analyze the immune system function with the administration of thymosin al (Tal) in mouse after skin transplantation; and to explore the mechanism of specific immune tolerance induced by Tal in vivo.

METHODS

80 C57 mice and 80 BABL/c mice were used as donor and acceptor respectively to establish C57-BABL/c mice allogeneic skin transplantation model and divided into four groups: Group A, control group (without any treatment, n=20); Group B, CsA treatment group (CsA 10 mg/kg, n=20); Group C, Tal treatment group (Tal 400 microg/kg, n=20) and Group D, combination therapy group (CsA 10 mg/kg & Talphal 400 microg/kg, n=20). In the three experimental group, the drug of each group were respectively administrated by intraperitoneal injection daily, for 21 d. The survival of skin graft were observed and recorded, the Luminexx MAP for cytokine detection were performed in 1, 7, 14, 21 d after treatment, skin grafts were taking for HE staining, and flow cytometry were performed for lymphocyte phenotype.

RESULTS

After transplantation, in 1, 7, 14, 21 d, the cytokine of Group B, C and ID compared to Group A, as well as Group D to B&C respectively, shows a decreaing of IL-1, IL-2, IL-6, IL-17 value and increasing of IL-10 significantly (P<0.05) at the same time point; While no statistical significance shows between Group B and C. Compared with other groups, Group D have a high ratio of CD4/CD8, and a high percentage of CD4+ CD25+ T cells (P<0.05).

CONCLUSION

Administrated Tal after transplantation, can decrease the graft damage from T cells, but could not prevent rejection.

Molecular and Physiological Characterization of Two Novel Multirepeat β-Thymosins from Silkworm, Bombyx mori

β-thymosin plays important roles in the development of the lymphatic system and the central nervous system in vertebrates. However, its role and function in invertebrates remain much less explored. Here, we firstly isolated a gene encoding β-thymosin in silkworm (Bombyx mori L.). Interestingly, this gene encodes two polypeptides, named as BmTHY1 and BmTHY2, via two different modes of RNA splicing. The recombinant proteins fused with an N-term GST tag were over-expressed in Escherichia coli (E. coli) and further purified to near homogenity to prepare mouse antibodies. The Western blot analysis showed that these proteins were expressed in various tissues and organs, as well as in different developmental stages. Amazingly, the expression of BmTHY2 was hugely increased during the pupae stage, indicating a specialized role in this period. The expression of these proteins was gradually decreased in BmN cells infected by BmNPV, suggesting they may play different roles in the virus infection. In addition, both BmTHY1 and BmTHY2 can interact with 14-3-3 of silkworm and Ubiquitin of BmNPV as shown by GST pull down and Co-IP assays, consistent with their roles in the regulation of the development of nervous system.

Effect of thymosin α₁ on the phenotypic and functional maturation of dendritic cells from children with acute lymphoblastic leukemia

To determine the effect of thymosin α1 (Tα1) on the phenotypic and functional maturation of HL‑60 cells, freeze‑thaw antigen‑loaded dendritic cells (DCs) were derived from peripheral blood mononuclear cells (PBMCs) of children with acute lymphoblastic leukemia (ALL). The DCs were generated from the PBMC samples that were collected from the PB of 10 consecutive ALL children. On day 3 of culturing, the cells in the antigen + no Tα1 (AN) and antigen + Tα1 (AT) groups were incubated with 100 µl lysates obtained from freeze‑thaw cycling. After 5 days of incubation, the AT group was administered with 100 ng/ml Tα1. On day 8, the DCs were stained with fluorescein isothiocyanate‑conjugated cluster of differentiation (CD)1a, CD83 and HLA‑DR antibodies and analyzed by flow cytometry. In addition, the killing activity of cytotoxic T lymphocytes (CTLs) from the different groups on wild‑type leukemia cells was measured. The DCs in the AT group exhibited more apparent, characteristic dendritic morphologies than the control and AN group DCs. Furthermore, the lowest expression level of CD1a, and the highest expression of CD83 and HLA‑DR were observed in the AT group when compared with the AN and control groups (P<0.05). The lactate dehydrogenase release assay demonstrated that the killing rate of CTL in the AT group was significantly higher than that in the control and AN groups (P<0.01). Thus, Tα1 may markedly promote the phenotypic and functional maturation of DCs, and may serve as a suitable immunomodulator of DC‑based immunotherapy for treatment of hematological malignancies.

The Effect of Thymosin β4 for Osteoblast Adhesion on Titanium Surface

Titanium (Ti) is the most widely used implant material in dentistry and orthopedics but the release of metal ions from Ti implants results in increased bone resorption by enhancing the production of inflammatory cytokines from the macrophages and facilitating osteoclast differentiation. Thymosin β4 (Tβ4) has several biological activities, such as promoting wound healing, angiogenesis, cell proliferation and migration in mammalian cells. This study examined the role of Tβ4 in osteoblasts via focal adhesions (FAs) and ERK1/2 signaling related to cell adhesion and proliferation for cell survival on the Ti surface. As a result, cell adhesion and proliferation increased in the Tβ4 treated cells (Tβ4/MC3T3-E1) but was significantly lower in the Tβ4 knock-down cells by Tβ4-siRNA (si-Tβ4/MC3T3-E1) than that of the untreated cells. The levels of FAK phosphorylation, paxillin expression, and paxillin localization were higher in the Tβ4/IMC3T3-E1 cells than that of the untreated cells but lower in the si-Tβ4/MC3T3-E1 cells. In addition, the levels of cell proliferation, Grb2 and Ras protein expression and phosphorylation of ERK1/2 were higher in the Tβ4/MC3T3-E1 cells than in the untreated cells but lower in the si-Tβ4/IMC3T3-E1 cells. These results suggest that Tβ4 might be a good nanomolecule that promotes osteoblast survival by facilitating adhesion and proliferation on the Ti surface.

[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.

[Triplet anti-tumor therapy based on thymosin α-1 attenuates incidence of hepatoma and serum alpha-fetoprotein level in rat hepatoma model]

OBJECTIVE

To explore the impact of triple anti-tumor therapy based on thymosin α1 (Tα1) combined with Huaier granule(HG) and sirolimus on the level of serum alpha-fetoprotein (AFP) in rat models of liver cancer.

METHODS

Ninety Sprague-Dawley rats were randomly divided into triple anti-tumor therapy group, Tα1 group, HG group, sirolimus group, positive control and blank control groups, with 15 rats in each group. Except the blank control group, the rats in the other groups were induced using diethylnitrosamine (DEN) to establish liver cancer models. After DEN treatment, the triple therapy group underwent 0.8 mg/kg Tα1 subcutaneous injection (from once a day for two weeks to twice a week since the third week), 0.35 g/kg HG gavage (three times a day) and 1 mg/kg sirolimus gavage (once a day). The dose of the rest single drug groups were the same with that of the triple therapy group. The positive control and blank control groups were not treated with the drugs. The treatment lasted 20 weeks. Then, the behavior of the rats were observed at the different time points, and the level of serum AFP in the rats were detected at 6, 16, 18, 20 weeks, respectively.

RESULTS

The typical symptoms of liver cancer were seen in the DEN-induced rats at 16 weeks. Since the tenth week, 6 rats died one after another. Pathological section of rat liver tissue suggested that the rat models were established successfully. According to the incidence rate of liver cancer and the survival rate at 20 weeks, the triple anti-tumor therapy was significantly superior to the single drug treatments. In addition, the triple anti-tumor therapy significantly reduced the level of serum AFP in the rats.

CONCLUSION

The triple anti-tumor therapy can significantly prolong the survival time of rats with liver cancer, decrease the cancer incidence rate and the level of serum AFP.

Human serum thymic factor in detecting acute T cell leukemia

In acute leukemia, the frequency of the E+ cells among the blood mononuclears before and after their incubation with human serum thymic factor was investigated by means of the E rosette assay. In 4 of 24 patients tested, the thymic factor incubation of their peripheral blood cells increased the number of the E+ cells among the mononuclears. Prospective importance of the test either in investigating whether a T0 leukemia might really exist, or in monitoring possible variations of the immature T cell counts in relationship to the patient's treatment and his disease course, are discussed.

Effect of thymosin beta 4 in the presence of up-regulation of the insulin-like growth factor-1 signaling pathway on high-glucose-exposed vascular endothelial cells

Thymosin beta 4 (Tβ4), which regulates vascular cell growth, can ameliorate some of the problems associated with diabetes. However, the precise signaling mechanisms by which Tβ4 protects against hyperglycemia-induced damage to endothelial cells have not been investigated in detail. Thus, the aim of this study was to elucidate the role of Tβ4 in diabetes and the possible involvement of insulin-like growth factor-1 (IGF-1), which affects cellular survival, metabolism, and glucose homeostasis in high-glucose (HG)-injured human umbilical vein endothelial cells (HUVECs). Immunoblotting assays revealed that under HG blockade conditions, Tβ4 did not alter the insulin-signaling pathway, but induced overexpression of IGF-1 protein, leading to activation of factors in alternative signaling pathway. Small interfering RNA of Tβ4 and IGF-1 were studied to clarify relationship between Tβ4 and IGF-1. These findings suggest that IGF-1 induction by Tβ4 ameliorates the damage in HG-injured HUVECs which manifest as diabetic vascular disorder.

Therapeutic Benefit of Extended Thymosin β4 Treatment Is Independent of Blood Glucose Level in Mice with Diabetic Peripheral Neuropathy

Peripheral neuropathy is a chronic complication of diabetes mellitus. To investigated the efficacy and safety of the extended treatment of diabetic peripheral neuropathy with thymosin β4 (Tβ4), male diabetic mice (db/db) at the age of 24 weeks were treated with Tβ4 or saline for 16 consecutive weeks. Treatment of diabetic mice with Tβ4 significantly improved motor (MCV) and sensory (SCV) conduction velocity in the sciatic nerve and the thermal and mechanical latency. However, Tβ4 treatment did not significantly alter blood glucose levels. Treatment with Tβ4 significantly increased intraepidermal nerve fiber density. Furthermore, Tβ4 counteracted the diabetes-induced axon diameter and myelin thickness reductions and the g-ratio increase in sciatic nerve. In vitro, compared with dorsal root ganglia (DRG) neurons derived from nondiabetic mice, DRG neurons derived from diabetic mice exhibited significantly decreased neurite outgrowth, whereas Tβ4 promoted neurite growth in these diabetic DRG neurons. Blockage of the Ang1/Tie2 signaling pathway with a neutralized antibody against Tie2 abolished Tβ4-increased neurite outgrowth. Our data demonstrate that extended Tβ4 treatment ameliorates diabetic-induced axonal degeneration and demyelination, which likely contribute to therapeutic effect of Tβ4 on diabetic neuropathy. The Ang1/Tie2 pathway may mediate Tβ4-induced axonal remodeling.

Thymosin Beta 4 protects mice from monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy

Pulmonary hypertension (PH) is a progressive vascular disease of pulmonary arteries that impedes ejection of blood by the right ventricle. As a result there is an increase in pulmonary vascular resistance and pulmonary arterial pressure causing right ventricular hypertrophy (RVH) and RV failure. The pathology of PAH involves vascular cell remodeling including pulmonary arterial endothelial cell (PAEC) dysfunction and pulmonary arterial smooth muscle cell (PASMC) proliferation. Current therapies are limited to reverse the vascular remodeling. Investigating a key molecule is required for development of new therapeutic intervention. Thymosin beta-4 (Tβ4) is a ubiquitous G-actin sequestering protein with diverse biological function and promotes wound healing and modulates inflammatory responses. However, it remains unknown whether Tβ4 has any protective role in PH. The purpose of this study is to evaluate the whether Tβ4 can be used as a vascular-protective agent. In monocrotaline (MCT)-induced PH mouse model, we showed that mice treated with Tβ4 significantly attenuated the systolic pressure and RVH, compared to the MCT treated mice. Our data revealed for the first time that Tβ4 selectively targets Notch3-Col 3A-CTGF gene axis in preventing MCT-induced PH and RVH. Our study may provide pre-clinical evidence for Tβ4 and may consider as vasculo-protective agent for the treatment of PH induced RVH.

[Effects of thymosin alpha1 on immune effector molecules of mouse]

OBJECTIVE

To analysis the effects of Talpha1 on the immune effector molecules in mouse immune system.

METHODS

Sixty five BABL/c mice were divided into four groups: CsA group (n=20), Talpha1 group (n= 20), CsA+Talpha1 group (n=20) and control group (n=5). In the 3 experimental groups, 10 mg/kg CsA, 400 microg/ kg Talpha1, 10 mg/kg CsA+400 microg/kg Talpha1 were respectively administrated by intraperitoneal injection daily. Luminex was performed for cytokine detection at 1 d, 7 d, 14 d, 21 d day after the above treatments. Lymphocyte culture was prepared with the mouse spleen suspension, and then treated with 0. 25 mg/mL CsA, 10 microg/mL Talpha1 or 0.25 mg/mL CsA+10 microg/mL Talpha1 in vitro, respectively. Three days later, OD values of each treated lymphocyte culture and several cytokines in the culture were measured.

RESULTS

Compared with other groups, CsA+Talpha1 group had significant lower IL-1alpha, IL-2, IL-6, IL-17, and significant higher IL-10 at 1 d, 7 d, 14 d, 21 d after the treatments (P < 0.05). Three days after the culture, OD value in the control group was significantly higher than that in Talppha1 group, CsA group, and CsA+ Talpha1 group (P < 0.05). IL-1alpa and IL-6 in the control group were significantly higher than those in the experiment groups (P < 0.05), while IL-10 in the control group was significantly lower than that in the experiment groups (P < 0.05). IL-2 and IL-17 were similar.

CONCLUSION

Talpha1 show regulatory effect on the immune effector molecules which could promote Th1 cells transforming to Th2 cells.

A tumor-penetrating peptide modification enhances the antitumor activity of thymosin alpha 1

A serious limitation of numerous antitumor drugs is the incapacity to penetrate solid tumors. However, addition of an RGD fragment to peptide drugs might solve this problem. In this study, we explored whether the introduction of a permeability-enhancing sequence, such as iRGD (CRGDK/RGPD/EC) fragments, would enhance the activity of thymosin alpha 1 (Tα1). The modified Tα1 (Tα1-iRGD) was successfully expressed and purified, and the in vitro assay showed that Tα1-iRGD presented a similar activity as Tα1 in promoting proliferation of mouse splenocytes. Meanwhile, cell adhesion analysis revealed that Tα1-iRGD exhibited more specific and greater binding with tumor cells compared with Tα1. Furthermore, the iRGD fragment evidently enhanced the basal ability of Tα1 to inhibit proliferation of cancer cells in vitro, particularly of mouse melanoma cell line B16F10 and human lung cancer cell line H460. Our findings indicated that the addition of an iRGD fragment increased the anti-proliferative activity of Tα1 against cancer cells by improving the ability of Tα1 to penetrate the tumor cells. This study highlighted the important roles of an iRGD sequence in the therapeutic strategy of Tα1-iRGD. Thus, Tα1-iRGD could be a novel drug candidate for cancer treatment.

[Protective effect of thymosin β4 against oxidative damage in cultured rabbit corneal epithelial cells]

OBJECTIVE

The aim of this study was to investigate the effects of thymosin β4 (Tβ4) against oxidative damage in rabbit corneal epithelial cells in vitro.

METHODS

Experimental study. Primary cultures of rabbit corneal epithelial cells were isolated and cultured from cornea tissue explants. Cell morphology was observed by phase-contrast microscope. The expression of keratin 12 and connexin 43 in cultured cells were examined with RT-PCR. The cultures were divided into 4 groups: control group, Tβ4 group, hydrogen peroxide (H2O2) group, and H2O2+Tβ4 group. The cell viability of cultured corneal epithelial cells was examined by MTT assay. TUNEL staining was used to detect the apoptotic cells. ROS levels were estimated by DCFH-DA using fluorescent microscopy. Cell migration was measured using the scratch wound technique. Data were analyzed using one-way analysis of variance (ANOVA) and secondary analysis for significance with post Hoc tests.

RESULTS

The morphology of cultured cells was round, ovoid, polygonal or paving stone appearance. The results of RT-PCR showed that cultured corneal epithelial cells expressed both keratin 12 and connexin 43, the characteristic genes of corneal epithelial cells. The cell viability in H2O2 group was significantly reduced than that in control group (67.20% ± 5.87% vs. 100.00% ± 9.99%, P = 0.000); the cell viability was significantly improved in Tβ4+ H2O2 group than that in H2O2 group (83.42% ± 7.23% vs. 67.20% ± 5.87%, P = 0.023) . Cell migration was significantly increased in Tβ4 group compared with the controls (117.6% ± 2.22% vs. 100.00% ± 4.06%, P = 0.005) ; Compared with H2O2 group, cell migration was significant increase in H2O2 + Tβ4 group (96.57% ± 8.22% vs. 64.38% ± 11.08%, P = 0.000) . Compared with the control group, the intracellular ROS level of the H2O2 group was significantly increased (234.42% ± 22.15% vs. 100.00% ± 5.28%, P = 0.000) . Intracellular ROS level of H2O2+Tβ4 group was significantly decreased as compared with the H2O2 group (163.26% ± 10.53% vs. 234.42% ± 22.15%, P = 0.000). TUNEL staining indicated that Tβ4 treatment markedly inhibited H2O2-induced apoptosis in cultured corneal epithelial cells.

CONCLUSIONS

Tβ4 has a strong protection effect against oxidative damage induced by H2O2 in corneal epithelial cells through promoting cell growth and cell migration, and the underlying mechanisms may due to the antioxidation and anti-apoptotic effects of Tβ4.

Mechanical effects on KATP channel gating in rat ventricular myocytes

Cardiac K_ATP channels link metabolism with electrical activity. They are implicated in arrhythmias, secretion of atrial natriuretic peptide and protection of the heart from hypertrophy and failure. These processes may involve mechanosensitivity. K_ATP channels can be activated by mechanical stimulation and disrupting the cortical actin increases the activity. We propose that K_ATP channels are modulated by local bilayer tension and this tension is affected by cortical F-actin. Here we measured K_ATP background activity and stretch sensitivity with inside-out patches of rat ventricular myocytes before and after disrupting F-actin. Disrupting F-actin potentiated background activity but did not influence the slope sensitivity in the semilog relationship of NP_o vs. suction that is a measure of the change in dimensions between closed and open states. Thus actin alters prestress on the channel probably by parallel elastic sharing of mean cortical tension with the bilayer.

Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes

Background

Thymosin beta-4 (Tβ4) is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H₂O₂ induced cardiac damage.

Methods

Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H₂O₂ and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H₂O₂-induced cardiac damage was evaluated.

Results

Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H₂O₂ in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl₂ ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4.

Conclusion

This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the myocardium under oxidative stress.

Controlled release of thymosin β4 from injected collagen-chitosan hydrogels promotes angiogenesis and prevents tissue loss after myocardial infarction

AIMS

Acute myocardial infarction (MI) leads to fibrosis and severe left ventricular wall thinning. Enhancing vascularization within the infarct reduces cell death and maintains a thick left ventricular wall, which is essential for proper cardiac function. Here, we evaluated the controlled delivery of thymosin β4 (Tβ4), which supports cardiomyocyte survival by inducing vascularization and upregulating Akt activity, in the treatment of MI.

MATERIALS & METHODS

We injected collagen-chitosan hydrogel with controlled release of Tβ4 into the infarct after performing left anterior descending artery ligation in rats.

RESULTS

Tβ4-encapsulated hydrogel (thymosin) significantly reduced tissue loss post-MI (13 ± 4%), compared with 58 ± 3% and 30 ± 8% tissue loss for no treatment (MI only) and Tβ4-free hydrogel (control). Significantly more Factor VIII-positive blood vessels with diameter >50 µm were in the thymosin group compared with both MI only and control (p < 0.0001), showing Tβ4-induced vascularization. Wall thickness was positively correlated with the mature blood vessel density (r = 0.9319; p < 0.0001).

CONCLUSION

Controlled release of Tβ4 within the infarct enhances angiogenesis and presence of cardiomyocytes that are necessary for cardiac repair.

The use of growth factors to modulate the activities of antigen-specific CD8+ T cells in vitro

RATIONALE

Adoptive T cell therapy depends on the harvesting of the cells from the host, their activation in vitro, and their infusion back to the same host. The way of activating the T cells in vitro is a critical factor for their homing, survival and function in vivo. Sustaining T cell homing molecules, particularly CD62L, is benefic for the trafficking of the adoptive transferred cells.

OBJECTIVE

The aim of the present study is to test whether insulin-like growth factor-1 (IGF-1), thymosin- α1 (T-α1) as well as all-trans retinoid acid (ATRA) alone or in combination with IL-2, IL-12, IL-15 can enhance the activation and survival phenotypes of antigen-activated T cells in vitro.

METHODS & RESULTS

To this end, OT-1 transgenic T cells were used as a model. These CD8+ T cells recognize OVA peptide presented by MHC class-I. The results showed that antigen stimulation of OT1 cells resulted in their activation as evidenced by the decrease in surface expression of CD62L, analyzed for 3 days after antigen stimulation and was more pronounced on day 5. The addition of IL-12 or IGF-1 alone but not of IL-2, IL-15 augmented OT-1 cell activation measured on day 5. Interestingly, the combination of IL-12 with IGF-1 sustained the expression of CD62L on OT1 cells. Although the addition of ATRA alone or in combination with IL-12 resulted in decreases in CD62L expression on day 3, they showed a dose-dependent effect on the restoration of CD62L expression on day 5. The analysis of the activation-induced cell death (apoptosis) of OT1 cells showed an increased rate of death on day 5 than on day 3-post antigen stimulation. The addition of only IL-12 or IGF-1 alone, but not of IL-2, IL-15 or T- α1, decreased OT1 cell apoptosis on day 3. These anti-apoptotic effects of IL-12 and IGF- 1, however, were recovered on day 5-post stimulation.

DISCUSSION

In conclusion, these results indicate that the activation phenotype and the survival of antigen-specific T cells can be differently modulated by immunomodulatory factors, where, interleukin-12 and IGF-1 induced the favorable effect. These results have a significant implication for T cell adoptive immunotherapy in different settings.

Controlled release of thymosin β4 using collagen-chitosan composite hydrogels promotes epicardial cell migration and angiogenesis

Rapid vascularization at the infarcted site is crucial for cardiac repair following myocardial infarction. Thymosin β4 (Tβ4), a 43-amino acid peptide, is both angiogenic and cardioprotective. Tβ4 in soluble form was previously shown to promote cell migration from quiescent adult cardiac explants. Here we developed a collagen-chitosan hydrogel for the encapsulation of Tβ4, which allowed its controlled release over 28days to elicit localized and prolonged effects. Contrastingly, Tβ4 was fully released over 3days when encapsulated in collagen-only hydrogels due to charge repulsion and lack of interconnected pores as shown by SEM. The charge of encapsulated molecules affected their release from collagen-chitosan hydrogels. While the release of neutral polyalanine was size-controlled diffusion, that of negatively-charged Tβ4 and positively-charged polylysine was affected by electrostatic interactions of peptides with collagen/chitosan molecules. Hydrogels with encapsulated Tβ4 significantly increased cell migration and outgrowth of CD31-positive capillaries from mouse and rat epicardial explants in vitro, compared to Tβ4-free and soluble controls. Potential advantage of Tβ4 over commonly-used angiogenic growth factors is that it can induce recruitment and differentiation of both endothelial and smooth muscle cells necessary for vascular stability. Importantly, Tβ4-encapsulated collagen-chitosan hydrogels promoted angiogenesis in vivo upon subcutaneous injection, compared to collagen-only hydrogels.