High Plasma Levels of Soluble Talin-1 in Patients with Coronary Artery Disease.

AIMS: Talin-1 is a cytoskeletal protein that binds integrin, thereby leading to integrin activation and affecting focal adhesions. Recently, talin-1 expression was reported to be downregulated in human atherosclerotic plaques. However, blood levels of soluble talin-1 (sTalin-1) in patients with atherosclerotic disease, such as coronary artery disease (CAD), have not been elucidated. METHODS: We measured plasma sTalin-1 levels in 349 patients undergoing elective coronary angiography. The severity of CAD was represented as the number of stenotic coronary vessels and segments. RESULTS: Of the 349 study patients, CAD was found in 194 patients, of whom 88 had 1-vessel disease (1-VD), 60 had 2-vessel disease (2-VD), and 46 had 3-vessel disease (3-VD). Plasma sTalin-1 levels were higher in 194 patients with CAD than in 155 without CAD (CAD(-) group) (median 0.30 vs. 0.23 ng/mL, P < 0.005). A stepwise increase in sTalin-1 levels was found depending on the number of >50% stenotic coronary vessels: 0.23 in CAD(-), 0.29 in 1-VD, 0.30 in 2-VD, and 0.32 ng/mL in 3-VD group, respectively, (P < 0.05). High sTalin-1 level (>0.28 ng/mL) was found in 36% of CAD(-), 51% of 1-VD, 53% of 2-VD, and 59% of 3-VD group (P < 0.025). sTalin-1 levels also correlated with the number of >50% stenotic segments (r = 0.14, P < 0.02). The multivariate analysis revealed that sTalin-1 levels were independently associated with CAD. The odds ratio for CAD was 1.83 (95%CI = 1.14 - 2.93) for high sTalin-1 level (>0.28 ng/mL) (P < 0.02). CONCLUSIONS: Plasma sTalin-1 levels in patients with CAD were found to be high and to be associated with the presence and severity of CAD, suggesting a role of sTalin-1 in the progression of coronary atherosclerosis.

Talin-1; other than a potential marker for hepatocellular carcinoma diagnosis.

BACKGROUND AND STUDY AIMS: Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide. Talin-1 was previously proposed as a potential novel biomarker for HCC diagnosis but with limited and inconsistent data. We aimed to study the possible role of talin-1 in diagnosis and prognostic stratification of patients with hepatocellular carcinoma. PATIENTS AND METHODS: Ninety-six patients were recruited and classified into three groups; 1) cirrhosis group: 40 patients with liver cirrhosis, 2) HCC group: 40 patients with HCC, 3) control group: 16 healthy volunteers with matched age and sex. Serum talin-1 level was detected using enzyme-linked immunosorbent assay (ELISA). RESULTS: The highest levels of talin-1 were observed among the HCC group followed by cirrhosis then control groups (p = 0.000). In the HCC group, a significant correlation was found between talin-1 and each of multifocal HCC (p = 0.013), portal vein invasion (p = 0.022) and presence of ascites (p = 0.001), while no significant correlation was detected with tumour foci size (p = 0.605). For HCC detection, talin-1 had AUC = 0.858, 100% sensitivity and 65% specificity, while AFP had AUC = 1.000, 100% sensitivity and specificity. CONCLUSION: Talin-1 is a potential marker for diagnosis and prognostic assessment of HCC. Further studies are needed to investigate the ultimate diagnostic and prognostic utility of serum talin-1.

Identification of actin network proteins, talin-1 and filamin-A, in circulating extracellular vesicles as blood biomarkers for human myalgic encephalomyelitis/chronic fatigue syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious, debilitating disorder with a wide spectrum of symptoms, including pain, depression, and neurocognitive deterioration. Over 17 million people around the world have ME/CFS, predominantly women with peak onset at 30-50 years. Given the wide spectrum of symptoms and unclear etiology, specific biomarkers for diagnosis and stratification of ME/CFS are lacking. Here we show that actin network proteins in circulating extracellular vesicles (EVs) offer specific non-invasive biomarkers for ME/CFS. We found that circulating EVs were significantly increased in ME/CFS patients correlating to C-reactive protein, as well as biological antioxidant potential. Area under the receiver operating characteristic curve for circulating EVs was 0.80, allowing correct diagnosis in 90-94% of ME/CFS cases. From two independent proteomic analyses using circulating EVs from ME/CFS, healthy controls, idiopathic chronic fatigue, and depression, proteins identified from ME/CFS patients are involved in focal adhesion, actin skeletal regulation, PI3K-Akt signaling pathway, and Epstein-Barr virus infection. In particular, talin-1, filamin-A, and 14-3-3 family proteins were the most abundant proteins, representing highly specific ME/CFS biomarkers. Our results identified circulating EV number and EV-specific proteins as novel biomarkers for diagnosing ME/CFS, providing important information on the pathogenic mechanisms of ME/CFS.

Serum agrin and talin are increased in major depression while agrin and creatine phosphokinase are associated with chronic fatigue and fibromyalgia symptoms in depression.

Chronic fatigue and fibromyalgia symptoms frequently occur in major depressive disorder (MDD). The pathophysiology of these symptoms may in part, be ascribed to activated immune pathways, although it is unclear whether muscular factors play a role in their onset. The aim of the present study is to examine the role of muscle proteins in major depression in association with symptoms of chronic fatigue and fibromyalgia. We measured serum levels of agrin, talin-2, titin, and creatine phosphokinase (CPK) as well as the FibroFatigue (FF), the Hamilton Depression Rating Scale (HAM-D) and the Beck Depression Inventory (BDI-II) scores in 60 MDD patients and 30 healthy controls. The results show a significant increase in agrin and talin-2 in MDD patients as compared with controls. There were highly significant correlations between agrin and HAM-D, BDI-II and FF scores. Agrin, but not talin or titin, was significantly and positively associated with all 12 items of the FF scale. We found that a large part of the variance in HAM-D (47.4%), BDI-II (43.4%) and FF (43.5%) scores was explained by the regression on agrin, smoking, female sex (positively associated) and education (inversely associated). CPK was significantly and inversely associated with the total FF score and with muscle and gastro-intestinal symptoms, fatigue, a flu-like malaise, headache and memory, autonomic and sleep disturbances. These results suggest that aberrations in neuromuscular (NMJs) and myotendinous junctions play a role in MDD and that the aberrations in NMJs coupled with lowered CPK may play a role in chronic fatigue and fibromyalgia symptoms in MDD. Moreover, the increase of agrin in MDD probably functions as part of the compensatory immune-regulatory system (CIRS).

FBP2 and Talin-1 are potential protein markers for Mongolian medicine symptom evaluation in viral infectious diseases.

BACKGROUND: Influenza, measles, and mumps are common viral infectious diseases in Mongolia. The traditional Mongolian medicine (TMM) classified them as warm disease, and still plays a major role in the diagnoses and treatments. METHODS: To interpret the connotation of the complex theoretical system in TMM with scientific technique, in this study, a high throughput mass spectrometry was used to identify potential protein markers of TMM symptom types. Fifty venous blood samples were drawn from influenza, measles and mumps patients. Differential proteins between samples of patients diagnosed as immature and mature heat in TMM were detected by mass spectrometry. RESULTS: After proteomics analysis, 1500 proteins and 7619 polypeptides were identified and 1323 in total showed differential expression between those 2 symptom types; then enrichment analysis of the differentially expressed proteins revealed the significant biological functions related to the differentially expressed proteins, including cardiomyopathy, several bacterial and parasitic infections, bacterial invasion of epithelial cells, insulin signaling pathway, and regulation of actin cytoskeleton. The network analysis showed that FBP2 and Talin-1 were critical points and might determine the evolution directions of TMM warm disease symptom. CONCLUSIONS: This study suggests that the identified core differential proteins may be regarded as potential biomarkers, and benefit to evaluate the evolutionary tendency of TMM warm disease symptoms.

Diagnostic and Prognostic Value of Talin-1 and Midkine as Tumor Markers in Hepatocellular Carcinoma in Egyptian Patients

Background: Hepatocellular carcinoma (HCC) is a main cause of cancer death all over the world. Treatment and outcome of HCC based on its early diagnosis. This study was conducted to estimate the role of talin-1 and midkine in combination with total antioxidant capacity (TAC) as tumor markers in HCC patients. Methods: Serum levels of talin-1 and midkine were measured in 90 Egyptian subjects including 44 patients with HCC, 31patients with cirrhosis and 15 healthy controls using enzyme-linked immunosorbent assay (ELISA) technique. While a colorimetric method was used for measurement of TAC. Results: Serum talin-1 in HCC patients was significantly lower than that in patients with cirrhosis (P<0.001) and normal control (P<0.001). In addition, increased invasion and metastasis correlated with reduced talin-1 level. Serum midkine in HCC patients was significantly higher compared to cirrhotic patients (P<0.001) and normal control (P<0.001). Midkine at a cut off value of 1683 pg/ml showed a sensitivity of (81.82%) and specificity of (83.87%). While alpha-fetoprotein (AFP) at a cut off value of 200 ng/ml had a sensitivity of (52.27%), while specificity was (96.77%). Midkine was positive in 80.9% of HCC patients with negative AFP. Serum TAC was significantly decreased in HCC patients when compared with control group (P<0.001). Conclusion: Talin-1 may be implicated in the carcinogenesis and metastasis of HCC and can be used as a useful tumor marker for HCC. Midkine may be a potential diagnostic marker for HCC and may be used in addition to AFP to increase the sensitivity of HCC detection.

Gain-of-Function Mutation in Filamin A Potentiates Platelet Integrin αIIbß3 Activation.

OBJECTIVE: Dominant mutations of the X-linked filamin A (FLNA) gene are responsible for filaminopathies A, which are rare disorders including brain periventricular nodular heterotopia, congenital intestinal pseudo-obstruction, cardiac valves or skeleton malformations, and often macrothrombocytopenia. APPROACH AND RESULTS: We studied a male patient with periventricular nodular heterotopia and congenital intestinal pseudo-obstruction, his unique X-linked FLNA allele carrying a stop codon mutation resulting in a 100-amino acid-long FLNa C-terminal extension (NP_001447.2: p.Ter2648SerextTer101). Platelet counts were normal, with few enlarged platelets. FLNa was detectable in all platelets but at 30% of control levels. Surprisingly, all platelet functions were significantly upregulated, including platelet aggregation and secretion, as induced by ADP, collagen, or von Willebrand factor in the presence of ristocetin, as well as thrombus formation in blood flow on a collagen or on a von Willebrand factor matrix. Most importantly, patient platelets stimulated with ADP exhibited a marked increase in αIIbß3 integrin activation and a parallel increase in talin recruitment to ß3, contrasting with normal Rap1 activation. These results are consistent with the mutant FLNa affecting the last step of αIIbß3 activation. Overexpression of mutant FLNa in the HEL megakaryocytic cell line correlated with an increase (compared with wild-type FLNa) in PMA-induced fibrinogen binding to and in talin and kindlin-3 recruitment by αIIbß3. CONCLUSIONS: Altogether, our results are consistent with a less binding of mutant FLNa to ß3 and the facilitated recruitment of talin by ß3 on platelet stimulation, explaining the increased αIIbß3 activation and the ensuing gain-of-platelet functions.

Serum soluble Talin-1 levels are elevated in patients with multiple sclerosis, reflecting its disease activity.

Previously, we identified anti-Talin-1 antibodies in the serum of MS. In this case, we measured the serum soluble Talin-1 (sTalin-1) levels by enzyme-linked immunosorbent assay. The serum sTalin-1 levels were significantly higher in 40 patients with MS than in 43 normal controls and in the acute phase of disease than in the remission phase. Interestingly, serum sTalin-1 levels were associated with a sustained increase in disability after MS attack but not with serum anti-Talin-1 antibody levels. sTalin-1 may be a biomarker for the acute phase of MS and may be used for the short-term prognosis of MS.

Talin-1 and Non-invasive Fibrosis Models in the Assessment of Patients with Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a dreadful complication of end stage liver disease with high morbidity and mortality. AIM: The aim was to assess the role of serum talin-1 and non-invasive brosis in patients with HCC. MATERIALS AND METHODS: A total of eighty seven subjects were enrolled, with 22 two healthy individuals as a control group (n=22), 22 patients in the cirrhosis group and finally 43 in the group with HCC diagnosed with positive triphasic CT abdomen criteria. Serum talin-1 and noninvasive fibrosis parameters were assessed in all subjects. RESULTS: Compared to the cirrhosis group, patients with HCC had higher serum talin-1 (32.9±12.6 vs. 11.1±2.79 ng/ml), FIB4 (9.96±15.3 vs. 2.90±1.87) and bro-α (10.9±18.1 vs. 1.55±0.28) but not fibrosis index scores (4.47±0.95 vs. 4.98±0.96; p=0.046). Patients with large focal lesions (≥5cm) had different ALBI scores (-1.02±0.63 vs. -1.72±0.59; p=0.001) serum talin-1 (9.72±13.81 vs. 28.6±38.89 ng/ml; p=0.007) and brosis index scores (0.85 ± 0.99 vs. 4.20±4.85; p=0.026). No statistical differences were noted between patients with and without portal vein thrombosis. For detection of HCC, serum talin-1 had 97.7% sensitivity and 100% specificity with a 17.2 ng/ml cutoff. AFP at a 13.7 ng/ml cutoff had 72.1% sensitivity and 6.3.6% specificity. The cutoff for the bro-α score was 1.61 with 81.4% sensitivity and 77.3% specificity. Serum talin-1 (odds=1.08; C.I=1.016-1.150; p=0.014), brosis index score (odds=2.35; C.I=1.055-5.217; p=0.037) and the ALBI score (odds=6.9; C.I=1.924-24.708; p=0.003) were predictors of large focal lesions. CONCLUSIONS: Serum talin-1, AST/ALT ratio, bro-α score are useful for the assessment of HCC patients.

Minimal amounts of kindlin-3 suffice for basal platelet and leukocyte functions in mice.

Hematopoietic cells depend on integrin-mediated adhesion and signaling, which is induced by kindlin-3 and talin-1. To determine whether platelet and polymorphonuclear neutrophil (PMN) functions require specific thresholds of kindlin-3, we generated mouse strains expressing 50%, 10%, or 5% of normal kindlin-3 levels. We report that in contrast to kindlin-3-null mice, which die perinatally of severe bleeding and leukocyte adhesion deficiency, mice expressing as little as 5% of kindlin-3 were viable and protected from spontaneous bleeding and infections. However, platelet adhesion and aggregation were reduced in vitro and bleeding times extended. Similarly, leukocyte adhesion, extravasation, and bacterial clearance were diminished. Quantification of protein copy numbers revealed stoichiometric quantities of kindlin-3 and talin-1 in platelets and neutrophils, indicating that reduction of kindlin-3 in our mouse strains progressively impairs the cooperation with talin-1. Our findings show that very low levels of kindlin-3 enable basal platelet and neutrophil functions, whereas in stress situations such as injury and infection, platelets and neutrophils require a maximum of functional integrins that is achieved with high and stoichiometric quantities of kindlin-3 and talin-1.

A novel screening test for colon cancer: Talin-1.

OBJECTIVE: Cell adhesion and angiogenesis within the extracellular matrix involve special signaling molecules, such as integrins and the actin binding protein Talin-1. The aim of this study was to investigate and describe the expression of Talin-1 for the early detection of colon cancer. PATIENTS AND METHODS: Blood serum samples were collected from 50 healthy volunteers and from 90 patients with colon cancer. Using an enzyme-linked immunosorbent assay (ELISA), all 140 samples were analyzed. RESULTS: Preoperative levels of Talin-1 in the serum were significantly higher in patients with colon cancer (p < 0.001). No significant correlation was found between preoperative levels of Talin-1 in the serum and the age and gender of the patients (p < 0.05). However, a significant correlation was found between Talin-1 levels and the tumor grade, TNM stage, and lymph node metastasis (p < 0.001). CONCLUSIONS: Talin-1 may play a role in the reinforcement of cell proliferation, cell adhesion, and angiogenesis in colon cancer. Thus, the Talin-1 protein activity may be a novel biomarker to detect colon cancer in humans.

Proteasome proteolysis supports stimulated platelet function and thrombosis.

OBJECTIVE: Proteasome inhibitors used in the treatment of hematologic cancers also reduce thrombosis. Whether the proteasome participates in platelet activation or function is unclear because little is known of the proteasome in these terminally differentiated cells. APPROACH AND RESULTS: Platelets displayed all 3 primary proteasome protease activities, which MG132 and bortezomib (Velcade) inhibited. Proteasome substrates are marked by ubiquitin, and platelets contained a functional ubiquitination system that modified the proteome by monoubiquitination and polyubiquitination. Systemic MG132 strongly suppressed the formation of occlusive, platelet-rich thrombi in FeCl3-damaged carotid arteries. Transfusion of platelets treated ex vivo with MG132 and washed before transfusion into thrombocytopenic mice also reduced carotid artery thrombosis. Proteasome inhibition reduced platelet aggregation by low thrombin concentrations and ristocetin-stimulated agglutination through the glycoprotein Ib-IX-V complex. This receptor was not appropriately internalized after proteasome inhibition in stimulated platelets, and spreading and clot retraction after MG132 exposure also were decreased. The effects of proteasome inhibitors were not confined to a single receptor as MG132 suppressed thrombin-stimulated, ADP-stimulated, and lipopolysaccharide-stimulated microparticle shedding. Proteasome inhibition increased ubiquitin decoration of cytoplasmic proteins, including the cytoskeletal proteins Filamin A and Talin-1. Mass spectrometry revealed a single MG132-sensitive tryptic cleavage after R1745 in an extended Filamin A loop, which would separate its actin-binding domain from its carboxy terminal glycoprotein Ibα-binding domain. CONCLUSIONS: Platelets contain a ubiquitin/proteasome system that marks cytoskeletal proteins for proteolytic modification to promote productive platelet-platelet and platelet-wall interactions.

Serum talin-1 is a potential novel biomarker for diagnosis of hepatocellular carcinoma in Egyptian patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide. The outcome of HCC depends mainly on its early diagnosis. To date, the performance of traditional biomarkers is unsatisfactory. Talins were firstly identified as cytoplasmic protein partners of integrins but Talin-1 appears to play a crucial role in cancer formation and progression. Our study was conducted to assess the diagnostic value of serum Talin-1 (TLN1) compared to the most feasible traditional biomarker alpha-fetoprotein (AFP) for the diagnosis of HCC. METHODS: TLN1 was detected using enzyme linked immunosorbent assay (ELISA) in serum samples from 120 Egyptian subjects including 40 with HCC, 40 with liver cirrhosis (LC) and 40 healthy controls (HC). RESULTS: ROC curve analysis was used to create a predictive model for TLN1 relative to AFP in HCC diagnosis. Serum levels of TLN1 in hepatocellular carcinoma patients were significantly higher compared to the other groups (p<0.0001). The diagnostic accuracy of TLN1 was higher than that of AFP regarding sensitivity, specificity, positive predictive value and negative predictive value in diagnosis of HCC. CONCLUSIONS: The present study showed for the first time that Talin-1 (TLN1) is a potential diagnostic marker for HCC, with a higher sensitivity and specificity compared to the traditional biomarker AFP.

Talin 2 concentrations in cerebrospinal fluid in patients with epilepsy.

OBJECTIVES: Talin 2 plays an important role in cell adhesion and recycling of synaptic vesicles. To explore the possible role of talin 2 in epilepsy, we designed current study to quantitatively evaluate the changes in talin 2 levels in different epilepsy patients. DESIGN AND METHODS: We measured talin 2 levels in CSF and the serum of postencephalitic epilepsy (PEE) patients (subdivided into drug-refractory PEE-RPEE, and drug-effective PEE-EPEE groups) and acute encephalitis patients (subdivided into acute encephalitis with secondary seizures-AESS, and acute encephalitis without seizures-AE) by enzyme-linked immunosorbent assay. RESULTS: We found that, in RPEE patients, interictal CSF-talin 2 concentrations significantly increased, whereas serum-talin 2 significantly decreased when compared with the AE, AESS, and EPEE groups. CONCLUSIONS: This result suggested that the differential concentration of CSF and serum-talin 2 in the RPEE group is an intractability-related phenomenon that might be involved in the development of RPEE.

GATA-1, G208S macrothrombocytes are deficient in talin: immunofluorescence studies.

Previous investigations from our laboratory identified the ultrastructural pathology and cytochemistry of macrothrombocytes (MTC) from patients with the X-linked, G208S varient of the GATA-1 mutation.A subsequent biochemical study of the MTC cytoskeletal proteins using polyacrylamide gel electrophoresis and western blot analysis revealed the MTC were deficient in the high-molecular weight, actin binding protein, talin. The present study has used immunofluorescent techniques to further characterize the talin deficiency. Results confirm that the GATA-1, G208S MTC are deficient in talin, and what little is present relocates to the undersurface of the plasma membrane following activations where it associates with adhesion plaques.

Abnormal subcellular distribution of myosin and talin in Wistar Furth rat platelets.

The roles of most cytoskeletal proteins in platelet formation and function remain largely undefined. We earlier detected megakaryocyte membrane blebbing and a unique antigenic determinant associated with a missense mutation in the cytoskeletal protein, talin, in an animal model of hereditary macrothrombocytopenia, the Wistar Furth (WF) rat, which led us to examine the distribution of talin and other cytoskeletal proteins in resting normal and WF rat platelets. In contrast to the conclusions of an earlier ultrastructural analysis, our biochemical and ultrastructural immunogold studies indicate a significant membrane-association of talin in both resting normal and WF rat platelets as found earlier for rat megakaryocytes. Talin was associated with plasma membranes, membranes of the surface-connected canalicular system, and with alpha-granule membranes of both normal and WF rat platelets, but as in WF megakaryocytes, talin was absent from the large membrane complexes of WF platelets. An even more striking difference was seen in the distribution of myosin in subcellular fractions of normal and WF rat platelets separated in density gradients, in which the proportion of myosin in the least dense WF rat platelet membrane fraction was one half that in the same normal platelet fraction. This difference was balanced by a fourfold increase in myosin in the most dense WF rat subcellular fraction, which is highly enriched for alpha-granules. These results support our hypothesis that the platelet abnormalities of the WF rat are related to defects in the megakaryocyte-platelet cytoskeleton.