Upregulated Tß4 expression in inflammatory bowel disease impairs the intestinal mucus barrier by inhibiting autophagy in mice.

Disrupted intestinal barrier homeostasis is fundamental to inflammatory bowel disease. Thymosin ß4 (Tß4) improves inflammation and has beneficial effects in dry-eye diseases, but its effects on the intestinal mucus barrier remain unknown. Therefore, this study evaluated the underlying regulatory mechanisms and effects of Tß4 by examining Tß4 expression in a mouse model with dextran sodium sulfate (DSS)-induced colitis and colonic barrier damage. Additionally, we intraperitoneally injected C57BL/6 mice with Tß4 to assess barrier function, microtubule-associated protein 1 light chain 3 (LC3II) protein expression, and autophagy. Finally, normal human colon tissue and colon carcinoma cells (Caco2) were cultured to verify Tß4-induced barrier function and autophagy changes. Mucin2 levels decreased, microbial infiltration increased, and Tß4 expression increased in the colitis mouse model versus the control mice, indicating mucus barrier damage. Moreover, Tß4-treated C57BL/6 mice had damaged intestinal mucus barriers and decreased LC3II levels. Tß4 also inhibited colonic mucin2 production, disrupted tight junctions, and downregulated autophagy; these results were confirmed in Caco2 cells and normal human colon tissue. In summary, Tß4 may be implicated in colitis by compromising the integrity of the intestinal mucus barrier and inhibiting autophagy. Thus, Tß4 could be a new diagnostic marker for intestinal barrier defects.

Construction of recombinant Lactococcus expressing thymosin and interferon fusion protein and its application as an immune adjuvant.

BACKGROUND: In recent years, biosafety and green food safety standards have increased the demand for immune enhancers and adjuvants. In the present study, recombinant food-grade Lactococcus lactis (r-L. lactis-Tα1-IFN) expressing thymosin Tα1 and chicken interferon fusion protein was constructed. RESULTS: The in vitro interactions with macrophages revealed a mixture of recombinant r-L. lactis-Tα1-IFN could significantly activate both macrophage J774-Dual™ NF-κB and interferon regulator (IRF) signaling pathways. In vitro interactions with chicken peripheral blood mononuclear cells (PBMCs) demonstrated that a mixture of recombinant r-L. lactis-Tα1-IFN significantly enhanced the expression levels of interferon (IFN)-γ, interleukin (IL)-10, CD80, and CD86 proteins in chicken PBMCs. Animal experiments displayed that injecting a lysis mixture of recombinant r-L. lactis-Tα1-IFN could significantly activate the proliferation of T cells and antigen-presenting cells in chicken PBMCs. Moreover, 16S analysis of intestinal microbiota demonstrated that injection of the lysis mixture of recombinant r-L. lactis-Tα1-IFN could significantly improve the structure and composition of chicken intestinal microbiota, with a significant increase in probiotic genera, such as Lactobacillus spp. Results of animal experiments using the lysis mixture of recombinant r-L. lactis-Tα1-IFN as an immune adjuvant for inactivated chicken Newcastle disease vaccine showed that the serum antibody titers of the experimental group were significantly higher than those of the vaccine control group, and the expression levels of cytokines IFN-γ and IL-2 were significantly higher than those of the vaccine control group. CONCLUSION: These results indicate that food-safe recombinant r-L. lactis-Tα1-IFN has potential as a vaccine immune booster and immune adjuvant. This study lays the foundation for the development of natural green novel animal immune booster or immune adjuvant.

PHB2 inhibits WSSV replication by promoting the nuclear translocation of STAT.

Prohibitins (PHBs) are ubiquitously expressed conserved proteins in eukaryotes that are associated with apoptosis, cancer formation, aging, stress responses and cell proliferation. However, the function of the PHBs in immune regulation has largely not been determined. In the present study, we identified PHB2 in the red swamp crayfish Procambarus clarkii. PHB2 was found to be widely distributed in several tissues, and its expression was significantly upregulated by white spot syndrome virus (WSSV) challenge. PHB2 significantly reduced the amount of WSSV in crayfish and the mortality of WSSV-infected crayfish. Here, we observed that PHB2 promotes the nuclear translocation of STAT by binding to STAT. After blocking PHB2 or STAT with antibodies or interfering with PHB2 or STAT, the expression levels of the antiviral genes ß-thymosin (PcThy-4) and crustin2 (Cru2) decreased. The gene sequence of PHB2 was analyzed and found to contain a nuclear introgression sequence (NIS). After in vivo injection of PHB2 with deletion of NIS (rΔNIS-PHB2), the nuclear translocation of STAT did not change significantly compared to that in the control group. These results suggest that PHB2 promoted the nuclear translocation of STAT through NIS and mediated the expression of antiviral proteins to inhibit WSSV infection.

Extreme disorder in an ultrahigh-affinity protein complex.

Molecular communication in biology is mediated by protein interactions. According to the current paradigm, the specificity and affinity required for these interactions are encoded in the precise complementarity of binding interfaces. Even proteins that are disordered under physiological conditions or that contain large unstructured regions commonly interact with well-structured binding sites on other biomolecules. Here we demonstrate the existence of an unexpected interaction mechanism: the two intrinsically disordered human proteins histone H1 and its nuclear chaperone prothymosin-α associate in a complex with picomolar affinity, but fully retain their structural disorder, long-range flexibility and highly dynamic character. On the basis of closely integrated experiments and molecular simulations, we show that the interaction can be explained by the large opposite net charge of the two proteins, without requiring defined binding sites or interactions between specific individual residues. Proteome-wide sequence analysis suggests that this interaction mechanism may be abundant in eukaryotes.

Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials.

Objective: This study aims to assess the safety and efficacy of Thymosin Alpha 1 (Tα1) through a comprehensive narrative review of clinical studies involving over 11 000 human subjects in more than 30 trials. The focus was on Tα1's application in COVID-19, autoimmune conditions, and cancer treatment, with implications for future considerations. Methods: We systematically searched articles relevant to critical studies on COVID-19, infectious diseases, cancer, and autoimmune diseases indexed on Pubmed, Google Scholar, and Cochrane Library. Our focus was on evaluating the safety and efficacy of Tα1 in human subjects. Clinical trials conducted worldwide involving diverse populations were analyzed to assess the safety and effectiveness of Tα1. The review examines explicit outcomes in over 11 000 human subjects, emphasizing its role in addressing COVID-19, autoimmune conditions, and cancer treatment. Results: Contrary to the FDA's restriction on Tα1 and 21 additional peptides in 2023, our analysis reveals consistent evidence of Tα1's safety and efficacy. The peptide has demonstrated significant effectiveness in treating various conditions, including COVID-19, autoimmune disorders, and cancer. This review summarizes conclusions drawn from a comprehensive examination of clinical trials worldwide. Conclusions: Based on substantial evidence from clinical trials, Tα1 emerges as a well-tolerated and effective immune modulator. The FDA>s restriction appears unfounded, as Tα1 has shown safety and efficacy beyond the initially specified conditions. Urgent attention and intervention are warranted to ensure the continued availability of this life-saving peptide through prescription. Therefore, it is recommended that the FDA permits 503A compounding pharmacies to compound Tα1, considering its potential to treat a variety of conditions effectively.

In Vitro Study of Thymosin Beta 4 Promoting Transplanted Fat Survival by Regulating Adipose-Derived Stem Cells.

BACKGROUND: Autologous fat grafting (AFG) has emerged as a highly sought-after plastic surgery procedure, although its success has been hampered by the uncertain fat survival rate. Current evidence suggests that adipose-derived stem cells (ADSCs) may contribute to fat retention in AFG. In previous studies, it was confirmed that thymosin beta 4 (Tß4) could enhance fat survival in vivo, although the precise mechanism remains unclear. METHODS: ADSCs were isolated from patients undergoing liposuction and their proliferation, apoptosis, anti-apoptosis, and migration were analyzed under Tß4 stimulation using cell counting kit-8, flow cytometry, wound healing assay, and real-time quantitative PCR. The mRNA levels of genes relating to angiogenesis and Hippo signaling were also determined. RESULTS: Tß4 at 100 ng/mL (p-value = 0.0171) and 1000 ng/mL (p-value = 0.0054) significantly increased ADSC proliferation from day 1 compared to the control group (0 ng/mL). In addition, the mRNA levels of proliferation-associated genes were elevated in the Tß4 group. Furthermore, Tß4 enhanced the anti-apoptotic ability of ADSCs when stimulated with Tß4 and an apoptotic induction reagent (0 ng/mL vs. 1000 ng/mL, p-value = 0.011). Crucially, the mRNA expression levels of angiogenesis-related genes and critical genes in the Hippo pathway were affected by Tß4 in ADSCs. CONCLUSIONS: Tß4 enhances adipose viability in AFG via facilitating ADSC proliferation and reducing apoptosis, and acts as a crucial positive regulator of ADSC-associated angiogenesis. Additionally, Tß4 could be accountable for the phenotypic adjustment of ADSCs by regulating the Hippo pathway. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Thymosin ß4 Regulates the Differentiation of Thymocytes by Controlling the Cytoskeletal Rearrangement and Mitochondrial Transfer of Thymus Epithelial Cells.

The thymus is one of the most crucial immunological organs, undergoing visible age-related shrinkage. Thymic epithelial cells (TECs) play a vital role in maintaining the normal function of the thymus, and their degeneration is the primary cause of age-induced thymic devolution. Thymosin ß4 (Tß4) serves as a significant important G-actin sequestering peptide. The objective of this study was to explore whether Tß4 influences thymocyte differentiation by regulating the cytoskeletal rearrangement and mitochondrial transfer of TECs. A combination of H&E staining, immunofluorescence, transmission electron microscopy, RT-qPCR, flow cytometry, cytoskeletal immunolabeling, and mitochondrial immunolabeling were employed to observe the effects of Tß4 on TECs' skeleton rearrangement, mitochondrial transfer, and thymocyte differentiation. The study revealed that the Tß4 primarily regulates the formation of microfilaments and the mitochondrial transfer of TECs, along with the formation and maturation of double-negative cells (CD4-CD8-) and CD4 single-positive cells (CD3+TCRß+CD4+CD8-) thymocytes. This study suggests that Tß4 plays a crucial role in thymocyte differentiation by influencing the cytoskeletal rearrangement and mitochondrial transfer of TECs. These effects may be associated with Tß4's impact on the aggregation of F-actin. This finding opens up new avenues for research in the field of immune aging.

A Pilot Trial of Thymalfasin (Thymosin-α-1) to Treat Hospitalized Patients With Hypoxemia and Lymphocytopenia Due to Coronavirus Disease 2019 Infection.

BACKGROUND: Thymosin-α-1 (Tα1) may be a treatment option for coronavirus disease 2019 (COVID-19), but efficacy and safety data remain limited. METHODS: Prospective, open-label, randomized trial assessing preliminary efficacy and safety of thymalfasin (synthetic form of Tα1), compared with the standard of care, among hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19. RESULTS: A total of 49 patients were included in this analysis. Compared with control patients, the incidence of clinical recovery was higher for treated patients with either baseline low-flow oxygen (subdistribution hazard ratio, 1.48 [95% confidence interval, .68-3.25]) or baseline high-flow oxygen (1.28 [.35-4.63]), although neither difference was significant. Among patients with baseline low-flow oxygen, treated patients, compared with control patients, had an average difference of 3.84 times more CD4+ T cells on day 5 than on day 1 (P = .01). Nine serious adverse events among treated patients were deemed not related to Tα1. CONCLUSIONS: Tα1 increases CD4+ T-cell count among patients with baseline low-flow oxygen support faster than the standard of care and may have a role in the management of hospitalized patients with hypoxemia and lymphocytopenia due to COVID-19. CLINICAL TRIALS REGISTRATION: NCT04487444.

Prothymosin Alpha: A Novel Contributor to Estradiol Receptor Alpha-Mediated CD8+ T-Cell Pathogenic Responses and Recognition of Type 1 Collagen in Rheumatic Heart Valve Disease.

BACKGROUND: Rheumatic heart valve disease (RHVD) is a leading cause of cardiovascular death in low- and middle-income countries and affects predominantly women. The underlying mechanisms of chronic valvular damage remain unexplored and regulators of sex predisposition are unknown. METHODS: Proteomics analysis of human heart valves (nondiseased aortic valves, nondiseased mitral valves [NDMVs], valves from patients with rheumatic aortic valve disease, and valves from patients with rheumatic mitral valve disease; n=30) followed by system biology analysis identified ProTα (prothymosin alpha) as a protein associated with RHVD. Histology, multiparameter flow cytometry, and enzyme-linked immunosorbent assay confirmed the expression of ProTα. In vitro experiments using peripheral mononuclear cells and valvular interstitial cells were performed using multiparameter flow cytometry and quantitative polymerase chain reaction. In silico analysis of the RHVD and Streptococcuspyogenes proteomes were used to identify mimic epitopes. RESULTS: A comparison of NDMV and nondiseased aortic valve proteomes established the baseline differences between nondiseased aortic and mitral valves. Thirteen unique proteins were enriched in NDMVs. Comparison of NDMVs versus valves from patients with rheumatic mitral valve disease and nondiseased aortic valves versus valves from patients with rheumatic aortic valve disease identified 213 proteins enriched in rheumatic valves. The expression of the 13 NDMV-enriched proteins was evaluated across the 213 proteins enriched in diseased valves, resulting in the discovery of ProTα common to valves from patients with rheumatic mitral valve disease and valves from patients with rheumatic aortic valve disease. ProTα plasma levels were significantly higher in patients with RHVD than in healthy individuals. Immunoreactive ProTα colocalized with CD8+ T cells in RHVD. Expression of ProTα and estrogen receptor alpha correlated strongly in circulating CD8+ T cells from patients with RHVD. Recombinant ProTα induced expression of the lytic proteins perforin and granzyme B by CD8+ T cells as well as higher estrogen receptor alpha expression. In addition, recombinant ProTα increased human leukocyte antigen class I levels in valvular interstitial cells. Treatment of CD8+ T cells with specific estrogen receptor alpha antagonist reduced the cytotoxic potential promoted by ProTα. In silico analysis of RHVD and Spyogenes proteomes revealed molecular mimicry between human type 1 collagen epitope and bacterial collagen-like protein, which induced CD8+ T-cell activation in vitro. CONCLUSIONS: ProTα-dependent CD8+ T-cell cytotoxicity was associated with estrogen receptor alpha activity, implicating ProTα as a potential regulator of sex predisposition in RHVD. ProTα facilitated recognition of type 1 collagen mimic epitopes by CD8+ T cells, suggesting mechanisms provoking autoimmunity.

Thymosin ß4 is essential for adherens junction stability and epidermal planar cell polarity.

Planar cell polarity (PCP) is essential for tissue morphogenesis and homeostasis; however, the mechanisms that orchestrate the cell shape and packing dynamics required to establish PCP are poorly understood. Here, we identified a major role for the globular (G)-actin-binding protein thymosin-ß4 (TMSB4X) in PCP establishment and cell adhesion in the developing epidermis. Depletion of Tmsb4x in mouse embryos hindered eyelid closure and hair-follicle angling owing to PCP defects. Tmsb4x depletion did not preclude epidermal cell adhesion in vivo or in vitro; however, it resulted in abnormal structural organization and stability of adherens junction (AJ) due to defects in filamentous (F)-actin and G-actin distribution. In cultured keratinocytes, TMSB4X depletion increased the perijunctional G/F-actin ratio and decreased G-actin incorporation into junctional actin networks, but it did not change the overall actin expression level or cellular F-actin content. A pharmacological treatment that increased the G/F-actin ratio and decreased actin polymerization mimicked the effects of Tmsb4x depletion on both AJs and PCP. Our results provide insights into the regulation of the actin pool and its involvement in AJ function and PCP establishment.

The Clinical Relevance and Functional Implications of Thymosin Beta-10 in Glioma.

Glioma is a highly aggressive form of brain cancer characterized by limited treatment options and poor patient prognosis. In this study, we aimed to elucidate the oncogenic role of thymosin beta-10 (TMSB10) in glioma through comprehensive analyses of patient data from the TCGA and GTEx databases. Our investigation encompassed several key aspects, including the analysis of patients' clinical characteristics, survival analysis, in vitro and in vivo functional experiments, and the exploration of correlations between TMSB10 expression and immune cell infiltration. Our findings revealed a significant upregulation of TMSB10 expression in glioma tissues compared to normal brain tissues, with higher expression levels observed in tumors of advanced histological grades. Moreover, we observed positive correlations between TMSB10 expression and patient age, while no significant association with gender was detected. Additionally, TMSB10 exhibited marked elevation in gliomas with wild-type IDH and noncodeletion of 1p/19q. Survival analysis indicated that high TMSB10 expression was significantly associated with worse overall survival, disease-specific survival, and progression-free survival in glioma patients. Functionally, knockdown of TMSB10 in glioma cells resulted in reduced cellular growth rates and impaired tumor growth in xenograft models. Furthermore, our study revealed intriguing correlations between TMSB10 expression and immune cell infiltration within the tumor microenvironment. Specifically, TMSB10 showed negative associations with plasmacytoid dendritic cells (pDC) and γδ T cells (Tgd), while displaying positive correlations with neutrophils and macrophages. These findings collectively provide valuable insights into the oncogenic properties of TMSB10 in glioma, suggesting its potential as a therapeutic target and a biomarker for patient stratification.

Hypermethylation of thymosin ß4 predicts a poor prognosis for patients with acute-on-chronic hepatitis B liver failure.

BACKGROUND: It has been demonstrated that thymosin ß4 (Tß4) could inflect the severity of acute-on-chronic hepatitis B liver failure (ACHBLF), but the relationship between its methylation status and the prognosis of liver failure is not clear. This study aimed to determine Tß4 promoter methylation status in patients with ACHBLF and to evaluate its prognostic value. METHODS: The study recruited 115 patients with ACHBLF, 80 with acute-on-chronic hepatitis B pre-liver failure (pre-ACHBLF), and 86 with chronic hepatitis B (CHB). In addition, there were 36 healthy controls (HCs) from the Department of Hepatology, Qilu Hospital of Shandong University. The 115 patients with ACHBLF were divided into three subgroups: 33 with early stage ACHBLF (E-ACHBLF), 42 with mid-stage ACHBLF (M-ACHBLF), and 40 with advanced stage ACHBLF (A-ACHBLF). Tß4 promoter methylation status in peripheral blood mononuclear cells (PBMCs) was measured by methylation-specific polymerase chain reaction, and mRNA was detected by quantitative real-time polymerase chain reaction. RESULTS: Methylation frequency of Tß4 was significantly higher in patients with ACHBLF than in those with pre-ACHBLF, CHB or HCs. However, expression of Tß4 mRNA showed the opposite trend. In patients with ACHBLF, Tß4 promoter methylation status correlated negatively with mRNA levels. The 3-month mortality of ACHBLF in the methylated group was significantly higher than that in the unmethylated group. Also, Tß4 promoter methylation frequency was lower in survivors than in non-survivors. When used to predict the 1-, 2-, and 3-month incidence of ACHBLF, Tß4 methylation status was better than the model for end-stage liver disease (MELD) score. The predictive value of Tß4 methylation was higher than that of MELD score for the mortality of patients with E-ACHBLF and M-ACHBLF, but not for A-ACHBLF. CONCLUSIONS: Tß4 methylation might be an important early marker for predicting disease incidence and prognosis in patients with ACHBLF.

The Pathophysiological Role of Thymosin ß4 in the Kidney Glomerulus.

Diseases affecting the glomerulus, the filtration unit of the kidney, are a major cause of chronic kidney disease. Glomerular disease is characterised by injury of glomerular cells and is often accompanied by an inflammatory response that drives disease progression. New strategies are needed to slow the progression to end-stage kidney disease, which requires dialysis or transplantation. Thymosin ß4 (Tß4), an endogenous peptide that sequesters G-actin, has shown potent anti-inflammatory function in experimental models of heart, kidney, liver, lung, and eye injury. In this review, we discuss the role of endogenous and exogenous Tß4 in glomerular disease progression and the current understanding of the underlying mechanisms.

Exogenous Thymosin Beta 4 Suppresses IPF-Lung Cancer in Mice: Possibly Associated with Its Inhibitory Effect on the JAK2/STAT3 Signaling Pathway.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung disease of unknown etiology. At present, the mortality rate of the deadly disease is still very high, while the existing treatments only delay the progression of the disease and improve the quality of life of patients. Lung cancer (LC) is the most fatal disease in the world. In recent years, IPF has been considered to be an independent risk factor for the development of LC. The incidence of lung cancer is increased in the patients with IPF and the mortality is also significantly increased in the patients inflicted with the two diseases. In this study, we evaluated an animal model of pulmonary fibrosis complicated with LC by implanting LC cells orthotopically into the lungs of mice several days after bleomycin induction of the pulmonary fibrosis in the same mice. In vivo studies with the model showed that exogenous recombinant human thymosin beta 4 (exo-rhTß4) alleviated the impairment of lung function and severity of damage of the alveolar structure by the pulmonary fibrosis and inhibited the proliferation of LC tumor growth. In addition, in vitro studies showed that exo-rhTß4 inhibited the proliferation and migration of A549 and Mlg cells. Furthermore, our results also showed that rhTß4 could effectively inhibit the JAK2-STAT3 signaling pathway and this might exert an anti-IPF-LC effect. The establishment of the IPF-LC animal model will be helpful for the development of drugs for the treatment of IPF-LC. Exogenous rhTß4 can be potentially used for the treatment of IPF and LC.

Thymosin Beta 4 Inhibits LPS and ATP-Induced Hepatic Stellate Cells via the Regulation of Multiple Signaling Pathways.

Risk signals are characteristic of many common inflammatory diseases and can function to activate nucleotide-binding oligomerization (NLR) family pyrin domain-containing 3 (NLRP3), the innate immune signal receptor in cytoplasm. The NLRP3 inflammasome plays an important role in the development of liver fibrosis. Activated NLRP3 nucleates the assembly of inflammasomes, leading to the secretion of interleukin (IL)-1ß and IL-18, the activation of caspase-1, and the initiation of the inflammatory process. Therefore, it is essential to inhibit the activation of the NLRP3 inflammasome, which plays a vital role in the immune response and in initiating inflammation. RAW 264.7 and LX-2 cells were primed with lipopolysaccharide (LPS) for 4 h and subsequently stimulated for 30 min with 5 mM of adenosine 5'-triphosphate (ATP) to activate the NLRP3 inflammasome. Thymosin beta 4 (Tß4) was supplemented to RAW264.7 and LX-2 cells 30 min before ATP was added. As a result, we investigated the effects of Tß4 on the NLRP3 inflammasome. Tß4 prevented LPS-induced NLRP3 priming by inhibiting NF-kB and JNK/p38 MAPK expression and the LPS and ATP-induced production of reactive oxygen species. Moreover, Tß4 induced autophagy by controlling autophagy markers (LC3A/B and p62) through the inhibition of the PI3K/AKT/mTOR pathway. LPS combined with ATP significantly increased thee protein expression of inflammatory mediators and NLRP3 inflammasome markers. These events were remarkably suppressed by Tß4. In conclusion, Tß4 attenuated NLRP3 inflammasomes by inhibiting NLRP3 inflammasome-related proteins (NLRP3, ASC, IL-1ß, and caspase-1). Our results indicate that Tß4 attenuated the NLRP3 inflammasome through multiple signaling pathway regulations in macrophage and hepatic stellate cells. Therefore, based on the above findings, it is hypothesized that Tß4 could be a potential inflammatory therapeutic agent targeting the NLRP3 inflammasome in hepatic fibrosis regulation.

Thymosin α1 and Its Role in Viral Infectious Diseases: The Mechanism and Clinical Application.

Thymosin α1 (Tα1) is an immunostimulatory peptide that is commonly used as an immune enhancer in viral infectious diseases such as hepatitis B, hepatitis C, and acquired immune deficiency syndrome (AIDS). Tα1 can influence the functions of immune cells, such as T cells, B cells, macrophages, and natural killer cells, by interacting with various Toll-like receptors (TLRs). Generally, Tα1 can bind to TLR3/4/9 and activate downstream IRF3 and NF-κB signal pathways, thus promoting the proliferation and activation of target immune cells. Moreover, TLR2 and TLR7 are also associated with Tα1. TLR2/NF-κB, TLR2/p38MAPK, or TLR7/MyD88 signaling pathways are activated by Tα1 to promote the production of various cytokines, thereby enhancing the innate and adaptive immune responses. At present, there are many reports on the clinical application and pharmacological research of Tα1, but there is no systematic review to analyze its exact clinical efficacy in these viral infectious diseases via its modulation of immune function. This review offers an overview and discussion of the characteristics of Tα1, its immunomodulatory properties, the molecular mechanisms underlying its therapeutic effects, and its clinical applications in antiviral therapy.

Thymosin Beta 4 Protects Hippocampal Neuronal Cells against PrP (106-126) via Neurotrophic Factor Signaling.

Prion protein peptide (PrP) has demonstrated neurotoxicity in brain cells, resulting in the progression of prion diseases with spongiform degenerative, amyloidogenic, and aggregative properties. Thymosin beta 4 (Tß4) plays a role in the nervous system and may be related to motility, axonal enlargement, differentiation, neurite outgrowth, and proliferation. However, no studies about the effects of Tß4 on prion disease have been performed yet. In the present study, we investigated the protective effect of Tß4 against synthetic PrP (106-126) and considered possible mechanisms. Hippocampal neuronal HT22 cells were treated with Tß4 and PrP (106-126) for 24 h. Tß4 significantly reversed cell viability and reactive oxidative species (ROS) affected by PrP (106-126). Apoptotic proteins induced by PrP (106-126) were reduced by Tß4. Interestingly, a balance of neurotrophic factors (nerve growth factor and brain-derived neurotrophic factor) and receptors (nerve growth factor receptor p75, tropomyosin related kinase A and B) were competitively maintained by Tß4 through receptors reacting to PrP (106-126). Our results demonstrate that Tß4 protects neuronal cells against PrP (106-126) neurotoxicity via the interaction of neurotrophic factors/receptors.

[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-1ß 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.

Thymosin ß4 is essential for thrombus formation by controlling the G-actin/F-actin equilibrium in platelets.

Coordinated rearrangements of the actin cytoskeleton are pivotal for platelet biogenesis from megakaryocytes but also orchestrate key functions of peripheral platelets in hemostasis and thrombosis, such as granule release, the formation of filopodia and lamellipodia, or clot retraction. Along with profilin (Pfn) 1, thymosin ß4 (encoded by Tmsb4x) is one of the two main G-actin-sequestering proteins within cells of higher eukaryotes, and its intracellular concentration is particularly high in cells that rapidly respond to external signals by increased motility, such as platelets. Here, we analyzed constitutive Tmsb4x knockout (KO) mice to investigate the functional role of the protein in platelet production and function. Thymosin ß4 deficiency resulted in a macrothrombocytopenia with only mildly increased platelet volume and an unaltered platelet life span. Megakaryocyte numbers in the bone marrow and spleen were unaltered, however, Tmsb4x KO megakaryocytes showed defective proplatelet formation in vitro and in vivo. Thymosin ß4-deficient platelets displayed markedly decreased G-actin levels and concomitantly increased F-actin levels resulting in accelerated spreading on fibrinogen and clot retraction. Moreover, Tmsb4x KO platelets showed activation defects and an impaired immunoreceptor tyrosine-based activation motif (ITAM) signaling downstream of the activating collagen receptor glycoprotein VI. These defects translated into impaired aggregate formation under flow, protection from occlusive arterial thrombus formation in vivo and increased tail bleeding times. In summary, these findings point to a critical role of thymosin ß4 for actin dynamics during platelet biogenesis, platelet activation downstream of glycoprotein VI and thrombus stability.