Thymosin beta 4 interactions

Treatable Traits in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic systemic disease within the spectrum of connective tissue diseases, specifically characterized by vascular abnormalities and inflammatory and fibrotic involvement of the skin and internal organs resulting in high morbidity and mortality. The clinical phenotype of SSc is heterogeneous, and serum autoantibodies together with the extent of skin involvement have a predictive value in the risk stratification. Current recommendations include an organ-based management according to the predominant involvement with only limited individual factors included in the treatment algorithm. Similar to what has been proposed for other chronic diseases, we hypothesize that a "treatable trait" approach based on relevant phenotypes and endotypes could address the unmet needs in SSc stratification and treatment to maximize the outcomes. We provide herein a comprehensive review and a critical discussion of the literature regarding potential treatable traits in SSc, focusing on established and candidate biomarkers, with the purpose of setting the bases for a precision medicine-based approach. The discussion, structured based on the organ involvement, allows to conjugate the pathogenetic mechanisms of tissue injury with the proposed predictors, particularly autoantibodies and other serum biomarkers. Ultimately, we are convinced that precision medicine is the ideal guide to manage a complex condition such as SSc for which available treatments are largely unsatisfactory.

Thymosin β4 cytoplasmic/nuclear translocation as a new marker of cellular stress. A Caco2 case study

Biomarkers of cell stress are important for proper diagnosis, and in studies of how cells respond to drug treatment. Biomarkers that respond early to pharmacological treatment could improve therapy by tailoring the treatment to the needs of the patient. Thymosin beta-4 (Tβ₄) plays a significant role in many aspects of cellular metabolism because of its actin-sequestering properties. Other physiological functions of Tβ₄ have been also reported. Among these, Tβ₄ may play a crucial role during cellular stress. We addressed the relevance of Tβ₄ in cellular stress conditions by using different treatments (serum starvation, DMSO, and butyrate administration) in a colon adenocarcinoma cell line (CaCo2), a cell line frequently used for in vitro experimental studies of Tβ₄. In this study, different stress stimuli were analyzed and the obtained results were compared using immunocytochemistry, and molecular and biochemical methods. Taken together, the data clearly indicate that the Tβ₄ peptide is involved in adaptive and defensive cellular mechanisms, and that different stress inducers lead to a similar Tβ₄ cytoplasmic/nuclear translocation. The translocation of Tβ₄ between the cytoplasm and the nucleus of the cell seems characteristic of a possible molecular response to cellular stress exerted by this peptide.

Biomarkers of cell stress are important for proper diagnosis, and in studies of how cells respond to drug treatment.

Effect of vitamin A deficiency on thymosin-β4 and CD4 concentrations

Vitamins are evaluated for their role in immunity. Recently, vitamin A received a particular attention as a critical micronutrient for regulating immune system. Therefore, the present study aimed to search for new about vitamin A. Forty-eight Egyptian adults aged from 18 to 42 years old from both sexes were subjected to clinical examination and nutrition questionnaire and were screened for vitamin A by using ELISA method. Forty subjects were selected and subdivided into two groups. Group 1 with vitamin A at level >200 µg/dl consists of 10 healthy subjects. Group 2 with vitamin A deficiency at level <50 µg/dl consists of 30 subjects. Tβ4 and CD4 levels were also determined by a commercial ELISA kit. Results showed a significant decrease in serum levels of Tβ4 and CD4 in group 2 than group 1 at P < .003 and P < .019 respectively. Both of Tβ4 and CD4 had positive correlation with vitamin A level at P < .000 and P < .003 respectively as well as with each other at p < .000. We concluded that vitamin A deficiency may be influence the levels of Tβ4 and CD4.

The Hidden Function of Vitamin D

AIM:

There are no reports regarding the influence of vitamin D on thymosin ß4 and the cluster of differentiation CD4 levels which are important for maintaining a healthy immune system. Consequently, we aimed to explore this relationship through a study.

MATERIAL AND METHODS:

The study was carried out on 35 subjects, screened for 25-hydroxy vitamin D[25 (OH) D] using ELISA method and they were divided into two groups: Group 1 consists of 10 healthy subjects with sufficient vit. D level > 24.8 ng/ml. Group 2 consists of 25 subjects suffering, severely, from vitamin D deficiency at level < 11.325 ng/ml. Also, Thymosin ß4, CD4 and zinc levels were performed.

RESULTS:

There were significant differences between the two groups in the concentration levels of thymosin β4, as the group 1 has shown higher levels (P = 0.005). Whereas, CD4 and zinc levels didn’t show any significant difference between the two groups. At the same time, a significant positive correlation has been observed between vitamin D, thymosin β4, and CD4 at (r = 0.719; P = 0.001), and (r = 0.559, P = 0.001) respectively.

CONCLUSION:

We concluded that vitamin D may be an essential factor that influence or determine the level of thymosin β4. This study is the first that focused on demonstrating that sufficient level of vitamin D may have the ability to influence the thymic hormone thymosin β4 levels. Further studies on large scale of subjects are needed to explore the positive correlation we had found between vitamin D and thymosin β4 and CD4.

Neuroprotective and neurorestorative effects of thymosin β4 treatment initiated 6 hours after traumatic brain injury in rats

OBJECT

Thymosin β4 (Tβ4) is a regenerative multifunctional peptide. The aim of this study was to test the hypothesis that Tβ4 treatment initiated 6 hours postinjury reduces brain damage and improves functional recovery in rats subjected to traumatic brain injury (TBI).

METHODS

Traumatic brain injury was induced by controlled cortical impact over the left parietal cortex in young adult male Wistar rats. The rats were randomly divided into the following groups: 1) saline group (n = 7); 2) 6 mg/kg Tβ4 group (n = 8); and 3) 30 mg/kg Tβ4 group (n = 8). Thymosin β4 or saline was administered intraperitoneally starting at 6 hours postinjury and again at 24 and 48 hours. An additional group of 6 animals underwent surgery without TBI (sham-injury group). Sensorimotor function and spatial learning were assessed using the modified Neurological Severity Score and the Morris water maze test, respectively. Animals were euthanized 35 days after injury, and brain sections were processed to assess lesion volume, hippocampal cell loss, cell proliferation, and neurogenesis after Tβ4 treatment.

RESULTS

Compared with saline administration, Tβ4 treatment initiated 6 hours postinjury significantly improved sensorimotor functional recovery and spatial learning, reduced cortical lesion volume and hippocampal cell loss, and enhanced cell proliferation and neurogenesis in the injured hippocampus. The high dose of Tβ4 showed better beneficial effects compared with the low-dose treatment.

CONCLUSIONS

Thymosin β4 treatment initiated 6 hours postinjury provides both neuroprotection and neurorestoration after TBI, indicating that Tβ4 has promising therapeutic potential in patients with TBI. These data warrant further investigation of the optimal dose and therapeutic window of Tβ4 treatment for TBI and the associated underlying mechanisms.

Thymosin beta 4 prevents oxidative stress by targeting antioxidant and anti-apoptotic genes in cardiac fibroblasts

Rationale

Thymosin beta-4 (Tβ4) is a ubiquitous protein with diverse functions relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory responses. The effecter molecules targeted by Tβ4 for cardiac protection remains unknown. The purpose of this study is to determine the molecules targeted by Tβ4 that mediate cardio-protection under oxidative stress.

Methods

Rat neonatal fibroblasts cells were exposed to hydrogen peroxide (H₂O₂) in presence and absence of Tβ4 and expression of antioxidant, apoptotic and pro-fibrotic genes was evaluated by quantitative real-time PCR and western blotting. Reactive oxygen species (ROS) levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant and antiapoptotic genes were silenced by siRNA transfections in cardiac fibroblasts and the effect of Tβ4 on H₂O₂-induced profibrotic events was evaluated.

Results

Pre-treatment with Tβ4 resulted in reduction of the intracellular ROS levels induced by H₂O₂ in the cardiac fibroblasts. This was associated with an increased expression of antioxidant enzymes Cu/Zn superoxide dismutase (SOD) and catalase and reduction of Bax/Bcl₂ ratio. Tβ4 treatment reduced the expression of pro-fibrotic genes [connective tissue growth factor (CTGF), collagen type-1 (Col-I) and collagen type-3 (Col-III)] in the cardiac fibroblasts. Silencing of Cu/Zn-SOD and catalase gene triggered apoptotic cell death in the cardiac fibroblasts, which was prevented by treatment with Tβ4.

Conclusion

This is the first report that exhibits the targeted molecules modulated by Tβ4 under oxidative stress utilizing the cardiac fibroblasts. Tβ4 treatment prevented the profibrotic gene expression in the in vitro settings. Our findings indicate that Tβ4 selectively targets and upregulates catalase, Cu/Zn-SOD and Bcl₂, thereby, preventing H₂O₂-induced profibrotic changes in the myocardium. Further studies are warranted to elucidate the signaling pathways involved in the cardio-protection afforded by Tβ4.

Exogenous thymosin beta4 prevents apoptosis in human intervertebral annulus cells in vitro

Loss of cells in the human disc due to programmed cell death (apoptosis) is a major factor in the aging and degenerating human intervertebral disc. Our objective here was to determine if thymosin beta(4) (TB4), a small, multifunctional 5 kDa protein with diverse activities, might block apoptosis in human annulus cells cultured in monolayer or three-dimensional (3D) culture. Apoptosis was induced in vitro using hydrogen peroxide or serum starvation. Annulus cells were processed for identification of apoptotic cells using the TUNEL method. The percentage of apoptotic cells was determined by cell counts. Annulus cells also were treated with TB4 for determination of proliferation, and proteoglycan production was assessed using cell titer and 1,2 dimethylmethylamine (DMB) assays and histological staining. A significant reduction in disc cell apoptosis occurred after TB4 treatment. The percentage of cells undergoing apoptosis decreased significantly in TB4 treated cells in both apoptosis induction designs. TB4 exposure did not alter proteoglycan production as assessed by either DMB measurement or histological staining. Our results indicate the need for further studies of the anti-apoptotic effect of TB4 and suggest that TB4 may have therapeutic application in future biological therapies for disc degeneration.

Study of the human plasma proteome of rheumatoid arthritis

In this study, we report a combined proteomic and peptidomic analysis of human plasma from patients with rheumatoid arthritis (RA) and controls. We used molecular weight cut-off filters (MWCO: 10kDa) to enrich low-molecular-weight (LMW) peptides from human plasma. The peptide fraction was analyzed without trypsin digestion by capillary reversed-phase high-performance liquid chromatography (HPLC) coupled to a linear ion trap-FT-MS system, which identified 771 unique peptides in the peptidome study (from 145 protein progenitors). An anti-albumin/anti-IgG column was used to remove albumin and immunoglobulin G (IgG) from the human plasma. After that, the albumin/IgG-depleted sample was fractionated into a bound fraction and an unbound fraction on a multi-lectin affinity column (M-LAC). LC-MS analysis of the corresponding tryptic digests identified 308 proteins using the M-LAC approach. Relative differences in the following protein classifications were observed in the RA human plasma samples compared with controls: structural proteins, immuno-related proteins, protease inhibitors, coagulation proteins, transport proteins and apolipoproteins. While some of these proteins/peptides have been previously reported to be associated with RA disease such as calgranulin A, B, C and C-reactive protein, several others were newly identified (such as thymosin beta4, actin, tubulin, and vimentin), which may further the understanding of the disease pathogenesis. Moreover, we have found that the peptidomic and glycoproteomic approaches were complementary and allow a more complete picture of the human plasma proteome which can be valuable in studies of disease etiology.

Functional anthology of intrinsic disorder. 3. Ligands, post-translational modifications, and diseases associated with intrinsically disordered proteins

Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was devoted to the presentation of 87 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions (Vucetic, S.; Xie, H.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions. J. Proteome Res. 2007, 5, 1899-1916). Protein structure and functionality can be modulated by various post-translational modifications or/and as a result of binding of specific ligands. Numerous human diseases are associated with protein misfolding/misassembly/misfunctioning. This work concludes the series of papers dedicated to the functional anthology of intrinsic disorder and describes approximately 80 Swiss-Prot functional keywords that are related to ligands, post-translational modifications, and diseases possessing strong positive or negative correlation with the predicted long disordered regions in proteins.

Most expressed transcripts in sexual organs and other tissues

This study characterizes the most highly expressed transcripts of 15 intact tissues in mice by using the serial analysis of gene expression (SAGE) strategy which indicates the relative level of expression for each transcript matched to the tag. We show that the most abundant transcripts in the prostate, testis, and skeletal muscle characterize the main functions of these organs as an exocrine gland of male reproduction, spermatogenesis, and contraction, respectively. In addition, the top nine most abundant transcripts in the testis are tissue-specific genes while the most abundant transcripts in the prostate are also abundantly expressed in the liver. Furthermore, the most abundant transcripts in the ovary, mammary gland, and vagina are related to steroidogenesis, adipocytes, and keratinization, respectively, whereas genes involved in the cell defence are abundantly expressed in the liver, lung, bone, mammary gland, and adipose tissue. These findings suggest that the top 10 transcripts are sufficient to characterize each tissue of the body.

Phylogenetic analysis and developmental expression of thymosin-β4 gene in amphioxus

Thymosin-beta4 is a highly conserved actin-binding protein that plays an important role in multiple early developmental events and functions in keeping the adult life in vertebrates. Here a cDNA for a thymosin-beta4 gene was isolated from the amphioxus, Branchiostoma belcheri. A molecular phylogenetic tree constructed from the deduced amino acid sequence of the isolated cDNA indicates that this gene belongs to the thymosin-beta4 subfamily, but it is split at the base of the vertebrate gene clade in evolution. In situ hybridization reveals that the expression is detected in the locations homologous to orthologous genes expressing regions of vertebrate embryos and adults, such as the neural plate, neural tube, paraxial mesoderm, differentiating somites, pharynx and gut, midgut diverticulus, blood vessels and body spaces. These results are interpreted to mean that thymosin-beta4 genes might play a conserved role in the patterning of chordate embryos and functions in adults.

Microarray and real-time RT-PCR analyses of differential human gene expression patterns induced by severe acute respiratory syndrome (SARS) coronavirus infection of Vero cells

Vero E6 African green monkey kidney cells are highly susceptible to infection with the newly emerging severe acute respiratory syndrome coronavirus (SARS-CoV), and they are permissive for rapid viral replication, with resultant cytopathic effects. We employed cDNA microarray analysis to characterize the cellular transcriptional responses of homologous human genes at 12 h post-infection. Seventy mRNA transcripts belonging to various functional classes exhibited significant alterations in gene expression. There was considerable induction of heat shock proteins that are crucial to the immune response mechanism. Modified levels of several transcripts involved in pro-inflammatory and anti-inflammatory processes exemplified the balance between opposing forces during SARS pathogenesis. Other genes displaying altered transcription included those associated with host translation, cellular metabolism, cell cycle, signal transduction, transcriptional regulation, protein trafficking, protein modulators, and cytoskeletal proteins. Alterations in the levels of several novel transcripts encoding hypothetical proteins and expressed sequence tags were also identified. In addition, transcription of apoptosis-related genes DENN and hIAP1 was upregulated in contrast to FAIM. Elevated Mx1 expression signified a strong host response to mediate antiviral resistance. Also expressed in infected cells was the C-terminal alternative splice variant of the p53 tumor suppressor gene encoding a modified truncated protein that can influence the activity of wild-type p53. We observed the interplay between various mechanisms to favor virus multiplication before full-blown apoptosis and the triggering of several pathways in host cells in an attempt to eliminate the pathogen. Microarray analysis identifies the critical host–pathogen interactions during SARS-CoV infection and provides new insights into the pathophysiology of SARS.