Protein biomarkers associated with frozen Japanese puffer fish (Takifugu rubripes) quality traits.

This study was designed to investigate proteome changes in Japanese puffer fish (Takifugu rubripes) during short- and long-term frozen storage. In total, 1484 proteins were quantified, and 164 proteins were identified as differential abundance proteins (DAPs) in Japanese puffer fish from two frozen storage treatment groups (14 days and 60 days) compared with the fresh control group. Correlation analysis between the DAPs and quality traits of the puffer fish muscle showed that 106 proteins were correlated closely with colour and texture (hardness, elasticity, and chewiness). Bioinformatics analysis revealed and Western blot analysis verified that Putative prothymosin alpha species, Bridging integrator 3, NADH: the ubiquinone oxidoreductase subunit and Mx species are candidate biomarkers for puffer fish properties. This study offers valuable evidence to improve the quality control and monitoring of Japanese puffer fish during transportation and storage.

Protective Effect of Thymosin ß4 against Abdominal Aortic Ischemia-Reperfusion-Induced Acute Lung Injury in Rats.

Background and objectives: Ischemia-reperfusion (IR) caused by infrarenal abdominal aorta cross-clamping is an important factor in the development of ischemia-reperfusion injury in various distant organs. Materials and Methods: We investigated potential antioxidant/anti-inflammatory effects of thymosin beta 4 (Tß4) in a rat model of abdominal aortic surgery-induced IR. Tß4 (10 mg/kg, intravenous (i.v.)) was administered to rats with IR (90-min ischemia, 180-min reperfusion) at two different periods. One group received Tß4 1 h before ischemia, and the other received 15 min before the reperfusion period. Results: Results were compared to control and non-Tß4-treated rats with IR. Serum, bronchoalveolar lavage fluid and lung tissue levels of oxidant parameters were higher, while antioxidant levels were lower in the IR group compared to control. IR also increased inflammatory cytokine levels. Tß4 reverted these parameters in both Tß4-treated groups compared to the untreated IR group. Conclusions: Since there is no statistical difference between the prescribed results of both Tß4-treated groups, our study demonstrates that Tß4 reduced lung oxidative stress and inflammation following IR and prevented lung tissue injury regardless of timing of administration.

Thymosin fraction 5 re-evaluated after 35 years by high-resolution mass spectrometry.

OBJECTIVES: We reevaluated a lyophilized sample of thymosin fraction 5, stored for 37 years at room temperature, by high-resolution mass spectrometry in terms of stability and yet uncharacterized polypeptides that could be biological important substances. METHODS: A top-down proteomic platform based on high-performance liquid chromatography (HPLC) coupled to high-resolution LTQ-Orbitrap mass spectrometry (MS) was applied to molecular characterization of polypeptides present in thymosin fraction 5. RESULTS: We detected more than 100 monoisotopic masses corresponding to thymosin ß4 and truncated forms of ubiquitin, prothymosin α, thymosin ß4, and thymosin ß9. Additionally, we discovered a new polypeptide present in thymosin fraction 5 and identified it as intact SH3 domain-binding glutamic acid-rich-like protein 3. CONCLUSION: In spite of the well-known proteolytic processes inherent to the preparation of thymosin fraction 5, still uncharacterized polypeptides as well as truncated forms of already well-known thymosins are present in fraction 5 after long-term storage. Therefore, continuing characterization of thymosin fraction 5 is even nowadays highly promising.

Sources of variability in quantifying circulating thymosin beta-4: literature review and recommendations.

INTRODUCTION: Thymosin beta-4 (TB4) is an endogenous peptide with protective and regenerative effects in models of cellular and organ injury. TB4 is increasingly measured as a potential plasma or serum biomarker in human cardiovascular, liver, infectious, and autoimmune disease. AREAS COVERED: The focus of this review is the quantification of TB4 in clinical cohort studies and whether reported TB4 concentrations differ with respect to method of sample preparation. We survey current literature for studies measuring TB4 in human serum or plasma and compare reported concentrations in healthy controls. EXPERT OPINION: We find substantial intra- and inter- study variability in healthy controls, and a lack of protocol standardization. We further highlight three factors that may confound TB4 clinical measurements and should be considered in future study design: 1) residual platelets remaining in suspension after centrifugation, 2) TB4 release following ex vivo platelet activation, and 3) specificity of assays towards posttranslational modifications. Accordingly, we put forth our recommendations to minimize residual and activated platelets during sample collection, and to cross-validate TB4 measurements using both antibody-based and mass spectrometry-based methods.

Thymosin beta-4 overexpression correlates with high-risk groups in gastric gastrointestinal stromal tumors: A retrospective analysis by immunohistochemistry.

BACKGROUND: Thymosin beta-4 (Tß4) is a protein that is linked to a number of important biological actions and recently tumor progression and poor prognosis of some tumors. The aim of this study was to evaluate Tß4 expression in gastric GISTs and correlate with some clinicopathological characteristics related with prognosis and clinical outcome in order to add further data to the current literature. METHODS: Tß4 antibody was applied to the 4µm-thick paraffin sections of 57 gastric GISTs by immunohistochemistry. RESULTS: Tß4 expression was found to be directly corrrelated with higher risk groups, tumor size, mitotic count, cellularity, and necrosis while it was inversely correlated with overall survival (OS) by univariate analysis (p=0.000, p=0.001, p=0.000, p=0.025, p=0.023, and p=0.042, respectively). The direct association between Tß4 expression and risk groups were also supported by multivariate analysis (p=0.000, ß=0.497, t=4.374). CONCLUSION: Overexpression of Tß4 was found to be related with predictive characteristics for tumor progression and adverse prognosis. Thus, we suggest that overexpression of Tß4 might play a role in the progression of gastric GISTs and might be used as a potential prognostic tool as well as a target for novel therapies.

Endogenous Thymosin ß4 Expression in Sacrococcygeal Pilonidal Sinus Disease: A Retrospective, Immunohistochemical Analysis of Excisional Skin Biopsy Samples.

Thymosin beta 4 (Tß4) is a peptide that has been shown in dermal, corneal, and cardiac preclinical injury models to potentially affect tissue protection, regeneration, and repair. Sacrococcygeal pilonidal sinus disease (SPSD) is a chronic inflammatory disorder associated with a high incidence of recurrence, chronic fistulation, and a challenging postoperative surgical wound healing process. Retrospectively, an immunohistochemical analysis was conducted to evaluate endogenous Tß4 expression in excisional skin biopsies from patients with SPSD. Patient demographics (age, gender) and surgical procedure data were obtained from their electronic medical records. Two (2) samples were cut from each specimen and prepared for histopathological assessment: 1 from the inflamed sinus tracts containing hair and granulation tissue (chronic wound group) and 1 from the normal tissue at least 1 cm away from the sinus tract (control group). Tß4 expression was evaluated in the epidermal, dermal/subcutaneous collagen, and vascular structures of the samples from the sinus tract and healthy tissue. Inflamed sinus tract tissue and noninflamed normal tissue adjacent to the sinus tract were sampled from each specimen to confirm the diagnosis of SPSD and to determine distribution and intensity of Tß4 expression. Presence of cytoplasmic staining for Tß4 was considered in favor of positive Tß4 expression; intensity of Tß4 expression was scored as 0 = no staining, 1 = mild, 2 = moderate, and 3 = strong level of expression. A total of 31 excisional skin biopsy specimens were available from 31 patients with SPSD (mean age 26.0 ± 7.6 years, 25 [80.6%] men, 6 [19.4%] women) who underwent primary surgical closure. Demographic variables were analyzed using descriptive statistics. Data compliance with normal distribution was evaluated using the Kolmogorov-Smirnov and Shapiro-Wilk tests, and the Mann-Whitney U test was used for comparison of numerical data. P <.05 was considered statistically significant. Inflamed sinus tract tissue had significantly higher Tß4 expression scores than noninflamed tissue samples in the epidermis (2.4 ± 0.8 [1.0-3.0] versus 0.8 ± 0.5 [0.0-2.0], P = .000), dermal/subcutaneous collagen (2.6 ± 0.5 [2.0-3.0] versus 1.6 ± 0.5 [1.0-2.0], P = .000), and vascular structure (2.6 ± 0.5 [2.0-3.0] versus 1.1 ± 0.3 [1.0-2.0], P = .000). Study findings indicate Tß4 is endogenously expressed in normal skin tissue and is overexpressed in inflamed sinus tract tissue in patients with SPSD. Preclinical studies with a larger sample size are needed to enhance understanding of the potential role of Tß4 in the inflammatory and tissue remodeling processes of SPSD by elucidating its mechanism of action at the molecular level, physiological role, and the therapeutic potential in dermal healing.

Selective improvement of peptides imaging on tissue by supercritical fluid wash of lipids for matrix-assisted laser desorption/ionization mass spectrometry.

There is a high analytical demand for improving the detection sensitivity for various peptides in matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) because exhaustive distribution analyses of various peptides could help to reveal the function of peptides in vivo. To improve the sensitivity of peptide detection, we used supercritical fluid of CO2 (scCO2) as washing solvent for a pretreatment to remove lipids. We evaluated whether our wash method using scCO2 with an entrainer improved the detection of peptides and suppressed lipid detection in MALDI-IMS. Our analysis revealed that the signal intensities of peptides such as m/z 3339.8, 3530.9, 4233.3, 4936.7, and 4963.7 were increased in scCO2-washed samples. The greatest improvement in the signal-to-noise ratio (S/N) was found at m/z 4963.7, which was identified as thymosin ß4, with the S/N reaching almost 190-fold higher than the control. Additionally, all of the improved signals were associated with the morphologic structure. Our method allows us to analyze the distribution of molecules, especially in the region of m/z 3000-5200. For these improvements, the polarity difference between scCO2 and the matrix solution used was considered as a key. A wider variety of molecules can be analyzed in the future due to this improvement of the detection sensitivity by optimizing the polarity of scCO2 with various entrainers. Graphical Abstract Mass spectra of m/z 4900-5000 obtained from a scCO2-washed tissue (upper, blue) and a control tissue (lower, red). Ion distribution of the signals at m/z 4936.7 and m/z 4963.7 specifically ditected from scCO2-washed samples.

Thymosin ß4 overexpression regulates neuron production and spatial distribution in the developing avian optic tectum.

Thymosin ß4 (Tß4), the principal G-actin regulating entity in eukaryotic cells, has also multiple intra- and extracellular functions related to tissue regeneration and healing. While its effect in adult organs is being widely investigated, currently, little is known about its influence on embryonic tissues, i.e., in the developing nervous system. The importance of Tß4 for neural stem cell proliferation in the embryonic chicken optic tectum (OT) has previously been shown by us for the first time. In the present study, using in ovo electroporation, we carried out a quantification of the effects of the Tß4-overexpression on the developing chicken OT between E4 and E6 at the hemisphere as well as cellular level. We precisely examined tissue growth and characterized cells arising from the elevated mitotic activity of progenitor cells. By using spinning-disk confocal laser scanning microscopy, we were able to visualize these effects across whole OT sections. Our experiments now demonstrate more clearly that the overexpression of Tß4 leads to a tangential expansion of the treated OT-hemisphere and that, under these circumstances, overall density of tectal and in particular of postmitotic neuronal cells is increased. Thanks to this new quantitative approach, the present results extend our previous findings that Tß4 is important for the proliferation of progenitor cells, neurogenesis, tangential expansion, and tissue growth in the young embryonic chicken optic tectum. Taken together, our results further illustrate and support the current idea that Tß4 is widely implicated in shaping and maintenance of the nervous system.

Matrix-assisted laser desorption/ionization imaging mass spectrometry for the spatial location of feline oviductal proteins.

With the purpose of identifying factors involved in early stages of embryo development in the domestic cat, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) was used for the first time to describe the spatial localization of proteins in the oviducts of queens. Oviducts were obtained from two 2 and 4 years old cross-bred queens, divided into three segments, snap-frozen in liquid nitrogen and then stored at -80°C until use. Next, they were sectioned in a cryostat, fixed on ITO (indium tin oxide) conductive glass slides for MALDI-IMS and serial sections were collected on microscope slides for histology. As confirmed by histology, MALDI-IMS was able to show contrasting protein distributions in the oviductal infundibulum, ampulla and isthmus. Mass spectra were characterized by abundant ions of m/z 1,259, 4,939, 4,960 and 10,626, which have been tentatively attributed to keratin, thymosin ß10, thymosin ß4 and S100, respectively. Keratin and thymosins are involved in the biological response to tissue damage. S100 proteins are calcium-modulated proteins implicated in a variety of cellular activities, including cell differentiation and regulation of cell motility. These results suggest that protein composition differs between segments of the cat oviduct, which corresponds to morphological changes within these sections. Further functional studies could elucidate the effects of these proteins on feline reproductive physiology.

MALDI imaging mass spectrometry analysis-A new approach for protein mapping in multiple sclerosis brain lesions.

Multiple sclerosis is a disease of the central nervous system characterized by recurrent inflammatory demyelinating lesions in the early disease stage. Lesion formation and mechanisms leading to lesion remyelination are not fully understood. Matrix Assisted Laser Desorption Ionisation Mass Spectrometry imaging (MALDI-IMS) is a technology which analyses proteins and peptides in tissue, preserves their spatial localization, and generates molecular maps within the tissue section. In a pilot study we employed MALDI imaging mass spectrometry to profile and identify peptides and proteins expressed in normal-appearing white matter, grey matter and multiple sclerosis brain lesions with different extents of remyelination. The unsupervised clustering analysis of the mass spectra generated images which reflected the tissue section morphology in luxol fast blue stain and in myelin basic protein immunohistochemistry. Lesions with low remyelination extent were defined by compounds with molecular weight smaller than 5300Da, while more completely remyelinated lesions showed compounds with molecular weights greater than 15,200Da. An in-depth analysis of the mass spectra enabled the detection of cortical lesions which were not seen by routine luxol fast blue histology. An ion mass, mainly distributed at the rim of multiple sclerosis lesions, was identified by liquid chromatography and tandem mass spectrometry as thymosin beta-4, a protein known to be involved in cell migration and in restorative processes. The ion mass of thymosin beta-4 was profiled by MALDI imaging mass spectrometry in brain slides of 12 multiple sclerosis patients and validated by immunohistochemical analysis. In summary, our results demonstrate the ability of the MALDI-IMS technology to map proteins within the brain parenchyma and multiple sclerosis lesions and to identify potential markers involved in multiple sclerosis pathogenesis and/or remyelination.

The expression of thymosin ß4 in chronic hepatitis B combined nonalcoholic fatty liver disease.

The aim of the study was to detect the expression level of thymosin ß4 (Tß4) in serum and tissues of patients with chronic hepatitis B (CHB) combined nonalcoholic fatty liver disease (NAFLD). The effects of Tß4 in hepatic steatosis, chronic inflammation, and fibrosis development in CHB combined NAFLD patients were also discussed. The study included 46 patients in the case group with CHB and NAFLD and 42 patients in the control group with CHB. ELISA was applied to detect serum Tß4 and TNF-α level. Furthermore, the correlation analysis of Tß4 levels with biochemical index, pathological index, and TNF-α level was performed. The Tß4 immunohistochemical levels of different inflammation fibrosis levels were compared, and the correlation analysis with TNF expression was performed. The Tß4 levels in patients with CHB combined NAFLD showed no statistical difference when compared to the control group. In patients with CHB combined NAFLD group, the Tß4 level had no correlation with ALT, AST, TG, FGP, hepatitis B virus (HBV)-DNA levels, and fat grading, but had negative correlation with inflammation score and fibrosis score (P <0.01). The immunohistochemical results of hepatic tissues showed that the expression intensity of severe inflammation fibrosis group had statistical significance compared with that of slight group, and the Tß4 expression both in serum and in liver tissue negatively correlated with TNF-α expression. Tß4 could be involved in the regulation of chronic inflammation and fibrosis and plays a defense role in the disease progression of CHB combined NAFLD patients.

High-resolution mass spectrometry for thymosins detection and characterization.

OBJECTIVES: The aim of this study was to characterize ß and α thymosins and their proteoforms in various tissues and bodily fluids by mass spectrometry and to look at their association with a wide variety of pathologies. METHODS: A top-down proteomic platform based on high-performance liquid chromatography (HPLC) coupled to high-resolution LTQ-Orbitrap mass spectrometry (MS) was applied to the characterization of naturally occurring peptides. RESULTS: In addition to thymosin ß4 (Tß4) and ß10 (Tß10), several post-translational modifications of both these peptides were identified not only in bodily fluids but also in normal and pathological tissues of different origins. The analysis of tissue specimens allowed the characterization of different C-terminal truncated forms of Tß4 and Tß10 together with other proteolytic fragments. The sulfoxide derivative of both Tß4 and Tß10 and the acetylated derivatives at lysine residues of Tß4 were also characterized. Different proteoforms of prothymosin α, parathymosin α, thymosin α1 and thymosin α11 together with diverse proteolytic fragments were identified too. CONCLUSION: The clinical and prognostic significance and the origin of these proteoforms have to be deeply investigated.

Potential role of thymosin Beta 4 in liver fibrosis.

Liver fibrosis, the main characteristic of chronic liver diseases, is strongly associated with the activation of hepatic stellate cells (HSCs), which are responsible for extracellular matrix production. As such, investigating the effective regulators controlling HSC activation provides important clues for developing therapeutics to inhibit liver fibrosis. Thymosin beta 4 (Tß4), a major actin-sequestering protein, is known to be involved in various cellular responses. A growing body of evidence suggests that Tß4 has a potential role in the pathogenesis of liver fibrosis and that it is especially associated with the activation of HSCs. However, it remains unclear whether Tß4 promotes or suppresses the activation of HSCs. Herein, we review the potential role of Tß4 in liver fibrosis by describing the effects of exogenous and endogenous Tß4, and we discuss the possible signaling pathway regulated by Tß4. Exogenous Tß4 reduces liver fibrosis by inhibiting the proliferation and migration of HSCs. Tß4 is expressed endogenously in the activated HSCs, but this endogenous Tß4 displays opposite effects in HSC activation, either as an activator or an inhibitor. Although the role of Tß4 has not been established, it is apparent that Tß4 influences HSC activation, suggesting that Tß4 is a potential therapeutic target for treating liver diseases.

Expression of prothymosin alpha predicts early recurrence and poor prognosis of hepatocellular carcinoma.

BACKGROUND: Prothymosin alpha (PTMA) is a nuclear oncoprotein-transcription factor essential for cell cycle progression and proliferation. PTMA was overexpressed in several human malignancies including hepatocellular carcinoma (HCC). However, the prognostic significance of PTMA protein expression in HCC remains unclear. In the present study, we evaluated PTMA protein expression by immunohistochemistry in order to elucidate the prognostic roles of PTMA in HCC patients. METHODS: By immunohistochemistry, we investigated the expression of PTMA protein in tumor tissue from 226 HCC patients who underwent curative hepatectomy. Univariate and multivariate analyses were performed to evaluate its predictive value for tumor recurrence and survival of patients. The median follow-up period was 120 months. RESULTS: PTMA expression was observed in 162 (71.7%) of the 226 HCC patients and was significantly associated with higher Edmondson grade, microvascular invasion, intrahepatic metastasis, higher American Joint Committee on Cancer (AJCC) T-stage, and lower albumin level. PTMA expression was an independent predictor of early recurrence (P=0.001). PTMA expression showed an unfavorable influence on recurrence-free survival (RFS) (P<0.001). Subgroup analysis showed that among patients with tumor size ≤5.0 cm (140 patients), patients at AJCC T-stage 1 (95 patients) and patients with alpha-fetoprotein ≤20 ng/mL (83 patients), the differences in RFS between PTMA-positive and PTMA-negative groups were also statistically significant (P=0.017, P=0.002 and P=0.002, respectively). In addition, PTMA expression was an independent predictor of shorter RFS (P=0.011). PTMA expression showed an unfavorable influence on overall survival (P=0.014), but was not an independent predictor of shorter overall survival (P=0.161). CONCLUSIONS: PTMA protein expression might be a novel predictor of early recurrence and RFS in HCC patients, even those at early stage or with alpha-fetoprotein-negative after curative hepatectomy. PTMA could be used as an immunohistochemical biomarker to detect patients with a high risk of recurrence.

Loss of nuclear prothymosin-α expression is associated with disease progression in human superficial bladder cancer.

In this paper, we report a study on the clinical relevance of prothymosin-α expression and its correlation with intratumoral Foxp3(+) and CD8(+) lymphocytes (Foxp3(+)TIL and CD8(+)TIL) in bladder cancer patients. We used immunohistochemical staining for prothymosin-α, Foxp3, and CD8 on 101 tumor specimens harvested by endoscopic resection. The results were correlated with clinicopathological variables and clinical outcome in bladder cancer patients, particularly in 73 patients with superficial disease, using the log-rank test and Cox proportional hazard model. Overall, of the tumors, 30 % were negative, 34 % showed nuclear, and 37 % showed cytoplasmic prothymosin-α expression. Foxp3(+)TILs were detected in 11 % of patients (nonnuclear vs. nuclear, p = 0.096). Patients with a history of urothelial carcinoma have a higher frequency of nonnuclear prothymosin-α expression than those without (p = 0.016, chi-square test). By univariate and multivariate analyses of cases with superficial disease, grade and stage were identified as independent predictors for recurrence-free survival (p = 0.016 and 0.016, respectively). Higher stage and nonnuclear prothymosin-α expression independently predict shorter progression-free survival (p = 0.006 and 0.043, respectively). The presence of Foxp3(+)TILs was significantly associated with disease progression by univariate analysis (p = 0.022), but not by multivariate analysis (p = 0.147). In vitro assays showed that J82 cells which express ectopically nuclear prothymosin-α exhibit higher growth rate and secrete less TGF-ß1 than those with cytoplasmic expression or control cells. Altogether, prothymosin-α expression is a determinant of disease progression in superficial bladder cancer. Foxp3(+)TILs tend to be found more often in bladder cancer with nonnuclear prothymosin-α expression. Future study is required to unravel their interaction.

Thymosin ß4 expression in colorectal polyps and adenomas.

OBJECTIVE: Thymosin beta 4 (Tß4) is a ubiquitous peptide that plays pivotal roles in the cytoskeletal system and in cell differentiation. Recently, a role for Tß4 has been proposed in experimental and human carcinogenesis, including gastrointestinal cancer. This study was aimed at evaluating the relationship between Tß4 immunoreactivity and the initial steps of carcinogenesis. METHODS: In total, 60 intestinal biopsies, including 10 hyperplastic polyps, 10 sessile serrated adenomas/polyps, 15 colorectal adenomas with low-grade dysplasia, 15 adenomas with high-grade dysplasia, 15 adenocarcinomas and 10 samples of normal colon mucosa, were analyzed for Tß4 expression by immunohistochemistry. RESULTS: Weak cytoplasmic reactivity for Tß4 was detected in the normal colon mucosa. No reactivity for Tß4 was found in hyperplastic and sessile serrated polyps/adenomas. Tß4 expression was observed in 10/15 colorectal adenocarcinomas. In adenomas with low-grade dysplasia, Tß4 immunoreactivity was mainly detected in dysplastic glands but was absent in hyperplastic glands. Tß4 immunoreactivity was characterized by spot-like perinuclear staining. In high-grade dysplastic polyps, immunostaining for Tß4 appeared diffuse throughout the entire cytoplasm of dysplastic cells. Spot-like perinuclear reactivity was detected in adenocarcinoma tumor cells. CONCLUSIONS: Our study shows for the first time that Tß4 is expressed during different steps of colon carcinogenesis. The shift of Tß4 immunolocalization from low-grade to high-grade dysplastic glands suggests a role for Tß4 in colorectal carcinogenesis. However, the real meaning of Tß4 reactivity in dysplastic intestinal epithelium remains unknown.

Thymosin ß4 expression in colorectal polyps and adenomas

OBJECTIVE: Thymosin beta 4 (Tβ4) is a ubiquitous peptide that plays pivotal roles in the cytoskeletal system and in cell differentiation. Recently, a role for Tβ4 has been proposed in experimental and human carcinogenesis, including gastrointestinal cancer. This study was aimed at evaluating the relationship between Tβ4 immunoreactivity and the initial steps of carcinogenesis. METHODS: In total, 60 intestinal biopsies, including 10 hyperplastic polyps, 10 sessile serrated adenomas/polyps, 15 colorectal adenomas with low-grade dysplasia, 15 adenomas with high-grade dysplasia, 15 adenocarcinomas and 10 samples of normal colon mucosa, were analyzed for Tβ4 expression by immunohistochemistry. RESULTS: Weak cytoplasmic reactivity for Tβ4 was detected in the normal colon mucosa. No reactivity for Tβ4 was found in hyperplastic and sessile serrated polyps/adenomas. Tβ4 expression was observed in 10/15 colorectal adenocarcinomas. In adenomas with low-grade dysplasia, Tβ4 immunoreactivity was mainly detected in dysplastic glands but was absent in hyperplastic glands. Tβ4 immunoreactivity was characterized by spot-like perinuclear staining. In high-grade dysplastic polyps, immunostaining for Tβ4 appeared diffuse throughout the entire cytoplasm of dysplastic cells. Spot-like perinuclear reactivity was detected in adenocarcinoma tumor cells. CONCLUSIONS: Our study shows for the first time that Tβ4 is expressed during different steps of colon carcinogenesis. The shift of Tβ4 immunolocalization from low-grade to high-grade dysplastic glands suggests a role for Tβ4 in colorectal carcinogenesis. However, the real meaning of Tβ4 reactivity in dysplastic intestinal epithelium remains unknown. .

Quantitative analysis of thymosin ß4 in whole saliva by capillary electrophoresis­mass spectrometry using multiple ions monitoring (CE-MIM-MS.).

Thymosin ß4 (Tß4) is a peptide present in almost any tissue and in extracellular media in mammals, having multiple amazing functions as wound healing, stimulation of angiogenesis, and suppression of inflammation. This study describes its determination in saliva through CE-MS using multiple ions monitoring scan mode by isolating the four most intense multicharged ions present in the MS spectra of the peptide. This scan modality, by reducing the baseline noise and interferences, increases the sensitivity and specificity in biological matrices. The CE-MS separation was optimized by studying different parameters influencing CE analysis, sample injection, and MS ionization, that is, the nebulizer gas flow, the sheath liquid, and BGE composition. The proposed technique can unambiguously identify in short time Tß4 in saliva after a very fast and reduced sample pretreatment procedure. The method was validated for quantitation showing linearity of the response in the range 0.25 (lower limit of quantification) to 4 µM (average R2 0.996 ± 0.005) and intra- and interassay precision and accuracy at three different concentrations with RSD values in the range of 7­16%. It was successfully applied to the analysis of Tß4 in whole saliva showing a variable peptide content from individual to individual (in the range of 0.3­1.4 µM) and in different days from the same individual. CE-MS in multiple ions monitoring scan mode provides a fast, selective, and economic method requiring only very few microliters of sample.

Doping control analysis of TB-500, a synthetic version of an active region of thymosin ß4, in equine urine and plasma by liquid chromatography-mass spectrometry.

A veterinary preparation known as TB-500 and containing a synthetic version of the naturally occurring peptide LKKTETQ has emerged. The peptide segment (17)LKKTETQ(23) is the active site within the protein thymosin ß(4) responsible for actin binding, cell migration and wound healing. The key ingredient of TB-500 is the peptide LKKTETQ with artificial acetylation of the N-terminus. TB-500 is claimed to promote endothelial cell differentiation, angiogenesis in dermal tissues, keratinocyte migration, collagen deposition and decrease inflammation. In order to control the misuse of TB-500 in equine sports, a method to definitely identify its prior use in horses is required. This study describes a method for the simultaneous detection of N-acetylated LKKTETQ and its metabolites in equine urine and plasma samples. The possible metabolites of N-acetylated LKKTETQ were first identified from in vitro studies. The parent peptide and its metabolites were isolated from equine urine or plasma by solid-phase extraction using ion-exchange cartridges, and analysed by liquid chromatography-mass spectrometry (LC/MS). These analytes were identified according to their LC retention times and relative abundances of the major product ions. The peptide N-acetylated LKKTETQ could be detected and confirmed at 0.02 ng/mL in equine plasma and 0.01 ng/mL in equine urine. This method was successful in confirming the presence of N-acetylated LKKTETQ and its metabolites in equine urine and plasma collected from horses administered with a single dose of TB-500 (containing 10mg of N-acetylated LKKTETQ). To our knowledge, this is the first identification of TB-500 and its metabolites in post-administration samples from horses.